A reliability analysis of cardiac repolarization time markers.

PubMed

Scacchi, S; Franzone, P Colli; Pavarino, L F; Taccardi, B

2009-06-01

Only a limited number of studies have addressed the reliability of extracellular markers of cardiac repolarization time, such as the classical marker RT(eg) defined as the time of maximum upslope of the electrogram T wave. This work presents an extensive three-dimensional simulation study of cardiac repolarization time, extending the previous one-dimensional simulation study of a myocardial strand by Steinhaus [B.M. Steinhaus, Estimating cardiac transmembrane activation and recovery times from unipolar and bipolar extracellular electrograms: a simulation study, Circ. Res. 64 (3) (1989) 449]. The simulations are based on the bidomain - Luo-Rudy phase I system with rotational fiber anisotropy and homogeneous or heterogeneous transmural intrinsic membrane properties. The classical extracellular marker RT(eg) is compared with the gold standard of fastest repolarization time RT(tap), defined as the time of minimum derivative during the downstroke of the transmembrane action potential (TAP). Additionally, a new extracellular marker RT90(eg) is compared with the gold standard of late repolarization time RT90(tap), defined as the time when the TAP reaches 90% of its resting value. The results show a good global match between the extracellular and transmembrane repolarization markers, with small relative mean discrepancy (or=0.92), ensuring a reasonably good global match between the associated repolarization sequences. However, large local discrepancies of the extracellular versus transmembrane markers may ensue in regions where the curvature of the repolarization front changes abruptly (e.g. near front collisions) or is negligible (e.g. where repolarization proceeds almost uniformly across fiber). As a consequence, the spatial distribution of activation-recovery intervals (ARI) may provide an inaccurate estimate of (and weakly correlated with) the spatial distribution of action potential durations (APD).

Recent advances in understanding sex differences in cardiac repolarization.

PubMed

James, Andrew F; Choisy, Stéphanie C M; Hancox, Jules C

2007-07-01

A number of gender differences exist in the human electrocardiogram (ECG): the P-wave and P-R intervals are slightly longer in men than in women, whilst women have higher resting heart rates than do men, but a longer rate-corrected QT (QT(C)) interval. Women with the LQT1 and LQT2 variants of congenital long-QT syndrome (LQTS) are at greater risk of adverse cardiac events. Similarly, many drugs associated with acquired LQTS have a greater risk of inducing torsades de pointes (TdP) arrhythmia in women than in men. There are also male:female differences in Brugada syndrome, early repolarisation syndrome and sudden cardiac death. The differences in the ECG between men and women, and in particular those relating to the QT interval, have been explored experimentally and provide evidence of differences in the processes underlying ventricular repolarization. The data available from rabbit, canine, rat, mouse and guinea pig models are reviewed and highlight involvement of male:female differences in Ca and K currents, although the possible involvement of rapid and persistent Na current and Na-Ca exchange currents cannot yet be excluded. The mechanisms underlying observed differences remain to be elucidated fully, but are likely to involve the influence of gonadal steroids. With respect to the QT interval and risk of TdP, a range of evidence implicates a protective role of testosterone in male hearts, possibly by both genomic and non-genomic pathways. Evidence regarding oestrogen and progesterone is less unequivocal, although the interplay between these two hormones may influence both repolarization and pro-arrhythmic risk.

Components of action potential repolarization in cerebellar parallel fibres.

PubMed

Pekala, Dobromila; Baginskas, Armantas; Szkudlarek, Hanna J; Raastad, Morten

2014-11-15

Repolarization of the presynaptic action potential is essential for transmitter release, excitability and energy expenditure. Little is known about repolarization in thin, unmyelinated axons forming en passant synapses, which represent the most common type of axons in the mammalian brain's grey matter.We used rat cerebellar parallel fibres, an example of typical grey matter axons, to investigate the effects of K(+) channel blockers on repolarization. We show that repolarization is composed of a fast tetraethylammonium (TEA)-sensitive component, determining the width and amplitude of the spike, and a slow margatoxin (MgTX)-sensitive depolarized after-potential (DAP). These two components could be recorded at the granule cell soma as antidromic action potentials and from the axons with a newly developed miniaturized grease-gap method. A considerable proportion of fast repolarization remained in the presence of TEA, MgTX, or both. This residual was abolished by the addition of quinine. The importance of proper control of fast repolarization was demonstrated by somatic recordings of antidromic action potentials. In these experiments, the relatively broad K(+) channel blocker 4-aminopyridine reduced the fast repolarization, resulting in bursts of action potentials forming on top of the DAP. We conclude that repolarization of the action potential in parallel fibres is supported by at least three groups of K(+) channels. Differences in their temporal profiles allow relatively independent control of the spike and the DAP, whereas overlap of their temporal profiles provides robust control of axonal bursting properties.

Targeting RAW 264.7 macrophages (M1 type) with Withaferin-A decorated mannosylated liposomes induces repolarization via downregulation of NF-κB and controlled elevation of STAT-3.

PubMed

Neog, Manoj Kumar; Sultana, Farhath; Rasool, Mahaboobkhan

2018-05-25

In the present study, we intend to gain an insight into the mechanism of Withaferin-A (WA), a steroidal lactone with reference to repolarization of RAW 264.7 macrophages (M1 to M2 type). We found that successful internalization of WA via mannosylated liposomal delivery system (ML-WA) reduced the RAW 264.7 macrophage (M1) mediated pro-inflammatory cytokines (IL-1β, IL-6, IL-23, and TNF-α) through the attenuation of transcription factor NF-κB-p65 expression. Whereas, ML-WA treatment induced a controlled upregulation of p-STAT3, and ablated the key oxidative stress markers (NO, iNOS, and ROS) in M1 → M2 RAW 264.7 macrophage repolarization, which suggested the recalibration of M1 macrophage metabolic function. Further, the elevated expression of M2 macrophage associated CD163 over the M1 macrophage related CD86 concluded that ML-WA induces an anti-inflammatory response by repolarizing the M1 → M2 RAW 264.7 macrophage. Copyright © 2018 Elsevier B.V. All rights reserved.

Identifying clinically relevant drug resistance genes in drug-induced resistant cancer cell lines and post- chemotherapy tissues

PubMed Central

Tong, Mengsha; Zheng, Weicheng; Lu, Xingrong; Ao, Lu; Li, Xiangyu; Guan, Qingzhou; Cai, Hao; Li, Mengyao; Yan, Haidan; Guo, You; Chi, Pan; Guo, Zheng

2015-01-01

Until recently, few molecular signatures of drug resistance identified in drug-induced resistant cancer cell models can be translated into clinical practice. Here, we defined differentially expressed genes (DEGs) between pre-chemotherapy colorectal cancer (CRC) tissue samples of non-responders and responders for 5-fluorouracil and oxaliplatin-based therapy as clinically relevant drug resistance genes (CRG5-FU/L-OHP). Taking CRG5-FU/L-OHP as reference, we evaluated the clinical relevance of several types of genes derived from HCT116 CRC cells with resistance to 5-fluorouracil and oxaliplatin, respectively. The results revealed that DEGs between parental and resistant cells, when both were treated with the corresponding drug for a certain time, were significantly consistent with the CRG5-FU/L-OHP as well as the DEGs between the post-chemotherapy CRC specimens of responders and non-responders. This study suggests a novel strategy to extract clinically relevant drug resistance genes from both drug-induced resistant cell models and post-chemotherapy cancer tissue specimens. PMID:26515599

Cellular mechanism underlying hypothermia-induced ventricular tachycardia/ventricular fibrillation in the setting of early repolarization and the protective effect of quinidine, cilostazol, and milrinone.

PubMed

Gurabi, Zsolt; Koncz, István; Patocskai, Bence; Nesterenko, Vladislav V; Antzelevitch, Charles

2014-02-01

Hypothermia has been reported to induce ventricular tachycardia and fibrillation (VT/VF) in patients with early repolarization (ER) pattern. This study examines the cellular mechanisms underlying VT/VF associated with hypothermia in an experimental model of ER syndrome and examines the effectiveness of quinidine, cilostazol, and milrinone to prevent hypothermia-induced arrhythmias. Transmembrane action potentials were simultaneously recorded from 2 epicardial and 1 endocardial site of coronary-perfused canine left ventricular wedge preparations, together with a pseudo-ECG. A combination of NS5806 (3-10 μmol/L) and verapamil (1 μmol/L) was used to pharmacologically model the genetic mutations responsible for ER syndrome. Acetylcholine (3 μmol/L) was used to simulate increased parasympathetic tone, which is known to promote ER. In controls, lowering the temperature of the coronary perfusate to induce mild hypothermia (32°C-34°C) resulted in increased J-wave area on the ECG and accentuated epicardial action potential notch but no arrhythmic activity. In the setting of ER, hypothermia caused further accentuation of the epicardial action potential notch, leading to loss of the action potential dome at some sites but not others, thus creating the substrate for development of phase 2 reentry and VT/VF. Addition of the transient outward current antagonist quinidine (5 μmol/L) or the phosphodiesterase III inhibitors cilostazol (10 μmol/L) or milrinone (5 μmol/L) diminished the ER manifestations and prevented the hypothermia-induced phase 2 reentry and VT/VF. Hypothermia leads to VT/VF in the setting of ER by exaggerating repolarization abnormalities, leading to development of phase 2 reentry. Quinidine, cilostazol, and milrinone suppress the hypothermia-induced VT/VF by reversing the repolarization abnormalities.

Action potential-based MEA platform for in vitro screening of drug-induced cardiotoxicity using human iPSCs and rat neonatal myocytes.

PubMed

Jans, Danny; Callewaert, Geert; Krylychkina, Olga; Hoffman, Luis; Gullo, Francesco; Prodanov, Dimiter; Braeken, Dries

2017-09-01

Drug-induced cardiotoxicity poses a negative impact on public health and drug development. Cardiac safety pharmacology issues urged for the preclinical assessment of drug-induced ventricular arrhythmia leading to the design of several in vitro electrophysiological screening assays. In general, patch clamp systems allow for intracellular recordings, while multi-electrode array (MEA) technology detect extracellular activity. Here, we demonstrate a complementary metal oxide semiconductor (CMOS)-based MEA system as a reliable platform for non-invasive, long-term intracellular recording of cardiac action potentials at high resolution. Quinidine (8 concentrations from 10 -7 to 2.10 -5 M) and verapamil (7 concentrations from 10 -11 to 10 -5 M) were tested for dose-dependent responses in a network of cardiomyocytes. Electrophysiological parameters, such as the action potential duration (APD), rates of depolarization and repolarization and beating frequency were assessed. In hiPSC, quinidine prolonged APD with EC 50 of 2.2·10 -6 M. Further analysis indicated a multifactorial action potential prolongation by quinidine: (1) decreasing fast repolarization with IC 50 of 1.1·10 -6 M; (2) reducing maximum upstroke velocity with IC 50 of 2.6·10 -6 M; and (3) suppressing spontaneous activity with EC 50 of 3.8·10 -6 M. In rat neonatal cardiomyocytes, verapamil blocked spontaneous activity with EC 50 of 5.3·10 -8 M and prolonged the APD with EC 50 of 2.5·10 -8 M. Verapamil reduced rates of fast depolarization and repolarization with IC 50 s of 1.8 and 2.2·10 -7 M, respectively. In conclusion, the proposed action potential-based MEA platform offers high quality and stable long-term recordings with high information content allowing to characterize multi-ion channel blocking drugs. We anticipate application of the system as a screening platform to efficiently and cost-effectively test drugs for cardiac safety. Copyright © 2017 Elsevier Inc. All rights reserved.

Roles of specific Kv channel types in repolarization of the action potential in genetically identified subclasses of pyramidal neurons in mouse neocortex

PubMed Central

Pathak, Dhruba; Guan, Dongxu

2016-01-01

The action potential (AP) is a fundamental feature of excitable cells that serves as the basis for long-distance signaling in the nervous system. There is considerable diversity in the appearance of APs and the underlying repolarization mechanisms in different neuronal types (reviewed in Bean BP. Nat Rev Neurosci 8: 451–465, 2007), including among pyramidal cell subtypes. In the present work, we used specific pharmacological blockers to test for contributions of Kv1, Kv2, or Kv4 channels to repolarization of single APs in two genetically defined subpopulations of pyramidal cells in layer 5 of mouse somatosensory cortex (etv1 and glt) as well as pyramidal cells from layer 2/3. These three subtypes differ in AP properties (Groh A, Meyer HS, Schmidt EF, Heintz N, Sakmann B, Krieger P. Cereb Cortex 20: 826–836, 2010; Guan D, Armstrong WE, Foehring RC. J Neurophysiol 113: 2014–2032, 2015) as well as laminar position, morphology, and projection targets. We asked what the roles of Kv1, Kv2, and Kv4 channels are in AP repolarization and whether the underlying mechanisms are pyramidal cell subtype dependent. We found that Kv4 channels are critically involved in repolarizing neocortical pyramidal cells. There are also pyramidal cell subtype-specific differences in the role for Kv1 channels. Only Kv4 channels were involved in repolarizing the narrow APs of glt cells. In contrast, in etv1 cells and layer 2/3 cells, the broader APs are partially repolarized by Kv1 channels in addition to Kv4 channels. Consistent with their activation in the subthreshold range, Kv1 channels also regulate AP voltage threshold in all pyramidal cell subtypes. PMID:26864770

Cardiac Repolarization Instability during Psychological Stress in Patients with Ventricular Arrhythmias

PubMed Central

Abisse, Saddam S.; Lampert, Rachel; Burg, Mattew; Soufer, Robert; Shusterman, Vladimir

2011-01-01

Introduction Changes in the autonomic nervous system activity (ANS) are a major trigger of life-threatening ventricular tachyarrhythmias (VTA). Mental arithmetic, a condition administered in a laboratory setting, can provide insight into the ANS effects on cardiac physiology. We examined the responses of cardiac repolarization to laboratory-induced psychological stressors in patients with implantable cardioverter defibrillators (ICDs) with the objective of identifying the indices that differentiate patients with and without subsequent VTA in follow-up. Methods Continuous ECG signals were recorded using 3 standard bipolar (Holter) leads in 56 patients (age: 63.6±11.9, female: 12%, LVEF: 32.3±11) with ICDs during mental arithmetic. The patients were separated into those with subsequent VTA during 3–4 years of follow-up (Group 1: N=9 pts) and those without VTA (Group 2: N=47 pts). Changes in repolarization (QT-interval, mean T-wave amplitude (Tamp), and T-wave area (Tarea) were analyzed during 5min of baseline, stress and recovery. The temporal instability of Tamp and Tarea was examined using the range (Δ) and variance (σ2) of beat-to-beat variations of the corresponding parameters. Results There were no significant differences in HR between the two groups at baseline (61 vs. 63 bpm, p=0.97), during stress (64 vs. 65 bpm, p=0.40), and recovery (62 vs. 61 bpm, p= 0.88). However, during mental stress and post-stress recovery ΔTamp was almost 2-fold greater in Group 1 compared with Group 2 (111 (57–203)) vs. 68 (44–94) μV p=0.04, respectively). Changes in QT-intervals were also greater in Group 1 compared with Group 2 (p=0.02). Conclusion Among patients with ICDs, changes of T-wave amplitude after psychological stress were greater in those with subsequent arrhythmic events. This might signal proarrhythmic repolarization response and help identify patients who would benefit the most from ICD implantation and proactive management. PMID:21920534

Anti-addiction Drug Ibogaine Prolongs the Action Potential in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

PubMed

Rubi, Lena; Eckert, Daniel; Boehm, Stefan; Hilber, Karlheinz; Koenig, Xaver

2017-04-01

Ibogaine is a plant alkaloid used as anti-addiction drug in dozens of alternative medicine clinics worldwide. Recently, alarming reports of life-threatening cardiac arrhythmias and cases of sudden death associated with the ingestion of ibogaine have accumulated. Using whole-cell patch clamp recordings, we assessed the effects of ibogaine and its main metabolite noribogaine on action potentials in human ventricular-like cardiomyocytes derived from induced pluripotent stem cells. Therapeutic concentrations of ibogaine and its long-lived active metabolite noribogaine significantly retarded action potential repolarization in human cardiomyocytes. These findings represent the first experimental proof that ibogaine application entails a cardiac arrhythmia risk for humans. In addition, they explain the clinically observed delayed incidence of cardiac adverse events several days after ibogaine intake. We conclude that therapeutic concentrations of ibogaine retard action potential repolarization in the human heart. This may give rise to a prolongation of the QT interval in the electrocardiogram and cardiac arrhythmias.

Glucose ingestion causes cardiac repolarization disturbances in type 1 long QT syndrome patients and healthy subjects.

PubMed

Hyltén-Cavallius, Louise; Iepsen, Eva W; Christiansen, Michael; Graff, Claus; Linneberg, Allan; Pedersen, Oluf; Holst, Jens J; Hansen, Torben; Torekov, Signe S; Kanters, Jørgen K

2017-08-01

Both hypoglycemia and severe hyperglycemia constitute known risk factors for cardiac repolarization changes potentially leading to malignant arrhythmias. Patients with loss of function mutations in KCNQ1 are characterized by long QT syndrome (LQTS) and may be at increased risk for glucose-induced repolarization disturbances. The purpose of this study was to test the hypothesis that KCNQ1 LQTS patients are at particular risk for cardiac repolarization changes during the relative hyperglycemia that occurs after an oral glucose load. Fourteen KCNQ1 LQTS patients and 28 control participants matched for gender, body mass index, and age underwent a 3-hour oral 75-g glucose tolerance test with ECGs obtained at 7 time points. Fridericia corrected QT interval (QTcF), Bazett corrected QT interval (QTcB), and the Morphology Combination Score (MCS) were calculated. QTc and MCS increased in both groups. MCS remained elevated until 150 minutes after glucose ingestion, and the maximal change from baseline was larger among KCNQ1 LQTS patients compared with control subjects (0.28 ± 0.27 vs 0.15 ± 0.13; P <.05). Relative hyperglycemia induced by ingestion of 75-g glucose caused cardiac repolarization disturbances that were more severe in KCNQ1 LQTS patients compared with control subjects. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Heart rate profile during exercise in patients with early repolarization.

PubMed

Cay, Serkan; Cagirci, Goksel; Atak, Ramazan; Balbay, Yucel; Demir, Ahmet Duran; Aydogdu, Sinan

2010-09-01

Both early repolarization and altered heart rate profile are associated with sudden death. In this study, we aimed to demonstrate an association between early repolarization and heart rate profile during exercise. A total of 84 subjects were included in the study. Comparable 44 subjects with early repolarization and 40 subjects with normal electrocardiogram underwent exercise stress testing. Resting heart rate, maximum heart rate, heart rate increment and decrement were analyzed. Both groups were comparable for baseline characteristics including resting heart rate. Maximum heart rate, heart rate increment and heart rate decrement of the subjects in early repolarization group had significantly decreased maximum heart rate, heart rate increment and heart rate decrement compared to control group (all P < 0.05). The lower heart rate increment (< 106 beats/min) and heart rate decrement (< 95 beats/min) were significantly associated with the presence of early repolarization. After adjustment for age and sex, the multiple-adjusted OR of the risk of presence of early repolarization was 2.98 (95%CI 1.21-7.34) (P = 0.018) and 7.73 (95%CI 2.84-21.03) (P < 0.001) for the lower heart rate increment and heart rate decrement compared to higher levels, respectively. Subjects with early repolarization have altered heart rate profile during exercise compared to control subjects. This can be related to sudden death.

The Role of Transmural Repolarization Gradient in the Inversion of Cardiac Electric Field: Model Study of ECG in Hypothermia.

PubMed

Arteyeva, Natalia V; Azarov, Jan E

2017-01-01

The changes in ventricular repolarization gradients lead to significant alterations of the electrocardiographic body surface T waves up to the T wave inversion. However, the contribution of a specific gradient remains to be elucidated. The objective of the present investigation was to study the role of the transmural repolarization gradient in the inversion of the body surface T wave with a mathematical model of the hypothermia-induced changes of ventricular repolarization. By means of mathematical simulation, we set the hypothermic action potential duration (APD) distribution on the rabbit ventricular epicardium as it was previously experimentally documented. Then the parameters of the body surface potential distribution were tested with the introduction of different scenarios of the endocardial and epicardial APD behavior in hypothermia resulting in the unchanged, reversed or enlarged transmural repolarization gradient. The reversal of epicardial repolarization gradients (apicobasal, anterior-posterior and interventricular) caused the inversion of the T waves regardless of the direction of the transmural repolarization gradient. However, the most realistic body surface potentials were obtained when the endocardial APDs were not changed under hypothermia while the epicardial APDs prolonged. This produced the reversed and increased transmural repolarization gradient in absolute magnitude. The body surface potentials simulated under the unchanged transmural gradient were reduced in comparison to those simulated under the reversed transmural gradient. The simulations demonstrated that the transmural repolarization gradient did not play a crucial role in the cardiac electric field inversion under hypothermia, but its magnitude and direction contribute to the T wave amplitude. © 2016 Wiley Periodicals, Inc.

Changes in autonomic regulation and ventricular repolarization induced by subclinical hyperthyroidism.

PubMed

Galetta, F; Franzoni, F; Fallahi, P; Tocchini, L; Graci, F; Gaddeo, C; Rossi, M; Cini, G; Carpi, A; Santoro, G; Antonelli, A

2010-10-01

The aim of the present study was to evaluate the effect of subclinical hyperthyroidism (SHT) on cardiovascular autonomic function and ventricular repolarization. Thirty subjects (25 females; mean age 49.6 ± 9.8 years) with SHT, as judged by reduced TSH serum levels and normal free T4 and T3 serum levels, and 30 age and sex-matched control subjects underwent standard 12-lead ECG, and 24h ambulatory ECG monitoring. The dispersion of the QT interval, an index of inhomogeneity of repolarization, and the heart rate variability (HRV), a measure of cardiac autonomic modulation, were studied. Patients with SHT showed higher QT dispersion (p<0.001) and lower HRV measures (0.01>p<0.001) than controls. In SHT patients, QT dispersion was inversely related to HRV (r=-0.47, p<0.01). The results of the present study demonstrated that SHT is associated with a sympathovagal imbalance, characterized by increased sympathetic activity in the presence of diminished vagal tone, and with an increased inhomogeneity of ventricular recovery times. The assessment of HRV and QT dispersion in patients with SHT may represent a useful tool in monitoring the cardiovascular risk of this condition. Copyright © 2009 Elsevier Masson SAS. All rights reserved.

Electrophysiological and structural determinants of electrotonic modulation of repolarization by the activation sequence

PubMed Central

Walton, Richard D.; Benson, Alan P.; Hardy, Matthew E. L.; White, Ed; Bernus, Olivier

2013-01-01

Spatial dispersion of repolarization is known to play an important role in arrhythmogenesis. Electrotonic modulation of repolarization by the activation sequence has been observed in some species and tissue preparations, but to varying extents. Our study sought to determine the mechanisms underlying species- and tissue-dependent electrotonic modulation of repolarization in ventricles. Epi-fluorescence optical imaging of whole rat hearts and pig left ventricular wedges were used to assess epicardial spatial activation and repolarization characteristics. Experiments were supported by computer simulations using realistic geometries. Tight coupling between activation times (AT) and action potential duration (APD) were observed in rat experiments but not in pig. Linear correlation analysis found slopes of −1.03 ± 0.59 and −0.26 ± 0.13 for rat and pig, respectively (p < 0.0001). In rat, maximal dispersion of APD was 11.0 ± 3.1 ms but dispersion of repolarization time (RT) was relatively homogeneous (8.2 ± 2.7, p < 0.0001). However, in pig no such difference was observed between the dispersion of APD and RT (17.8 ± 6.1 vs. 17.7 ± 6.5, respectively). Localized elevations of APD (12.9 ± 8.3%) were identified at ventricular insertion sites of rat hearts both in experiments and simulations. Tissue geometry and action potential (AP) morphology contributed significantly to determining influence of electrotonic modulation. Simulations of a rat AP in a pig geometry decreased the slope of AT and APD relationships by 70.6% whereas slopes were increased by 75.0% when implementing a pig AP in a rat geometry. A modified pig AP, shortened to match the rat APD, showed little coupling between AT and APD with greatly reduced slope compared to the rat AP. Electrotonic modulation of repolarization by the activation sequence is especially pronounced in small hearts with murine-like APs. Tissue architecture and AP morphology play an important role in electrotonic modulation of

Flecainide attenuates rate adaptation of ventricular repolarization in guinea-pig heart.

PubMed

Osadchii, Oleg E

2016-01-01

Flecainide is class Ic antiarrhythmic agent that was found to increase the risk of sudden cardiac death. Arrhythmic responses to flecainide could be precipitated by exercise, suggesting a role played by inappropriate rate adaptation of ventricular repolarization. This study therefore examined flecainide effect on adaptation of the QT interval and ventricular action potential duration (APD) to abrupt reductions of the cardiac cycle length. ECG and ventricular epicardial and endocardial monophasic APD were recorded in isolated, perfused guinea-pig heart preparations upon a sustained cardiac acceleration (rapid pacing for 30 s), and following a single perturbation of the cycle length evoked by extrasystolic stimulation. Sustained increase in heart rate was associated with progressive bi-exponential shortening of the QT interval and APD. Flecainide prolonged ventricular repolarization, delayed its rate adaptation, and decreased the amplitude of QT interval and APD shortening upon rapid cardiac pacing. During extrasystolic stimulation, flecainide attenuated APD shortening in premature ventricular beats, with effect being greater upon using a longer basic drive cycle length (S1-S1=550 ms versus S1-S1=300 ms). Flecainide-induced arrhythmia may be partly accounted for by attenuated adaptation of ventricular repolarization to sudden changes in cardiac cycle length provoked by transient tachycardia or ectopic beats.

Can non‐clinical repolarization assays predict the results of clinical thorough QT studies? Results from a research consortium

PubMed Central

Park, Eunjung; Gintant, Gary A; Bi, Daoqin; Kozeli, Devi; Pettit, Syril D; Skinner, Matthew; Willard, James; Wisialowski, Todd; Koerner, John; Valentin, Jean‐Pierre

2018-01-01

Background and Purpose Translation of non‐clinical markers of delayed ventricular repolarization to clinical prolongation of the QT interval corrected for heart rate (QTc) (a biomarker for torsades de pointes proarrhythmia) remains an issue in drug discovery and regulatory evaluations. We retrospectively analysed 150 drug applications in a US Food and Drug Administration database to determine the utility of established non‐clinical in vitro IKr current human ether‐à‐go‐go‐related gene (hERG), action potential duration (APD) and in vivo (QTc) repolarization assays to detect and predict clinical QTc prolongation. Experimental Approach The predictive performance of three non‐clinical assays was compared with clinical thorough QT study outcomes based on free clinical plasma drug concentrations using sensitivity and specificity, receiver operating characteristic (ROC) curves, positive (PPVs) and negative predictive values (NPVs) and likelihood ratios (LRs). Key Results Non‐clinical assays demonstrated robust specificity (high true negative rate) but poor sensitivity (low true positive rate) for clinical QTc prolongation at low‐intermediate (1×–30×) clinical exposure multiples. The QTc assay provided the most robust PPVs and NPVs (ability to predict clinical QTc prolongation). ROC curves (overall test accuracy) and LRs (ability to influence post‐test probabilities) demonstrated overall marginal performance for hERG and QTc assays (best at 30× exposures), while the APD assay demonstrated minimal value. Conclusions and Implications The predictive value of hERG, APD and QTc assays varies, with drug concentrations strongly affecting translational performance. While useful in guiding preclinical candidates without clinical QT prolongation, hERG and QTc repolarization assays provide greater value compared with the APD assay. PMID:29181850

Remodeling of repolarization and arrhythmia susceptibility in a myosin-binding protein C knockout mouse model.

PubMed

Toib, Amir; Zhang, Chen; Borghetti, Giulia; Zhang, Xiaoxiao; Wallner, Markus; Yang, Yijun; Troupes, Constantine D; Kubo, Hajime; Sharp, Thomas E; Feldsott, Eric; Berretta, Remus M; Zalavadia, Neil; Trappanese, Danielle M; Harper, Shavonn; Gross, Polina; Chen, Xiongwen; Mohsin, Sadia; Houser, Steven R

2017-09-01

Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiac diseases and among the leading causes of sudden cardiac death (SCD) in the young. The cellular mechanisms leading to SCD in HCM are not well known. Prolongation of the action potential (AP) duration (APD) is a common feature predisposing hypertrophied hearts to SCD. Previous studies have explored the roles of inward Na + and Ca 2+ in the development of HCM, but the role of repolarizing K + currents has not been defined. The objective of this study was to characterize the arrhythmogenic phenotype and cellular electrophysiological properties of mice with HCM, induced by myosin-binding protein C (MyBPC) knockout (KO), and to test the hypothesis that remodeling of repolarizing K + currents causes APD prolongation in MyBPC KO myocytes. We demonstrated that MyBPC KO mice developed severe hypertrophy and cardiac dysfunction compared with wild-type (WT) control mice. Telemetric electrocardiographic recordings of awake mice revealed prolongation of the corrected QT interval in the KO compared with WT control mice, with overt ventricular arrhythmias. Whole cell current- and voltage-clamp experiments comparing KO with WT mice demonstrated ventricular myocyte hypertrophy, AP prolongation, and decreased repolarizing K + currents. Quantitative RT-PCR analysis revealed decreased mRNA levels of several key K + channel subunits. In conclusion, decrease in repolarizing K + currents in MyBPC KO ventricular myocytes contributes to AP and corrected QT interval prolongation and could account for the arrhythmia susceptibility. NEW & NOTEWORTHY Ventricular myocytes isolated from the myosin-binding protein C knockout hypertrophic cardiomyopathy mouse model demonstrate decreased repolarizing K + currents and action potential and QT interval prolongation, linking cellular repolarization abnormalities with arrhythmia susceptibility and the risk for sudden cardiac death in hypertrophic cardiomyopathy. Copyright © 2017

Excess centrosomes perturb dynamic endothelial cell repolarization during blood vessel formation

PubMed Central

Kushner, Erich J.; Ferro, Luke S.; Yu, Zhixian; Bautch, Victoria L.

2016-01-01

Blood vessel formation requires dynamic movements of endothelial cells (ECs) within sprouts. The cytoskeleton regulates migratory polarity, and centrosomes organize the microtubule cytoskeleton. However, it is not well understood how excess centrosomes, commonly found in tumor stromal cells, affect microtubule dynamics and interphase cell polarity. Here we find that ECs dynamically repolarize during sprouting angiogenesis, and excess centrosomes block repolarization and reduce migration and sprouting. ECs with excess centrosomes initially had more centrosome-derived microtubules but, paradoxically, fewer steady-state microtubules. ECs with excess centrosomes had elevated Rac1 activity, and repolarization was rescued by blockade of Rac1 or actomyosin blockers, consistent with Rac1 activity promoting cortical retrograde actin flow and actomyosin contractility, which precludes cortical microtubule engagement necessary for dynamic repolarization. Thus normal centrosome numbers are required for dynamic repolarization and migration of sprouting ECs that contribute to blood vessel formation. PMID:27099371

How the knowledge of genetic "makeup" and cellular data can affect the analysis of repolarization in surface electrocardiogram.

PubMed

Shimizu, Wataru

2010-01-01

This review article sought to describe patterns of repolarization on the surface electrocardiogram in inherited cardiac arrhythmias and to discuss how the knowledge of genetic makeup and cellular data can affect the analysis based on the data derived from the experimental studies using arterially perfused canine ventricular wedge preparations. Molecular genetic studies have established a link between a number of inherited cardiac arrhythmia syndromes and mutations in genes encoding cardiac ion channels or membrane components during the past 2 decades. Twelve forms of congenital long QT syndrome have been so far identified, and genotype-phenotype correlations have been investigated especially in the 3 major genotypes-LQT1, LQT2, and LQT3. Abnormal T waves are reported in the LQT1, LQT2, and LQT3, and the differences in the time course of repolarization of the epicardial, midmyocardial, and endocardial cells give rise to voltage gradients responsible for the manifestation of phenotypic appearance of abnormal T waves. Brugada syndrome is characterized by ST-segment elevation in leads V1 to V3 and an episode of ventricular fibrillation, in which 7 genotypes have been reported. An intrinsically prominent transient outward current (I(to))-mediated action potential notch and a subsequent loss of action potential dome in the epicardium, but not in the endocardium of the right ventricular outflow tract, give rise to a transmural voltage gradient, resulting in ST-segment elevation, and a subsequent phase 2 reentry-induced ventricular fibrillation. In conclusion, transmural electrical heterogeneity of repolarization across the ventricular wall profoundly affects the phenotypic manifestation of repolarization patterns on the surface electrocardiogram in inherited cardiac arrhythmias. Copyright © 2010 Elsevier Inc. All rights reserved.

Bifurcation diagrams of frequency dependence of repolarization during long QT syndrome using the Luo-Rudy model of cardiac repolarization

NASA Astrophysics Data System (ADS)

Bondarenko, V. E.; Doedel, E. J.; Rasmusson, R. L.

2000-02-01

We applied bifurcation analysis to the Luo-Rudy model of the guinea pig cardiac ventricular cell to investigate the behavior of repolarization in response to a simulated form of inherited arrhythmia, long QT syndrome. In this paper, we simulate pathological changes in cardiac repolarization through reductions in IKr. Decreased expression of this current has been linked to an inherited form of long QT syndrome which results in a high mortality, presumably due to sudden cardiac death from ventricular fibrillation.

Effects of sildenafil on cardiac repolarization.

PubMed

Chiang, Chern-En; Luk, Hsiang-Ning; Wang, Tsui-Min; Ding, Philip Yu-An

2002-08-01

Sudden death has occasionally been reported in patients taking sildenafil. The objective of this study was to investigate the effect of sildenafil on cardiac repolarization. We used conventional microelectrode recording technique in isolated guinea pig papillary muscles and canine Purkinje fibers, whole-cell patch clamp techniques in guinea pig ventricular myocytes, and in vivo ECG measurements in guinea pigs. Action potential duration at 90% repolarization (APD(90)) was not affected by sildenafil in the therapeutic ranges (< or =1 microM), but shortened by higher concentration (> or =10 microM) in both guinea pig papillary muscles and canine Purkinje fibers. D-Sotalol prolonged APD(90) in the same preparations with concentrations > or =1 microM in a reverse frequency-dependent manner. Co-administration of sildenafil (10 and 30 microM) abolished the APD-prolonging effects of D-sotalol (30 microM) and amiodarone (100 microM). Sildenafil, with concentrations up to 30 microM, had no significant effect on both the rapid (I(Kr)) and the slow (I(Ks)) components of the delayed rectifier potassium currents in guinea pig ventricular myocytes. Sildenafil dose-dependently blocked L-type Ca(2+) current (I(Ca,L)), but had no effect on persistent Na(+) current in guinea pig ventricular myocytes. ECG recordings in intact guinea pigs revealed significant shortening of QTc interval by sildenafil (10 and 30 mg/kg orally). The QT-prolonging effects by D,L-sotalol (50 mg/kg) and amiodarone (100 mg/kg) were abolished by sildenafil (30 mg/kg). Sildenafil does not prolong cardiac repolarization. Instead, in supra-therapeutic concentrations, it accelerates cardiac repolarization, presumably through its blocking effect on I(Ca,L).

Early afterdepolarizations promote transmural reentry in ischemic human ventricles with reduced repolarization reserve

PubMed Central

Dutta, Sara; Mincholé, Ana; Zacur, Ernesto; Quinn, T. Alexander; Taggart, Peter; Rodriguez, Blanca

2016-01-01

Aims Acute ischemia is a major cause of sudden arrhythmic death, further promoted by potassium current blockers. Macro-reentry around the ischemic region and early afterdepolarizations (EADs) caused by electrotonic current have been suggested as potential mechanisms in animal and isolated cell studies. However, ventricular and human-specific arrhythmia mechanisms and their modulation by repolarization reserve remain unclear. The goal of this paper is to unravel multiscale mechanisms underlying the modulation of arrhythmic risk by potassium current (IKr) block in human ventricles with acute regional ischemia. Methods and results A human ventricular biophysically-detailed model, with acute regional ischemia is constructed by integrating experimental knowledge on the electrophysiological ionic alterations caused by coronary occlusion. Arrhythmic risk is evaluated by determining the vulnerable window (VW) for reentry following ectopy at the ischemic border zone. Macro-reentry around the ischemic region is the main reentrant mechanism in the ischemic human ventricle with increased repolarization reserve due to the ATP-sensitive potassium current (IK(ATP)) activation. Prolongation of refractoriness by 4% caused by 30% IKr reduction counteracts the establishment of macro-reentry and reduces the VW for reentry (by 23.5%). However, a further decrease in repolarization reserve (50% IKr reduction) is less anti-arrhythmic despite further prolongation of refractoriness. This is due to the establishment of transmural reentry enabled by electrotonically-triggered EADs in the ischemic border zone. EADs are produced by L-type calcium current (ICaL) reactivation due to prolonged low amplitude electrotonic current injected during the repolarization phase. Conclusions Electrotonically-triggered EADs are identified as a potential mechanism facilitating intramural reentry in a regionally-ischemic human ventricles model with reduced repolarization reserve. PMID:26850675

Re-polarization of nuclear spins using selective SABRE-INEPT

NASA Astrophysics Data System (ADS)

Knecht, Stephan; Kiryutin, Alexey S.; Yurkovskaya, Alexandra V.; Ivanov, Konstantin L.

2018-02-01

A method is proposed for significant improvement of NMR pulse sequences used in high-field SABRE (Signal Amplification By Reversible Exchange) experiments. SABRE makes use of spin order transfer from parahydrogen (pH2, the H2 molecule in its singlet spin state) to a substrate in a transient organometallic Ir-based complex. The technique proposed here utilizes "re-polarization", i.e., multiple application of an NMR pulse sequence used for spin order transfer. During re-polarization only the form of the substrate, which is bound to the complex, is excited by selective NMR pulses and the resulting polarization is transferred to the free substrate via chemical exchange. Owing to the fact that (i) only a small fraction of the substrate molecules is in the bound form and (ii) spin relaxation of the free substrate is slow, the re-polarization scheme provides greatly improved NMR signal enhancement, ε . For instance, when pyridine is used as a substrate, single use of the SABRE-INEPT sequence provides ε ≈ 260 for 15N nuclei, whereas SABRE-INEPT with re-polarization yields ε > 2000 . We anticipate that the proposed method is useful for achieving maximal NMR enhancement with spin hyperpolarization techniques.

Drug-Induced Acute Myocardial Infarction: Identifying ‘Prime Suspects’ from Electronic Healthcare Records-Based Surveillance System

PubMed Central

Coloma, Preciosa M.; Schuemie, Martijn J.; Trifirò, Gianluca; Furlong, Laura; van Mulligen, Erik; Bauer-Mehren, Anna; Avillach, Paul; Kors, Jan; Sanz, Ferran; Mestres, Jordi; Oliveira, José Luis; Boyer, Scott; Helgee, Ernst Ahlberg; Molokhia, Mariam; Matthews, Justin; Prieto-Merino, David; Gini, Rosa; Herings, Ron; Mazzaglia, Giampiero; Picelli, Gino; Scotti, Lorenza; Pedersen, Lars; van der Lei, Johan; Sturkenboom, Miriam

2013-01-01

Background Drug-related adverse events remain an important cause of morbidity and mortality and impose huge burden on healthcare costs. Routinely collected electronic healthcare data give a good snapshot of how drugs are being used in ‘real-world’ settings. Objective To describe a strategy that identifies potentially drug-induced acute myocardial infarction (AMI) from a large international healthcare data network. Methods Post-marketing safety surveillance was conducted in seven population-based healthcare databases in three countries (Denmark, Italy, and the Netherlands) using anonymised demographic, clinical, and prescription/dispensing data representing 21,171,291 individuals with 154,474,063 person-years of follow-up in the period 1996–2010. Primary care physicians’ medical records and administrative claims containing reimbursements for filled prescriptions, laboratory tests, and hospitalisations were evaluated using a three-tier triage system of detection, filtering, and substantiation that generated a list of drugs potentially associated with AMI. Outcome of interest was statistically significant increased risk of AMI during drug exposure that has not been previously described in current literature and is biologically plausible. Results Overall, 163 drugs were identified to be associated with increased risk of AMI during preliminary screening. Of these, 124 drugs were eliminated after adjustment for possible bias and confounding. With subsequent application of criteria for novelty and biological plausibility, association with AMI remained for nine drugs (‘prime suspects’): azithromycin; erythromycin; roxithromycin; metoclopramide; cisapride; domperidone; betamethasone; fluconazole; and megestrol acetate. Limitations Although global health status, co-morbidities, and time-invariant factors were adjusted for, residual confounding cannot be ruled out. Conclusion A strategy to identify potentially drug-induced AMI from electronic healthcare data has

Choline-modulated arsenic trioxide-induced prolongation of cardiac repolarization in Guinea pig.

PubMed

Sun, Hong-Li; Chu, Wen-Feng; Dong, De-Li; Liu, Yan; Bai, Yun-Long; Wang, Xiao-Hui; Zhou, Jin; Yang, Bao-Feng

2006-04-01

Arsenic trioxide (As(2)O(3)) has been found to be effective for relapsed or refractory acute promyelocytic leukaemia, but its clinical use is burdened by QT prolongation, Torsade de pointes tachycardias, and sudden cardiac death. The aim of the present study was to elucidate the ionic mechanisms of As(2)O(3)-induced abnormalities of cardiac electrophysiology and the therapeutic action of choline on As(2)O(3)-caused QT prolongation in guinea pig. Intravenous administration of As(2)O(3) prolonged the QT interval in a dose- and time-dependent manner in guinea pig hearts, and the QT prolongation could be modulated by choline. By using whole-cell patch clamp technique and confocal laser scanning microscopy, we found that As(2)O(3) significantly lengthened action potential duration measured at 50 and 90% of repolarization, enhanced L-type calcium currents (I(Ca-L)), inhibited delayed rectifier potassium currents (I(K)), and increased intracellular calcium concentration ([Ca(2+)](i)) in guinea pig ventricular myocytes. Choline corrected As(2)O(3)-mediated alterations of action potential duration, I(Ca-L) and [Ca(2+)](i), but had no effect on the I(K) inhibition. As(2)O(3) markedly disturbed the normal equilibrium of transmembrane currents (increasing I(Ca-L) and suppressing I(K)) in guinea pig cardiomyocyte, and induced prolongation of action potential duration, further degenerated into QT prolongation. Choline normalized QT interval abnormality and corrected lengthened action potential duration by inhibiting the elevated I(Ca-L) and [Ca(2+)](i) in ventricular myocytes during As(2)O(3) application.

Re-polarization of nuclear spins using selective SABRE-INEPT.

PubMed

Knecht, Stephan; Kiryutin, Alexey S; Yurkovskaya, Alexandra V; Ivanov, Konstantin L

2018-02-01

A method is proposed for significant improvement of NMR pulse sequences used in high-field SABRE (Signal Amplification By Reversible Exchange) experiments. SABRE makes use of spin order transfer from parahydrogen (pH 2 , the H 2 molecule in its singlet spin state) to a substrate in a transient organometallic Ir-based complex. The technique proposed here utilizes "re-polarization", i.e., multiple application of an NMR pulse sequence used for spin order transfer. During re-polarization only the form of the substrate, which is bound to the complex, is excited by selective NMR pulses and the resulting polarization is transferred to the free substrate via chemical exchange. Owing to the fact that (i) only a small fraction of the substrate molecules is in the bound form and (ii) spin relaxation of the free substrate is slow, the re-polarization scheme provides greatly improved NMR signal enhancement, ε. For instance, when pyridine is used as a substrate, single use of the SABRE-INEPT sequence provides ε≈260 for 15 N nuclei, whereas SABRE-INEPT with re-polarization yields ε>2000. We anticipate that the proposed method is useful for achieving maximal NMR enhancement with spin hyperpolarization techniques. Copyright © 2017 Elsevier Inc. All rights reserved.

A Novel Lead Configuration for Optimal Spatio-Temporal Detection of Intracardiac Repolarization Alternans

PubMed Central

Weiss, Eric H.; Merchant, Faisal M.; d’Avila, Andre; Foley, Lori; Reddy, Vivek Y.; Singh, Jagmeet P.; Mela, Theofanie; Ruskin, Jeremy N.; Armoundas, Antonis A.

2011-01-01

Background Electrical alternans is a pattern of variation in the shape of electrocardiographic waveform that occurs every other beat. In humans, alternation in ventricular repolarization, known as repolarization alternans (RA), has been associated with increased vulnerability to ventricular tachycardia/fibrillation and sudden cardiac death. Methods and Results This study investigates the spatio-temporal variability of intracardiac RA and its relationship to body surface RA in an acute myocardial ischemia model in swine. We developed a real-time multi-channel repolarization signal acquisition, display and analysis system to record electrocardiographic signals from catheters in the right ventricle, coronary sinus, left ventricle, and epicardial surface prior to and following circumflex coronary artery balloon occlusion. We found that RA is detectable within 4 minutes following the onset ischemia, and is most prominently seen during the first half of the repolarization interval. Ischemia-induced RA was detectable on unipolar and bipolar leads (both in near- and far-field configurations) and on body surface leads. Far-field bipolar intracardiac leads were more sensitive for RA detection than body surface leads, with the probability of body surface RA detection increasing as the number of intracardiac leads detecting RA increased, approaching 100% when at least three intracardiac leads detected RA. We developed a novel, clinically-applicable intracardiac lead system based on a triangular arrangement of leads spanning the right ventricular (RV) and coronary sinus (CS) catheters which provided the highest sensitivity for intracardiac RA detection when compared to any other far-field bipolar sensing configurations (p < 0.0001). Conclusions In conclusion, intracardiac alternans, a complex spatio-temporal phenomenon associated with arrhythmia susceptibility and sudden cardiac death, can be reliably detected through a novel triangular RV-CS lead configuration. PMID:21430127

Drug-induced Brugada syndrome: Clinical characteristics and risk factors.

PubMed

Konigstein, Maayan; Rosso, Raphael; Topaz, Guy; Postema, Pieter G; Friedensohn, Limor; Heller, Karin; Zeltser, David; Belhassen, Bernard; Adler, Arnon; Viskin, Sami

2016-05-01

Cardiac arrest may result from seemingly innocuous medications that do not necessarily have cardiac indications. The best-known example is the drug-induced long QT syndrome. A less known but not necessarily less important form of drug-induced proarrhythmia is the drug-induced Brugada syndrome. The purpose of this study was to identify clinical and ECG risk markers for drug-induced Brugada syndrome. Reports of drug-induced Brugada syndrome recounted by an international database (http://www.brugadadrugs.org) were reviewed to define characteristics that identify patients prone to developing this complication. For each patient with drug-induced Brugada syndrome who had an ECG recorded in the absence of drugs, we included 5 healthy controls matched by gender and age. All ECGs were evaluated for Brugada-like abnormalities. Seventy-four cases of drug-induced Brugada syndrome from noncardiac medications were identified: 77% were male, and drug toxicity was involved in 46%. Drug-induced Brugada syndrome from oral medications generally occurred weeks after the initiation of therapy. Mortality was 13%. By definition, all cases had a type I Brugada pattern during drug therapy. Nevertheless, their ECG in the absence of drugs was more frequently abnormal than the ECG of controls (56% vs 33%, P = .04). Drug-induced Brugada syndrome from noncardiac drugs occurs predominantly in adult males, is frequently due to drug toxicity, and occurs late after the onset of therapy. Minor changes are frequently noticeable on baseline ECG, but screening is impractical because of a prohibitive false-positive rate. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Differences between Drug-Induced and Contrast Media-Induced Adverse Reactions Based on Spontaneously Reported Adverse Drug Reactions.

PubMed

Ryu, JiHyeon; Lee, HeeYoung; Suh, JinUk; Yang, MyungSuk; Kang, WonKu; Kim, EunYoung

2015-01-01

We analyzed differences between spontaneously reported drug-induced (not including contrast media) and contrast media-induced adverse reactions. Adverse drug reactions reported by an in-hospital pharmacovigilance center (St. Mary's teaching hospital, Daejeon, Korea) from 2010-2012 were classified as drug-induced or contrast media-induced. Clinical patterns, frequency, causality, severity, Schumock and Thornton's preventability, and type A/B reactions were recorded. The trends among causality tools measuring drug and contrast-induced adverse reactions were analyzed. Of 1,335 reports, 636 drug-induced and contrast media-induced adverse reactions were identified. The prevalence of spontaneously reported adverse drug reaction-related admissions revealed a suspected adverse drug reaction-reporting rate of 20.9/100,000 (inpatient, 0.021%) and 3.9/100,000 (outpatients, 0.004%). The most common adverse drug reaction-associated drug classes included nervous system agents and anti-infectives. Dermatological and gastrointestinal adverse drug reactions were most frequently and similarly reported between drug and contrast media-induced adverse reactions. Compared to contrast media-induced adverse reactions, drug-induced adverse reactions were milder, more likely to be preventable (9.8% vs. 1.1%, p < 0.001), and more likely to be type A reactions (73.5% vs. 18.8%, p < 0.001). Females were over-represented among drug-induced adverse reactions (68.1%, p < 0.001) but not among contrast media-induced adverse reactions (56.6%, p = 0.066). Causality patterns differed between the two adverse reaction classes. The World Health Organization-Uppsala Monitoring Centre causality evaluation and Naranjo algorithm results significantly differed from those of the Korean algorithm version II (p < 0.001). We found differences in sex, preventability, severity, and type A/B reactions between spontaneously reported drug and contrast media-induced adverse reactions. The World Health Organization

Differences between Drug-Induced and Contrast Media-Induced Adverse Reactions Based on Spontaneously Reported Adverse Drug Reactions

PubMed Central

Suh, JinUk; Yang, MyungSuk; Kang, WonKu; Kim, EunYoung

2015-01-01

Objective We analyzed differences between spontaneously reported drug-induced (not including contrast media) and contrast media-induced adverse reactions. Methods Adverse drug reactions reported by an in-hospital pharmacovigilance center (St. Mary’s teaching hospital, Daejeon, Korea) from 2010–2012 were classified as drug-induced or contrast media-induced. Clinical patterns, frequency, causality, severity, Schumock and Thornton’s preventability, and type A/B reactions were recorded. The trends among causality tools measuring drug and contrast-induced adverse reactions were analyzed. Results Of 1,335 reports, 636 drug-induced and contrast media-induced adverse reactions were identified. The prevalence of spontaneously reported adverse drug reaction-related admissions revealed a suspected adverse drug reaction-reporting rate of 20.9/100,000 (inpatient, 0.021%) and 3.9/100,000 (outpatients, 0.004%). The most common adverse drug reaction-associated drug classes included nervous system agents and anti-infectives. Dermatological and gastrointestinal adverse drug reactions were most frequently and similarly reported between drug and contrast media-induced adverse reactions. Compared to contrast media-induced adverse reactions, drug-induced adverse reactions were milder, more likely to be preventable (9.8% vs. 1.1%, p < 0.001), and more likely to be type A reactions (73.5% vs. 18.8%, p < 0.001). Females were over-represented among drug-induced adverse reactions (68.1%, p < 0.001) but not among contrast media-induced adverse reactions (56.6%, p = 0.066). Causality patterns differed between the two adverse reaction classes. The World Health Organization–Uppsala Monitoring Centre causality evaluation and Naranjo algorithm results significantly differed from those of the Korean algorithm version II (p < 0.001). Conclusions We found differences in sex, preventability, severity, and type A/B reactions between spontaneously reported drug and contrast media-induced adverse

A Text Searching Tool to Identify Patients with Idiosyncratic Drug-Induced Liver Injury.

PubMed

Heidemann, Lauren; Law, James; Fontana, Robert J

2017-03-01

Idiosyncratic drug-induced liver injury (DILI) is an uncommon but important cause of liver disease that is challenging to diagnose and identify in the electronic medical record (EMR). To develop an accurate, reliable, and efficient method of identifying patients with bonafide DILI in an EMR system. In total, 527,000 outpatient and ER encounters in an EPIC-based EMR were searched for potential DILI cases attributed to eight drugs. A searching algorithm that extracted 200 characters of text around 14 liver injury terms in the EMR were extracted and collated. Physician investigators reviewed the data outputs and used standardized causality assessment methods to adjudicate the potential DILI cases. A total of 101 DILI cases were identified from the 2564 potential DILI cases that included 62 probable DILI cases, 25 possible DILI cases, nine historical DILI cases, and five allergy-only cases. Elimination of the term "liver disease" from the search strategy improved the search recall from 4 to 19 %, while inclusion of the four highest yield liver injury terms further improved the positive predictive value to 64 % but reduced the overall case detection rate by 47 %. RUCAM scores of the 57 probable DILI cases were generally high and concordant with expert opinion causality assessment scores. A novel text searching tool was developed that identified a large number of DILI cases from a widely used EMR system. A computerized extraction of dictated text followed by the manual review of text snippets can rapidly identify bona fide cases of idiosyncratic DILI.

Myocyte repolarization modulates myocardial function in aging dogs

PubMed Central

Sorrentino, Andrea; Signore, Sergio; Borghetti, Giulia; Meo, Marianna; Cannata, Antonio; Zhou, Yu; Wybieralska, Ewa; Luciani, Marco; Kannappan, Ramaswamy; Zhang, Eric; Matsuda, Alex; Webster, Andrew; Cimini, Maria; Kertowidjojo, Elizabeth; D'Alessandro, David A.; Wunimenghe, Oriyanhan; Michler, Robert E.; Royer, Christopher; Goichberg, Polina; Leri, Annarosa; Barrett, Edward G.; Anversa, Piero; Hintze, Thomas H.

2016-01-01

Studies of myocardial aging are complex and the mechanisms involved in the deterioration of ventricular performance and decreased functional reserve of the old heart remain to be properly defined. We have studied a colony of beagle dogs from 3 to 14 yr of age kept under a highly regulated environment to define the effects of aging on the myocardium. Ventricular, myocardial, and myocyte function, together with anatomical and structural properties of the organ and cardiomyocytes, were evaluated. Ventricular hypertrophy was not observed with aging and the structural composition of the myocardium was modestly affected. Alterations in the myocyte compartment were identified in aged dogs, and these factors negatively interfere with the contractile reserve typical of the young heart. The duration of the action potential is prolonged in old cardiomyocytes contributing to the slower electrical recovery of the myocardium. Also, the remodeled repolarization of cardiomyocytes with aging provides inotropic support to the senescent muscle but compromises its contractile reserve, rendering the old heart ineffective under conditions of high hemodynamic demand. The defects in the electrical and mechanical properties of cardiomyocytes with aging suggest that this cell population is an important determinant of the cardiac senescent phenotype. Collectively, the delayed electrical repolarization of aging cardiomyocytes may be viewed as a critical variable of the aging myopathy and its propensity to evolve into ventricular decompensation under stressful conditions. PMID:26801307

The effect of cardiac electric anisotropy on epicardial potential fields during ventricular repolarization.

PubMed

Spaggiari, S; Baruffi, S; Macchi, E; Traversa, M; Arisi, G; Taccardi, B

1986-11-01

We tried to establish whether some of the manifestations of electrical anisotropy previously observed on the canine ventricular epicardium during the spread of excitation were also present during repolarization, with the appropriate polarity. To this end we determined the potential distribution on the ventricular surface of exposed dog hearts during ventricular excitation and repolarization. The ventricles were paced by means of epicardial or intramural electrodes. During the early stages of ventricular excitation following epicardial pacing we observed typical, previously described potential patterns, with negative, elliptical equipotential lines surrounding the pacing site, and two maxima aligned along the direction of subepicardial fibers. Intramural pacing gave rise to similar patterns. The axis joining the maxima, however, was oriented along the direction of intramural fibers. The repolarization potential pattern relating to epicardial excitation exhibited some features similar to those observed during the spread of excitation, namely the presence of families of elliptical equipotential lines around the pacing site, with pairs of potential extrema along the major or minor axes of the ellipses or both. The location of the extrema and the distribution of the epicardial potential gradients during repolarization suggested the presence of anisotropic current generators mainly oriented along the direction of deep myocardial fibers, with some contribution from more superficial sources which were oriented along the direction of subepicardial fibers. Deep stimulation elicited more complicated epicardial patterns whose interpretation is still obscure. We conclude that the electrical anisotropy of the heart affects the distribution of repolarization potentials and probably the strength of electrical generators during ventricular repolarization.

T-wave alternans and beat-to-beat variability of repolarization: pathophysiological backgrounds and clinical relevance.

PubMed

Floré, Vincent; Willems, Rik

2012-12-01

In this review, we focus on temporal variability of cardiac repolarization. This phenomenon has been related to a higher risk for ventricular arrhythmia and is therefore interesting as a marker of sudden cardiac death risk. We review two non-invasive clinical techniques quantifying repolarization variability: T-wave alternans (TWA) and beat-to-beat variability of repolarization (BVR). We discuss their pathophysiological link with ventricular arrhythmia and the current clinical relevance of these techniques.

Update on the evaluation of a new drug for effects on cardiac repolarization in humans: issues in early drug development

PubMed Central

Salvi, Vaibhav; Karnad, Dilip R; Panicker, Gopi Krishna; Kothari, Snehal

2010-01-01

Following reports of death from cardiac arrhythmias with drugs like terfenadine and cisapride, the International Conference for Harmonization formulated a guidance (E14) document. This specifies that all new drugs must undergo a ‘thorough QT/QTc’ (TQT) study to detect drug-induced QT prolongation, a surrogate marker of ventricular tachycardia, especially torsades de pointes (TdPs). With better understanding of data from several completed TQT studies, regulatory requirements have undergone some changes since the E14 guidance was implemented in October 2005. This article reviews the implications of the E14 guidance and the changes in its interpretation including choice of baseline QT, demonstration of assay sensitivity, statistical analysis of the effect of new drug and positive control, and PK-PD modelling. Some issues like use of automated QT measurements remain unresolved. Pharmaceutical companies too are modifying Phase 1 studies to detect QTc liability early in order to save time and resources. After the E14 guidance, development of several drugs that prolong QTc by >5 ms is being abandoned by sponsors. However, all drugs that prolong the QT interval do not increase risk of TdP. Researchers in regulatory agencies, academia and industry are working to find better biomarkers of drug-induced TdP which could prevent many useful drugs from being prematurely abandoned. Drug-induced TdP is a rare occurrence. With fewer drugs that prolong QT interval reaching the licensing stage, knowing which of these drugs are torsadogenic is proving to be elusive. Thus, paradoxically, the effectiveness of the E14 guidance itself has made prospective validation of new biomarkers difficult. This article is part of a themed section on QT safety. To view this issue visit http://www3.interscience.wiley.com/journal/121548564/issueyear?year=2010 PMID:19775279

Hysteresis effect implicates calcium cycling as a mechanism of repolarization alternans.

PubMed

Walker, Mariah L; Wan, Xiaoping; Kirsch, Glenn E; Rosenbaum, David S

2003-11-25

T-wave alternans is due to alternation of membrane repolarization at the cellular level and is a risk factor for sudden cardiac death. Recently, a hysteresis effect has been reported in patients whereby T-wave alternans, once induced by rapid heart rate, persists even when heart rate is subsequently slowed. We hypothesized that alternans hysteresis is an intrinsic property of cardiac myocytes, directly related to an underlying mechanism for repolarization alternans that involves intracellular calcium cycling. Stepwise pacing was used to induce alternans in Langendorff-perfused guinea pig hearts from which optical action potentials were recorded simultaneously at 256 ventricular sites with voltage-sensitive dyes and in whole-cell patch-clamped cardiac myocytes treated with or without BAPTA-AM (1,2-bis[2-aminophenoxy]ethane-N,N,N',N'-tetraacetic acid tetrakis [acetoxymethyl ester]). Alternans hysteresis was observed in every isolated heart: threshold heart rate for alternans was 280+/-12 bpm, but during subsequent deceleration of pacing, alternans persisted to significantly slower heart rates (238+/-5 bpm, P<0.05). Optical mapping showed that this effect also applied to the threshold for spatially discordant alternans (313+/-2.2 bpm during acceleration versus 250+/-6.6 bpm during deceleration, P<0.05). Alternans hysteresis was also observed in isolated cardiac myocytes. Moreover, calcium chelation by BAPTA-AM raised the threshold for alternans and inhibited hysteresis in a dose-dependent manner with no effect on baseline action potential duration. Alternans hysteresis is an intrinsic property of cardiac myocytes that can lead to persistence of arrhythmogenic discordant alternans even after heart rate is slowed. These results also support an important underlying role of calcium cycling in the mechanism of alternans.

Identifying the translational gap in the evaluation of drug-induced QTc interval prolongation

PubMed Central

Chain, Anne SY; Dubois, Vincent FS; Danhof, Meindert; Sturkenboom, Miriam CJM; Della Pasqua, Oscar

2013-01-01

Aims Given the similarities in QTc response between dogs and humans, dogs are used in pre-clinical cardiovascular safety studies. The objective of our investigation was to characterize the PKPD relationships and identify translational gaps across species following the administration of three compounds known to cause QTc interval prolongation, namely cisapride, d, l-sotalol and moxifloxacin. Methods Pharmacokinetic and pharmacodynamic data from experiments in conscious dogs and clinical trials were included in this analysis. First, pharmacokinetic modelling and deconvolution methods were applied to derive drug concentrations at the time of each QT measurement. A Bayesian PKPD model was then used to describe QT prolongation, allowing discrimination of drug-specific effects from other physiological factors known to alter QT interval duration. A threshold of ≥10 ms was used to explore the probability of prolongation after drug administration. Results A linear relationship was found to best describe the pro-arrhythmic effects of cisapride, d,l-sotalol and moxifloxacin both in dogs and in humans. The drug-specific parameter (slope) in dogs was statistically significantly different from humans. Despite such differences, our results show that the probability of QTc prolongation ≥10 ms in dogs nears 100% for all three compounds at the therapeutic exposure range in humans. Conclusions Our findings indicate that the slope of PKPD relationship in conscious dogs may be used as the basis for the prediction of drug-induced QTc prolongation in humans. Furthermore, the risk of QTc prolongation can be expressed in terms of the probability associated with an increase ≥10 ms, allowing direct inferences about the clinical relevance of the pro-arrhythmic potential of a molecule. PMID:23351036

Role of suppression of the inward rectifier current in terminal action potential repolarization in the failing heart.

PubMed

Klein, Michael G; Shou, Matie; Stohlman, Jayna; Solhjoo, Soroosh; Haigney, Myles; Tidwell, Richard R; Goldstein, Robert E; Flagg, Thomas P; Haigney, Mark C

2017-08-01

The failing heart exhibits an increased arrhythmia susceptibility that is often attributed to action potential (AP) prolongation due to significant ion channel remodeling. The inwardly rectifying K + current (I K1 ) has been reported to be reduced, but its contribution to shaping the AP waveform and cell excitability in the failing heart remains unclear. The purpose of this study was to define the effect of I K1 suppression on the cardiac AP and excitability in the normal and failing hearts. We used electrophysiological and pharmacological approaches to investigate I K1 function in a swine tachy-pacing model of heart failure (HF). Terminal repolarization of the AP (TRAP; the time constant of the exponential fit to terminal repolarization) was markedly prolonged in both myocytes and arterially perfused wedges from animals with HF. TRAP was increased by 54.1% in HF myocytes (P < .001) and 26.2% in HF wedges (P = .014). The increase in TRAP was recapitulated by the potent and specific I K1 inhibitor, PA-6 (pentamidine analog 6), indicating that I K1 is the primary determinant of the final phase of repolarization. Moreover, we find that I K1 suppression reduced the ratio of effective refractory period to AP duration at 90% of repolarization, permitting re-excitation before full repolarization, reduction of AP upstroke velocity, and likely promotion of slow conduction. Using an objective measure of terminal repolarization, we conclude that I K1 is the major determinant of the terminal repolarization time course. Moreover, suppression of I K1 prolongs repolarization and reduces postrepolarization refractoriness without marked effects on the overall AP duration. Collectively, these findings demonstrate how I K1 suppression may contribute to arrhythmogenesis in the failing heart. Published by Elsevier Inc.

[The influence of occupational lead exposure on transmural repolarization dispersion].

PubMed

Zyśko, Dorota; Gajek, Jacek; Chlebda, Ewa; Mazurek, Walentyna

2005-02-01

The parts of QT interval: time from Q wave to the peak of T wave (QTp) representing the de- and repolarization of subepicardial layer and the time from the peak of T wave to its end (QTp-e) building the transmural dispersion of repolarization enable more exact assessment of repolarization period of the heart muscle. Occupational exposure to lead influences the electrophysiologic properties of the heart. The aim of our study was to assess the QTp and QTp-e interval in workers occupationally exposed to lead. The study was carried out in 22 copper smelters aged 41.8 +/- 8.7 years, occupationally exposed to lead. The control group consisted of 14 healthy men. In all studied subjects blood lead concentration (Pb) and the concentration of free protoporphyrins in erytrocytes were assessed. 24-hour ECG holter monitoring was done to study rhythm disturbances and the duration in lead CM5 of QT interval, QTp interval, RR interval preceding the assessed QT interval (pRR) during sleep, rest during the awake state and moderate daily activity. The QTp-e interval is the difference between the duration of QT and QTp interval. The duration of QTp and QTp-e in occupationally exposed workers and healthy persons did not differ significantly. These parameters were significantly lower in both groups during moderately physical activity comparing to the values during sleep. The QTp-e/ QTp ratio in occupationally exposed workers during night hours was significantly lower than during daily activity what was not the case in control persons. Occupational exposure to lead do not change significantly the transmural dispersion of repolarization. Occupational exposure to lead diminishes the QTp-e/QTp ratio during the night.

Modeling and quantification of repolarization feature dependency on heart rate.

PubMed

Minchole, A; Zacur, E; Pueyo, E; Laguna, P

2014-01-01

This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems". This work aims at providing an efficient method to estimate the parameters of a non linear model including memory, previously proposed to characterize rate adaptation of repolarization indices. The physiological restrictions on the model parameters have been included in the cost function in such a way that unconstrained optimization techniques such as descent optimization methods can be used for parameter estimation. The proposed method has been evaluated on electrocardiogram (ECG) recordings of healthy subjects performing a tilt test, where rate adaptation of QT and Tpeak-to-Tend (Tpe) intervals has been characterized. The proposed strategy results in an efficient methodology to characterize rate adaptation of repolarization features, improving the convergence time with respect to previous strategies. Moreover, Tpe interval adapts faster to changes in heart rate than the QT interval. In this work an efficient estimation of the parameters of a model aimed at characterizing rate adaptation of repolarization features has been proposed. The Tpe interval has been shown to be rate related and with a shorter memory lag than the QT interval.

Modulation of KCNQ1 alternative splicing regulates cardiac IKs and action potential repolarization.

PubMed

Lee, Hsiang-Chun; Rudy, Yoram; Po-Yuan, Phd; Sheu, Sheng-Hsiung; Chang, Jan-Gowth; Cui, Jianmin

2013-08-01

Slow delayed-rectifier potassium current (IKs) channels, made of the pore-forming KCNQ1 and auxiliary KCNE1 subunits, play a key role in determining action potential duration (APD) in cardiac myocytes. The consequences of drug-induced KCNQ1 splice alteration remain unknown. To study the modulation of KCNQ1 alternative splicing by amiloride and the consequent changes in IKs and action potentials (APs) in ventricular myocytes. Canine endocardial, midmyocardial, and epicardial ventricular myocytes were isolated. Levels of KCNQ1a and KCNQ1b as well as a series of splicing factors were quantified by using the reverse transcriptase-polymerase chain reaction and Western blot. The effect of amiloride-induced changes in the KCNQ1b/total KCNQ1 ratio on AP was measured by using whole-cell patch clamp with and without isoproterenol. With 50 μmol/L of amiloride for 6 hours, KCNQ1a at transcriptional and translational levels increased in midmyocardial myocytes but decreased in endo- and epicardial myocytes. Likewise, changes in splicing factors in midmyocardial were opposite to that in endo- and epicardial myocytes. In midmyocardial myocytes amiloride shortened APD and decreased isoproterenol-induced early afterdepolarizations significantly. The same amiloride-induced effects were demonstrated by using human ventricular myocyte model for AP simulations under beta-adrenergic stimulation. Moreover, amiloride reduced the transmural dispersion of repolarization in pseudo-electrocardiogram. Amiloride regulates IKs and APs with transmural differences and reduces arrhythmogenicity through the modulation of KCNQ1 splicing. We suggested that the modulation of KCNQ1 splicing may help prevent arrhythmia. Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Drug-Path: a database for drug-induced pathways

PubMed Central

Zeng, Hui; Cui, Qinghua

2015-01-01

Some databases for drug-associated pathways have been built and are publicly available. However, the pathways curated in most of these databases are drug-action or drug-metabolism pathways. In recent years, high-throughput technologies such as microarray and RNA-sequencing have produced lots of drug-induced gene expression profiles. Interestingly, drug-induced gene expression profile frequently show distinct patterns, indicating that drugs normally induce the activation or repression of distinct pathways. Therefore, these pathways contribute to study the mechanisms of drugs and drug-repurposing. Here, we present Drug-Path, a database of drug-induced pathways, which was generated by KEGG pathway enrichment analysis for drug-induced upregulated genes and downregulated genes based on drug-induced gene expression datasets in Connectivity Map. Drug-Path provides user-friendly interfaces to retrieve, visualize and download the drug-induced pathway data in the database. In addition, the genes deregulated by a given drug are highlighted in the pathways. All data were organized using SQLite. The web site was implemented using Django, a Python web framework. Finally, we believe that this database will be useful for related researches. Database URL: http://www.cuilab.cn/drugpath PMID:26130661

Drug-Path: a database for drug-induced pathways.

PubMed

Zeng, Hui; Qiu, Chengxiang; Cui, Qinghua

2015-01-01

Some databases for drug-associated pathways have been built and are publicly available. However, the pathways curated in most of these databases are drug-action or drug-metabolism pathways. In recent years, high-throughput technologies such as microarray and RNA-sequencing have produced lots of drug-induced gene expression profiles. Interestingly, drug-induced gene expression profile frequently show distinct patterns, indicating that drugs normally induce the activation or repression of distinct pathways. Therefore, these pathways contribute to study the mechanisms of drugs and drug-repurposing. Here, we present Drug-Path, a database of drug-induced pathways, which was generated by KEGG pathway enrichment analysis for drug-induced upregulated genes and downregulated genes based on drug-induced gene expression datasets in Connectivity Map. Drug-Path provides user-friendly interfaces to retrieve, visualize and download the drug-induced pathway data in the database. In addition, the genes deregulated by a given drug are highlighted in the pathways. All data were organized using SQLite. The web site was implemented using Django, a Python web framework. Finally, we believe that this database will be useful for related researches. © The Author(s) 2015. Published by Oxford University Press.

Contemporary review of drug-induced pancreatitis: A different perspective

PubMed Central

Hung, Whitney Y; Abreu Lanfranco, Odaliz

2014-01-01

Although gallstone and alcohol use have been considered the most common causes of acute pancreatitis, hundreds of frequently prescribed medications are associated with this disease state. The true incidence is unknown since there are few population based studies available. The knowledge of drug induced acute pancreatitis is limited by the availability and the quality of the evidence as the majority of data is extrapolated from case reports. Establishing a definitive causal relationship between a drug and acute pancreatitis poses a challenge to clinicians. Several causative agent classification systems are often used to identify the suspected agents. They require regular updates since new drug induced acute pancreatitis cases are reported continuously. In addition, infrequently prescribed medications and herbal medications are often omitted. Furthermore, identification of drug induced acute pancreatitis with new medications often requires accumulation of post market case reports. The unrealistic expectation for a comprehensive list of medications and the multifactorial nature of acute pancreatitis call for a different approach. In this article, we review the potential mechanisms of drug induced acute pancreatitis and provide the perspective of deductive reasoning in order to allow clinicians to identify potential drug induced acute pancreatitis with limited data. PMID:25400984

Characterization of drug-induced transcriptional modules: towards drug repositioning and functional understanding

PubMed Central

Iskar, Murat; Zeller, Georg; Blattmann, Peter; Campillos, Monica; Kuhn, Michael; Kaminska, Katarzyna H; Runz, Heiko; Gavin, Anne-Claude; Pepperkok, Rainer; van Noort, Vera; Bork, Peer

2013-01-01

In pharmacology, it is crucial to understand the complex biological responses that drugs elicit in the human organism and how well they can be inferred from model organisms. We therefore identified a large set of drug-induced transcriptional modules from genome-wide microarray data of drug-treated human cell lines and rat liver, and first characterized their conservation. Over 70% of these modules were common for multiple cell lines and 15% were conserved between the human in vitro and the rat in vivo system. We then illustrate the utility of conserved and cell-type-specific drug-induced modules by predicting and experimentally validating (i) gene functions, e.g., 10 novel regulators of cellular cholesterol homeostasis and (ii) new mechanisms of action for existing drugs, thereby providing a starting point for drug repositioning, e.g., novel cell cycle inhibitors and new modulators of α-adrenergic receptor, peroxisome proliferator-activated receptor and estrogen receptor. Taken together, the identified modules reveal the conservation of transcriptional responses towards drugs across cell types and organisms, and improve our understanding of both the molecular basis of drug action and human biology. PMID:23632384

Drug-Induced Hematologic Syndromes

PubMed Central

Mintzer, David M.; Billet, Shira N.; Chmielewski, Lauren

2009-01-01

Objective. Drugs can induce almost the entire spectrum of hematologic disorders, affecting white cells, red cells, platelets, and the coagulation system. This paper aims to emphasize the broad range of drug-induced hematological syndromes and to highlight some of the newer drugs and syndromes. Methods. Medline literature on drug-induced hematologic syndromes was reviewed. Most reports and reviews focus on individual drugs or cytopenias. Results. Drug-induced syndromes include hemolytic anemias, methemoglobinemia, red cell aplasia, sideroblastic anemia, megaloblastic anemia, polycythemia, aplastic anemia, leukocytosis, neutropenia, eosinophilia, immune thrombocytopenia, microangiopathic syndromes, hypercoagulability, hypoprothrombinemia, circulating anticoagulants, myelodysplasia, and acute leukemia. Some of the classic drugs known to cause hematologic abnormalities have been replaced by newer drugs, including biologics, accompanied by their own syndromes and unintended side effects. Conclusions. Drugs can induce toxicities spanning many hematologic syndromes, mediated by a variety of mechanisms. Physicians need to be alert to the potential for iatrogenic drug-induced hematologic complications. PMID:19960059

Evaluation of the acute electrophysiologic effects of intravenous dronedarone, an amiodarone-like agent, with special emphasis on ventricular repolarization and acquired torsade de pointes arrhythmias.

PubMed

Verduyn, S C; Vos, M A; Leunissen, H D; van Opstal, J M; Wellens, H J

1999-02-01

In the anesthetized dog with complete chronic AV block (CAVB), we evaluated and compared the acute electrophysiologic effects of dronedarone i.v. (Dron, 2 times 2.5 mg/kg/10 min) and amiodarone i.v. (Amio, 2 times 5 mg/kg/10 min). This canine model with a high sensitivity for acquired torsade de pointes (TdP) provides an ideal substrate to evaluate ventricular repolarization abnormalities. Six ECG leads and two endocardial monophasic action potential (MAP) recordings in the left and right ventricle (LV and RV) were simultaneously recorded to measure QT time, action-potential duration (APD), interventricular dispersion (deltaAPD = LV(APD) - RV(APD)), early afterdepolarizations (EADs), ectopic beats (EBs), and TdP. Measurements were made at the spontaneous idioventricular rhythm (IVR) and 1,000-ms steady-state pacing. To investigate its short-term, antiarrhythmic properties, Dron was given after almokalant (0.12 mg/kg)-induced TdP. Furthermore, in another set of experiments, oral Dron (20 mg/kg, b.i.d) was given for 3 weeks to conscious CAVB dogs. Dron, i.v., shortened ventricular repolarization (QT, 435 +/- 60 to 360 +/- 55; LV(APD) 395 +/- 75 to 335 +/- 60 ms; p < 0.05), whereas IVR and ventricular effective refractory period (VERP, 225 +/- 30 to 230 +/- 30 ms) remained similar. Therefore the VERP/QT ratio increased (0.55 +/- 0.04 to 0.61 +/- 0.03; p < 0.05). Similar results were obtained with Amio, i.v.. Almokalant-induced TdP was characterized by an increased repolarization duration, deltaAPD, and EADs. Dron, i.v., suppressed the EADs, EBs, and TdP by a reduction and homogenization of repolarization (LV(APD), 505 +/- 110 to 455 +/- 80 ms, and deltaAPD, 110 +/- 55 to 65 +/- 40 ms). Long-term oral Dron increased the PP interval, CL-IVR, and QT(c) time. In contrast to oral treatment, Dron i.v. shortens ventricular repolarization parameters, resulting in suppression of EAD-dependent acquired TdP. The increased VERP/QT ratio after Dron i.v. may indicate an important

A case of brugada syndrome presenting with ventricular fibrillation storm and prominent early repolarization.

PubMed

Iizuka, Chifumi; Sato, Masahito; Kitazawa, Hitoshi; Ikeda, Yoshio; Okabe, Masaaki; Kugiyama, Kiyotaka; Aizawa, Yoshifusa

2016-01-01

A 21-year-old man developed ventricular fibrillation (VF) while drinking alcohol and was admitted to our hospital. An electrocardiogram (ECG) on admission revealed remarkably prominent slurs on the terminal part of QRS complexes in the left precordial leads and a coved type ST elevation at higher intercostal spaces. After hypothermia therapy, he underwent implantation of an implantable cardioverter-defibrillator (ICD). Standard twelve-lead follow-up ECGs revealed early repolarization pattern and an intermittent coved type ST elevation. When the coved type ST elevation appeared, the early repolarization pattern in the inferior and left precordial leads was attenuated. Prominent early repolarization pattern was the most likely trigger of the VF storm in this Brugada patient. Copyright © 2016 Elsevier Inc. All rights reserved.

Ontology-based literature mining and class effect analysis of adverse drug reactions associated with neuropathy-inducing drugs.

PubMed

Hur, Junguk; Özgür, Arzucan; He, Yongqun

2018-06-07

Adverse drug reactions (ADRs), also called as drug adverse events (AEs), are reported in the FDA drug labels; however, it is a big challenge to properly retrieve and analyze the ADRs and their potential relationships from textual data. Previously, we identified and ontologically modeled over 240 drugs that can induce peripheral neuropathy through mining public drug-related databases and drug labels. However, the ADR mechanisms of these drugs are still unclear. In this study, we aimed to develop an ontology-based literature mining system to identify ADRs from drug labels and to elucidate potential mechanisms of the neuropathy-inducing drugs (NIDs). We developed and applied an ontology-based SciMiner literature mining strategy to mine ADRs from the drug labels provided in the Text Analysis Conference (TAC) 2017, which included drug labels for 53 neuropathy-inducing drugs (NIDs). We identified an average of 243 ADRs per NID and constructed an ADR-ADR network, which consists of 29 ADR nodes and 149 edges, including only those ADR-ADR pairs found in at least 50% of NIDs. Comparison to the ADR-ADR network of non-NIDs revealed that the ADRs such as pruritus, pyrexia, thrombocytopenia, nervousness, asthenia, acute lymphocytic leukaemia were highly enriched in the NID network. Our ChEBI-based ontology analysis identified three benzimidazole NIDs (i.e., lansoprazole, omeprazole, and pantoprazole), which were associated with 43 ADRs. Based on ontology-based drug class effect definition, the benzimidazole drug group has a drug class effect on all of these 43 ADRs. Many of these 43 ADRs also exist in the enriched NID ADR network. Our Ontology of Adverse Events (OAE) classification further found that these 43 benzimidazole-related ADRs were distributed in many systems, primarily in behavioral and neurological, digestive, skin, and immune systems. Our study demonstrates that ontology-based literature mining and network analysis can efficiently identify and study specific group of

Prime-, Stress- and Cue-Induced Reinstatement of Extinguished Drug-Reinforced Responding in Rats: Cocaine as the Prototypical Drug of Abuse

PubMed Central

Beardsley, Patrick M.; Shelton, Keith L.

2012-01-01

This unit describes the testing of rats in prime-, footshock- and cue-induced reinstatement procedures. Evaluating rats in these procedures enables the assessment of treatments on behavior thought to model drug relapse precipitated by re-contact with an abused drug (prime-induced), induced by stress (footshock-induced), or by stimuli previously associated with drug administration (cue-induced). For instance, levels of reinstatement under the effects of test compound administration could be compared to levels under vehicle administration to help identify potential treatments for drug relapse, or reinstatement levels of different rat strains could be compared to identify potential genetic determinants of perseverative drug-seeking behavior. Cocaine is used as a prototypical drug of abuse, and relapse to its use serves as the model in this unit, but other self-administered drugs could readily be substituted with little modification to the procedures. PMID:23093352

The prognostic value of early repolarization with ST-segment elevation in African Americans.

PubMed

Perez, Marco V; Uberoi, Abhimanyu; Jain, Nikhil A; Ashley, Euan; Turakhia, Mintu P; Froelicher, Victor

2012-04-01

Increased prevalence of classic early repolarization, defined as ST-segment elevation (STE) in the absence of acute myocardial injury, in African Americans is well established. The prognostic value of this pattern in different ethnicities remains controversial. Measure association between early repolarization and cardiovascular mortality in African Americans. The resting electrocardiograms of 45,829 patients were evaluated at the Palo Alto Veterans Affairs Hospital. Subjects with inpatient status or electrocardiographic evidence of acute myocardial infarction were excluded, leaving 29,281 subjects. ST-segment elevation, defined as an elevation of >0.1 mV at the end of the QRS, was electronically flagged and visually adjudicated by 3 observers blinded to outcomes. An association between ethnicity and early repolarization was measured by using multivariate logistic regression. We analyzed associations between early repolarization and cardiovascular mortality by using the Cox proportional hazards regression analysis. Subjects were 13% women and 13.3% African Americans, with an average age of 55 years and followed for an average of 7.6 years, resulting in 1995 cardiovascular deaths. There were 479 subjects with lateral STE and 185 with inferior STE. After adjustment for age, sex, heart rate, and coronary artery disease, African American ethnicity was associated with lateral or inferior STE (odds ratio 3.1; P = .0001). While lateral or inferior STE in non-African Americans was independently associated with cardiovascular death (hazard ratio 1.6; P = .02), it was not associated with cardiovascular death in African Americans (hazard ratio 0.75; P = .50). Although early repolarization is more prevalent in African Americans, it is not predictive of cardiovascular death in this population and may represent a distinct electrophysiologic phenomenon. Copyright © 2012 Heart Rhythm Society. All rights reserved.

Characterization of Myocardial Repolarization Reserve in Adolescent Females With Anorexia Nervosa.

PubMed

Padfield, Gareth J; Escudero, Carolina A; DeSouza, Astrid M; Steinberg, Christian; Gibbs, Karen; Puyat, Joseph H; Lam, Pei Yoong; Sanatani, Shubhayan; Sherwin, Elizabeth; Potts, James E; Sandor, George; Krahn, Andrew D

2016-02-09

Patients with anorexia nervosa exhibit abnormal myocardial repolarization and are susceptible to sudden cardiac death. Exercise testing is useful in unmasking QT prolongation in disorders associated with abnormal repolarization. We characterized QT adaptation during exercise in anorexia. Sixty-one adolescent female patients with anorexia nervosa and 45 age- and sex-matched healthy volunteers performed symptom-limited cycle ergometry during 12-lead ECG monitoring. Changes in the QT interval during exercise were measured, and QT/RR-interval slopes were determined by using mixed-effects regression modeling. Patients had significantly lower body mass index than controls; however, resting heart rates and QT/QTc intervals were similar at baseline. Patients had shorter exercise times (13.7±4.5 versus 20.6±4.5 minutes; P<0.001) and lower peak heart rates (159±20 versus 184±9 beats/min; P<0.001). The mean QTc intervals were longer at peak exercise in patients (442±29 versus 422±19 ms; P<0.001). During submaximal exertion at comparable heart rates (114±6 versus 115±11 beats/min; P=0.54), the QTc interval had prolonged significantly more in patients than controls (37±28 versus 24±25 ms; P<0.016). The RR/QT slope, best described by a curvilinear relationship, was more gradual in patients than in controls (13.4; 95% confidence interval, 12.8-13.9 versus 15.8; 95% confidence interval, 15.3-16.4 ms QT change per 10% change in RR interval; P<0.001) and steepest in patients within the highest body mass index tertile versus the lowest (13.9; 95% confidence interval, 12.9-14.9 versus 12.3; 95% confidence interval, 11.3-13.3; P=0.026). Despite the absence of manifest QT prolongation, adolescent anorexic females have impaired repolarization reserve in comparison with healthy controls. Further study may identify impaired QT dynamics as a risk factor for arrhythmias in anorexia nervosa. © 2016 American Heart Association, Inc.

Cellular and ionic mechanisms underlying the effects of cilostazol, milrinone, and isoproterenol to suppress arrhythmogenesis in an experimental model of early repolarization syndrome.

PubMed

Patocskai, Bence; Barajas-Martinez, Hector; Hu, Dan; Gurabi, Zsolt; Koncz, István; Antzelevitch, Charles

2016-06-01

Early repolarization syndrome (ERS) is associated with polymorphic ventricular tachycardia (PVT) and ventricular fibrillation, leading to sudden cardiac death. The present study tests the hypothesis that the transient outward potassium current (Ito)-blocking effect of phosphodiesterase-3 (PDE-3) inhibitors plays a role in reversing repolarization heterogeneities responsible for arrhythmogenesis in experimental models of ERS. Transmembrane action potentials (APs) were simultaneously recorded from epicardial and endocardial regions of coronary-perfused canine left ventricular (LV) wedge preparations, together with a transmural pseudo-electrocardiogram. The Ito agonist NS5806 (7-15 μM) and L-type calcium current (ICa) blocker verapamil (2-3 μM) were used to induce an early repolarization pattern and PVT. After stable induction of arrhythmogenesis, the PDE-3 inhibitors cilostazol and milrinone or isoproterenol were added to the coronary perfusate. All were effective in restoring the AP dome in the LV epicardium, thus abolishing the repolarization defects responsible for phase 2 reentry and PVT. Arrhythmic activity was suppressed in 7 of 8 preparations by cilostazol (10 μM), 6 of 7 by milrinone (2.5 μM), and 7 of 8 by isoproterenol (0.1-1 μM). Using voltage clamp techniques applied to LV epicardial myocytes, both cilostazol (10 μM) and milrinone (2.5 μM) were found to reduce Ito by 44.4% and 40.4%, respectively, in addition to their known effects to augment ICa. Our findings suggest that PDE-3 inhibitors exert an ameliorative effect in the setting of ERS by producing an inward shift in the balance of current during the early phases of the epicardial AP via inhibition of Ito as well as augmentation of ICa, thus reversing the repolarization defects underlying the development of phase 2 reentry and ventricular tachycardia/ventricular fibrillation. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

[Drug induced diarrhea].

PubMed

Morard, Isabelle; Hadengue, Antoine

2008-09-03

Diarrhea is a frequent adverse event involving the most frequently antibiotics, laxatives and NSAI. Drug induced diarrhea may be acute or chronic. It may be due to expected, dose dependant properties of the drug, to immuno-allergic or bio-genomic mechanisms. Several pathophysiological mechanisms have been described resulting in osmotic, secretory or inflammatory diarrhea, shortened transit time, or malabsorption. Histopathological lesions sometimes associated with drug induced diarrhea are usually non specific and include ulcerations, inflammatory or ischemic lesions, fibrous diaphragms, microscopic colitis and apoptosis. The diagnosis of drug induced diarrhea, sometimes difficult to assess, relies on the absence of other obvious causes and on the rapid disappearance of the symptoms after withdrawal of the suspected drug.

Identification of Drugs Inducing Phospholipidosis by Novel in vitro Data

PubMed Central

Muehlbacher, Markus; Tripal, Philipp; Roas, Florian; Kornhuber, Johannes

2012-01-01

Drug-induced phospholipidosis (PLD) is a lysosomal storage disorder characterized by the accumulation of phospholipids within the lysosome. This adverse drug effect can occur in various tissues and is suspected to impact cellular viability. Therefore, it is important to test chemical compounds for their potential to induce PLD during the drug design process. PLD has been reported to be a side effect of many commonly used drugs, especially those with cationic amphiphilic properties. To predict drug-induced PLD in silico, we established a high-throughput cell-culture-based method to quantitatively determine the induction of PLD by chemical compounds. Using this assay, we tested 297 drug-like compounds at two different concentrations (2.5 μm and 5.0 μm). We were able to identify 28 previously unknown PLD-inducing agents. Furthermore, our experimental results enabled the development of a binary classification model to predict PLD-inducing agents based on their molecular properties. This random forest prediction system yields a bootstrapped validated accuracy of 86 %. PLD-inducing agents overlap with those that target similar biological processes; a high degree of concordance with PLD-inducing agents was identified for cationic amphiphilic compounds, small molecules that inhibit acid sphingomyelinase, compounds that cross the blood–brain barrier, and compounds that violate Lipinski’s rule of five. Furthermore, we were able to show that PLD-inducing compounds applied in combination additively induce PLD. PMID:22945602

Constitutional rho-kinase regulates atrioventricular nodal conduction and ventricular repolarization of the canine heart.

PubMed

Sugiyama, Atsushi; Takahara, Akira; Yatomi, Yutaka; Satoh, Yoshioki; Nakamura, Yuji; Hashimoto, Keitaro

2003-06-01

Given the limited information, physiological roles of Rho-kinase in the cardiac conduction system and ventricular repolarization process were assessed in comparison with those in the coronary vascular tone. A specific Rho-kinase inhibitor Y-27632 was administered to the nutrient coronary artery of the canine isolated, blood-perfused atrioventricular node preparation under the monitoring of the ventricular monophasic action potentials. Administration of Y-27632 moderately suppressed the atrioventricular nodal conduction, slightly but significantly accelerated the repolarization process, and potently increased the coronary blood flow, whereas it hardly affected the intraventricular conduction. The estimated concentrations of Y-27632 causing the currently observed effects were enough to inhibit Rho-kinase. These results suggest that constitutional Rho-kinase functions to moderately facilitate the atrioventricular nodal conduction, slightly delay ventricular repolarization process, and significantly increase the coronary vascular tone.

Rhinovirus Delays Cell Repolarization in a Model of Injured/Regenerating Human Airway Epithelium

PubMed Central

Faris, Andrea N.; Ganesan, Shyamala; Chattoraj, Asamanja; Chattoraj, Sangbrita S.; Comstock, Adam T.; Unger, Benjamin L.; Hershenson, Marc B.

2016-01-01

Rhinovirus (RV), which causes exacerbation in patients with chronic airway diseases, readily infects injured airway epithelium and has been reported to delay wound closure. In this study, we examined the effects of RV on cell repolarization and differentiation in a model of injured/regenerating airway epithelium (polarized, undifferentiated cells). RV causes only a transient barrier disruption in a model of normal (mucociliary-differentiated) airway epithelium. However, in the injury/regeneration model, RV prolongs barrier dysfunction and alters the differentiation of cells. The prolonged barrier dysfunction caused by RV was not a result of excessive cell death but was instead associated with epithelial-to-mesenchymal transition (EMT)-like features, such as reduced expression of the apicolateral junction and polarity complex proteins, E-cadherin, occludin, ZO-1, claudins 1 and 4, and Crumbs3 and increased expression of vimentin, a mesenchymal cell marker. The expression of Snail, a transcriptional repressor of tight and adherence junctions, was also up-regulated in RV-infected injured/regenerating airway epithelium, and inhibition of Snail reversed RV-induced EMT-like features. In addition, compared with sham-infected cells, the RV-infected injured/regenerating airway epithelium showed more goblet cells and fewer ciliated cells. Inhibition of epithelial growth factor receptor promoted repolarization of cells by inhibiting Snail and enhancing expression of E-cadherin, occludin, and Crumbs3 proteins, reduced the number of goblet cells, and increased the number of ciliated cells. Together, these results suggest that RV not only disrupts barrier function, but also interferes with normal renewal of injured/regenerating airway epithelium by inducing EMT-like features and subsequent goblet cell hyperplasia. PMID:27119973

Drug-Induced Hyperglycaemia and Diabetes.

PubMed

Fathallah, Neila; Slim, Raoudha; Larif, Sofien; Hmouda, Houssem; Ben Salem, Chaker

2015-12-01

. Hyperglycaemia has been associated with oral contraceptives containing high doses of oestrogen. Growth hormone therapy and somatostatin analogues may also induce hyperglycaemia. Clinicians should be aware of medications that may alter glycaemia. Efforts should be made to identify and closely monitor patients receiving drugs that are known to induce hyperglycaemia.

Drug-induced corneal damage.

PubMed

2014-04-01

Corneal damage can have a variety of causes, including infections, chemical splashes, environmental factors (radiation, trauma, contact lenses, etc.), and systemic diseases (genetic, autoimmune, inflammatory, metabolic, etc.). A wide range of drugs can also damage the cornea. The severity of drug-induced corneal changes can range from simple asymptomatic deposits to irreversible, sight-threatening damage. Several factors can influence the onset of corneal lesions. Some factors, such as the dose, are treatment-related, while others such as contact lenses, are patient-related. A variety of mechanisms may be involved, including corneal dryness, changes in the corneal epithelium, impaired wound healing and deposits. Many drugs can damage the cornea through direct contact, after intraocular injection or instillation, including VEGF inhibitors, anti-inflammatory drugs, local anaesthetics, glaucoma drugs, fluoroquinolones, and preservatives. Some systemically administered drugs can also damage the cornea, notably cancer drugs, amiodarone and isotretinoin. Vulnerable patients should be informed of this risk if they are prescribed a drug with the potential to damage the cornea so that they can identify problems in a timely manner. It may be necessary to discontinue the suspect drug when signs and symptoms of corneal damage occur.

Clinical presentation and management of drug-induced agranulocytosis.

PubMed

Andrès, Emmanuel; Zimmer, Jacques; Mecili, Mustapha; Weitten, Thierry; Alt, Martine; Maloisel, Frédéric

2011-04-01

In this article, we report and discuss the clinical presentation and management of idiosyncratic drug-induced agranulocytosis (neutrophil count <0.5 × 10(9)/l). Idiosyncratic drug-induced agranulocytosis remains a potentially serious adverse event owing to the frequency of severe sepsis with severe deep tissue infections (e.g., pneumonia), septicemia and septic shock in approximately two-thirds of all hospitalized patients. However, several prognostic factors have recently been identified that may be helpful in practice to identify 'susceptible' patients. Old age (>65 years), septicemia or shock, metabolic disorders such as renal failure and a neutrophil count below 0.1 × 10(9)/l are currently consensually accepted as poor prognostic factors. In this potentially life-threatening disorder, modern management with broad-spectrum antibiotics and hematopoietic growth factors (particularly granulocyte colony-stimulating factor) is likely to improve prognosis. Thus, with appropriate management, the mortality rate from idiosyncratic drug-induced agranulocytosis is currently approximately 5%.

The Role of Serotonin in Ventricular Repolarization in Pregnant Mice

PubMed Central

Park, Hyelim; Mun, Dasom; Lee, Seung-Hyun; Kim, Hyoeun; Yun, Nuri; Kim, Hail; Kim, Michael; Pak, Hui-Nam; Lee, Moon-Hyoung

2018-01-01

Purpose The mechanisms underlying repolarization abnormalities during pregnancy are not fully understood. Although maternal serotonin (5-hydroxytryptamine, 5-HT) production is an important determinant for normal fetal development in mice, its role in mothers remains unclear. We evaluated the role of serotonin in ventricular repolarization in mice hearts via 5Htr3 receptor (Htr3a) and investigated the mechanism of QT-prolongation during pregnancy. Materials and Methods We measured current amplitudes and the expression levels of voltage-gated K+ (Kv) channels in freshly-isolated left ventricular myocytes from wild-type non-pregnant (WT-NP), late-pregnant (WT-LP), and non-pregnant Htr3a homozygous knockout mice (Htr3a−/−-NP). Results During pregnancy, serotonin and tryptophan hydroxylase 1, a rate-limiting enzyme for the synthesis of serotonin, were markedly increased in hearts and serum. Serotonin increased Kv current densities concomitant with the shortening of the QT interval in WT-NP mice, but not in WT-LP and Htr3a−/−-NP mice. Ondansetron, an Htr3 antagonist, decreased Kv currents in WT-LP mice, but not in WT-NP mice. Kv4.3 directly interacted with Htr3a, and this binding was facilitated by serotonin. Serotonin increased the trafficking of Kv4.3 channels to the cellular membrane in WT-NP. Conclusion Serotonin increases repolarizing currents by augmenting Kv currents. Elevated serotonin levels during pregnancy counterbalance pregnancy-related QT prolongation by facilitating Htr3-mediated Kv currents. PMID:29436197

The Role of Serotonin in Ventricular Repolarization in Pregnant Mice.

PubMed

Cui, Shanyu; Park, Hyewon; Park, Hyelim; Mun, Dasom; Lee, Seung Hyun; Kim, Hyoeun; Yun, Nuri; Kim, Hail; Kim, Michael; Pak, Hui Nam; Lee, Moon Hyoung; Joung, Boyoung

2018-03-01

The mechanisms underlying repolarization abnormalities during pregnancy are not fully understood. Although maternal serotonin (5-hydroxytryptamine, 5-HT) production is an important determinant for normal fetal development in mice, its role in mothers remains unclear. We evaluated the role of serotonin in ventricular repolarization in mice hearts via 5Htr3 receptor (Htr3a) and investigated the mechanism of QT-prolongation during pregnancy. We measured current amplitudes and the expression levels of voltage-gated K⁺ (Kv) channels in freshly-isolated left ventricular myocytes from wild-type non-pregnant (WT-NP), late-pregnant (WT-LP), and non-pregnant Htr3a homozygous knockout mice (Htr3a(-/-)-NP). During pregnancy, serotonin and tryptophan hydroxylase 1, a rate-limiting enzyme for the synthesis of serotonin, were markedly increased in hearts and serum. Serotonin increased Kv current densities concomitant with the shortening of the QT interval in WT-NP mice, but not in WT-LP and Htr3a(-/-)-NP mice. Ondansetron, an Htr3 antagonist, decreased Kv currents in WT-LP mice, but not in WT-NP mice. Kv4.3 directly interacted with Htr3a, and this binding was facilitated by serotonin. Serotonin increased the trafficking of Kv4.3 channels to the cellular membrane in WT-NP. Serotonin increases repolarizing currents by augmenting Kv currents. Elevated serotonin levels during pregnancy counterbalance pregnancy-related QT prolongation by facilitating Htr3-mediated Kv currents. © Copyright: Yonsei University College of Medicine 2018

Identifying drugs that cause acute thrombocytopenia: an analysis using 3 distinct methods

PubMed Central

Reese, Jessica A.; Li, Xiaoning; Hauben, Manfred; Aster, Richard H.; Bougie, Daniel W.; Curtis, Brian R.; George, James N.

2010-01-01

Drug-induced immune thrombocytopenia (DITP) is often suspected in patients with acute thrombocytopenia unexplained by other causes, but documenting that a drug is the cause of thrombocytopenia can be challenging. To provide a resource for diagnosis of DITP and for drug safety surveillance, we analyzed 3 distinct methods for identifying drugs that may cause thrombocytopenia. (1) Published case reports of DITP have described 253 drugs suspected of causing thrombocytopenia; using defined clinical criteria, 87 (34%) were identified with evidence that the drug caused thrombocytopenia. (2) Serum samples from patients with suspected DITP were tested for 202 drugs; drug-dependent, platelet-reactive antibodies were identified for 67 drugs (33%). (3) The Food and Drug Administration's Adverse Event Reporting System database was searched for drugs associated with thrombocytopenia by use of data mining algorithms; 1444 drugs had at least 1 report associated with thrombocytopenia, and 573 (40%) drugs demonstrated a statistically distinctive reporting association with thrombocytopenia. Among 1468 drugs suspected of causing thrombocytopenia, 102 were evaluated by all 3 methods, and 23 of these 102 drugs had evidence for an association with thrombocytopenia by all 3 methods. Multiple methods, each with a distinct perspective, can contribute to the identification of drugs that can cause thrombocytopenia. PMID:20530792

Pharmacokinetics and repolarization effects of intravenous and transdermal granisetron.

PubMed

Mason, Jay W; Selness, Daniel S; Moon, Thomas E; O'Mahony, Bridget; Donachie, Peter; Howell, Julian

2012-05-15

The need for greater clarity about the effects of 5-HT(3) receptor antagonists on cardiac repolarization is apparent in the changing product labeling across this therapeutic class. This study assessed the repolarization effects of granisetron, a 5-HT(3) receptor antagonist antiemetic, administered intravenously and by a granisetron transdermal system (GTDS). In a parallel four-arm study, healthy subjects were randomized to receive intravenous granisetron, GTDS, placebo, or oral moxifloxacin (active control). The primary endpoint was difference in change from baseline in mean Fridericia-corrected QT interval (QTcF) between GTDS and placebo (ddQTcF) on days 3 and 5. A total of 240 subjects were enrolled, 60 in each group. Adequate sensitivity for detection of QTc change was shown by a 5.75 ms lower bound of the 90% confidence interval (CI) for moxifloxacin versus placebo at 2 hours postdose on day 3. Day 3 ddQTcF values varied between 0.2 and 1.9 ms for GTDS (maximum upper bound of 90% CI, 6.88 ms), between -1.2 and 1.6 ms for i.v. granisetron (maximum upper bound of 90% CI, 5.86 ms), and between -3.4 and 4.7 ms for moxifloxacin (maximum upper bound of 90% CI, 13.45 ms). Day 5 findings were similar. Pharmacokinetic-ddQTcF modeling showed a minimally positive slope of 0.157 ms/(ng/mL), but a very low correlation (r = 0.090). GTDS was not associated with statistically or clinically significant effects on QTcF or other electrocardiographic variables. This study provides useful clarification on the effect of granisetron delivered by GTDS on cardiac repolarization. ©2012 AACR.

Delayed Repolarization Underlies Ventricular Arrhythmias in Rats With Heart Failure and Preserved Ejection Fraction.

PubMed

Cho, Jae Hyung; Zhang, Rui; Kilfoil, Peter J; Gallet, Romain; de Couto, Geoffrey; Bresee, Catherine; Goldhaber, Joshua I; Marbán, Eduardo; Cingolani, Eugenio

2017-11-21

Heart failure with preserved ejection fraction (HFpEF) represents approximately half of heart failure, and its incidence continues to increase. The leading cause of mortality in HFpEF is sudden death, but little is known about the underlying mechanisms. Dahl salt-sensitive rats were fed a high-salt diet (8% NaCl) from 7 weeks of age to induce HFpEF (n=38). Rats fed a normal-salt diet (0.3% NaCl) served as controls (n=13). Echocardiograms were performed to assess systolic and diastolic function from 14 weeks of age. HFpEF-verified and control rats underwent programmed electrical stimulation. Corrected QT interval was measured by surface ECG. The mechanisms of ventricular arrhythmias (VA) were probed by optical mapping, whole-cell patch clamp to measure action potential duration and ionic currents, and quantitative polymerase chain reaction and Western blotting to investigate changes in ion channel expression. After 7 weeks of a high-salt diet, 31 of 38 rats showed diastolic dysfunction and preserved ejection fraction along with signs of heart failure and hence were diagnosed with HFpEF. Programmed electric stimulation demonstrated increased susceptibility to VA in HFpEF rats ( P <0.001 versus controls). The arrhythmogenicity index was increased ( P <0.001) and the corrected QT interval on ECG was prolonged ( P <0.001) in HFpEF rats. Optical mapping of HFpEF hearts demonstrated prolonged action potentials ( P <0.05) and multiple reentry circuits during induced VA. Single-cell recordings of cardiomyocytes isolated from HFpEF rats confirmed a delay of repolarization ( P =0.001) and revealed downregulation of transient outward potassium current ( I to ; P <0.05). The rapid components of the delayed rectifier potassium current ( I Kr ) and the inward rectifier potassium current ( I K1 ) were also downregulated ( P <0.05), but the current densities were much lower than for I to . In accordance with the reduction of I to , both Kcnd3 transcript and Kv4.3 protein levels

Early changes in myocardial repolarization and coronary perfusion after cardiopulmonary bypass surgery for ASD repair in children.

PubMed

Aburawi, Elhadi H; Souid, Abdul-Kader; Liuba, Petru; Zoubeidi, Taoufik; Pesonen, Erkki

2013-09-10

In adults, impaired myocardial repolarization and increased risk of arrhythmia are known consequences of open heart surgery. Little is known, however, about post-operative consequences of cardiopulmonary bypass surgery in children. The aim of this study was to assess ventricular repolarization and coronary perfusion after bypass surgery for atrial septal defect (ASD) repair in children. Twelve patients with ASD were assessed one day before and 5-6 days after ASD repair. Myocardial repolarization (corrected QT interval, QTc, QT dispersion, QTd, and PQ interval) was determined on 12-lead electrocardiograms. Coronary flow in proximal left anterior descending artery (peak flow velocity in diastole, PFVd) was assessed by transthoracic Doppler echocardiography. Ten of the 12 (83%) children had normal myocardial repolarization before and after surgery. After surgery, QTc increased 1-9% in 5 (42%) patients, decreased 2-11% in 5 (42%) patients and did not change in 2 (16%) patients. Post-op QTc positively correlated with bypass time (R=0.686, p=0.014) and changes in PFVd (R=0.741, p=0.006). After surgery, QTd increased 33-67% in 4 (33%) patients, decreased 25-50% in 6 patients (50%) and did not change in 2 (16%) patients. After surgery, PQ interval increased 5-30% in 4 (33%) patients, decreased 4-29% in 6 (50%) patients and did not change in 1 (8%) patient. Post-op PQ positively correlated with bypass time (R=0.636, p=0.027). As previously reported, PFVd significantly increased after surgery (p<0.001). Changes in QTc, PQ and PFVd are common in young children undergoing surgery for ASD repair. Post-op QTc significantly correlates with bypass time, suggesting prolonged cardiopulmonary bypass may impair ventricular repolarization. Post-op QTc significantly correlates with PFVd changes, suggesting increased coronary flow may also impair ventricular repolarization. The clinical significance and reversibility of these alternations require further investigations.

Intermittent atrial tachycardia promotes repolarization alternans and conduction slowing during rapid rates, and increases susceptibility to atrial fibrillation in a free-behaving sheep model.

PubMed

Monigatti-Tenkorang, Joanna; Jousset, Florian; Pascale, Patrizio; Vesin, Jean-Marc; Ruchat, Patrick; Fromer, Martin; Narayan, Sanjiv M; Pruvot, Etienne

2014-04-01

Paroxysmal atrial fibrillation (AF) may be triggered by intermittent atrial tachycardia, and ultimately lead to persistent AF. However, the mechanisms by which intermittent atrial tachycardia promotes sustained AF are not well understood. Eight sheep were chronically implanted with 2 pacemakers for the recording of broadband right atrial unipolar electrograms, and for the delivery of electrophysiological stimulation protocols and intermittent right atrial tachycardia. Right atrial kinetics of activation recovery interval (ARI) as a surrogate for action potential duration, of conduction time and velocity, and of repolarization alternans were analyzed at incremental pacing rates during the remodeling process induced by weeks of intermittent atrial tachycardia until the development of sustained AF. Intermittent atrial tachycardia decreased ARI and blunted its rate adaptation, facilitated atrial capture, and slowed conduction at high rates, and increased susceptibility to pacing-induced AF. In spite of blunted ARI rate adaptation, right atrial repolarization alternans was maintained during remodeling, and further increased in magnitude just before rapid pacing-induced AF. This study suggests that weeks of intermittent right atrial tachycardia result in a gradual electrical remodeling favorable for wavebreaks and reentry that may facilitate fibrillation. © 2014 Wiley Periodicals, Inc.

Effects of sildenafil citrate (viagra) on cardiac repolarization and on autonomic control in subjects with chronic heart failure.

PubMed

Piccirillo, Gianfranco; Nocco, Marialuce; Lionetti, Marco; Moisè, Antonio; Naso, Camilla; Marigliano, Vincenzo; Cacciafesta, Mauro

2002-04-01

Cases of sudden death associated with sildenafil citrate use have been reported in men with coronary artery disease. The aim of this study was to investigate the drug's effect on cardiac repolarization and sinus autonomic and vascular control in men with mild chronic heart failure (CHF; New York Heart Association classification II). Changes in these variables could predispose patients to malignant ventricular arrhythmias. We measured QT dispersion, the QT-RR slope, and the index of QT variability (QTVI) and analyzed spectral power of RR and systolic blood pressure variability in 10 men with dilated cardiomyopathy and in 10 control subjects after administration of a single 50-mg oral dose of sildenafil citrate or placebo at rest (not followed with any attempt at intercourse). In both groups, oral sildenafil citrate decreased the systolic blood pressure (P <.05) and increased the heart rate (P <.05). In subjects with CHF, it also increased the QT-RR (P <.001) and QTVI (from -0.45 +/- 0.07 to -0.27 +/- 0.07; P <.001), but in controls, it increased the QTVI (from -1.20 +/- 0.08 to -0.78 +/-.014; P <.001). In these subjects and controls, oral sildenafil citrate induced a significant reduction in high frequency, expressed in absolute power (subjects with CHF: from 4.04 +/- 0.14 to 3.43 +/- 0.16 natural logarithm ms2; P <.001; controls: from 5.61 +/- 0.44 to 4.98 +/- 0.32 natural logarithm ms2; P <.05) and in normalized units (P <.05). In subjects with CHF but not in controls, it also significantly increased the low frequency to high frequency ratio (from 1.3 +/- 0.12 to 1.89 +/- 0.16; P <.001) and low frequency expressed in normalized units (P <.05). Sildenafil citrate caused no significant changes in the QT interval or dispersion. These findings indicate that, in men with heart failure, sildenafil citrate reduces vagal modulation and increases sympathetic modulation, probably through its reflex vasodilatory action. The autonomic system changes induced with sildenafil

Drug-Induced Metabolic Acidosis

PubMed Central

Pham, Amy Quynh Trang; Xu, Li Hao Richie; Moe, Orson W.

2015-01-01

Metabolic acidosis could emerge from diseases disrupting acid-base equilibrium or from drugs that induce similar derangements. Occurrences are usually accompanied by comorbid conditions of drug-induced metabolic acidosis, and clinical outcomes may range from mild to fatal. It is imperative that clinicians not only are fully aware of the list of drugs that may lead to metabolic acidosis but also understand the underlying pathogenic mechanisms. In this review, we categorized drug-induced metabolic acidosis in terms of pathophysiological mechanisms, as well as individual drugs’ characteristics. PMID:26918138

Drug-induced gynecomastia.

PubMed

Bowman, John D; Kim, Hyunah; Bustamante, Juan J

2012-12-01

Drugs account for about 20% of gynecomastia cases in men. As a number of factors can alter the estrogen:androgen ratio, several pathophysiologic mechanisms are associated with drugs causing this disorder. Antiandrogens, protease inhibitors, and nucleoside reverse transcriptase inhibitors are the most common drug causes of gynecomastia, whereas first-generation antipsychotics, spironolactone, verapamil, and cimetidine are less common causes. Other drugs have been reported rarely as causes. Treatment may involve switching to an alternative agent or may require surgery or irradiation if the causative agent cannot be discontinued. We reviewed the literature on drug-induced gynecomastia and provided another perspective by reviewing data from the United States Food and Drug Administration's Adverse Event Reporting System. Epidemiologic studies are needed to provide a more accurate description of the frequency of drug-induced gynecomastia. © 2012 Pharmacotherapy Publications, Inc.

Drug-induced status epilepticus.

PubMed

Cock, Hannah R

2015-08-01

Drug-induced status epilepticus (SE) is a relatively uncommon phenomenon, probably accounting for less than 5% of all SE cases, although limitations in case ascertainment and establishing causation substantially weaken epidemiological estimates. Some antiepileptic drugs, particularly those with sodium channel or GABA(γ-aminobutyric acid)-ergic properties, frequently exacerbate seizures and may lead to SE if used inadvertently in generalized epilepsies or less frequently in other epilepsies. Tiagabine seems to have a particular propensity for triggering nonconvulsive SE sometimes in patients with no prior history of seizures. In therapeutic practice, SE is most commonly seen in association with antibiotics (cephalosporins, quinolones, and some others) and immunotherapies/chemotherapies, the latter often in the context of a reversible encephalopathy syndrome. Status epilepticus following accidental or intentional overdoses, particularly of antidepressants or other psychotropic medications, has also featured prominently in the literature: whilst there are sometimes fatal consequences, this is more commonly because of cardiorespiratory or metabolic complications than as a result of seizure activity. A high index of suspicion is required in identifying those at risk and in recognizing potential clues from the presentation, but even with a careful analysis of patient and drug factors, establishing causation can be difficult. In addition to eliminating the potential trigger, management should be as for SE in any other circumstances, with the exception that phenobarbitone is recommended as a second-line treatment for suspected toxicity-related SE where the risk of cardiovascular complications is higher anyways and may be exacerbated by phenytoin. There are also specific recommendations/antidotes in some situations. The outcome of drug-induced status epilepticus is mostly good when promptly identified and treated, though less so in the context of overdoses. This article is

A simultaneous multichannel monophasic action potential electrode array for in vivo epicardial repolarization mapping.

PubMed

Sahakian, A V; Peterson, M S; Shkurovich, S; Hamer, M; Votapka, T; Ji, T; Swiryn, S

2001-03-01

While the recording of extracellular monophasic action potentials (MAPs) from single epicardial or endocardial sites has been performed for over a century, we are unaware of any previous successful attempt to record MAPs simultaneously from a large number of sites in vivo. We report here the design and validation of an array of MAP electrodes which records both depolarization and repolarization simultaneously at up to 16 epicardial sites in a square array on the heart in vivo. The array consists of 16 sintered Ag-AgCl electrodes mounted in a common housing with individual suspensions allowing each electrode to exert a controlled pressure on the epicardial surface. The electrodes are arranged in a square array, with each quadrant of four having an additional recessed sintered Ag-AgCl reference electrode at its center. A saline-soaked sponge establishes ionic contact between the reference electrodes and the tissue. The array was tested on six anesthetized open-chested pigs. Simultaneous diagnostic-quality MAP recordings were obtained from up to 13 out of 16 ventricular sites. Ventricular MAPs had amplitudes of 10-40 mV with uniform morphologies and stable baselines for up to 30 min. MAP duration at 90% repolarization was measured and shown to vary as expected with cycle length during sustained pacing. The relationship between MAP duration and effective refractory period was also confirmed. The ability of the array to detect local differences in repolarization was tested in two ways. Placement of the array straddling the atrioventricular (AV) junction yielded simultaneous atrial or ventricular recordings at corresponding sites during 1:1 and 2:1 AV conduction. Localized ischemia via constriction of a coronary artery branch resulted in shortening of the repolarization phase at the ischemic, but not the nonischemic, sites. In conclusion, these results indicate that the simultaneous multichannel MAP electrode array is a viable method for in vivo epicardial repolarization

Cellular and Ionic Mechanisms Underlying Effects of Cilostazol, Milrinone and Isoproterenol to Suppress Arrhythmogenesis in an Experimental Model of Early Repolarization Syndrome

PubMed Central

Patocskai, Bence; Barajas-Martinez, Hector; Hu, Dan; Gurabi, Zsolt; Koncz, István; Antzelevitch, Charles

2016-01-01

Background Early Repolarization Syndrome (ERS) is associated with polymorphic ventricular tachycardia (PVT) and fibrillation (VF), leading to sudden cardiac death. Objective The present study tests the hypothesis that the Ito-blocking effect of phosphodiesterase-3 (PDE-3) inhibitors plays a role in reversing repolarization heterogeneities responsible for arrhythmogenesis in experimental models of ERS. Methods Transmembrane action potentials (AP) were simultaneously recorded from epicardial and endocardial regions of coronary-perfused canine left-ventricular (LV) wedge preparations, together with a transmural pseudo-ECG. The Ito-agonist NS5806 (7–15 μM) and ICa-blocker verapamil (2–3 uM) were used to induce an ER pattern and PVT. Results Following stable induction of arrhythmogenesis, the PDE-3 inhibitors cilostazol and milrinone or isoproterenol were added to the coronary perfusate. All were effective in restoring the AP dome in the LV epicardium, thus abolishing the repolarization defects responsible for phase-2-reentry (P2R) and PVT. Arrhythmic activity was suppressed in 7/8 preparations by cilostazol (10 μM), 6/7 by milrinone (2.5 μM) and 7/8 by isoproterenol (0.1–1μM). Using voltage clamp techniques applied to LV epicardial myocytes, both cilostazol (10 μM) and milrinone (2.5 μM) were found to reduce Ito by 44.4% and 40.4%, respectively, in addition to their known effects to augment ICa. Conclusions Our findings suggest that PDE-3 inhibitors exert an ameliorative effect in the setting of ERS by producing an inward shift in the balance of current in the early phases of the epicardial AP via inhibition of Ito as well as augmentation of ICa, thus reversing the repolarization defects underlying development of P2R and VT/VF. PMID:26820510

A new method to calculate the beat-to-beat instability of QT duration in drug-induced long QT in anesthetized dogs.

PubMed

van der Linde, H; Van de Water, A; Loots, W; Van Deuren, B; Lu, H R; Van Ammel, K; Peeters, M; Gallacher, D J

2005-01-01

Instability of QT duration is a marker to predict Torsade de Pointes (TdP) associated with both congenital and drug-induced long QT syndrome. We describe a new method for the quantification of instability of repolarization. Female, adult beagle dogs anesthetized with a potent morphinomimetic were treated with either solvent (n=7) or dofetilide (n=7). Poincaré plots with QT(n) versus QT(n+1) were constructed to visualize the beat-to-beat variation in QT intervals from the lead II ECG. Short-term instability (STI), long-term instability (LTI) and total instability (TI) were quantified by calculating the distances of 30 consecutive data-points from the x and y-coordinate to the "centre of gravity" of the data cluster. Dofetilide at 0.0025 to 0.04 mg/kg i.v. (plasma concentrations of 4+/-0.6 to 41+/-2.7 ng/ml), dose-dependently prolonged QT and QTcV (at 0.04 mg/kg i.v.: QT: 280+/-ms versus 236+/-5 ms with solvent; p<0.05 and QTcV: 290+/-9 ms versus 252+/-4 ms with solvent; p<0.05). Concomitantly, the compound induced an increase in the instability parameters in a similar dose-dependent manner (at 0.04 mg/kg i.v.: TI: 6.8+/-0.9 ms versus 1.7+/-0.3 ms; p<0.05, LTI: 3.6+/-0.5 ms versus 1.0+/-0.2 ms; p<0.05 and STI: 4.2+/-0.6 ms versus 1.0+/-0.2 ms; p<0.05). The increases induced by dofetilide were associated with a high incidence of early afterdepolarizations (EADs) in the endocardial monophasic action potential (in 6 out of the 7 compound-treated animals versus 0 out of the 7 solvent animals; p<0.05). Quantification of beat-to-beat QT instability by our method clearly detects changes in short-term, long-term and total instability induced by dofetilide, already at pre-arrhythmic doses. Dofetilide administration to anesthetized dogs prolongs ventricular repolarization, concomitantly increases beat-to-beat QT instability and induces early after depolarizations (EADs). As such, the use of these parameters in this in vivo model shows clear potential for risk identification

Cross-Site Reliability of Human Induced Pluripotent Stem-Cell Derived Cardiomyocyte Based Safety Assays using Microelectrode Arrays: Results from a Blinded CiPA Pilot Study.

PubMed

Millard, Daniel; Dang, Qianyu; Shi, Hong; Zhang, Xiaou; Strock, Chris; Kraushaar, Udo; Zeng, Haoyu; Levesque, Paul; Lu, Hua-Rong; Guillon, Jean-Michel; Wu, Joseph C; Li, Yingxin; Luerman, Greg; Anson, Blake; Guo, Liang; Clements, Mike; Abassi, Yama A; Ross, James; Pierson, Jennifer; Gintant, Gary

2018-04-27

Recent in vitro cardiac safety studies demonstrate the ability of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to detect electrophysiologic effects of drugs. However, variability contributed by unique approaches, procedures, cell lines and reagents across laboratories makes comparisons of results difficult, leading to uncertainty about the role of hiPSC-CMs in defining proarrhythmic risk in drug discovery and regulatory submissions. A blinded pilot study was conducted to evaluate the electrophysiologic effects of eight well-characterized drugs on four cardiomyocyte lines using a standardized protocol across three microelectrode array (MEA) platforms (18 individual studies). Drugs were selected to define assay sensitivity of prominent repolarizing currents (E-4031 for IKr, JNJ303 for IKs) and depolarizing currents (nifedipine for ICaL, mexiletine for INa) as well as drugs affecting multi-channel block (flecainide, moxifloxacin, quinidine, and ranolazine). Inclusion criteria for final analysis was based on demonstrated sensitivity to IKr block (20% prolongation with E-4031) and L-type calcium current block (20% shortening with nifedipine). Despite differences in baseline characteristics across cardiomyocyte lines, multiple sites and instrument platforms, 10 of 18 studies demonstrated adequate sensitivity to IKr block with E-4031 and ICaL block with nifedipine for inclusion in the final analysis. Concentration-dependent effects on repolarization were observed with this qualified dataset consistent with known ionic mechanisms of single and multi-channel blocking drugs. hiPSC-CMs can detect repolarization effects elicited by single and multi-channel blocking drugs after defining pharmacologic sensitivity to IKr and ICaL block, supporting further validation efforts using hiPSC-CMs for cardiac safety studies.

Drug-induced apnea.

PubMed

Boutroy, M J

1994-01-01

Drugs have been in the past and will in the future still be liable to induce apnea in neonates, infants and older children. At these different stages of development, the child may be abnormally vulnerable to respiratory disorders and apnea, and doses of drugs, without any abnormal side effects in adult patients, can be harmful in younger subjects. Drugs responsible for apnea during development are numerous, but more than half of the problems are induced by sedatives and hypnotics, among which phenothiazines, barbiturates, benzodiazepines (included transplacentally acquired) and general anesthetics are a few. Other pharmacological families are apnea inducers in the neonatal period and childhood: analgesics and opioid narcotics, agents acting at the levels of neuromuscular function and autonomic ganglia, and cardiovascular agents. The pathogenesis of these apneas depends on the disturbance of any mechanism responsible for the respiratory activity: medullary centers and brain stem structures, afferent influx to CNS, sleep stages, upper airways, lungs and respiratory muscles. At key stages such as birth and infancy, drugs may emphasize the particular sensitivity of the mechanisms responsible for inducing apnea. This might explain unexpected respiratory disorders during development.

Left ventricular epicardial activation increases transmural dispersion of repolarization in healthy, long QT, and dilated cardiomyopathy dogs.

PubMed

Bai, Rong; Lü, Jiagao; Pu, Jun; Liu, Nian; Zhou, Qiang; Ruan, Yanfei; Niu, Huiyan; Zhang, Cuntai; Wang, Lin; Kam, Ruth

2005-10-01

Benefits of cardiac resynchronization therapy (CRT) are well established. However, less is understood concerning its effects on myocardial repolarization and the potential proarrhythmic risk. Healthy dogs (n = 8) were compared to a long QT interval (LQT) model (n = 8, induced by cesium chloride, CsCl) and a dilated cardiomyopathy with congestive heart failure (DCM-CHF, induced by rapid ventricular pacing, n = 5). Monophasic action potential (MAP) recordings were obtained from the subendocardium, midmyocardium, subepicardium, and the transmural dispersion of repolarization (TDR) was calculated. The QT interval and the interval from the peak to the end of the T wave (T(p-e)) were measured. All these characteristics were compared during left ventricular epicardial (LV-Epi), right ventricular endocardial (RV-Endo), and biventricular (Bi-V) pacing. In healthy dogs, TDR prolonged to 37.54 ms for Bi-V pacing and to 47.16 ms for LV-Epi pacing as compared to 26.75 ms for RV-Endo pacing (P < 0.001), which was parallel to an augmentation in T(p-e) interval (Bi-V pacing, 64.29 ms; LV-Epi pacing, 57.89 ms; RV-Endo pacing, 50.29 ms; P < 0.01). During CsCl exposure, Bi-V and LV-Epi pacing prolonged MAPD, TDR, and T(p-e) interval as compared to RV-Endo pacing. The midmyocardial MAPD (276.30 ms vs 257.35 ms, P < 0.0001) and TDR (33.80 ms vs 27.58 ms, P=0.002) were significantly longer in DCM-CHF dogs than those in healthy dogs. LV-Epi and Bi-V pacing further prolonged the MAPD and TDR in this model. LV-Epi and Bi-V pacing result in prolongation of ventricular repolarization time, and increase of TDR accounted for a parallel augmentation of the T(p-e) interval, which provides evidence that T(p-e) interval accurately represents TDR. These effects are magnified in the LQT and DCM-CHF canine models in addition to their intrinsic transmural heterogeneity in the intact heart. This mechanism may contribute to the development of malignant ventricular arrhythmias, such as torsades de

Terbinafine-induced lichenoid drug eruption.

PubMed

Zheng, Yue; Zhang, Jie; Chen, Haiyan; Lai, Wei; Maibach, Howard I

2017-03-01

Drug-induced lichen planus has been induced by antibiotics, anticonvulsants, antidiabetics, antimalarials, antitubercular drugs, antihypertensives, psychiatric drugs, chemotherapeutic agents, diuretic, heavy metals, NSAIDs, etc. Terbinafine, an antifungal agent, is widely used for dermatophyte infections and onychomycosis. Cutaneous adverse effects of terbinafine are rarely reported. Here, we report a case of terbinafine-induced lichenoid drug eruption in a 22-year-old who presented with generalized lichenoid eruption 2 weeks after terbinafine initiation of. The body and lip cleared completely after 8 weeks of drug withdrawal; nail change cleared after 12 weeks.

Leptin decreases heart rate associated with increased ventricular repolarization via its receptor.

PubMed

Lin, Yen-Chang; Huang, Jianying; Hileman, Stan; Martin, Karen H; Hull, Robert; Davis, Mary; Yu, Han-Gang

2015-11-15

Leptin has been proposed to modulate cardiac electrical properties via β-adrenergic receptor activation. The presence of leptin receptors and adipocytes in myocardium raised a question as to whether leptin can directly modulate cardiac electrical properties such as heart rate and QT interval via its receptor. In this work, the role of local direct actions of leptin on heart rate and ventricular repolarization was investigated. We identified the protein expression of leptin receptors at cell surface of sinus node, atrial, and ventricular myocytes isolated from rat heart. Leptin at low doses (0.1-30 μg/kg) decreased resting heart rate; at high doses (150-300 μg/kg), leptin induced a biphasic effect (decrease and then increase) on heart rate. In the presence of high-dose propranolol (30 mg/kg), high-dose leptin only reduced heart rate and sometimes caused sinus pauses and ventricular tachycardia. The leptin-induced inhibition of resting heart rate was fully reversed by leptin antagonist. Leptin also increased heart rate-corrected QT interval (QTc), and leptin antagonist did not. In isolated ventricular myocytes, leptin (0.03-0.3 μg/ml) reversibly increased the action potential duration. These results supported our hypothesis that in addition to indirect pathway via sympathetic tone, leptin can directly decrease heart rate and increase QT interval via its receptor independent of β-adrenergic receptor stimulation. During inhibition of β-adrenergic receptor activity, high concentration of leptin in myocardium can cause deep bradycardia, prolonged QT interval, and ventricular arrhythmias. Copyright © 2015 the American Physiological Society.

Leptin decreases heart rate associated with increased ventricular repolarization via its receptor

PubMed Central

Lin, Yen-Chang; Huang, Jianying; Hileman, Stan; Martin, Karen H.; Hull, Robert; Davis, Mary

2015-01-01

Leptin has been proposed to modulate cardiac electrical properties via β-adrenergic receptor activation. The presence of leptin receptors and adipocytes in myocardium raised a question as to whether leptin can directly modulate cardiac electrical properties such as heart rate and QT interval via its receptor. In this work, the role of local direct actions of leptin on heart rate and ventricular repolarization was investigated. We identified the protein expression of leptin receptors at cell surface of sinus node, atrial, and ventricular myocytes isolated from rat heart. Leptin at low doses (0.1–30 μg/kg) decreased resting heart rate; at high doses (150–300 μg/kg), leptin induced a biphasic effect (decrease and then increase) on heart rate. In the presence of high-dose propranolol (30 mg/kg), high-dose leptin only reduced heart rate and sometimes caused sinus pauses and ventricular tachycardia. The leptin-induced inhibition of resting heart rate was fully reversed by leptin antagonist. Leptin also increased heart rate-corrected QT interval (QTc), and leptin antagonist did not. In isolated ventricular myocytes, leptin (0.03–0.3 μg/ml) reversibly increased the action potential duration. These results supported our hypothesis that in addition to indirect pathway via sympathetic tone, leptin can directly decrease heart rate and increase QT interval via its receptor independent of β-adrenergic receptor stimulation. During inhibition of β-adrenergic receptor activity, high concentration of leptin in myocardium can cause deep bradycardia, prolonged QT interval, and ventricular arrhythmias. PMID:26408544

Impact of Ancillary Subunits on Ventricular Repolarization

PubMed Central

Abbott, Geoffrey W.; Xu, Xianghua; Roepke, Torsten K.

2007-01-01

Voltage-gated potassium (Kv) channels generate the outward K+ ion currents that constitute the primary force in ventricular repolarization. Kv channels comprise tetramers of pore-forming α subunits and, in probably the majority of cases in vivo, ancillary or β subunits that help define the properties of the Kv current generated. Ancillary subunits can be broadly categorized as cytoplasmic or transmembrane, and can modify Kv channel trafficking, conductance, gating, ion selectivity, regulation and pharmacology. Because of their often profound effects on Kv channel function, studies of the molecular correlates of ventricular repolarization must take into account ancillary subunits as well as α subunits. Cytoplasmic ancillary subunits include the Kvβ subunits, which regulate a range of Kv channels and may link channel gating to redox potential; and the KChIPs, which appear most often associated with Kv4 subfamily channels that generate the ventricular Ito current. Transmembrane ancillary subunits include the MinK-related proteins (MiRPs) encoded by KCNE genes, which modulate members of most Kv α subunit subfamilies; and the putative 12-transmembrane domain KCR1 protein which modulates hERG. In some cases, such as the ventricular IKs channel complex, it is well-established that the KCNQ1 α subunit must co-assemble with the MinK (KCNE1) single transmembrane domain ancillary subunit for recapitulation of the characteristic, unusually slowly-activating IKs current. In other cases it is not so clear-cut, and in particular the roles of the other MinK-related proteins (MiRPs 1–4) in regulating cardiac Kv channels such as KCNQ1 and hERG in vivo are under debate. MiRP1 alters hERG function and pharmacology, and inherited MiRP1 mutations are associated with inherited and acquired arrhythmias, but controversy exists over the native role of MiRP1 in regulating hERG (and therefore ventricular IKr) in vivo. Some ancillary subunits may exhibit varied expression to shape

Drug-induced sexual dysfunction.

PubMed

Aldridge, S A

1982-01-01

Commonly used drugs that may cause sexual dysfunction are reviewed. The anatomy and physiology of the normal sexual response are reviewed. The influence of drugs on neurogenic, hormonal, and vascular mechanisms may result in diminished libido, impotence, ejaculatory and orgasmic difficulties, inhibited vaginal lubrication, menstrual irregularities, and gynecomastia in men or painful breast enlargement in women. Parasympatholytic agents, which interfere with cholinergic transmission, may affect erectile potency, while adrenergic inhibiting agents may interfere with ejaculatory control. Central nervous system depressants or sedating drugs, drugs producing hyperprolactinemia, and antiandrogenic drugs also may affect the normal sexual response. Drugs such as antihypertensive and antipsychotic agents may induce sexual dysfunction that can result in patient noncompliance. Usually, drug-induced side effects are reversible with discontinuation of the offending agent.

Drug-Induced Urinary Calculi

PubMed Central

Matlaga, Brian R; Shah, Ojas D; Assimos, Dean G

2003-01-01

Urinary calculi may be induced by a number of medications used to treat a variety of conditions. These medications may lead to metabolic abnormalities that facilitate the formation of stones. Drugs that induce metabolic calculi include loop diuretics; carbonic anhydrase inhibitors; and laxatives, when abused. Correcting the metabolic abnormality may eliminate or dramatically attenuate stone activity. Urinary calculi can also be induced by medications when the drugs crystallize and become the primary component of the stones. In this case, urinary supersaturation of the agent may promote formation of the calculi. Drugs that induce calculi via this process include magnesium trisilicate; ciprofloxacin; sulfa medications; triamterene; indinavir; and ephedrine, alone or in combination with guaifenesin. When this situation occurs, discontinuation of the medication is usually necessary. PMID:16985842

Mechanistic review of drug-induced steatohepatitis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schumacher, Justin D., E-mail: Justin.d.schumacher@rutgers.edu; Guo, Grace L.

Drug-induced steatohepatitis is a rare form of liver injury known to be caused by only a handful of compounds. These compounds stimulate the development of steatohepatitis through their toxicity to hepatocyte mitochondria; inhibition of beta-oxidation, mitochondrial respiration, and/or oxidative phosphorylation. Other mechanisms discussed include the disruption of phospholipid metabolism in lysosomes, prevention of lipid egress from hepatocytes, targeting mitochondrial DNA and topoisomerase, decreasing intestinal barrier function, activation of the adenosine pathway, increasing fatty acid synthesis, and sequestration of coenzyme A. It has been found that the majority of compounds that induce steatohepatitis have cationic amphiphilic structures; a lipophilic ring structuremore » with a side chain containing a cationic secondary or tertiary amine. Within the last decade, the ability of many chemotherapeutics to cause steatohepatitis has become more evident coining the term chemotherapy-associated steatohepatitis (CASH). The mechanisms behind drug-induced steatohepatitis are discussed with a focus on cationic amphiphilic drugs and chemotherapeutic agents. - Highlights: • Reviewed the mechanisms underlying drug-induced steatohepatitis for many compounds • Mitochondrial dysfunction is critical in the development of drug-induced steatohepatitis. • Majority of drugs that induce steatohepatitis are cationic amphiphilic drugs. • Chemotherapeutics that induce CASH are cationic amphiphilic drugs. • Majority of drugs that induce steatohepatitis are carnitine palmitoyltransferase-I inhibitors.« less

Drug-Induced Acute Pancreatitis: A Review

PubMed Central

Jones, Mark R.; Hall, Oliver Morgan; Kaye, Adam M.; Kaye, Alan David

2015-01-01

Background The majority of drug-induced pancreatitis cases are mild to moderate in severity, but severe and even fatal cases can occur. Management of drug-induced pancreatitis requires withdrawal of the offending agent and supportive care. Methods This review focuses on differential diagnosis, clinical presentation, drug-mediated effects, treatments, and mechanisms of pancreatitis, with an emphasis on drug-induced pancreatitis. Results Although only a minority of cases associated with acute pancreatitis are linked to drugs, clinical presentation and mechanisms of injury to the pancreas are not well understood by clinicians in terms of individual drug effects in the mediation or modulation of injury to the pancreas. In recent years, a large number of commonly prescribed medications has been linked to drug-induced pancreatitis pathogenesis. Although mechanisms are proposed, the exact cause of injury is either not well understood or controversial. Conclusion Future investigation into the mechanisms of pancreatitis and an appreciation by clinicians of the drugs commonly linked to the condition will help establish earlier diagnosis and quicker cessation of offending drugs in the treatment of drug-induced acute pancreatitis. PMID:25829880

Human induced pluripotent stem cell‐derived versus adult cardiomyocytes: an in silico electrophysiological study on effects of ionic current block

PubMed Central

Paci, M; Hyttinen, J; Rodriguez, B

2015-01-01

Background and Purpose Two new technologies are likely to revolutionize cardiac safety and drug development: in vitro experiments on human‐induced pluripotent stem cell‐derived cardiomyocytes (hiPSC‐CMs) and in silico human adult ventricular cardiomyocyte (hAdultV‐CM) models. Their combination was recently proposed as a potential replacement for the present hERG‐based QT study for pharmacological safety assessments. Here, we systematically compared in silico the effects of selective ionic current block on hiPSC‐CM and hAdultV‐CM action potentials (APs), to identify similarities/differences and to illustrate the potential of computational models as supportive tools for evaluating new in vitro technologies. Experimental Approach In silico AP models of ventricular‐like and atrial‐like hiPSC‐CMs and hAdultV‐CM were used to simulate the main effects of four degrees of block of the main cardiac transmembrane currents. Key Results Qualitatively, hiPSC‐CM and hAdultV‐CM APs showed similar responses to current block, consistent with results from experiments. However, quantitatively, hiPSC‐CMs were more sensitive to block of (i) L‐type Ca2+ currents due to the overexpression of the Na+/Ca2+ exchanger (leading to shorter APs) and (ii) the inward rectifier K+ current due to reduced repolarization reserve (inducing diastolic potential depolarization and repolarization failure). Conclusions and Implications In silico hiPSC‐CMs and hAdultV‐CMs exhibit a similar response to selective current blocks. However, overall hiPSC‐CMs show greater sensitivity to block, which may facilitate in vitro identification of drug‐induced effects. Extrapolation of drug effects from hiPSC‐CM to hAdultV‐CM and pro‐arrhythmic risk assessment can be facilitated by in silico predictions using biophysically‐based computational models. PMID:26276951

[Drug-induced oral ulcerations].

PubMed

Madinier, I; Berry, N; Chichmanian, R M

2000-06-01

Different side effects of drugs have been described in the oral cavity, including oral ulcerations. Direct contact between drugs and oral mucosa may induce chemical burn or local hypersensitivity. Less frequently, these drug-induced oral ulcerations are part of a complex reaction with cutaneous or systemic manifestations. Sometimes, one or more oral ulcerations appear as the main side-effect of a drug, or exceptionally as solitary lesions. Solitary oral ulcerations usually appear after few weeks of treatment. In most of cases, these lesions resist to conventional treatments, with a rapid healing following the suppression of the responsible drug. This diagnosis is usually difficult, particularly with patients receiving multiple drug therapy. Besides, special attention must be paid to new drugs. Oral ulcerations following symptoms of burning mouth, metallic taste, dysgueusia or agueusia are strongly suggestive of a pharmacological origin. Most of the molecules able to induce solitary oral ulcerations are commonly prescribed in a) rheumatology: NSAI (diclofenac, flurbiprofen, indomethacin, naproxen), long-term rheumatoid arthritis therapy (azathioprine, methotrexate, penicillamine, gold compounds, tiopronin); b) cardiology: angiotensin-converting-enzyme inhibitors (captopril, enalapril), angiotensin 2-receptor antagonist (losartan), anti-angorous (nicorandil), c) psychiatry: antidepressants (fluoxetine, lithium), d) AIDS therapy (foscarnet, zalcitabine).

Cardiac Autonomic Regulation and Repolarization During Acute Experimental Hypoglycemia in Type 2 Diabetes

PubMed Central

Chow, Elaine; Bernjak, Alan; Walkinshaw, Emma; Lubina-Solomon, Alexandra; Freeman, Jenny; Macdonald, Ian A.; Sheridan, Paul J.

2017-01-01

Hypoglycemia is associated with increased cardiovascular mortality in trials of intensive therapy in type 2 diabetes mellitus (T2DM). We previously observed an increase in arrhythmias during spontaneous prolonged hypoglycemia in patients with T2DM. We examined changes in cardiac autonomic function and repolarization during sustained experimental hypoglycemia. Twelve adults with T2DM and 11 age- and BMI-matched control participants without diabetes underwent paired hyperinsulinemic clamps separated by 4 weeks. Glucose was maintained at euglycemia (6.0 mmol/L) or hypoglycemia (2.5 mmol/L) for 1 h. Heart rate, blood pressure, and heart rate variability were assessed every 30 min and corrected QT intervals and T-wave morphology every 60 min. Heart rate initially increased in participants with T2DM but then fell toward baseline despite maintained hypoglycemia at 1 h accompanied by reactivation of vagal tone. In control participants, vagal tone remained depressed during sustained hypoglycemia. Participants with T2DM exhibited greater heterogeneity of repolarization during hypoglycemia as demonstrated by T-wave symmetry and principal component analysis ratio compared with control participants. Epinephrine levels during hypoglycemia were similar between groups. Cardiac autonomic regulation during hypoglycemia appears to be time dependent. Individuals with T2DM demonstrate greater repolarization abnormalities for a given hypoglycemic stimulus despite comparable sympathoadrenal responses. These mechanisms could contribute to arrhythmias during clinical hypoglycemic episodes. PMID:28137792

Test systems in drug discovery for hazard identification and risk assessment of human drug-induced liver injury.

PubMed

Weaver, Richard J; Betts, Catherine; Blomme, Eric A G; Gerets, Helga H J; Gjervig Jensen, Klaus; Hewitt, Philip G; Juhila, Satu; Labbe, Gilles; Liguori, Michael J; Mesens, Natalie; Ogese, Monday O; Persson, Mikael; Snoeys, Jan; Stevens, James L; Walker, Tracy; Park, B Kevin

2017-07-01

The liver is an important target for drug-induced toxicities. Early detection of hepatotoxic drugs requires use of well-characterized test systems, yet current knowledge, gaps and limitations of tests employed remains an important issue for drug development. Areas Covered: The current state of the science, understanding and application of test systems in use for the detection of drug-induced cytotoxicity, mitochondrial toxicity, cholestasis and inflammation is summarized. The test systems highlighted herein cover mostly in vitro and some in vivo models and endpoint measurements used in the assessment of small molecule toxic liabilities. Opportunities for research efforts in areas necessitating the development of specific tests and improved mechanistic understanding are highlighted. Expert Opinion: Use of in vitro test systems for safety optimization will remain a core activity in drug discovery. Substantial inroads have been made with a number of assays established for human Drug-induced Liver Injury. There nevertheless remain significant gaps with a need for improved in vitro tools and novel tests to address specific mechanisms of human Drug-Induced Liver Injury. Progress in these areas will necessitate not only models fit for application, but also mechanistic understanding of how chemical insult on the liver occurs in order to identify translational and quantifiable readouts for decision-making.

Factors affecting drug-induced liver injury: antithyroid drugs as instances

PubMed Central

Niknahad, Hossein; Jamshidzadeh, Akram; Abdoli, Narges

2014-01-01

Methimazole and propylthiouracil have been used in the management of hyperthyroidism for more than half a century. However, hepatotoxicity is one of the most deleterious side effects associated with these medications. The mechanism(s) of hepatic injury induced by antithyroid agents is not fully recognized yet. Furthermore, there are no specific tools for predicting the occurrence of hepatotoxicity induced by these drugs. The purpose of this article is to give an overview on possible susceptibility factors in liver injury induced by antithyroid agents. Age, gender, metabolism characteristics, alcohol consumption, underlying diseases, immunologic mechanisms, and drug interactions are involved in enhancing antithyroid drugs-induced hepatic damage. An outline on the clinically used treatments for antithyroid drugs-induced hepatotoxicity and the potential therapeutic strategies found to be effective against this complication are also discussed. PMID:25320726

[Drug-induced gynecomastia].

PubMed

Schirren, U; Hinz, B; Schirren, C

1986-01-01

Concerning four own observations by men in the age of 41-69 years it has been reported about the drug-induced gynecomastia. It can be demonstrated that the spironolactone induced gynecomastia disappeared after stopping this drug. The knowledge of such side effects is the condition for a pre-information of the patient at the beginning of therapy. The mode of action of spironolactone is discussed. It is referred about the important role of the disturbance of the relation androgen: estrogens under spironolactone as well as the peripheral antiandrogen effect of this substance.

Glucosylceramide and Lysophosphatidylcholines as Potential Blood Biomarkers for Drug-Induced Hepatic Phospholipidosis

PubMed Central

Saito, Kosuke; Maekawa, Keiko; Ishikawa, Masaki; Senoo, Yuya; Urata, Masayo; Murayama, Mayumi; Nakatsu, Noriyuki; Yamada, Hiroshi; Saito, Yoshiro

2014-01-01

Drug-induced phospholipidosis is one of the major concerns in drug development and clinical treatment. The present study involved the use of a nontargeting lipidomic analysis with liquid chromatography-mass spectrometry to explore noninvasive blood biomarkers for hepatic phospholipidosis from rat plasma. We used three tricyclic antidepressants (clomipramine [CPM], imipramine [IMI], and amitriptyline [AMT]) for the model of phospholipidosis in hepatocytes and ketoconazole (KC) for the model of phospholipidosis in cholangiocytes and administered treatment for 3 and 28 days each. Total plasma lipids were extracted and measured. Lipid molecules contributing to the separation of control and drug-treated rat plasma in a multivariate orthogonal partial least squares discriminant analysis were identified. Four lysophosphatidylcholines (LPCs) (16:1, 18:1, 18:2, and 20:4) and 42:1 hexosylceramide (HexCer) were identified as molecules separating control and drug-treated rats in all models of phospholipidosis in hepatocytes. In addition, 16:1, 18:2, and 20:4 LPCs and 42:1 HexCer were identified in a model of hepatic phospholipidosis in cholangiocytes, although LPCs were identified only in the case of 3-day treatment with KC. The levels of LPCs were decreased by drug-induced phospholipidosis, whereas those of 42:1 HexCer were increased. The increase in 42:1 HexCer was much higher in the case of IMI and AMT than in the case of CPM; moreover, the increase induced by IMI was dose-dependent. Structural characterization determining long-chain base and hexose delineated that 42:1 HexCer was d18:1/24:0 glucosylceramide (GluCer). In summary, our study demonstrated that d18:1/24:0 GluCer and LPCs are potential novel biomarkers for drug-induced hepatic phospholipidosis. PMID:24980264

Cardiac Repolarization Changes in the Children with Breath-Holding Spells

PubMed Central

Amoozgar, Hamid; Saleh, Fazl; Farhani, Nahal; Rafiei, Mohammad; Inaloo, Soroor; Asadipooya, Ali-Akbar

2013-01-01

Objective Breath-holding spells are known as benign attacks, frequencies of which decrease by the development of the autonomic nervous system. The present study aims to compare the electrocardiographic repolarization in children with breath-holding spells. Methods In this study, QT dispersion, QTc dispersion, T peak to T end dispersion, and P wave dispersion of the twelve-lead surface electrocardiography of fifty children who had breath-holding spells were measured and compared with normal children from April 2011 to August 2012. Findings Forty-four (88%) patients had cyanotic spells, while 6 (12%) had pallid spells. QTc dispersion was increased in the patients with breath-holding spells (148.2±33.1) compared to the healthy children (132±27.3) and the difference was statically significant (P = 0.01). Meanwhile, no statistically significant differences were observed between the patients and the control subjects regarding the other parameters (P > 0.05). Conclusion QTc dispersion was significantly increased in the patients with breath-holding spells compared to normal children and this is a sign of cardiac repolarization abnormality as well as the increased risk of cardiac arrhythmia in patients with breath-holding spells. PMID:24910749

MSBIS: A Multi-Step Biomedical Informatics Screening Approach for Identifying Medications that Mitigate the Risks of Metoclopramide-Induced Tardive Dyskinesia.

PubMed

Xu, Dong; Ham, Alexandrea G; Tivis, Rickey D; Caylor, Matthew L; Tao, Aoxiang; Flynn, Steve T; Economen, Peter J; Dang, Hung K; Johnson, Royal W; Culbertson, Vaughn L

2017-12-01

In 2009 the U.S. Food and Drug Administration (FDA) placed a black box warning on metoclopramide (MCP) due to the increased risks and prevalence of tardive dyskinesia (TD). In this study, we developed a multi-step biomedical informatics screening (MSBIS) approach leveraging publicly available bioactivity and drug safety data to identify concomitant drugs that mitigate the risks of MCP-induced TD. MSBIS includes (1) TargetSearch (http://dxulab.org/software) bioinformatics scoring for drug anticholinergic activity using CHEMBL bioactivity data; (2) unadjusted odds ratio (UOR) scoring for indications of TD-mitigating effects using the FDA Adverse Event Reporting System (FAERS); (3) adjusted odds ratio (AOR) re-scoring by removing the effect of cofounding factors (age, gender, reporting year); (4) logistic regression (LR) coefficient scoring for confirming the best TD-mitigating drug candidates. Drugs with increasing TD protective potential and statistical significance were obtained at each screening step. Fentanyl is identified as the most promising drug against MCP-induced TD (coefficient: -2.68; p-value<0.01). The discovery is supported by clinical reports that patients fully recovered from MCP-induced TD after fentanyl-induced general anesthesia. Loperamide is identified as a potent mitigating drug against a broader range of drug-induced movement disorders through pharmacokinetic modifications. Using drug-induced TD as an example, we demonstrated that MSBIS is an efficient in silico tool for unknown drug-drug interaction detection, drug repurposing, and combination therapy design. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Drug-induced cholestasis: mechanisms, models, and markers.

PubMed

Chatterjee, Sagnik; Annaert, Pieter

2018-04-27

Drug-induced cholestasis is a risk factor in progression of drug candidates, and poses serious health hazard if not detected before going into human. Intrahepatic accumulation of bile acids (BAs) represents a characteristic phenomenon associated with drug-induced cholestasis. The major challenges in obtaining a complete understanding of drug-induced cholestasis lies in the complexity of BA-mediated toxicity mechanisms and the impact of bile acids at different 'targets' such as transporters, enzymes and nuclear receptors. At the same time, it is not trivial to have a relevant in vitro system that recapitulates these features. In addition, lack of sensitive and early preclinical biomarkers, relevant to the clinical situation, complicates proper detection of drug-induced cholestasis. Significant overlap in biomarker signatures between different mechanisms of drug-induced liver injury (DILI) precludes identification of specific mechanisms. Over the last decade the knowledge gaps in drug-induced cholestasis are closing due to growing mechanistic understanding of BA-mediated toxicity at (patho)physiologically relevant BA concentrations. Significant progress has been made in the mechanistic understanding of drug-induced cholestasis and associated toxicity, biomarkers and susceptibility factors. In addition, novel in vitro models are evolving which provide a holistic understanding of processes underlying drug-induced cholestasis. This review summarizes the challenges and recent understandings about drug-induced cholestasis with a potential path forward. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Identifying novel drug indications through automated reasoning.

PubMed

Tari, Luis; Vo, Nguyen; Liang, Shanshan; Patel, Jagruti; Baral, Chitta; Cai, James

2012-01-01

With the large amount of pharmacological and biological knowledge available in literature, finding novel drug indications for existing drugs using in silico approaches has become increasingly feasible. Typical literature-based approaches generate new hypotheses in the form of protein-protein interactions networks by means of linking concepts based on their cooccurrences within abstracts. However, this kind of approaches tends to generate too many hypotheses, and identifying new drug indications from large networks can be a time-consuming process. In this work, we developed a method that acquires the necessary facts from literature and knowledge bases, and identifies new drug indications through automated reasoning. This is achieved by encoding the molecular effects caused by drug-target interactions and links to various diseases and drug mechanism as domain knowledge in AnsProlog, a declarative language that is useful for automated reasoning, including reasoning with incomplete information. Unlike other literature-based approaches, our approach is more fine-grained, especially in identifying indirect relationships for drug indications. To evaluate the capability of our approach in inferring novel drug indications, we applied our method to 943 drugs from DrugBank and asked if any of these drugs have potential anti-cancer activities based on information on their targets and molecular interaction types alone. A total of 507 drugs were found to have the potential to be used for cancer treatments. Among the potential anti-cancer drugs, 67 out of 81 drugs (a recall of 82.7%) are indeed known cancer drugs. In addition, 144 out of 289 drugs (a recall of 49.8%) are non-cancer drugs that are currently tested in clinical trials for cancer treatments. These results suggest that our method is able to infer drug indications (original or alternative) based on their molecular targets and interactions alone and has the potential to discover novel drug indications for existing drugs.

Early repolarization in Wolff-Parkinson-White syndrome: prevalence and clinical significance.

PubMed

Mizumaki, Koichi; Nishida, Kunihiro; Iwamoto, Jotaro; Nakatani, Yosuke; Yamaguchi, Yoshiaki; Sakamoto, Tamotsu; Tsuneda, Takayuki; Inoue, Hiroshi; Sakabe, Masao; Fujiki, Akira

2011-08-01

Idiopathic ventricular fibrillation (IVF) with early repolarization (ER) has recently been reported; however, ER is a common finding in healthy subjects and is also found sporadically in patients with Wolff-Parkinson-White (WPW) syndrome. The present study was designed to evaluate the prevalence and clinical significance of ER in patients with WPW syndrome. One hundred and eleven patients with WPW syndrome were studied retrospectively. Early repolarization was defined as QRS slurring or notching with J-point elevation ≥ 1 mm. The prevalence of ER was determined before and after successful catheter ablation. Before ablation, ER was found in 35 of 75 patients with a left free wall, 6 of 23 with a right free wall, and 7 of 13 with a septal accessory pathway (48 of 111, 43% as a whole). Early repolarization was always observed in leads with positive deflection of the initial part of the delta wave. After successful ablation of accessory pathways, ER was preserved in 28 (25%), disappeared in 20 (18%), and newly developed in 8 (7%) patients. In the remaining 55 (50%) patients, ER was not observed either before or after ablation. In patients with persistent ER, the amplitude and width of ER were significantly decreased 3-7 days after the ablation (1.7 ± 0.7 vs. 1.4 ± 0.6 mm, P < 0.005 and 42 ± 11 vs. 34 ± 9 ms, P < 0.001, respectively). In patients with WPW syndrome, ER could be partly related to early depolarization through the accessory pathway. However, persistent ER and new ER appearing after the ablation were frequently found. Therefore, in these patients, mechanisms other than early depolarization may be involved in the genesis of ER.

Electrical storm in patients with brugada syndrome is associated with early repolarization.

PubMed

Kaneko, Yoshiaki; Horie, Minoru; Niwano, Shinichi; Kusano, Kengo F; Takatsuki, Seiji; Kurita, Takashi; Mitsuhashi, Takeshi; Nakajima, Tadashi; Irie, Tadanobu; Hasegawa, Kanae; Noda, Takashi; Kamakura, Shiro; Aizawa, Yoshiyasu; Yasuoka, Ryobun; Torigoe, Katsumi; Suzuki, Hiroshi; Ohe, Toru; Shimizu, Akihiko; Fukuda, Keiichi; Kurabayashi, Masahiko; Aizawa, Yoshifusa

2014-12-01

Electrical storms (ESs) in patients with Brugada syndrome (BrS) are rare though potentially lethal. We studied 22 men with BrS and ES, defined as ≥3 episodes/d of ventricular fibrillation (VF) and compared their characteristics with those of 110 age-matched, control men with BrS without ES. BrS was diagnosed by a spontaneous or drug-induced type 1 pattern on the ECG in the absence of structural heart disease. Early repolarization (ER) was diagnosed by J waves, ie, >0.1 mV notches or slurs of the terminal portion of the QRS complex. The BrS ECG pattern was provoked with pilsicainide. A spontaneous type I ECG pattern, J waves, and horizontal/descending ST elevation were found, respectively, in 77%, 36%, and 88% of patients with ES, versus 28% (P<0.0001), 9% (P=0.003), and 60% (P=0.06) of controls. The J-wave amplitude was significantly higher in patients with than without ES (P=0.03). VF occurred during undisturbed sinus rhythm in 14 of 19 patients (74%), and ES were controlled by isoproterenol administration. All patients with ES received an implantable cardioverter defibrillator and over a 6.0±5.4 years follow-up, the prognosis of patients with ES was significantly worse than that of patients without ES. Bepridil was effective in preventing VF in 6 patients. A high prevalence of ER was found in a subgroup of patients with BrS associated with ES. ES appeared to be suppressed by isoproterenol or quinidine, whereas bepridil and quinidine were effective in the long-term prevention of VF in the highest-risk patients. © 2014 American Heart Association, Inc.

Estrogen Contributes to Gender Differences in Mouse Ventricular Repolarization

PubMed Central

Saito, Tomoaki; Ciobotaru, Andrea; Bopassa, Jean Chrisostome; Toro, Ligia; Stefani, Enrico; Eghbali, Mansoureh

2010-01-01

Rationale Fast-transient outward K+ (Ito,f) and ultra-rapid delayed rectifier K+ currents (IKur or IK,slow) contribute to mouse cardiac repolarization. Gender studies on these currents have reported conflicting results. Objective One key missing piece information in these studies is the animals’ estral stage. We decided to revisit gender-related differences in K+ currents, taking into consideration the females’ estral stage. Methods and Results We hypothesized that changes in estrogen levels during the estral cycle could play a role in determining the densities of K+ currents underlying ventricular repolarization. Peak total K+ current (IK,total) densities (pA/pF, at +40 mV) were much higher in males (48.6±3.0) than in females at estrus (27.2±2.3) but not at diestrus-2 (39.1±3.4). Underlying this change, Ito,f and IK,slow were lower in females at estrus vs males and diestrus-2 (IK,slow: male 21.9±1.8, estrus 14.6±0.6, diestrus-2 20.3±1.4; Ito,f: male 26.8±1.9, estrus 14.9±1.6, diestrus-2 22.1±2.1). The lower IK,slow in estrus was only due to IK,slow1 reduction without changes of IK,slow2. Estrogen treatment of ovariectomized mice decreased IK,total (46.4±3.0 to 28.4±1.6), Ito,f (26.6±1.6 to 12.8±1.0) and IK,slow (22.2±1.6 to 17.2±1.4). Transcript levels of Kv4.3 and Kv1.5 (underlying Ito,f and IK,slow, respectively) were lower in estrus vs. diestrus-2 and male. In ovariectomized mice, estrogen treatment resulted in downregulation of Kv4.3 and Kv1.5, but not Kv4.2, KChIP2 and Kv2.1 transcripts. K+ current reduction in high estrogenic conditions were associated with prolongation of the action potential duration and corrected QT interval. Conclusion Downregulation of Kv4.3 and Kv1.5 transcripts by estrogen are one mechanism defining gender-related differences in mouse ventricular repolarization. PMID:19608983

Drug-induced psoriasis: clinical perspectives.

PubMed

Balak, Deepak Mw; Hajdarbegovic, Enes

2017-01-01

Exposure to certain drugs can elicit an induction or exacerbation of psoriasis. Although well-conducted systematic studies on drug-related psoriasis are mostly lacking, traditionally strong associations have been documented for beta-blockers, lithium, antimalarial drugs such as (hydroxy)chloroquine, interferons, imiquimod, and terbinafine. More recently, new associations have been reported for monoclonal antibody- and small-molecule-based targeted therapies used for oncological and immunological indications, such as tumor necrosis factor-alpha antagonists and anti-programmed cell death protein 1 immune checkpoint inhibitors. Recognizing potential drug-related psoriasis is of clinical relevance to allow an optimal management of psoriasis. However, in clinical practice, identifying medication-related exacerbations and induction of psoriasis can be challenging. The clinical and histopathological features of drug-provoked psoriasis may differ little from that of "classical" nondrug-related forms of psoriasis. In addition, the latency period between start of the medication and onset of psoriasis can be significantly long for some drugs. Assessment of the Naranjo adverse drug reaction probability scale could be used as a practical tool to better differentiate drug-related psoriasis. The first step in the management of drug-related psoriasis is cessation and replacement of the offending drug when deemed clinically possible. However, the induced psoriasis skin lesions may persist after treatment withdrawal. Additional skin-directed treatment options for drug-related psoriasis follows the conventional psoriasis treatment guidelines and includes topical steroids and vitamin D analogs, ultraviolet phototherapy, systemic treatments, such as acitretin, methotrexate, and fumaric acid esters, and biological treatments.

Measurement and regulation of cardiac ventricular repolarization: from the QT interval to repolarization morphology

PubMed Central

Couderc, Jean-Philippe

2009-01-01

Ventricular repolarization (VR) is a crucial step in cardiac electrical activity because it corresponds to a recovery period setting the stage for the next heart contraction. Small perturbations of the VR process can predispose an individual to lethal arrhythmias. In this review, I aim to provide an overview of the methods developed to analyse static and dynamic aspects of the VR process when recorded from a surface electrocardiogram (ECG). The first section describes the list of physiological and clinical factors that can affect the VR. Technical aspects important to consider when digitally processing ECGs are provided as well. Special attention is given to the analysis of the effect of heart rate on the VR and its regulation by the autonomic nervous system. The final section provides the rationale for extending the analysis of the VR from its duration to its morphology. Several modelling techniques and measurement methods will be presented and their role within the arena of cardiac safety will be discussed. PMID:19324709

Drug-induced Liver Injury

PubMed Central

David, Stefan; Hamilton, James P

2011-01-01

Drug-induced liver injury (DILI) is common and nearly all classes of medications can cause liver disease. Most cases of DILI are benign, and improve after drug withdrawal. It is important to recognize and remove the offending agent as quickly as possible to prevent the progression to chronic liver disease and/or acute liver failure. There are no definite risk factors for DILI, but pre-existing liver disease and genetic susceptibility may predispose certain individuals. Although most patients have clinical symptoms that are identical to other liver diseases, some patients may present with symptoms of systemic hypersensitivity. Treatment of drug and herbal-induced liver injury consists of rapid drug discontinuation and supportive care targeted to alleviate unwanted symptoms. PMID:21874146

Screening drug-induced arrhythmia [corrected] using human induced pluripotent stem cell-derived cardiomyocytes and low-impedance microelectrode arrays.

PubMed

Navarrete, Enrique G; Liang, Ping; Lan, Feng; Sanchez-Freire, Verónica; Simmons, Chelsey; Gong, Tingyu; Sharma, Arun; Burridge, Paul W; Patlolla, Bhagat; Lee, Andrew S; Wu, Haodi; Beygui, Ramin E; Wu, Sean M; Robbins, Robert C; Bers, Donald M; Wu, Joseph C

2013-09-10

Drug-induced arrhythmia is one of the most common causes of drug development failure and withdrawal from market. This study tested whether human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) combined with a low-impedance microelectrode array (MEA) system could improve on industry-standard preclinical cardiotoxicity screening methods, identify the effects of well-characterized drugs, and elucidate underlying risk factors for drug-induced arrhythmia. hiPSC-CMs may be advantageous over immortalized cell lines because they possess similar functional characteristics as primary human cardiomyocytes and can be generated in unlimited quantities. Pharmacological responses of beating embryoid bodies exposed to a comprehensive panel of drugs at 65 to 95 days postinduction were determined. Responses of hiPSC-CMs to drugs were qualitatively and quantitatively consistent with the reported drug effects in literature. Torsadogenic hERG blockers, such as sotalol and quinidine, produced statistically and physiologically significant effects, consistent with patch-clamp studies, on human embryonic stem cell-derived cardiomyocytes hESC-CMs. False-negative and false-positive hERG blockers were identified accurately. Consistent with published studies using animal models, early afterdepolarizations and ectopic beats were observed in 33% and 40% of embryoid bodies treated with sotalol and quinidine, respectively, compared with negligible early afterdepolarizations and ectopic beats in untreated controls. We found that drug-induced arrhythmias can be recapitulated in hiPSC-CMs and documented with low impedance MEA. Our data indicate that the MEA/hiPSC-CM assay is a sensitive, robust, and efficient platform for testing drug effectiveness and for arrhythmia screening. This system may hold great potential for reducing drug development costs and may provide significant advantages over current industry standard assays that use immortalized cell lines or animal models.

Kinetics of cycle length dependence of ventricular repolarization: effect of autonomic blockade

NASA Technical Reports Server (NTRS)

Raeder, E. A.; Albrecht, P.; Perrott, M.; Cohen, R. J.

1995-01-01

INTRODUCTION: Beat-to-beat adaptation of ventricular repolarization duration to cardiac cycle length and autonomic activity has not been previously characterized in the spontaneously beating human heart. METHODS AND RESULTS: The ECG of 14 healthy subjects was recorded from the supine and upright positions. Autonomic blockade was accomplished by atropine and propranolol. RR and RT intervals were measured by a computer algorithm, and the impulse response (h) from RR to RT computed. In the supine position the maximal adjustment of the RT interval occurred in the first beat following a change in cycle length (hpeak = 17.8 +/- 1.6 msec/sec), but continued to be detectable for 3.8 seconds (2.9-4.7 sec). Propranolol attenuated the peak impulse response to 15.8 +/- 4.0 msec/sec (P = NS). In the standing position the peak impulse response was increased to 25.2 +/- 5.0 msec/sec (P = 0.004 vs supine), and the impulse response duration (hdur) shortened to 1.4 seconds (1.3-1.6). This was reversed by beta blockade (hpeak = 10.7 +/- 3.6 [P = 0.005 vs standing]; hdur = 5.5 sec [4.8-6.1]). Parasympathetic and combined autonomic blockade resulted in too little residual heart rate variability to estimate the impulse response accurately. The slope of the regression of delta RT and delta RR in the supine position was 0.0177 +/- 0.0016, which was closely correlated with the peak impulse response (r = 0.91). CONCLUSIONS: System identification techniques can assist in characterizing the cycle dependence of ventricular repolarization and may provide new insights into conditions associated with abnormal repolarization.

Sex differences in repolarization and slow delayed rectifier potassium current and their regulation by sympathetic stimulation in rabbits.

PubMed

Zhu, Yujie; Ai, Xun; Oster, Robert A; Bers, Donald M; Pogwizd, Steven M

2013-06-01

Slow delayed rectifier potassium current (IKs) is important in action potential (AP) repolarization and repolarization reserve. We tested the hypothesis that there are sex-specific differences in IKs, AP, and their regulation by β-adrenergic receptors (β-AR's) using whole-cell patch-clamp. AP duration (APD90) was significantly longer in control female (F) than in control male (M) myocytes. Isoproterenol (ISO, 500 nM) shortened APD90 comparably in M and F, and was largely reversed by β1-AR blocker CGP 20712A (CGP, 300 nM). Inhibition of IKs with chromanol 293B (10 μM) resulted in less APD prolongation in F at baseline (3.0 vs 8.9 %, p < 0.05 vs M) and even in the presence of ISO (5.4 vs 20.9 %, p < 0.05). This suggests that much of the ISO-induced APD abbreviation in F is independent of IKs. In F, baseline IKs was 42 % less and was more weakly activated by ISO (19 vs 68 % in M, p < 0.01). ISO enhancement of IKs was comparably attenuated by CGP in M and F. After ovariectomy, IKs in F had greater enhancement by ISO (72 %), now comparable to control M. After orchiectomy, IKs in M was only slightly enhanced by ISO (23 %), comparable to control F. Pretreatment with thapsigargin (to block SR Ca release) had bigger impact on ISO-induced APD shortening in F than that in M (p < 0.01). In conclusion, we found that there are sex differences in IKs, AP, and their regulation by β-AR's that are modulated by sex hormones, suggesting the potential for sex-specific antiarrhythmic therapy.

Doxycycline-induced drug fever: a case report.

PubMed

Yuan, Hai-Ling; Lu, Ning-Wei; Xie, Hua; Zheng, Yuan-Yuan; Wang, Qiu-Hong

2016-01-01

Drug fever is a febrile reaction induced by a drug without additional clinical symptoms. This adverse reaction is not rare but under diagnosed and under reported. Doxycycline is a tetracycline compound with broad-spectrum antibiotic activity. Drug fever induced by doxycycline is rarely reported. In this study, we describe a patient in whom doxycycline induced drug fever after 17 days of therapy for brucellosis.

Sleep-disordered breathing is associated with disturbed cardiac repolarization in patients with a coronary artery bypass graft surgery.

PubMed

Schmidleitner, Christina; Arzt, Michael; Tafelmeier, Maria; Ripfel, Sarah; Fauser, Miriam; Weizenegger, Teresa; Flörchinger, Bernhard; Camboni, Daniele; Wittmann, Sigrid; Zeman, Florian; Schmid, Christof; Maier, Lars S; Wagner, Stefan; Fisser, Christoph

2018-02-01

The development of malignant ventricular arrhythmias due to abnormal cardiac repolarization is a major complication after coronary artery bypass graft surgery (CABG). Sleep-disordered breathing (SDB) is linked to prolonged cardiac repolarization in non-surgical patients. This study evaluates cardiac repolarization in patients with and without SDB who underwent CABG. 100 patients who had received CABG (84% men, age 68 ± 10 years, body-mass-index [BMI] 28.7 ± 4.2 kg/m 2 ) were retrospectively evaluated. Polygraphy was recorded the night before CABG. SDB was defined as an apnea-hypopnea index (AHI) of ≥15/h and differentiated into central (CSA) and obstructive (OSA) sleep apnea. Cardiac repolarization was assessed by means of T-peak-to-end (TpTe) and QTc-intervals and TpTe/QT-ratios derived from 12-lead electrocardiography (ECG). 37% of patients had SDB, 14% CSA and 23% OSA. Before CABG, patients with CSA and OSA had longer TpTe intervals than those without SDB (TpTe: CSA 100 ± 26 vs. OSA 97 ± 19 vs. no SDB 85 ± 14 ms, p = 0.013). QTc intervals and TpTe/QT ratios differed between the two groups (QTc: 444 ± 54 vs. 462 ± 36 vs. 421 ± 32 ms, p < 0.001; TpTe/QT ratio: 0.24 ± 0.04 vs. 0.23 ± 0.05 vs. 0.21 ± 0.03, p = 0.045). SDB was associated with abnormal cardiac repolarization independent of known risk factors for cardiac arrhythmias, such as age, sex, BMI, N-terminal-pro-brain-natriuretic-peptide (NT-proBNP), and heart failure (TpTe: B-coefficient [95%CI]: 16.0, [7.6-24.3], p < 0.001; QTc: 27.2 [9.3-45.1], p = 0.003; TpTe/QT ratio: 2.9 [1.2-4.6], p < 0.001). Independent of known risk factors for cardiac arrhythmias, SDB was significantly associated with abnormal cardiac repolarization before CABG. Data suggest that SDB may contribute to an increased risk of ventricular arrhythmias after CABG. Copyright © 2018 Elsevier B.V. All rights reserved.

Adverse drug reactions induced by cardiovascular drugs in outpatients.

PubMed

Gholami, Kheirollah; Ziaie, Shadi; Shalviri, Gloria

2008-01-01

Considering increased use of cardiovascular drugs and limitations in pre-marketing trials for drug safety evaluation, post marketing evaluation of adverse drug reactions (ADRs) induced by this class of medicinal products seems necessary. To determine the rate and seriousness of adverse reactions induced by cardiovascular drugs in outpatients. To compare sex and different age groups in developing ADRs with cardiovascular agents. To assess the relationship between frequencies of ADRs and the number of drugs used. This cross-sectional study was done in cardiovascular clinic at a teaching hospital. All patients during an eight months period were evaluated for cardiovascular drugs induced ADRs. Patient and reaction factors were analyzed in detected ADRs. Patients with or without ADRs were compared in sex and age by using chi-square test. Assessing the relationship between frequencies of ADRs and the number of drugs used was done by using Pearson analysis. The total number of 518 patients was visited at the clinic. ADRs were detected in 105 (20.3%) patients. The most frequent ADRs were occurred in the age group of 51-60. The highest rate of ADRs was recorded to be induced by Diltiazem (23.5%) and the lowest rate with Atenolol (3%). Headache was the most frequent detected ADR (23%). Assessing the severity and preventability of ADRs revealed that 1.1% of ADRs were detected as severe and 1.9% as preventable reactions. Women significantly developed more ADRs in this study (chi square = 3.978, P<0.05). ADRs more frequently occurred with increasing age in this study (chi square = 15.871, P<0.05). With increasing the number of drugs used, the frequency of ADRs increased (Pearson=0.259, P<0.05). Monitoring ADRs in patients using cardiovascular drugs is a matter of importance since this class of medicines is usually used by elderly patients with critical conditions and underlying diseases.

Drug-induced seizures in children and adolescents presenting for emergency care: current and emerging trends.

PubMed

Finkelstein, Y; Hutson, J R; Freedman, S B; Wax, P; Brent, J

2013-01-01

Seizures may be the presenting manifestation of acute poisoning in children. Knowledge of the etiologic agent, or likely drug-class exposure, is crucial to minimize morbidity and optimize care. To describe the agents most commonly responsible for pediatric drug-induced seizures, whose evaluation included a medical toxicology consultation in the United States. Using the 37 participating sites of the Toxicology Investigators Consortium (ToxIC) Case Registry, a cross-country surveillance tool, we conducted an observational study of a prospectively collected cohort. We identified all pediatric (younger than 18 years) reports originating from an Emergency Department (ED) which included a chemical or drug-induced seizure, and required a medical toxicology consultation between April 1, 2010 and March 31, 2012. Results. We identified 142 pediatric drug-induced seizure cases (56% male), which represent nearly 5% of pediatric cases requiring bedside consultation by medical toxicologists. One-hundred and seven cases (75%) occurred in children aged 13-18 years, and 86 (61%) resulted from intentional ingestions. Antidepressants were the most commonly identified agents ingested (n = 61; 42%), of which bupropion was the leading drug (n = 30; 50% of antidepressants), followed by anticholinergics/antihistamines (n = 31; 22%). All antidepressant-induced seizures in teenagers were intentional and represented self-harm behavior. Sympathomimetic agents, including street drugs, represent the most common agents in children younger than 2 years (n = 4/19). Antidepressants, and specifically bupropion, are presently the most common medications responsible for pediatric drug-induced seizures requiring medical toxicology consultation in the United States. In teenagers presenting with new-onset seizures of unknown etiology, the possibility of deliberate self-poisoning should be explored, since most drug-induced seizures in this age group resulted from intentional ingestion.

Role of dermatology in pharmacogenomics: drug-induced skin injury.

PubMed

Borroni, Riccardo G

2015-01-01

Different individuals may respond diversely to the same drug, in terms of efficacy and toxicity. Adverse drug reactions cause about 6% of all hospital admissions and account for up to 9% of hospitalization costs. Drug-induced skin injury (DISI) is the most common presentation of adverse drug reactions, ranging from maculopapular eruptions to severe adverse cutaneous drug reactions (SCARs) with mortality of up to 40%. Specific genetic polymorphisms confer susceptibility to different types of DISI. Identifying patients genetically at risk for SCARs is one of the goals of pharmacogenomics. In this article, the aspects of clinical dermatology relevant to the pharmacogenetics of DISI are reviewed. Many SCARs are now preventable, with consequent reduction of morbidity, mortality and healthcare costs.

Repolarization of hepatocytes in culture.

PubMed

Talamini, M A; Kappus, B; Hubbard, A

1997-01-01

We have evaluated the biochemical, morphological, and functional redevelopment of polarity in freshly isolated hepatocytes cultured using a double layer collagen gel sandwich technique. Western blot analysis showed increased cellular levels of the cell adhesion protein uvomorulin as cultured hepatocytes repolarized. Immunofluorescence studies using antibodies against domain-specific membrane proteins showed polarity as early as 48 hours, although the pattern of the polymeric Immunoglobulin-A receptor (pIgA-R) differed from in vivo liver. Electron microscopy showed developing bile canaliculi at 1 day. However, the functional presence of tight junctions was absent at 1 day, but present at 5 days. We further showed functional polarity to be present at 4 days by documenting the ability of cultured hepatocytes to metabolize and excrete fluorescein diacetate into visible bile canaliculi. We conclude that hepatocytes cultured appropriately develop morphological and functional polarity. Hepatocyte culture is therefore a useful tool for the study of mechanisms responsible for the development of polarized function.

[Machine Learning-based Prediction of Seizure-inducing Action as an Adverse Drug Effect].

PubMed

Gao, Mengxuan; Sato, Motoshige; Ikegaya, Yuji

2018-01-01

　During the preclinical research period of drug development, animal testing is widely used to help screen out a drug's dangerous side effects. However, it remains difficult to predict side effects within the central nervous system. Here, we introduce a machine learning-based in vitro system designed to detect seizure-inducing side effects before clinical trial. We recorded local field potentials from the CA1 alveus in acute mouse neocortico-hippocampal slices that were bath-perfused with each of 14 different drugs, and at 5 different concentrations of each drug. For each of these experimental conditions, we collected seizure-like neuronal activity and merged their waveforms as one graphic image, which was further converted into a feature vector using Caffe, an open framework for deep learning. In the space of the first two principal components, the support vector machine completely separated the vectors (i.e., doses of individual drugs) that induced seizure-like events, and identified diphenhydramine, enoxacin, strychnine and theophylline as "seizure-inducing" drugs, which have indeed been reported to induce seizures in clinical situations. Thus, this artificial intelligence-based classification may provide a new platform to pre-clinically detect seizure-inducing side effects of drugs.

Repurposed drug screen identifies cardiac glycosides as inhibitors of TGF-β-induced cancer-associated fibroblast differentiation.

PubMed

Coleman, David T; Gray, Alana L; Stephens, Charles A; Scott, Matthew L; Cardelli, James A

2016-05-31

The tumor microenvironment, primarily composed of myofibroblasts, directly influences the progression of solid tumors. Through secretion of growth factors, extracellular matrix deposition, and contractile mechanotransduction, myofibroblasts, or cancer-associated fibroblasts (CAFs), support angiogenesis and cancer cell invasion and metastasis. The differentiation of fibroblasts to CAFs is primarily induced by TGF-β from cancer cells. To discover agents capable of blocking CAF differentiation, we developed a high content immunofluorescence-based assay to screen repurposed chemical libraries utilizing fibronectin expression as an initial CAF marker. Screening of the Prestwick chemical library and NIH Clinical Collection repurposed drug library, totaling over 1700 compounds, identified cardiac glycosides as particularly potent CAF blocking agents. Cardiac glycosides are traditionally used to regulate intracellular calcium by inhibiting the Na+/K+ ATPase to control cardiac contractility. Herein, we report that multiple cardiac glycoside compounds, including digoxin, are able to inhibit TGF-β-induced fibronectin expression at low nanomolar concentrations without undesirable cell toxicity. We found this inhibition to hold true for multiple fibroblast cell lines. Using real-time qPCR, we determined that digoxin prevented induction of multiple CAF markers. Furthermore, we report that digoxin is able to prevent TGF-β-induced fibroblast contraction of extracellular matrix, a major phenotypic consequence of CAF differentiation. Assessing the mechanism of inhibition, we found digoxin reduced SMAD promoter activity downstream of TGF-β, and we provide data that the effect is through inhibition of its known target, the Na+/K+ ATPase. These findings support a critical role for calcium signaling during CAF differentiation and highlight a novel, repurposable modality for cancer therapy.

A drug repositioning approach identifies tricyclic antidepressants as inhibitors of small cell lung cancer and other neuroendocrine tumors

PubMed Central

Jahchan, Nadine S; Dudley, Joel T; Mazur, Pawel K; Flores, Natasha; Yang, Dian; Palmerton, Alec; Zmoos, Anne-Flore; Vaka, Dedeepya; Tran, Kim QT; Zhou, Margaret; Krasinska, Karolina; Riess, Jonathan W; Neal, Joel W; Khatri, Purvesh; Park, Kwon S; Butte, Atul J; Sage, Julien

2013-01-01

Small cell lung cancer (SCLC) is an aggressive neuroendocrine subtype of lung cancer with high mortality. We used a systematic drug-repositioning bioinformatics approach querying a large compendium of gene expression profiles to identify candidate FDA-approved drugs to treat SCLC. We found that tricyclic antidepressants and related molecules potently induce apoptosis in both chemonaïve and chemoresistant SCLC cells in culture, in mouse and human SCLC tumors transplanted into immunocompromised mice, and in endogenous tumors from a mouse model for human SCLC. The candidate drugs activate stress pathways and induce cell death in SCLC cells, at least in part by disrupting autocrine survival signals involving neurotransmitters and their G protein-coupled receptors. The candidate drugs inhibit the growth of other neuroendocrine tumors, including pancreatic neuroendocrine tumors and Merkel cell carcinoma. These experiments identify novel targeted strategies that can be rapidly evaluated in patients with neuroendocrine tumors through the repurposing of approved drugs. PMID:24078773

Cardiac repolarization during fingolimod treatment in patients with relapsing-remitting multiple sclerosis.

PubMed

Laiho, Aapo; Laitinen, Tiina M; Hartikainen, Päivi; Hartikainen, Juha E K; Laitinen, Tomi P; Simula, Sakari

2018-02-01

Fingolimod is a sphingosine-1-phosphate receptor modulator for the treatment of relapsing-remitting multiple sclerosis (RRMS). Despite an established effect on heart rate, the effect of fingolimod on cardiac repolarization is not completely known. Twenty-seven patients with RRMS underwent 24-hr ambulatory ECG before fingolimod (baseline), at the day of fingolimod initiation (1D) and after three-month treatment (3M). The mean values of RR-interval as well as QT-interval corrected by Bazzet's (QTcBaz) and Fridericia's (QTcFri) formula were compared between baseline, 1D, and 3M over 24-hr period as well as at daytime and nighttime. QTcBaz over 24-hr was shorter at 1D (414 ± 20 ms, p  < .001) and at 3M (414 ± 20 ms, p  < .001) than at baseline (418 ± 20 ms). In contrast, QTcFri over 24-hr was longer at 1D (410 ± 19 ms, p  < .001) but similar at 3M (406 ± 19 ms, p  = .355) compared to baseline (407 ± 19 ms). Daytime QTcBaz was shorter at 1D ( p  < .001) and at 3M ( p  = .007), whereas daytime QTcFri was longer at 1D ( p  < .05) but similar at 3M ( p  = ns) compared to baseline. During the night, changes were observed neither in QTcBaz nor in QTcFri between baseline, 1D, and 3M. Changes in cardiac repolarization after fingolimod initiation were mild and occurred at daytime. Ambiguously, QTcBaz demonstrated shortening, whereas QTcFri showed prolongation in cardiac repolarization after fingolimod initiation. The formula applied for QT-interval correction needs to be taken carefully into account as evaluating pharmacovigilance issues related to fingolimod.

Drug-induced gynecomastia.

PubMed

Eckman, Ari; Dobs, Adrian

2008-11-01

Gynecomastia is caused by drugs in 10 - 25% of all cases. The pathophysiologic mechanism for some drugs includes exogenous estrogens exposure, medications that cause hypogonadism, anti-androgenic effects and hyperprolactinemia. This manuscript reviews common examples of drug-induced gynecomastia, discussing the mechanisms and possible treatments. Discontinuing the medication is always the best choice; however, if this is not possible, then testosterone replacement therapy may be needed for hypogonadism. When a man is euogonadal, a trial of the anti-estrogen, tamoxifen or an aromatase inhibitor may be an option.

DITOP: drug-induced toxicity related protein database.

PubMed

Zhang, Jing-Xian; Huang, Wei-Juan; Zeng, Jing-Hua; Huang, Wen-Hui; Wang, Yi; Zhao, Rui; Han, Bu-Cong; Liu, Qing-Feng; Chen, Yu-Zong; Ji, Zhi-Liang

2007-07-01

Drug-induced toxicity related proteins (DITRPs) are proteins that mediate adverse drug reactions (ADRs) or toxicities through their binding to drugs or reactive metabolites. Collection of these proteins facilitates better understanding of the molecular mechanisms of drug-induced toxicity and the rational drug discovery. Drug-induced toxicity related protein database (DITOP) is such a database that is intending to provide comprehensive information of DITRPs. Currently, DITOP contains 1501 records, covering 618 distinct literature-reported DITRPs, 529 drugs/ligands and 418 distinct toxicity terms. These proteins were confirmed experimentally to interact with drugs or their reactive metabolites, thus directly or indirectly cause adverse effects or toxicities. Five major types of drug-induced toxicities or ADRs are included in DITOP, which are the idiosyncratic adverse drug reactions, the dose-dependent toxicities, the drug-drug interactions, the immune-mediated adverse drug effects (IMADEs) and the toxicities caused by genetic susceptibility. Molecular mechanisms underlying the toxicity and cross-links to related resources are also provided while available. Moreover, a series of user-friendly interfaces were designed for flexible retrieval of DITRPs-related information. The DITOP can be accessed freely at http://bioinf.xmu.edu.cn/databases/ADR/index.html. Supplementary data are available at Bioinformatics online.

Drug-induced liver injury due to antimicrobials, central nervous system agents, and nonsteroidal anti-inflammatory drugs.

PubMed

Devarbhavi, Harshad; Andrade, Raúl J

2014-05-01

Antimicrobial agents including antituberculosis (anti-TB) agents are the most common cause of idiosyncratic drug-induced liver injury (DILI) and drug-induced liver failure across the world. Better molecular and genetic biomarkers are acutely needed to help identify those at risk of liver injury particularly for those needing antituberculosis therapy. Some antibiotics such as amoxicillin-clavulanate and isoniazid consistently top the lists of agents in retrospective and prospective DILI databases. Central nervous system agents, particularly antiepileptics, account for the second most common class of agents implicated in DILI registries. Hepatotoxicity from older antiepileptics such as carbamazepine, phenytoin, and phenobarbital are often associated with hypersensitivity features, whereas newer antiepileptic drugs have a more favorable safety profile. Antidepressants and nonsteroidal anti-inflammatory drugs carry very low risk of significant liver injury, but their prolific use make them important causes of DILI. Early diagnosis and withdrawal of the offending agent remain the mainstays of minimizing hepatotoxicity. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

On the Cellular and Molecular Mechanisms of Drug-Induced Gingival Overgrowth

PubMed Central

Ramírez-Rámiz, Albert; Brunet-LLobet, Lluís; Lahor-Soler, Eduard; Miranda-Rius, Jaume

2017-01-01

Introduction: Gingival overgrowth has been linked to multiple factors such as adverse drug effects, inflammation, neoplastic processes, and hereditary gingival fibromatosis. Drug-induced gingival overgrowth is a well-established adverse event. In early stages, this gingival enlargement is usually located in the area of the interdental papilla. Histologically, there is an increase in the different components of the extracellular matrix. Objective: The aim of this manuscript is to describe and analyze the different cellular and molecular agents involved in the pathogenesis of Drug-induced gingival overgrowth. Method: A literature search of the MEDLINE/PubMed database was conducted to identify the mechanisms involved in the process of drug-induced gingival overgrowth, with the assistance of a research librarian. We present several causal hypotheses and discuss the advances in the understanding of the mechanisms that trigger this gingival alteration. Results: In vitro studies have revealed phenotypic cellular changes in keratinocytes and fibroblasts and an increase of the extracellular matrix with collagen and glycosaminoglycans. Drug-induced gingival overgrowth confirms the key role of collagenase and integrins, membrane receptors present in the fibroblasts, due to their involvement in the catabolism of collagen. The three drug categories implicated: calcineuron inhibitors (immunosuppressant drugs), calcium channel blocking agents and anticonvulsant drugs appear to present a multifactorial pathogenesis with a common molecular action: the blockage of the cell membrane in the Ca2+/Na+ ion flow. The alteration of the uptake of cellular folic acid, which depends on the regulated channels of active cationic transport and on passive diffusion, results in a dysfunctional degradation of the connective tissue. Certain intermediate molecules such as cytokines and prostaglandins play a role in this pathological mechanism. The concomitant inflammatory factor encourages the

Characterization of ventricular depolarization and repolarization changes in a porcine model of myocardial infarction.

PubMed

Romero, Daniel; Ringborn, Michael; Demidova, Marina; Koul, Sasha; Laguna, Pablo; Platonov, Pyotr G; Pueyo, Esther

2012-12-01

In this study, several electrocardiogram (ECG)-derived indices corresponding to both ventricular depolarization and repolarization were evaluated during acute myocardial ischemia in an experimental model of myocardial infarction produced by 40 min coronary balloon inflation in 13 pigs. Significant changes were rapidly observed from minute 4 after the start of coronary occlusion, achieving their maximum values between 11 and 22 min for depolarization and between 9 and 12 min for repolarization indices, respectively. Subsequently, these maximum changes started to decrease during the latter part of the occlusion. Depolarization changes associated with the second half of the QRS complex showed a significant but inverse correlation with the myocardium at risk (MaR) estimated by scintigraphic images. The correlation between MaR and changes of the downward slope of the QRS complex, [Formula: see text], evaluated at the two more relevant peaks observed during the occlusion, was r = -0.75, p < 0.01 and r = -0.79, p < 0.01 for the positive and negative deflections observed in [Formula: see text], temporal evolution, respectively. Repolarization changes, analyzed by evaluation of ST segment elevation at the main observed positive peak, also showed negative, however non-significant correlation with MaR: r = -0.34, p = 0.28. Our results suggest that changes evaluated in the latter part of the depolarization, such as those described by [Formula: see text], which are influenced by R-wave amplitude, QRS width and ST level variations simultaneously, correlate better with the amount of ischemia than other indices evaluated in the earlier part of depolarization or during the ST segment.

Machine learning-based prediction of adverse drug effects: An example of seizure-inducing compounds.

PubMed

Gao, Mengxuan; Igata, Hideyoshi; Takeuchi, Aoi; Sato, Kaoru; Ikegaya, Yuji

2017-02-01

Various biological factors have been implicated in convulsive seizures, involving side effects of drugs. For the preclinical safety assessment of drug development, it is difficult to predict seizure-inducing side effects. Here, we introduced a machine learning-based in vitro system designed to detect seizure-inducing side effects. We recorded local field potentials from the CA1 alveus in acute mouse neocortico-hippocampal slices, while 14 drugs were bath-perfused at 5 different concentrations each. For each experimental condition, we collected seizure-like neuronal activity and merged their waveforms as one graphic image, which was further converted into a feature vector using Caffe, an open framework for deep learning. In the space of the first two principal components, the support vector machine completely separated the vectors (i.e., doses of individual drugs) that induced seizure-like events and identified diphenhydramine, enoxacin, strychnine and theophylline as "seizure-inducing" drugs, which indeed were reported to induce seizures in clinical situations. Thus, this artificial intelligence-based classification may provide a new platform to detect the seizure-inducing side effects of preclinical drugs. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Drug-Induced Dental Caries: A Disproportionality Analysis Using Data from VigiBase.

PubMed

de Campaigno, Emilie Patras; Kebir, Inès; Montastruc, Jean-Louis; Rueter, Manuela; Maret, Delphine; Lapeyre-Mestre, Maryse; Sallerin, Brigitte; Despas, Fabien

2017-12-01

Dental caries is defined as a pathological breakdown of the tooth. It is an infectious phenomenon involving a multifactorial aetiology. The impact of drugs on cariogenic risk has been poorly investigated. In this study, we identified drugs suspected to induce dental caries as adverse drug reactions (ADRs) and then studied a possible pathogenic mechanism for each drug that had a statistically significant disproportionality. We extracted individual case safety reports of dental caries associated with drugs from VigiBase ® (the World Health Organization global individual case safety report database). We calculated disproportionality for each drug with a reporting odds ratio (ROR) and 99% confidence interval. We analysed the pharmacodynamics of each drug that had a statistically significant disproportionality. In VigiBase ® , 5229 safety reports for dental caries concerning 733 drugs were identified. Among these drugs, 88 had a significant ROR, and for 65 of them (73.9%), no information about dental caries was found in the summaries of the product characteristics, the Micromedex ® DRUGDEX, or the Martindale databases. Regarding the pharmacological classes of drugs involved in dental caries, we identified bisphosphonates, atropinic drugs, antidepressants, corticoids, immunomodulating drugs, antipsychotics, antiepileptics, opioids and β 2 -adrenoreceptor agonist drugs. Regarding possible pathogenic mechanisms for these drugs, we identified changes in salivary flow/composition for 54 drugs (61.4%), bone metabolism changes for 31 drugs (35.2%), hyperglycaemia for 32 drugs (36.4%) and/or immunosuppression for 23 drugs (26.1%). For nine drugs (10.2%), the mechanism was unclear. We identified 88 drugs with a significant positive disproportionality for dental caries. Special attention has to be paid to bisphosphonates, atropinic drugs, immunosuppressants and drugs causing hyperglycaemia.

A review and assessment of drug-induced parotitis.

PubMed

Brooks, Krista G; Thompson, Dennis F

2012-12-01

To review the current literature on drug-induced parotitis. Literature was accessed through MEDLINE/PubMed (1980-May 2012), using the search terms sialadenitis/chemically induced and parotitis/chemically induced. EMBASE (1980-May 2012) was searched using the terms parotitis/diagnosis, sialadenitis/side effect, and parotitis/side effect. International Pharmaceutical Abstracts (1970-May 2012) was searched using the search terms parotitis and sialadenitis. All searches were limited to articles on humans written in English. Inclusion criteria were published letters, case reports, reviews, and clinical trials involving drugs that may be associated with parotitis. Articles pertaining to parotitis induced by iodine-containing drugs were excluded. References of all relevant articles were reviewed for additional citations. Review articles, clinical trials, background data, and case reports of drug-induced parotitis were collected and case reports were assessed for causality. Parotitis is an uncommon adverse effect; however, signs and symptoms of parotitis have been noted in case reports as an adverse drug reaction related to various medications. Assessing causality of an adverse drug reaction such as parotitis is challenging. To help determine the probability of causality for these events, algorithms such as the Naranjo probability scale have been developed. Eighty-four case reports of drug-induced parotitis from 40 different drugs were reviewed using a modified Naranjo probability scale that included criteria specific for parotitis. Medications that met the criteria for establishing causality included l-asparaginase with 7 case reports, clozapine with 13 case reports, and phenylbutazone with 13 case reports. Drug-induced parotitis is a rare adverse drug reaction. Based on the quantitative and qualitative evidence collected from the case reports, medications that are associated with drug-induced parotitis include l-asparaginase, clozapine, and phenylbutazone. Many other

Electrophysiological determinants of hypokalaemia-induced arrhythmogenicity in the guinea-pig heart.

PubMed

Osadchii, O E; Olesen, S P

2009-12-01

Hypokalaemia is an independent risk factor contributing to arrhythmic death in cardiac patients. In the present study, we explored the mechanisms of hypokalaemia-induced tachyarrhythmias by measuring ventricular refractoriness, spatial repolarization gradients, and ventricular conduction time in isolated, perfused guinea-pig heart preparations. Epicardial and endocardial monophasic action potentials from distinct left ventricular (LV) and right ventricular (RV) recording sites were monitored simultaneously with volume-conducted electrocardiogram (ECG) during steady-state pacing and following a premature extrastimulus application at progressively reducing coupling stimulation intervals in normokalaemic and hypokalaemic conditions. Hypokalaemic perfusion (2.5 mm K(+) for 30 min) markedly increased the inducibility of tachyarrhythmias by programmed ventricular stimulation and rapid pacing, prolonged ventricular repolarization and shortened LV epicardial and endocardial effective refractory periods, thereby increasing the critical interval for LV re-excitation. Hypokalaemia increased the RV-to-LV transepicardial repolarization gradients but had no effect on transmural dispersion of APD(90) and refractoriness across the LV wall. As determined by local activation time recordings, the LV-to-RV transepicardial conduction and the LV transmural (epicardial-to-endocardial) conduction were slowed in hypokalaemic heart preparations. This change was attributed to depressed diastolic excitability as evidenced by increased ventricular pacing thresholds. These findings suggest that hypokalaemia-induced arrhythmogenicity is attributed to shortened LV refractoriness, increased critical intervals for LV re-excitation, amplified RV-to-LV transepicardial repolarization gradients and slowed ventricular conduction in the guinea-pig heart.

Coronary Artery Disease Alters Ventricular Repolarization Dynamics in Type 2 Diabetes

NASA Technical Reports Server (NTRS)

Vrtovec, Bojan; Sinkovec, Matjaz; Starc, Vito; Radovancevic, Branislav; Schlegel, Todd T.

2005-01-01

Ventricular repolarization dynamics (VRD) is an important predictor of outcome in diabetes. We examined the potential impact of coronary artery disease (CAD) on VRD in type 2 diabetic patients. We recorded 5-min high-resolution resting electrocardiograms (ECG) in 38 diabetic patients undergoing elective coronary angiography, and in 38 age- and gender- matched apparently healthy subjects (Controls). Using leads I and II, time-domain indices of VRD were calculated. Coronary angiography was regarded as positive if a 350% stenosis was found. Angiography was positive in 21 diabetic patients (55%). Patients with CAD had a significantly higher degree of VRD than Controls (SDNN(QT): 15.81+/-7.22 ms vs. 8.94+/-6.04 ms; P <0.001, rMSSD(QT): 21.02k7.07 ms vs. 11.18k7.45 ms; P <0.001). VRD in diabetic patients with negative angiograms did not differ from VRD in Controls (SDNN(QT): 8.94+/-6.04 ms vs. 7.44+/-5.72 ms; P=0.67, rMSSD(QT): 11.18+/-7.45 ms vs. 10.22+/-5.35 ms; P=O. 82). CAD increases VRD in patients with type 2 diabetes. Therefore, changes in ventricular repolarization in diabetic patients may be due to silent CAD rather than to diabetes per se.

HLA Association with Drug-Induced Adverse Reactions

PubMed Central

Fan, Wen-Lang; Shiao, Meng-Shin; Hui, Rosaline Chung-Yee; Wang, Chuang-Wei; Chang, Ya-Ching

2017-01-01

Adverse drug reactions (ADRs) remain a common and major problem in healthcare. Severe cutaneous adverse drug reactions (SCARs), such as Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) with mortality rate ranges from 10% to more than 30%, can be life threatening. A number of recent studies demonstrated that ADRs possess strong genetic predisposition. ADRs induced by several drugs have been shown to have significant associations with specific alleles of human leukocyte antigen (HLA) genes. For example, hypersensitivity to abacavir, a drug used for treating of human immunodeficiency virus (HIV) infection, has been proposed to be associated with allele 57:01 of HLA-B gene (terms HLA-B∗57:01). The incidences of abacavir hypersensitivity are much higher in Caucasians compared to other populations due to various allele frequencies in different ethnic populations. The antithyroid drug- (ATDs- ) induced agranulocytosis are strongly associated with two alleles: HLA-B∗38:02 and HLA-DRB1∗08:03. In addition, HLA-B∗15:02 allele was reported to be related to carbamazepine-induced SJS/TEN, and HLA-B∗57:01 in abacavir hypersensitivity and flucloxacillin induced drug-induced liver injury (DILI). In this review, we summarized the alleles of HLA genes which have been proposed to have association with ADRs caused by different drugs. PMID:29333460

Metabolic activation of hepatotoxic drug (benzbromarone) induced mitochondrial membrane permeability transition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shirakawa, Maho; Sekine, Shuichi; Tanaka, Ayaka

The risk of drug-induced liver injury (DILI) is of great concern to the pharmaceutical industry. It is well-known that metabolic activation of drugs to form toxic metabolites (TMs) is strongly associated with DILI onset. Drug-induced mitochondrial dysfunction is also strongly associated with increased risk of DILI. However, it is difficult to determine the target of TMs associated with exacerbation of DILI because of difficulties in identifying and purifying TMs. In this study, we propose a sequential in vitro assay system to assess TM formation and their ability to induce mitochondrial permeability transition (MPT) in a one-pot process. In this assaymore » system, freshly-isolated rat liver mitochondria were incubated with reaction solutions of 44 test drugs preincubated with liver microsomes in the presence or absence of NADPH; then, NADPH-dependent MPT pore opening was assessed as mitochondrial swelling. In this assay system, several hepatotoxic drugs, including benzbromarone (BBR), significantly induced MPT in a NADPH-dependent manner. We investigated the rationality of using BBR as a model drug, since it showed the most prominent MPT in our assay system. Both the production of a candidate toxic metabolite of BBR (1′,6-(OH){sub 2} BBR) and NADPH-dependent MPT were inhibited by several cytochrome P450 (CYP) inhibitors (clotrimazole and SKF-525A, 100 μM). In summary, this assay system can be used to evaluate comprehensive metabolite-dependent MPT without identification or purification of metabolites. - Highlights: • We constructed a sequential assay system for toxic metabolite induced MPT in one pot. • 14 drugs (e.g. benzbromarone (BBR)) induced toxic metabolite dependent MPT. • Both the production of toxic metabolite and MPT could be inhibited by CYP inhibitors. • This system could evaluate the comprehensive MPT without purification of metabolites.« less

Rationale, objectives, and design of the EUTrigTreat clinical study: a prospective observational study for arrhythmia risk stratification and assessment of interrelationships among repolarization markers and genotype

PubMed Central

Seegers, Joachim; Vos, Marc A.; Flevari, Panagiota; Willems, Rik; Sohns, Christian; Vollmann, Dirk; Lüthje, Lars; Kremastinos, Dimitrios T.; Floré, Vincent; Meine, Mathias; Tuinenburg, Anton; Myles, Rachel C.; Simon, Dirk; Brockmöller, Jürgen; Friede, Tim; Hasenfuß, Gerd; Lehnart, Stephan E.; Zabel, Markus

2012-01-01

Aims The EUTrigTreat clinical study has been designed as a prospective multicentre observational study and aims to (i) risk stratify patients with an implantable cardioverter defibrillator (ICD) for mortality and shock risk using multiple novel and established risk markers, (ii) explore a link between repolarization biomarkers and genetics of ion (Ca2+, Na+, K+) metabolism, (iii) compare the results of invasive and non-invasive electrophysiological (EP) testing, (iv) assess changes of non-invasive risk stratification tests over time, and (v) associate arrythmogenomic risk through 19 candidate genes. Methods and results Patients with clinical ICD indication are eligible for the trial. Upon inclusion, patients will undergo non-invasive risk stratification, including beat-to-beat variability of repolarization (BVR), T-wave alternans, T-wave morphology variables, ambient arrhythmias from Holter, heart rate variability, and heart rate turbulence. Non-invasive or invasive programmed electrical stimulation will assess inducibility of ventricular arrhythmias, with the latter including recordings of monophasic action potentials and assessment of restitution properties. Established candidate genes are screened for variants. The primary endpoint is all-cause mortality, while one of the secondary endpoints is ICD shock risk. A mean follow-up of 3.3 years is anticipated. Non-invasive testing will be repeated annually during follow-up. It has been calculated that 700 patients are required to identify risk predictors of the primary endpoint, with a possible increase to 1000 patients based on interim risk analysis. Conclusion The EUTrigTreat clinical study aims to overcome current shortcomings in sudden cardiac death risk stratification and to answer several related research questions. The initial patient recruitment is expected to be completed in July 2012, and follow-up is expected to end in September 2014. Clinicaltrials.gov identifier: NCT01209494. PMID:22117037

Short-term action potential memory and electrical restitution: A cellular computational study on the stability of cardiac repolarization under dynamic pacing

PubMed Central

2018-01-01

Electrical restitution (ER) is a major determinant of repolarization stability and, under fast pacing rate, it reveals memory properties of the cardiac action potential (AP), whose dynamics have never been fully elucidated, nor their ionic mechanisms. Previous studies have looked at ER mainly in terms of changes in AP duration (APD) when the preceding diastolic interval (DI) changes and described dynamic conditions where this relationship shows hysteresis which, in turn, has been proposed as a marker of short-term AP memory and repolarization stability. By means of numerical simulations of a non-propagated human ventricular AP, we show here that measuring ER as APD versus the preceding cycle length (CL) provides additional information on repolarization dynamics which is not contained in the companion formulation. We focus particularly on fast pacing rate conditions with a beat-to-beat variable CL, where memory properties emerge from APD vs CL and not from APD vs DI and should thus be stored in APD and not in DI. We provide an ion-currents characterization of such conditions under periodic and random CL variability, and show that the memory stored in APD plays a stabilizing role on AP repolarization under pacing rate perturbations. The gating kinetics of L-type calcium current seems to be the main determinant of this safety mechanism. We also show that, at fast pacing rate and under otherwise identical pacing conditions, a periodically beat-to-beat changing CL is more effective than a random one in stabilizing repolarization. In summary, we propose a novel view of short-term AP memory, differentially stored between systole and diastole, which opens a number of methodological and theoretical implications for the understanding of arrhythmia development. PMID:29494628

Potential candidate genomic biomarkers of drug induced vascular injury in the rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dalmas, Deidre A., E-mail: Deidre.A.Dalmas@gsk.com; Scicchitano, Marshall S., E-mail: Marshall.S.Scicchitano@gsk.com; Mullins, David, E-mail: David.R.Mullins@gsk.com

2011-12-15

Drug-induced vascular injury is frequently observed in rats but the relevance and translation to humans present a hurdle for drug development. Numerous structurally diverse pharmacologic agents have been shown to induce mesenteric arterial medial necrosis in rats, but no consistent biomarkers have been identified. To address this need, a novel strategy was developed in rats to identify genes associated with the development of drug-induced mesenteric arterial medial necrosis. Separate groups (n = 6/group) of male rats were given 28 different toxicants (30 different treatments) for 1 or 4 days with each toxicant given at 3 different doses (low, mid andmore » high) plus corresponding vehicle (912 total rats). Mesentery was collected, frozen and endothelial and vascular smooth muscle cells were microdissected from each artery. RNA was isolated, amplified and Affymetrix GeneChip Registered-Sign analysis was performed on selectively enriched samples and a novel panel of genes representing those which showed a dose responsive pattern for all treatments in which mesenteric arterial medial necrosis was histologically observed, was developed and verified in individual endothelial cell- and vascular smooth muscle cell-enriched samples. Data were confirmed in samples containing mesentery using quantitative real-time RT-PCR (TaqMan Trade-Mark-Sign ) gene expression profiling. In addition, the performance of the panel was also confirmed using similarly collected samples obtained from a timecourse study in rats given a well established vascular toxicant (Fenoldopam). Although further validation is still required, a novel gene panel has been developed that represents a strategic opportunity that can potentially be used to help predict the occurrence of drug-induced mesenteric arterial medial necrosis in rats at an early stage in drug development. -- Highlights: Black-Right-Pointing-Pointer A gene panel was developed to help predict rat drug-induced mesenteric MAN. Black

Hepatocyte-based in vitro model for assessment of drug-induced cholestasis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chatterjee, Sagnik, E-mail: Sagnik.Chatterjee@pharm.kuleuven.be; Richert, Lysiane, E-mail: l.richert@kaly-cell.com; Augustijns, Patrick, E-mail: Patrick.Augustijns@pharm.kuleuven.be

Early detection of drug-induced cholestasis remains a challenge during drug development. We have developed and validated a biorelevant sandwich-cultured hepatocytes- (SCH) based model that can identify compounds causing cholestasis by altering bile acid disposition. Human and rat SCH were exposed (24–48 h) to known cholestatic and/or hepatotoxic compounds, in the presence or in the absence of a concentrated mixture of bile acids (BAs). Urea assay was used to assess (compromised) hepatocyte functionality at the end of the incubations. The cholestatic potential of the compounds was expressed by calculating a drug-induced cholestasis index (DICI), reflecting the relative residual urea formation bymore » hepatocytes co-incubated with BAs and test compound as compared to hepatocytes treated with test compound alone. Compounds with clinical reports of cholestasis, including cyclosporin A, troglitazone, chlorpromazine, bosentan, ticlopidine, ritonavir, and midecamycin showed enhanced toxicity in the presence of BAs (DICI ≤ 0.8) for at least one of the tested concentrations. In contrast, the in vitro toxicity of compounds causing hepatotoxicity by other mechanisms (including diclofenac, valproic acid, amiodarone and acetaminophen), remained unchanged in the presence of BAs. A safety margin (SM) for drug-induced cholestasis was calculated as the ratio of lowest in vitro concentration for which was DICI ≤ 0.8, to the reported mean peak therapeutic plasma concentration. SM values obtained in human SCH correlated well with reported % incidence of clinical drug-induced cholestasis, while no correlation was observed in rat SCH. This in vitro model enables early identification of drug candidates causing cholestasis by disturbed BA handling. - Highlights: • Novel in vitro assay to detect drug-induced cholestasis • Rat and human sandwich-cultured hepatocytes (SCH) as in vitro models • Cholestatic compounds sensitize SCH to toxic effects of accumulating bile acids �

Genomes2Drugs: Identifies Target Proteins and Lead Drugs from Proteome Data

PubMed Central

Toomey, David; Hoppe, Heinrich C.; Brennan, Marian P.; Nolan, Kevin B.; Chubb, Anthony J.

2009-01-01

Background Genome sequencing and bioinformatics have provided the full hypothetical proteome of many pathogenic organisms. Advances in microarray and mass spectrometry have also yielded large output datasets of possible target proteins/genes. However, the challenge remains to identify new targets for drug discovery from this wealth of information. Further analysis includes bioinformatics and/or molecular biology tools to validate the findings. This is time consuming and expensive, and could fail to yield novel drugs if protein purification and crystallography is impossible. To pre-empt this, a researcher may want to rapidly filter the output datasets for proteins that show good homology to proteins that have already been structurally characterised or proteins that are already targets for known drugs. Critically, those researchers developing novel antibiotics need to select out the proteins that show close homology to any human proteins, as future inhibitors are likely to cross-react with the host protein, causing off-target toxicity effects later in clinical trials. Methodology/Principal Findings To solve many of these issues, we have developed a free online resource called Genomes2Drugs which ranks sequences to identify proteins that are (i) homologous to previously crystallized proteins or (ii) targets of known drugs, but are (iii) not homologous to human proteins. When tested using the Plasmodium falciparum malarial genome the program correctly enriched the ranked list of proteins with known drug target proteins. Conclusions/Significance Genomes2Drugs rapidly identifies proteins that are likely to succeed in drug discovery pipelines. This free online resource helps in the identification of potential drug targets. Importantly, the program further highlights proteins that are likely to be inhibited by FDA-approved drugs. These drugs can then be rapidly moved into Phase IV clinical studies under ‘change-of-application’ patents. PMID:19593435

Risperidone prolongs cardiac repolarization by blocking the rapid component of the delayed rectifier potassium current.

PubMed

Drolet, Benoit; Yang, Tao; Daleau, Pascal; Roden, Dan M; Turgeon, Jacques

2003-06-01

Cases of QT prolongation and sudden death have been reported with risperidone, a neuroleptic agent increasingly prescribed worldwide. Although hypokalemia was present in some of these events, we hypothesized that risperidone may have unsuspected electrophysiologic effects predisposing patients to proarrhythmia. In six isolated guinea pig hearts, risperidone elicited prolongation of cardiac repolarization: action potential duration increased from a baseline value of 128 ms +/- 5 to 147 ms +/- 5 (15%) with risperidone 1 microM during pacing at 250-ms cycle length, whereas the increase was only 10%, from 101 ms +/- 2 to 111 ms +/- 4, with pacing at a cycle length of 150 ms. In human ether-a-go-go (HERG)-transfected Chinese hamster ovary cells (n = 16), risperidone caused concentration-dependent block of the rapid component (I(Kr)) of the delayed rectifier potassium current with an IC(50) for tail block of 261 nM. Risperidone did not block I(Ks). Risperidone exerts cardiac electrophysiologic effects similar to those of Class III antiarrhythmic drugs. These effects are observed at clinically relevant concentrations. Because risperidone is metabolized primarily by CYP2D6, these actions likely enhance risk for risperidone-related QT prolongation and proarrhythmia in specific patient subsets (e.g., poor metabolizers and those taking interacting drugs).

Detection and evaluation of ventricular repolarization alternans: an approach to combined ECG, thoracic impedance, and beat-to-beat heart rate variability analysis.

PubMed

Kriščiukaitis, Algimantas; Šimoliūnienė, Renata; Macas, Andrius; Petrolis, Robertas; Drėgūnas, Kęstutis; Bakšytė, Giedrė; Pieteris, Linas; Bertašienė, Zita; Žaliūnas, Remigijus

2014-01-01

Beat-to-beat alteration in ventricles repolarization reflected by alternans of amplitude and/or shape of ECG S-T,T segment (TWA) is known as phenomena related with risk of severe arrhythmias leading to sudden cardiac death. Technical difficulties have caused limited its usage in clinical diagnostics. Possibilities to register and analyze multimodal signals reflecting heart activity inspired search for new technical solutions. First objective of this study was to test whether thoracic impedance signal and beat-to-beat heart rate reflect repolarization alternans detected as TWA. The second objective was revelation of multimodal signal features more comprehensively representing the phenomena and increasing its prognostic usefulness. ECG, and thoracic impedance signal recordings made during 24h follow-up of the patients hospitalized in acute phase of myocardial infarction were used for investigation. Signal morphology variations reflecting estimates were obtained by the principal component analysis-based method. Clinical outcomes of patients (survival and/or rehospitalization in 6 and 12 months) were compared to repolarization alternans and heart rate variability estimates. Repolarization alternans detected as TWA was also reflected in estimates of thoracic impedance signal shape and variation in beat-to-beat heart rate. All these parameters showed correlation with clinical outcomes of patients. The strongest significant correlation showed magnitude of alternans in estimates of thoracic impedance signal shape. The features of ECG, thoracic impedance signal and beat-to-beat variability of heart rate, give comprehensive estimates of repolarization alternans, which correlate, with clinical outcomes of the patients and we recommend using them to improve diagnostic reliability. Copyright © 2014 Lithuanian University of Health Sciences. Production and hosting by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Thymus function in drug-induced lupus.

PubMed

Rubin, R L; Salomon, D R; Guerrero, R S

2001-01-01

Autoimmunity develops when a lupus-inducing drug is introduced into the thymus of normal mice, but the relevance of this model to the human disorder is unclear in part because it is widely assumed that the thymus is non-functional in the adult. We compared thymus function in 10 patients with symptomatic procainamide-induced lupus to that in 13 asymptomatic patients who only developed drug-induced autoantibodies. T cell output from the thymus was quantified using a competitive polymerase chain reaction that detects T cell receptor DNA excision circles in peripheral blood lymphocytes. Despite the advanced age of the patient population under study, newly generated T cells were detected in all subjects. Although there was no overall quantitative difference between the symptomatic and asymptomatic patients, we found a positive correlation between the level of T cell receptor excision circles in peripheral lymphocytes and serum IgG anti-chromatin antibody activity in patients with drug-induced lupus. The association between autoantibodies and nascent peripheral T cells supports the requirement for T cells in autoantibody production. Our observations are consistent with findings in mice in which autoreactive T cells derived from drug-induced abnormalities in T cell development in the thymus.

Cyclosporine A: Novel concepts in its role in drug-induced gingival overgrowth

PubMed Central

Ponnaiyan, Deepa; Jegadeesan, Visakan

2015-01-01

Cyclosporine is a selective immunosuppressant that has a variety of applications in medical practice. Like phenytoin and the calcium channel blockers, the drug is associated with gingival overgrowth. This review considers the pharmacokinetics, pharmacodynamics, and unwanted effects of cyclosporine, in particular the action of the drug on the gingival tissues. In addition, elucidates the current concepts in mechanisms of cyclosporine-induced gingival overgrowth. Clinical and cell culture studies suggest that the mechanism of gingival overgrowth is a result of the interaction between the drug and its metabolites with susceptible gingival fibroblasts. Plaque-induced gingival inflammation appears to enhance this interaction. However, understanding of the pathogenesis of gingival overgrowth is incomplete at best. Hence, it would be pertinent to identify and explore possible risk factors relating to both prevalence and severity of drug-induced gingival overgrowth. Newer molecular approaches are needed to clearly establish the pathogenesis of gingival overgrowth and to provide novel information for the design of future preventive and therapeutic modalities. PMID:26759584

Cyclosporine A: Novel concepts in its role in drug-induced gingival overgrowth.

PubMed

Ponnaiyan, Deepa; Jegadeesan, Visakan

2015-01-01

Cyclosporine is a selective immunosuppressant that has a variety of applications in medical practice. Like phenytoin and the calcium channel blockers, the drug is associated with gingival overgrowth. This review considers the pharmacokinetics, pharmacodynamics, and unwanted effects of cyclosporine, in particular the action of the drug on the gingival tissues. In addition, elucidates the current concepts in mechanisms of cyclosporine-induced gingival overgrowth. Clinical and cell culture studies suggest that the mechanism of gingival overgrowth is a result of the interaction between the drug and its metabolites with susceptible gingival fibroblasts. Plaque-induced gingival inflammation appears to enhance this interaction. However, understanding of the pathogenesis of gingival overgrowth is incomplete at best. Hence, it would be pertinent to identify and explore possible risk factors relating to both prevalence and severity of drug-induced gingival overgrowth. Newer molecular approaches are needed to clearly establish the pathogenesis of gingival overgrowth and to provide novel information for the design of future preventive and therapeutic modalities.

New descriptors of homogeneity of the propagation of ventricular repolarization.

PubMed

Batchvarov, V; Dilaveris, P; Färbom, P; Ghuran, A; Acar, B; Hnatkova, K; Camm, A J; Malik, M

2000-11-01

Available descriptors of irregularities of ventricular repolarization are of limited clinical value. We studied the effect of autonomic variations on several new descriptors of the three-dimensional T loop. Twelve-lead digital ECGs were recorded continuously in 40 healthy subjects at baseline in the supine position, during postural changes (supine-->sitting-->standing-->supine-->standing), and during Valsalva maneuver performed three times in the supine and three times in the standing positions. A minimum dimensional space was constructed from the 12-lead ECG, using singular value decomposition, on the basis of median ECG beats constructed from 10-second consecutive ECG recordings. Temporal variations (TLA and PL, which measure the T loop area, and LD, the interlead relationship during repolarization) and wavefront direction descriptors (TCRT, the deviation between the QRS and T vectors) were calculated and expressed as normalized values. Values of TLA, PL, and TCRT were significantly lower in the sitting than in the supine position (-38,139 +/- 9099 vs 47,133 +/- 7511, -0.017 +/- 0.005 vs 0.033 +/- 0.005 and -0.032 +/- 0.019 vs 0.071 +/- 0.015, respectively, P < 0.001 for all) and decreased further in the standing position (-88,288 +/- 14,468, -0.067 +/- 0.013, -0.198 +/- 0.025, respectively, P < 0.001 for all). LD increased from supine to sitting (98.7 +/- 29.4 vs -87.5 +/- 15.2, P < 0.001) and increased further, though nonsignificantly in the standing position (118.3 +/- 35.2). TLA, PL, and TCRT decreased from baseline during Valsalva in the supine (-34,118 +/- 11,424 vs 62,234 +/- 12,215, -0.038 +/- 0.014 vs 0.065 +/- 0.010, -0.08 +/- 0.03 vs 0.10 +/- 0.02, respectively, P < 0.001 for all) and standing positions (-108,263 +/- 21,051 vs -68,909 +/- 10,271, -0.109 +/- 0.014 vs -0.048 +/- 0.009, -0.30 +/- 0.035 vs -015 +/- 0.016, respectively, P < 0.05 for all). LD was significantly increased by Valsalva in the supine position (13 +/- 46 vs -153 +/- 30, P < 0

Shock wave compression and self-generated electric field repolarization in ferroelectric ceramics Pb0.99[(Zr0.90Sn0.10)0.96Ti0.04]0.98Nb0.02O3

NASA Astrophysics Data System (ADS)

Jiang, Dongdong; Du, Jinmei; Gu, Yan; Feng, Yujun

2012-03-01

The shock wave induced depoling current of Pb0.99[(Zr0.90Sn0.10)0.96Ti0.04]0.98Nb0.02O3 ceramics was investigated with a system composed of a resistive load and an unpoled ceramic. Disparity in the depoling current was explained by considering the drawing charge effect of unpoled ceramic. The drawing effect for poled ceramics was analysed by developing a model incorporating a time- and electric-field-dependent repolarization. This model predicts that the high-impedance current eventually becomes higher than the short-circuit current, which is consistent with the experimental results in the literature. This work indicates that both the repolarization of uncompressed ceramics caused by the self-generated electric field and depolarization of compressed ceramics caused by the shock wave govern the output current.

Fractional diffusion models of cardiac electrical propagation: role of structural heterogeneity in dispersion of repolarization

PubMed Central

Bueno-Orovio, Alfonso; Kay, David; Grau, Vicente; Rodriguez, Blanca; Burrage, Kevin

2014-01-01

Impulse propagation in biological tissues is known to be modulated by structural heterogeneity. In cardiac muscle, improved understanding on how this heterogeneity influences electrical spread is key to advancing our interpretation of dispersion of repolarization. We propose fractional diffusion models as a novel mathematical description of structurally heterogeneous excitable media, as a means of representing the modulation of the total electric field by the secondary electrical sources associated with tissue inhomogeneities. Our results, analysed against in vivo human recordings and experimental data of different animal species, indicate that structural heterogeneity underlies relevant characteristics of cardiac electrical propagation at tissue level. These include conduction effects on action potential (AP) morphology, the shortening of AP duration along the activation pathway and the progressive modulation by premature beats of spatial patterns of dispersion of repolarization. The proposed approach may also have important implications in other research fields involving excitable complex media. PMID:24920109

Pyrimethamine as a Potent and Selective Inhibitor of Acute Myeloid Leukemia Identified by High-throughput Drug Screening.

PubMed

Sharma, Amit; Jyotsana, Nidhi; Lai, Courteney K; Chaturvedi, Anuhar; Gabdoulline, Razif; Görlich, Kerstin; Murphy, Cecilia; Blanchard, Jan E; Ganser, Arnold; Brown, Eric; Hassell, John A; Humphries, R Keith; Morgan, Michael; Heuser, Michael

2016-01-01

Hematopoietic stem and progenitor cell differentiation are blocked in acute myeloid leukemia (AML) resulting in cytopenias and a high risk of death. Most patients with AML become resistant to treatment due to lack of effective cytotoxic and differentiation promoting compounds. High MN1 expression confers poor prognosis to AML patients and induces resistance to cytarabine and alltrans-retinoic acid (ATRA) induced differentiation. Using a high-throughput drug screening, we identified the dihydrofolate reductase (DHFR) antagonist pyrimethamine to be a potent inducer of apoptosis and differentiation in several murine and human leukemia cell lines. Oral pyrimethamine treatment was effective in two xenograft mouse models and specifically targeted leukemic cells in human AML cell lines and primary patient cells, while CD34+ cells from healthy donors were unaffected. The antileukemic effects of PMT could be partially rescued by excess folic acid, suggesting an oncogenic function of folate metabolism in AML. Thus, our study identifies pyrimethamine as a candidate drug that should be further evaluated in AML treatment.

Ranolazine improves abnormal repolarization and contraction in left ventricular myocytes of dogs with heart failure by inhibiting late sodium current

PubMed Central

Undrovinas, Albertas I.; Belardinelli, Luiz; Undrovinas, Nidas A.; Sabbah, Hani N.

2005-01-01

Background Ventricular repolarization and contractile function are frequently abnormal in ventricular myocytes from human failing hearts as well as canine hearts with experimentally induced heart failure (HF). These abnormalities have been attributed to dysfunction involving various steps of the excitation-contraction coupling process, leading to impaired intracellular sodium and calcium homeostasis. We previously reported that the slow inactivating component of the Na+ current (late INa) is augmented in myocytes from failing hearts, and this appears to play a significant role in abnormal ventricular myocytes repolarization and function. We tested the effect of ranolazine, a novel drug being developed to treat angina, on 1) action potential duration (APD), 2) peak transient and late INa (INaT and INaL respectively), 3) early afterdepolarizations (EADs), and 4) twitch contraction (TC) including aftercontractions and contracture. Methods: Myocytes were isolated from the left ventricle of normal dogs and of dogs with chronic HF caused by multiple sequential intracoronary microembolizations. INaT and INaL were recorded using conventional whole-cell patch-clamp techniques. APs were recorded using the β-escin perforated patch-clamp configuration at frequencies of 0.25 and 0.5 Hz. TCs were recorded using an edge movement detector at stimulation frequencies ranging from 0.5 to 2.0 Hz. Results Ranolazine significantly (p < 0.05) and reversibly shortened the APD of myocytes stimulated at either 0.5 or 0.25 Hz in a concentration-dependent manner. At a stimulation frequency of 0.5 Hz, 5, 10 and 20 μM ranolazine shortened the APD90 (APD measured at 90% repolarization) from 516 ± 51 to 304 ± 22, 212 ± 34 and 160 ± 11 ms, respectively, and markedly decreased beat-to-beat variability of APD90, EADs and dispersion of APDs. Ranolazine preferentially blocked INaL relative to INaT in a state-dependent manner; with a ~ 38-fold greater potency against INaL to produce tonic block

Non-chemotherapy drug-induced neutropenia - an update.

PubMed

Andrès, Emmanuel; Mourot-Cottet, Rachel

2017-11-01

To date, non-chemotherapy drug-induced severe neutropenia (neutrophil count of ≤0.5 x 10 9 /L) also called idiosyncratic drug-induced agranulocytosis is little discussed in the literature. In the present paper, we report and discuss the clinical data and management of this rare disorder. Areas covered: To do this, we carried out a review of the literature using PubMed database of the US National Library of Medicine. We also used data from the American Society of Hematology educational books, textbooks of Hematology and Internal medicine, and information gleaned from international meetings. Expert opinion: Idiosyncratic agranulocytosis remains a potentially serious adverse event due to the frequency of severe sepsis with severe deep tissue infections (e.g., pneumonia), septicemia, and septic shock in approximately two-thirds of all hospitalized patients. In this context, several prognostic factors have been identified that may be helpful when identifying 'susceptible' patients. Old age (>65 years), septicemia or shock, renal failure, and a neutrophil count ≤0.1 × 10 9 /L have been consensually accepted as poor prognostic factors. In our experience, modern management with pre-established procedures, intravenous broad-spectrum antibiotics and hematopoietic growth factors (particularly G-CSF) is likely to improve the prognosis. Thus with appropriate management, the mortality rate is currently between 5 to 10%.

The hidden side of drug action: Brain temperature changes induced by neuroactive drugs

PubMed Central

Kiyatkin, Eugene A.

2013-01-01

Rationale Most neuroactive drugs affect brain metabolism as well as systemic and cerebral blood flow, thus altering brain temperature. Although this aspect of drug action usually remains in the shadows, drug-induced alterations in brain temperature reflect their metabolic neural effects and affect neural activity and neural functions. Objectives Here, I review brain temperature changes induced by neuroactive drugs, which are used therapeutically (general anesthetics), as a research tool (dopamine agonists and antagonists), and self-administered to induce desired psychic effects (cocaine, methamphetamine, ecstasy). I consider the mechanisms underlying these temperature fluctuations and their influence on neural, physiological, and behavioral effects of these drugs. Results By interacting with neural mechanisms regulating metabolic activity and heat exchange between the brain and the rest of the body, neuroactive drugs either increase or decrease brain temperatures both within (35-39°C) and exceeding the range of physiological fluctuations. These temperature effects differ drastically depending upon the environmental conditions and activity state during drug administration. This state-dependence is especially important for drugs of abuse that are usually taken by humans during psycho-physiological activation and in environments that prevent proper heat dissipation from the brain. Under these conditions, amphetamine-like stimulants induce pathological brain hyperthermia (>40°C) associated with leakage of the blood-brain barrier and structural abnormalities of brain cells. Conclusions The knowledge on brain temperature fluctuations induced by neuroactive drugs provides new information to understand how they influence metabolic neural activity, why their effects depend upon the behavioral context of administration, and the mechanisms underlying adverse drug effects including neurotoxicity PMID:23274506

Drug induced hepatotoxicity: data from the Serbian pharmacovigilance database.

PubMed

Petronijevic, Marija; Ilic, Katarina; Suzuki, Ayako

2011-04-01

The main aim of this study was to determine the most frequently reported drugs to the Serbian Pharmacovigilance Database (SPD) with suspected induced hepatotoxicity. Additionally, reasons for the low reporting rate of adverse drug reactions (ADRs) in Serbia were identified. Retrospective observational study of spontaneously reported ADRs recorded in the SPD from January 1995 to December 2008 was performed. The Medical Dictionary for Regulatory Activities (MedDRA) was used to identify cases of hepatobiliary disorders (HD). Drugs were classified using the Anatomical Therapeutic Chemical (ATC) classification. Medline and WHO-UMC databases were used to address specific queries suggested by our results. The questionnaire was used to investigate the health care professionals' knowledge and practice related to spontaneous reporting. Among the 1804 reports of ADRs recorded in the SPD between 1995 and 2008, 70 (3.9%) cases of HD were identified. Drugs most frequently associated with hepatotoxicity were anti-infectives for systemic use, drugs affecting the nervous system, herbal products, hypolipemics, and anticoagulant drugs (26.83, 24.39, 12.20, 9.76, and 8.54% cases, respectively). Four cases (5.71%) of liver injury resulted in death, which accounted for 10.26% of all ADR fatalities reported to the SPD. The main reasons for not reporting ADRs were lack of reporting knowledge (30.26%), well-known ADRs (29.89%), and insecurity about causality relationship (15.50%). Anti-infectives, nervous system drugs, and herbal products were the most common drug classes reported for hepatotoxicity in Serbia. There is a need for additional education about ADRs, and enhanced reporting by health care professionals. Copyright © 2011 John Wiley & Sons, Ltd.

Drug Repurposing Screening Identifies Novel Compounds That Effectively Inhibit Toxoplasma gondii Growth

PubMed Central

Dittmar, Ashley J.; Drozda, Allison A.

2016-01-01

ABSTRACT The urgent need to develop new antimicrobial therapies has spawned the development of repurposing screens in which well-studied drugs and other types of compounds are tested for potential off-label uses. As a proof-of-principle screen to identify compounds effective against Toxoplasma gondii, we screened a collection of 1,120 compounds for the ability to significantly reduce Toxoplasma replication. A total of 94 compounds blocked parasite replication with 50% inhibitory concentrations of <5 µM. A significant number of these compounds are established inhibitors of dopamine or estrogen signaling. Follow-up experiments with the dopamine receptor inhibitor pimozide revealed that the drug impacted both parasite invasion and replication but did so independently of inhibition of dopamine or other neurotransmitter receptor signaling. Tamoxifen, which is an established inhibitor of the estrogen receptor, also reduced parasite invasion and replication. Even though Toxoplasma can activate the estrogen receptor, tamoxifen inhibits parasite growth independently of this transcription factor. Tamoxifen is also a potent inducer of autophagy, and we find that the drug stimulates recruitment of the autophagy marker light chain 3-green fluorescent protein onto the membrane of the vacuolar compartment in which the parasite resides and replicates. In contrast to other antiparasitic drugs, including pimozide, tamoxifen treatment of infected cells leads to a time-dependent elimination of intracellular parasites. Taken together, these data suggest that tamoxifen restricts Toxoplasma growth by inducing xenophagy or autophagic destruction of this obligate intracellular parasite. IMPORTANCE There is an urgent need to develop new therapies to treat microbial infections, and the repurposing of well-characterized compounds is emerging as one approach to achieving this goal. Using the protozoan parasite Toxoplasma gondii, we screened a library of 1,120 compounds and identified several

Sildenafil (Viagra) prolongs cardiac repolarization by blocking the rapid component of the delayed rectifier potassium current.

PubMed

Geelen, P; Drolet, B; Rail, J; Bérubé, J; Daleau, P; Rousseau, G; Cardinal, R; O'Hara, G E; Turgeon, J

2000-07-18

BACKGROUND-Several cases of unexpected death have been reported with sildenafil in patients predisposed to ischemic cardiac events. Although acute episodes of ischemia could account for some of these deaths, we hypothesized that sildenafil may have unsuspected electrophysiological effects predisposing some patients to proarrhythmia. METHODS AND RESULTS-Studies were undertaken in 10 isolated guinea pig hearts that demonstrated prolongation of cardiac repolarization in a reverse use-dependent manner by sildenafil 30 mcmol/L. Action potential duration increased 15% from baseline 117+/-3 to 134+/-2 ms with sildenafil during pacing at 250 ms cycle length, whereas a 6% increase from 99+/-2 to 105+/-2 ms was seen with pacing at 150 ms cycle length. Experiments in human ether-a-go-go-related gene (HERG)-transfected HEK293 cells (n=30) demonstrated concentration-dependent block of the rapid component (I(Kr)) of the delayed rectifier potassium current: activating current was 50% decreased at 100 mcmol/L. This effect was confirmed using HERG-transfected Chinese hamster ovary (CHO) cells, which exhibit no endogenous I(K)-like current. CONCLUSIONS-Sildenafil possesses direct cardiac electrophysiological effects similar to class III antiarrhythmic drugs. These effects are observed at concentrations that may be found in conditions of impaired drug elimination such as renal or hepatic insufficiency, during coadministration of another CYP3A substrate/inhibitor, or after drug overdose and offer a new potential explanation for sudden death during sildenafil treatment.

Drug-induced gynecomastia in children and adolescents

PubMed Central

Goldman, Ran D.

2010-01-01

ABSTRACT QUESTION I frequently see adolescent boys in my practice with transient gynecomastia. My management includes reassuring the boys and their families; however, I also understand that specific medication, alcohol, and drugs can cause gynecomastia. How common is this phenomenon, and what medications can induce gynecomastia? ANSWER While gynecomastia is a physiologic phenomenon in most newborns and adolescents, it is important to consider pathologic conditions and medications that can cause breast enlargement. Antibiotics, antiulcer drugs, growth hormones, and chemotherapy have been reported to induce gynecomastia. Adolescents who use anabolic steroids, or who abuse alcohol, marijuana, heroin, or amphetamines, should be alerted to the fact that gynecomastia might develop. Treatment of drug-induced gynecomastia includes discontinuation of the offending drug. Very rarely is surgical intervention required. PMID:20393092

Drug-induced gynecomastia in children and adolescents.

PubMed

Goldman, Ran D

2010-04-01

I frequently see adolescent boys in my practice with transient gynecomastia. My management includes reassuring the boys and their families; however, I also understand that specific medication, alcohol, and drugs can cause gynecomastia. How common is this phenomenon, and what medications can induce gynecomastia? While gynecomastia is a physiologic phenomenon in most newborns and adolescents, it is important to consider pathologic conditions and medications that can cause breast enlargement. Antibiotics, antiulcer drugs, growth hormones, and chemotherapy have been reported to induce gynecomastia. Adolescents who use anabolic steroids, or who abuse alcohol, marijuana, heroin, or amphetamines, should be alerted to the fact that gynecomastia might develop. Treatment of drug-induced gynecomastia includes discontinuation of the offending drug. Very rarely is surgical intervention required.

Rehabilitating drug-induced long-QT promoters: in-silico design of hERG-neutral cisapride analogues with retained pharmacological activity.

PubMed

Durdagi, Serdar; Randall, Trevor; Duff, Henry J; Chamberlin, Adam; Noskov, Sergei Y

2014-03-08

The human ether-a-go-go related gene 1 (hERG1), which codes for a potassium ion channel, is a key element in the cardiac delayed rectified potassium current, IKr, and plays an important role in the normal repolarization of the heart's action potential. Many approved drugs have been withdrawn from the market due to their prolongation of the QT interval. Most of these drugs have high potencies for their principal targets and are often irreplaceable, thus "rehabilitation" studies for decreasing their high hERG1 blocking affinities, while keeping them active at the binding sites of their targets, have been proposed to enable these drugs to re-enter the market. In this proof-of-principle study, we focus on cisapride, a gastroprokinetic agent withdrawn from the market due to its high hERG1 blocking affinity. Here we tested an a priori strategy to predict a compound's cardiotoxicity using de novo drug design with molecular docking and Molecular Dynamics (MD) simulations to generate a strategy for the rehabilitation of cisapride. We focused on two key receptors, a target interaction with the (adenosine) receptor and an off-target interaction with hERG1 channels. An analysis of the fragment interactions of cisapride at human A2A adenosine receptors and hERG1 central cavities helped us to identify the key chemical groups responsible for the drug activity and hERG1 blockade. A set of cisapride derivatives with reduced cardiotoxicity was then proposed using an in-silico two-tier approach. This set was compared against a large dataset of commercially available cisapride analogs and derivatives. An interaction decomposition of cisapride and cisapride derivatives allowed for the identification of key active scaffolds and functional groups that may be responsible for the unwanted blockade of hERG1.

Rehabilitating drug-induced long-QT promoters: In-silico design of hERG-neutral cisapride analogues with retained pharmacological activity

PubMed Central

2014-01-01

Background The human ether-a-go-go related gene 1 (hERG1), which codes for a potassium ion channel, is a key element in the cardiac delayed rectified potassium current, IKr, and plays an important role in the normal repolarization of the heart’s action potential. Many approved drugs have been withdrawn from the market due to their prolongation of the QT interval. Most of these drugs have high potencies for their principal targets and are often irreplaceable, thus “rehabilitation” studies for decreasing their high hERG1 blocking affinities, while keeping them active at the binding sites of their targets, have been proposed to enable these drugs to re-enter the market. Methods In this proof-of-principle study, we focus on cisapride, a gastroprokinetic agent withdrawn from the market due to its high hERG1 blocking affinity. Here we tested an a priori strategy to predict a compound’s cardiotoxicity using de novo drug design with molecular docking and Molecular Dynamics (MD) simulations to generate a strategy for the rehabilitation of cisapride. Results We focused on two key receptors, a target interaction with the (adenosine) receptor and an off-target interaction with hERG1 channels. An analysis of the fragment interactions of cisapride at human A2A adenosine receptors and hERG1 central cavities helped us to identify the key chemical groups responsible for the drug activity and hERG1 blockade. A set of cisapride derivatives with reduced cardiotoxicity was then proposed using an in-silico two-tier approach. This set was compared against a large dataset of commercially available cisapride analogs and derivatives. Conclusions An interaction decomposition of cisapride and cisapride derivatives allowed for the identification of key active scaffolds and functional groups that may be responsible for the unwanted blockade of hERG1. PMID:24606761

Aging modulates dispersion of ventricular repolarization in the very old of the geriatric population.

PubMed

Huang, Jen-Hung; Lin, Ying-Qin; Pan, Nan-Hung; Chen, Yi-Jen

2010-11-01

Aging plays an essential role in cardiac pathophysiology. Knowledge on the ventricular repolarization in very old individuals is limited. An increase of QT dispersion is associated with higher cardiovascular mortality. The purpose of this study is to investigate whether aging changes the QT dispersion in the very old. Heart rate, P wave duration, PR interval, QRS axis, QRS duration, QT interval, and QTc interval were measured from 12-lead resting ECG. QT dispersion (46 ± 21, 47 ± 17, 69 ± 31 ms, p < 0.005) was significantly increased in the age group ≧85 years (n = 29, 89 ± 4 years) than in the age group 75-84 years (n = 33, 79 ± 3 years) and the age group 65-74 years (n = 32, 68 ± 3 years). Aging modulates dispersion of ventricular repolarization, which may contribute to the cardiac mortality in the very old Asian population.

A proteomic approach to identifying new drug targets (potentiating topoisomerase II poisons).

PubMed

Jenkins, J R

2008-10-01

Topoisomerase II poisons are an established part of best clinical practice for the treatment of a number of solid tumours and haematological malignancies. However, toxicity and resistance to chemotherapeutic drugs often complicate the treatment. Furthermore, topoisomerase II poisons can also induce sister chromatid exchange, chromosomal recombination and chromosome aberrations and are associated with a significant risk of secondary leukaemia. It would therefore be of great clinical benefit if the efficacy of topoisomerase II inhibitors could be enhanced without the increased toxic side effects. It is proposed that clinical agents targeting topoisomerase II can be enhanced by inhibiting proteins that modulate topoisomerase II. The aim is to identify proteins, that by the nature of their interaction with topoisomerase II, represent putative drug targets.

Drug-induced gingival overgrowth: The nemesis of gingiva unravelled.

PubMed

Bharti, Vipin; Bansal, Chhaya

2013-03-01

Drug-induced gingival overgrowth or enlargement manifests as abnormal growth of the gingiva due to an adverse drug reaction (ADR) in patients treated with anticonvulsants, immunosuppressants, and calcium channel blockers. As gingival enlargement develops, it affects the normal oral hygiene practice and may interfere with masticatory functions. It gradually becomes a source of pain and the condition often leads to disfiguration. Within the group of patients that develop this unwanted effect, there appears to be variability in the extent and severity of the gingival changes. It would seem pertinent to identify and explore possible risk factors and relating them with the treatment plan. This article throws light on respective drugs and their association with gingival overgrowth and approaches to treatment based on current knowledge and investigative observations.

Drug-induced uveitis

PubMed Central

2013-01-01

A number of medications have been associated with uveitis. This review highlights both well-established and recently reported systemic, topical, intraocular, and vaccine-associated causes of drug-induced uveitis, and assigns a quantitative score to each medication based upon criteria originally described by Naranjo and associates. PMID:23522744

In silico prediction of drug-induced myelotoxicity by using Naïve Bayes method.

PubMed

Zhang, Hui; Yu, Peng; Zhang, Teng-Guo; Kang, Yan-Li; Zhao, Xiao; Li, Yuan-Yuan; He, Jia-Hui; Zhang, Ji

2015-11-01

Drug-induced myelotoxicity usually leads to decrease the production of platelets, red cells, and white cells. Thus, early identification and characterization of myelotoxicity hazard in drug development is very necessary. The purpose of this investigation was to develop a prediction model of drug-induced myelotoxicity by using a Naïve Bayes classifier. For comparison, other prediction models based on support vector machine and single-hidden-layer feed-forward neural network  methods were also established. Among all the prediction models, the Naïve Bayes classification model showed the best prediction performance, which offered an average overall prediction accuracy of [Formula: see text] for the training set and [Formula: see text] for the external test set. The significant contributions of this study are that we first developed a Naïve Bayes classification model of drug-induced myelotoxicity adverse effect using a larger scale dataset, which could be employed for the prediction of drug-induced myelotoxicity. In addition, several important molecular descriptors and substructures of myelotoxic compounds have been identified, which should be taken into consideration in the design of new candidate compounds to produce safer and more effective drugs, ultimately reducing the attrition rate in later stages of drug development.

Analysis of National Drug Code Identifiers in Ambulatory E-Prescribing.

PubMed

Dhavle, Ajit A; Ward-Charlerie, Stacy; Rupp, Michael T; Amin, Vishal P; Ruiz, Joshua

2015-11-01

Communication of an accurate and interpretable drug identifier between prescriber and pharmacist is critically important for realizing the potential benefits of electronic prescribing (e-prescribing) while minimizing its risk. The National Drug Code (NDC) is the most commonly used codified drug identifier in ambulatory care e-prescribing, but concerns have been raised regarding its use for this purpose.  To (a) assess the frequency of NDC identifier transmission in ambulatory e-prescribing; (b) characterize the type of NDC identifier transmitted (representative, repackaged, obsolete, private label, and unit dose); and (c) assess the level of agreement between drug descriptions corresponding to NDC identifiers in electronic prescriptions (e-prescriptions) and the free-text drug descriptions that were entered by prescribers.  We analyzed a sample of 49,997 e-prescriptions that were transmitted by ambulatory care prescribers to outlets of a national retail drugstore chain during a single day in April 2014. The First Databank MedKnowledge drug database was used as the primary reference data base to assess the frequency and types of NDC numbers in the e-prescription messages. The FDA's Comprehensive NDC Standard Product Labeling Data Elements File and the National Library of Medicine's RxNorm data file were used as secondary and tertiary references, respectively, to identify NDC numbers that could not be located in the primary reference file. Three experienced reviewers compared the free-text drug description that had been entered by the prescriber with the drug description corresponding to the NDC number from 1 of the 3 reference database files to identify discrepancies. Two licensed pharmacists with residency training and ambulatory care experience served as final adjudicators. A total of 42,602 e-prescriptions contained a value in the NDC field, of which 42,335 (84.71%) were found in 1 of the 3 study reference databases and were thus considered to be valid NDC

Indexes of temporal myocardial repolarization dispersion and sudden cardiac death in heart failure: any difference?

PubMed

Piccirillo, Gianfranco; Rossi, Pietro; Mitra, Marilena; Quaglione, Raffaele; Dell'Armi, Annalaura; Di Barba, Daniele; Maisto, Damiana; Lizio, Andrea; Barillà, Francesco; Magrì, Damiano

2013-03-01

The QT variability index, calculated between Q- and the T-wave end (QTend VI), is an index of temporal myocardial repolarization lability associated with sudden cardiac death (SCD) in chronic heart failure (CHF). Little is known about temporal variability in the other two temporal myocardial repolarization descriptors obtained from Q-Tpeak and Tpeak -Tend intervals. We therefore investigated differences between these indexes in patients with CHF who died suddenly and in those who survived with a left ventricular ejection fraction (LVEF) ≤35% or >35%. We selected 127 ECG and systolic blood pressure (SPB) recordings from outpatients with CHF all of whom had been followed up for 30 months. We calculated RR and SPB variability by power spectral analysis and QTend VI, QTpeak VI, Tpeak Tend VI. We then subdivided data patients into three groups SCD, LVEF ≤ 35%, and LVEF > 35%. The LVEF was higher in the SCD than in the LVEF ≤ 35% group, whereas no difference was found between the SCD and LVEF > 35% groups. QTend VI, QTpeak VI, and Tpeak Tend VI were higher in the SCD and LVEF ≤ 35% groups than in the LVEF > 35% group. Multivariate analysis detected a negative relationship between all repolarization variability indexes, low frequency obtained from RR intervals and LVEF. Our data show that variability in the first (QTpeak VI) and second halves of the QT interval (Tpeak -Tend VI) significantly contributes to the QTend VI in patients with CHF. Further studies should investigate whether these indexes might help stratify the risk of SCD in patients with a moderately depressed LVEF. ©2012, Wiley Periodicals, Inc.

In Silico Identification of Proteins Associated with Drug-induced Liver Injury Based on the Prediction of Drug-target Interactions.

PubMed

Ivanov, Sergey; Semin, Maxim; Lagunin, Alexey; Filimonov, Dmitry; Poroikov, Vladimir

2017-07-01

Drug-induced liver injury (DILI) is the leading cause of acute liver failure as well as one of the major reasons for drug withdrawal from clinical trials and the market. Elucidation of molecular interactions associated with DILI may help to detect potentially hazardous pharmacological agents at the early stages of drug development. The purpose of our study is to investigate which interactions with specific human protein targets may cause DILI. Prediction of interactions with 1534 human proteins was performed for the dataset with information about 699 drugs, which were divided into three categories of DILI: severe (178 drugs), moderate (310 drugs) and without DILI (211 drugs). Based on the comparison of drug-target interactions predicted for different drugs' categories and interpretation of those results using clustering, Gene Ontology, pathway and gene expression analysis, we identified 61 protein targets associated with DILI. Most of the revealed proteins were linked with hepatocytes' death caused by disruption of vital cellular processes, as well as the emergence of inflammation in the liver. It was found that interaction of a drug with the identified targets is the essential molecular mechanism of the severe DILI for the most of the considered pharmaceuticals. Thus, pharmaceutical agents interacting with many of the identified targets may be considered as candidates for filtering out at the early stages of drug research. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomedical Informatics Approaches to Identifying Drug-Drug Interactions: Application to Insulin Secretagogues

PubMed Central

Han, Xu; Chiang, ChienWei; Leonard, Charles E.; Bilker, Warren B.; Brensinger, Colleen M.; Li, Lang; Hennessy, Sean

2017-01-01

Background Drug-drug interactions with insulin secretagogues are associated with increased risk of serious hypoglycemia in patients with type 2 diabetes. We aimed to systematically screen for drugs that interact with the five most commonly used secretagogues―glipizide, glyburide, glimepiride, repaglinide, and nateglinide―to cause serious hypoglycemia. Methods We screened 400 drugs frequently co-prescribed with the secretagogues as candidate interacting precipitants. We first predicted the drug–drug interaction potential based on the pharmacokinetics of each secretagogue–precipitant pair. We then performed pharmacoepidemiologic screening for each secretagogue of interest, and for metformin as a negative control, using an administrative claims database and the self-controlled case series design. The overall rate ratios (RRs) and those for four predefined risk periods were estimated using Poisson regression. The RRs were adjusted for multiple estimation using semi-Bayes method, and then adjusted for metformin results to distinguish native effects of the precipitant from a drug–drug interaction. Results We predicted 34 pharmacokinetic drug–drug interactions with the secretagogues, nine moderate and 25 weak. There were 140 and 61 secretagogue–precipitant pairs associated with increased rates of serious hypoglycemia before and after the metformin adjustment, respectively. The results from pharmacokinetic prediction correlated poorly with those from pharmacoepidemiologic screening. Conclusions The self-controlled case series design has the potential to be widely applicable to screening for drug–drug interactions that lead to adverse outcomes identifiable in healthcare databases. Coupling pharmacokinetic prediction with pharmacoepidemiologic screening did not notably improve the ability to identify drug–drug interactions in this case. PMID:28169935

Structural and functional screening in human induced-pluripotent stem cell-derived cardiomyocytes accurately identifies cardiotoxicity of multiple drug types

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doherty, Kimberly R., E-mail: kimberly.doherty@quintiles.com; Talbert, Dominique R.; Trusk, Patricia B.

Safety pharmacology studies that evaluate new drug entities for potential cardiac liability remain a critical component of drug development. Current studies have shown that in vitro tests utilizing human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CM) may be beneficial for preclinical risk evaluation. We recently demonstrated that an in vitro multi-parameter test panel assessing overall cardiac health and function could accurately reflect the associated clinical cardiotoxicity of 4 FDA-approved targeted oncology agents using hiPS-CM. The present studies expand upon this initial observation to assess whether this in vitro screen could detect cardiotoxicity across multiple drug classes with known clinical cardiac risks.more » Thus, 24 drugs were examined for their effect on both structural (viability, reactive oxygen species generation, lipid formation, troponin secretion) and functional (beating activity) endpoints in hiPS-CM. Using this screen, the cardiac-safe drugs showed no effects on any of the tests in our panel. However, 16 of 18 compounds with known clinical cardiac risk showed drug-induced changes in hiPS-CM by at least one method. Moreover, when taking into account the Cmax values, these 16 compounds could be further classified depending on whether the effects were structural, functional, or both. Overall, the most sensitive test assessed cardiac beating using the xCELLigence platform (88.9%) while the structural endpoints provided additional insight into the mechanism of cardiotoxicity for several drugs. These studies show that a multi-parameter approach examining both cardiac cell health and function in hiPS-CM provides a comprehensive and robust assessment that can aid in the determination of potential cardiac liability. - Highlights: • 24 drugs were tested for cardiac liability using an in vitro multi-parameter screen. • Changes in beating activity were the most sensitive in predicting cardiac risk. • Structural effects add in

Intramural activation and repolarization sequences in canine ventricles. Experimental and simulation studies.

PubMed

Taccardi, Bruno; Punske, Bonnie B; Sachse, Frank; Tricoche, Xavier; Colli-Franzone, Piero; Pavarino, Luca F; Zabawa, Christine

2005-10-01

There are no published data showing the three-dimensional sequence of repolarization and the associated potential fields in the ventricles. Knowledge of the sequence of repolarization has medical relevance because high spatial dispersion of recovery times and action potential durations favors cardiac arrhythmias. In this study we describe measured and simulated 3-D excitation and recovery sequences and activation-recovery intervals (ARIs) (measured) or action potential durations (APDs) (simulated) in the ventricular walls. We recorded from 600 to 1400 unipolar electrograms from canine ventricular walls during atrial and ventricular pacing at 350-450 ms cycle length. Measured excitation and recovery times and ARIs were displayed as 2-D maps in transmural planes or 3-D maps in the volume explored, using specially developed software. Excitation and recovery sequences and APD distributions were also simulated in parallelepipedal slabs using anisotropic monodomain or bidomain models based on the Lou-Rudy version 1 model with homogeneous membrane properties. Simulations showed that in the presence of homogeneous membrane properties, the sequence of repolarization was similar but not identical to the excitation sequence. In a transmural plane perpendicular to epicardial fiber direction, both activation and recovery pathways starting from an epicardial pacing site returned toward the epicardium at a few cm distance from the pacing site. However, APDs were not constant, but had a dispersion of approximately 14 ms in the simulated domain. The maximum APD value was near the pacing site and two minima appeared along a line perpendicular to fiber directions, passing through the pacing site. Electrical measurements in dog ventricles showed that, for short cycle lengths, both excitation and recovery pathways, starting from an epicardial pacing site, returned toward the epicardium. For slower pacing rates, pathways of recovery departed from the pathway of excitation. Highest ARI

Acute effects of Red Bull energy drink on ventricular repolarization in healthy young volunteers: a prospective study

PubMed Central

Elitok, Ali; Öz, Fahrettin; Panc, Cafer; Sarıkaya, Remzi; Sezikli, Selim; Pala, Yasin; Bugan, Övgü Sinem; Ateş, Müge; Parıldar, Hilal; Ayaz, Mustafa Buğra; Atıcı, Adem; Oflaz, Hüseyin

2016-01-01

Objective: Energy drinks (EDs) are widely consumed products of the beverage industry and are often chosen by teenagers and young adults. Several adverse cardiovascular events and malignant cardiac arrhythmias following consumption of EDs have been reported in the literature. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the dispersion of repolarization and that an increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. This study investigated the acute effects of Red Bull ED on ventricular repolarization as assessed by the Tp-e interval and Tp-e/QT ratio. Methods: A prospective, open-label study design was used. After an 8-h fast, 50 young, healthy subjects consumed 355 mL of Red Bull ED. The Tp-e interval, Tp-e/QTc ratio, and several other electrocardiographic parameters were measured at baseline and 2 h after ingestion of Red Bull ED. Results: No significant changes in the Tp-e interval or Tp-e/QTc ratio were observed with Red Bull ED consumption. Red Bull ED consumption led to increases in both systolic and diastolic blood pressures, which were associated with an increased heart rate. Conclusion: Although ingestion of Red Bull ED increases the heart rate and diastolic and systolic blood pressures, it does not cause alterations in ventricular repolarization as assessed by the Tp-e interval and Tp-e/QTc ratio. PMID:25868042

Acute effects of Red Bull energy drink on ventricular repolarization in healthy young volunteers: a prospective study.

PubMed

Elitok, Ali; Öz, Fahrettin; Panc, Cafer; Sarıkaya, Remzi; Sezikli, Selim; Pala, Yasin; Bugan, Övgü Sinem; Ateş, Müge; Parıldar, Hilal; Ayaz, Mustafa Buğra; Atıcı, Adem; Oflaz, Hüseyin

2015-11-01

Energy drinks (EDs) are widely consumed products of the beverage industry and are often chosen by teenagers and young adults. Several adverse cardiovascular events and malignant cardiac arrhythmias following consumption of EDs have been reported in the literature. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the dispersion of repolarization and that an increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. This study investigated the acute effects of Red Bull ED on ventricular repolarization as assessed by the Tp-e interval and Tp-e/QT ratio. A prospective, open-label study design was used. After an 8-h fast, 50 young, healthy subjects consumed 355 mL of Red Bull ED. The Tp-e interval, Tp-e/QTc ratio, and several other electrocardiographic parameters were measured at baseline and 2 h after ingestion of Red Bull ED. No significant changes in the Tp-e interval or Tp-e/QTc ratio were observed with Red Bull ED consumption. Red Bull ED consumption led to increases in both systolic and diastolic blood pressures, which were associated with an increased heart rate. Although ingestion of Red Bull ED increases the heart rate and diastolic and systolic blood pressures, it does not cause alterations in ventricular repolarization as assessed by the Tp-e interval and Tp-e/QTc ratio.

Vitiligo, drug induced (image)

MedlinePlus

... this person's face have resulted from drug-induced vitiligo. Loss of melanin, the primary skin pigment, occasionally ... is the case with this individual. The typical vitiligo lesion is flat and depigmented, but maintains the ...

Role of nonalcoholic fatty liver disease as risk factor for drug-induced hepatotoxicity

PubMed Central

Massart, Julie; Begriche, Karima; Moreau, Caroline; Fromenty, Bernard

2017-01-01

Background Obesity is often associated with nonalcoholic fatty liver disease (NAFLD), which refers to a large spectrum of hepatic lesions including fatty liver, nonalcoholic steatohepatitis (NASH) and cirrhosis. Different investigations showed or suggested that obesity and NAFLD are able to increase the risk of hepatotoxicity of different drugs. Some of these drugs could induce more frequently an acute hepatitis in obese individuals whereas others could worsen pre-existing NAFLD. Aim The main objective of the present review was to collect the available information regarding the role of NAFLD as risk factor for drug-induced hepatotoxicity. For this purpose, we performed a data-mining analysis using different queries including drug-induced liver injury (or DILI), drug-induced hepatotoxicity, fatty liver, nonalcoholic fatty liver disease (or NAFLD), steatosis and obesity. The main data from the collected articles are reported in this review and when available, some pathophysiological hypotheses are put forward. Relevance for patients Drugs that could pose a potential risk in obese patients include compounds belonging to different pharmacological classes such as acetaminophen, halothane, methotrexate, rosiglitazone, stavudine and tamoxifen. For some of these drugs, experimental investigations in obese rodents confirmed the clinical observations and unveiled different pathophysiological mechanisms which could explain why these pharmaceuticals are particularly hepatotoxic in obesity and NAFLD. Other drugs such as pentoxifylline, phenobarbital and omeprazole might also pose a risk but more investigations are required to determine whether this risk is significant or not. Because obese people often take several drugs for the treatment of different obesity-related diseases such as type 2 diabetes, hyperlipidemia and coronary heart disease, it is urgent to identify the main pharmaceuticals that can cause acute hepatitis on a fatty liver background or induce NAFLD worsening

Drug-induced sarcoidosis-like reactions (DISR).

PubMed

Chopra, Amit; Nautiyal, Amit; Kalkanis, Alexander; Judson, Marc A

2018-04-23

A drug-induced sarcoidosis-like reaction (DISR) is a systemic granulomatous reaction that is indistinguishable from sarcoidosis and occurs in temporal relationship with initiation of an offending drug. DISRs typically improve or resolve after the withdrawal of offending drug. Four common categories of drugs that have been associated with the development of a DISR are immune checkpoint inhibitors (ICIs), highly active anti-retroviral therapy (HAART), interferons (IFNs) and tumor necrosis factor alpha antagonists (TNF-alpha antagonists). Similar to sarcoidosis, DISRs do not necessarily require treatment, as they may cause no significant symptoms, quality of life impairment or organ dysfunction. When treatment of a DISR is required, standard anti-sarcoidosis regimens seem to be effective. As a DISR tends to improve or resolve when the offending drug is discontinued, this is another effective treatment for a DISR. However, the offending drug need not be discontinued if it is useful, and anti-granulomatous therapy can be added. In some situations, the development of a DISR may suggest a beneficial effect of the inducing drug. Understanding the mechanisms leading to DISRs may yield important insights into the immunopathogenesis of sarcoidosis. Copyright © 2018. Published by Elsevier Inc.

Drug-induced Epistaxis: An Often-Neglected Adverse Effect.

PubMed

Meirinho, Sara; Relvas, Ricardo; Alves, Gilberto

2018-02-12

Epistaxis is an active nose bleeding with a population occurrence of approximately 60%. Although epistaxis is a common clinical complaint, the majority of the cases are benign and caused by local induced factors (e.g., trauma and local inflammation). Nevertheless, it is also recognised that epistaxis can be induced after some drugs intake. Due to the increasing use of drugs or drug combinations that potentially may induce epistaxis, this review aims to alert healthcare professionals for this often neglected adverse drug effect and its possible complications. A comprehensive literature search was performed on PubMed and Google Scholar databases, considering the literature published from January 1985 to December 2015, using medical terms related to the scope of drug-induced epistaxis, nosebleeds and nasal blood supply. As expected, anticoagulant and antiplatelet drugs are the main pharmacotherapeutic agents associated with epistaxis, particularly warfarin, dabigatran, rivaroxaban and aspirin. However, it was reported that some selective serotonin reuptake inhibitors, intranasal corticosteroids, certain antibiotics and other drugs or drug associations can also be responsible by nosebleeds. Although most of these epistaxis episodes are mild to moderate, being spontaneously reversed or requiring only minor medical approaches to control it, there are also several case reports, as well as retrospective and prospective studies, documenting severe epistaxis episodes after specific medicines intake. In these cases some invasive medical interventions are demanded to manage the bleeding and avoid life-threatening consequences. This work provides an integrated and comprehensive review on drug-induced epistaxis bridging the gap in the current scientific literature addressing this topic. Therefore, the scientific information gathered and discussed will be valuable to raise awareness of doctors and pharmacists for this drug-related problem, as well as to promote their active

Nonacetaminophen Drug-Induced Acute Liver Failure.

PubMed

Thomas, Arul M; Lewis, James H

2018-05-01

Acute liver failure of all causes is diagnosed in between 2000 and 2500 patients annually in the United States. Drug-induced acute liver failure is the leading cause of acute liver failure, accounting for more than 50% of cases. Nonacetaminophen drug injury represents 11% of all cases in the latest registry from the US Acute Liver Failure Study Group. Although rare, acute liver failure is clinically dramatic when it occurs, and requires a multidisciplinary approach to management. In contrast with acetaminophen-induced acute liver failure, non-acetaminophen-induced acute liver failure has a more ominous prognosis with a lower liver transplant-free survival. Copyright © 2018 Elsevier Inc. All rights reserved.

Gap Junction Inhibition Prevents Drug-induced Liver Toxicity and Fulminant Hepatic Failure

PubMed Central

Patel, Suraj J; Milwid, Jack M; King, Kevin R; Bohr, Stefan; Iracheta, Arvin; Li, Matthew; Vitalo, Antonia; Parekkadan, Biju; Jindal, Rohit; Yarmush, Martin L

2013-01-01

Drug-induced liver injury (DILI) limits the development and utilization of numerous therapeutic compounds, and consequently presents major challenges to the pharmaceutical industry and clinical medicine1, 2. Acetaminophen (APAP) containing compounds are among the most frequently prescribed drugs, and also the most common cause of DILI3. Here we describe a pharmacological strategy that targets gap junction communication to prevent amplification of fulminant hepatic failure and APAP-induced hepatotoxicity. We report that connexin 32 (Cx32), a key hepatic gap junction protein, is an essential mediator of DILI by showing that mice deficient in Cx32 are protected against liver damage, acute inflammation, and death. We identified a small molecule inhibitor of Cx32 as a novel hepatoprotectant that achieves the same result in wildtype mice when coadministered with known hepatotoxic drugs. These findings demonstrate that gap junction inhibition is an effective therapy for limiting DILI, and suggest a novel pharmaceutical strategy to improve drug safety. PMID:22252509

Selective activation of heteromeric SK channels contributes to action potential repolarization in mouse atrial myocytes.

PubMed

Hancock, Jane M; Weatherall, Kate L; Choisy, Stéphanie C; James, Andrew F; Hancox, Jules C; Marrion, Neil V

2015-05-01

Activation of small conductance calcium-activated potassium (SK) channels is proposed to contribute to repolarization of the action potential in atrial myocytes. This role is controversial, as these cardiac SK channels appear to exhibit an uncharacteristic pharmacology. The objectives of this study were to resolve whether activation of SK channels contributes to atrial action potential repolarization and to determine the likely subunit composition of the channel. The effect of 2 SK channel inhibitors was assessed on outward current evoked in voltage clamp and on action potential duration in perforated patch and whole-cell current clamp recording from acutely isolated mouse atrial myocytes. The presence of SK channel subunits was assessed using immunocytochemistry. A significant component of outward current was reduced by the SK channel blockers apamin and UCL1684. Block by apamin displayed a sensitivity indicating that this current was carried by homomeric SK2 channels. Action potential duration was significantly prolonged by UCL1684, but not by apamin. This effect was accompanied by an increase in beat-to-beat variability and action potential triangulation. This pharmacology was matched by that of expressed heteromeric SK2-SK3 channels in HEK293 cells. Immunocytochemistry showed that atrial myocytes express both SK2 and SK3 channels with an overlapping expression pattern. Only proposed heteromeric SK2-SK3 channels are physiologically activated to contribute to action potential repolarization, which is indicated by the difference in pharmacology of evoked outward current and prolongation of atrial action potential duration. The effect of blocking this channel on the action potential suggests that SK channel inhibition during cardiac function has the potential to be proarrhythmic. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Drug induced acute pancreatitis: incidence and severity.

PubMed Central

Lankisch, P G; Dröge, M; Gottesleben, F

1995-01-01

To determine the incidence and severity of drug induced acute pancreatitis, data from 45 German centres of gastroenterology were evaluated. Among 1613 patients treated for acute pancreatitis in 1993, drug induced acute pancreatitis was diagnosed in 22 patients (incidence 1.4%). Drugs held responsible were azathioprine, mesalazine/sulfasalazine, 2',3'-dideoxyinosine (ddI), oestrogens, frusemide, hydrochlorothiazide, and rifampicin. Pancreatic necrosis not exceeding 33% of the organ was found on ultrasonography or computed tomography, or both, in three patients (14%). Pancreatic pseudocysts did not occur. A decrease of arterial PO2 reflecting respiratory insufficiency, and an increase of serum creatinine, reflecting renal insufficiency as complications of acute pancreatitis were seen in two (9%) and four (18%) patients, respectively. Artificial ventilation was not needed, and dialysis was necessary in only one (5%) case. Two patients (9%) died of AIDS and tuberculosis, respectively; pancreatitis did not seem to have contributed materially to their death. In conclusion, drugs rarely cause acute pancreatitis, and drug induced acute pancreatitis usually runs a benign course. PMID:7489946

Non-steroidal anti-inflammatory drug-induced small bowel injuries identified by double-balloon endoscopy

PubMed Central

Hayashi, Yoshikazu; Yamamoto, Hironori; Kita, Hiroto; Sunada, Keijiro; Sato, Hiroyuki; Yano, Tomonori; Iwamoto, Michiko; Sekine, Yutaka; Miyata, Tomohiko; Kuno, Akiko; Iwaki, Takaaki; Kawamura, Yoshiyuki; Ajibe, Hironari; Ido, Kenichi; Sugano, Kentaro

2005-01-01

AIM: To clarify clinical features of the NSAID-induced small bowel lesions using a new method of endoscopy. METHODS: This is a retrospective study and we analyzed seven patients with small bowel lesions while taking NSAIDs among 61 patients who had undergone double-balloon endoscopy because of gastro-intestinal bleeding or anemia between September 2000 and March 2004, at Jichi Medical School Hospital in Japan. Neither conventional EGD nor colonoscopy revealed any lesions of potential bleeding sources including ulcerations. Double-balloon endoscopy was carried out from oral approach in three patients, from anal approach in three patients, and from both approaches in one patient. RESULTS: Ulcers or erosions were observed in the ileum in six patients and in the jejunum in one patient, respectively. The ulcers were multiple in all the patients with different features from tiny punched out ulcers to deep ulcerations with oozing hemorrhage or scar. All the patients recovered uneventfully and had full resolution of symptoms after suspension of the drug. CONCLUSION: NSAIDs can induce injuries in the small bowel even in patients without any lesions in both the stomach and colon. PMID:16097059

High-throughput identification of off-targets for the mechanistic study of severe adverse drug reactions induced by analgesics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Jian-Bo; Ji, Nan; Pan, Wen

2014-01-01

Drugs may induce adverse drug reactions (ADRs) when they unexpectedly bind to proteins other than their therapeutic targets. Identification of these undesired protein binding partners, called off-targets, can facilitate toxicity assessment in the early stages of drug development. In this study, a computational framework was introduced for the exploration of idiosyncratic mechanisms underlying analgesic-induced severe adverse drug reactions (SADRs). The putative analgesic-target interactions were predicted by performing reverse docking of analgesics or their active metabolites against human/mammal protein structures in a high-throughput manner. Subsequently, bioinformatics analyses were undertaken to identify ADR-associated proteins (ADRAPs) and pathways. Using the pathways and ADRAPsmore » that this analysis identified, the mechanisms of SADRs such as cardiac disorders were explored. For instance, 53 putative ADRAPs and 24 pathways were linked with cardiac disorders, of which 10 ADRAPs were confirmed by previous experiments. Moreover, it was inferred that pathways such as base excision repair, glycolysis/glyconeogenesis, ErbB signaling, calcium signaling, and phosphatidyl inositol signaling likely play pivotal roles in drug-induced cardiac disorders. In conclusion, our framework offers an opportunity to globally understand SADRs at the molecular level, which has been difficult to realize through experiments. It also provides some valuable clues for drug repurposing. - Highlights: • A novel computational framework was developed for mechanistic study of SADRs. • Off-targets of drugs were identified in large scale and in a high-throughput manner. • SADRs like cardiac disorders were systematically explored in molecular networks. • A number of ADR-associated proteins were identified.« less

Drug repurposing identifies a synergistic combination therapy with imatinib mesylate for gastrointestinal stromal tumor.

PubMed

Pessetto, Ziyan Y; Ma, Yan; Hirst, Jeff J; von Mehren, Margaret; Weir, Scott J; Godwin, Andrew K

2014-10-01

Gastrointestinal stromal tumor (GIST) is a rare and therefore often neglected disease. Introduction of the kinase inhibitor imatinib mesylate radically improved the clinical response of patients with GIST; however, its effects are often short-lived, with GISTs demonstrating a median time-to-progression of approximately two years. Although many investigational drugs, approved first for other cancers, have been subsequently evaluated for the management of GIST, few have greatly affected the overall survival of patients with advanced disease. We employed a novel, focused, drug-repurposing effort for GIST, including imatinib mesylate-resistant GIST, evaluating a large library of FDA-approved drugs regardless of current indication. As a result of the drug-repurposing screen, we identified eight FDA-approved drugs, including fludarabine phosphate (F-AMP), that showed synergy with and/or overcame resistance to imatinib mesylate. F-AMP induces DNA damage, Annexin V, and caspase-3/7 activities as the cytotoxic effects on GIST cells, including imatinib mesylate-resistant GIST cells. F-AMP and imatinib mesylate combination treatment showed greater inhibition of GIST cell proliferation when compared with imatinib mesylate and F-AMP alone. Successful in vivo experiments confirmed the combination of imatinib mesylate with F-AMP enhanced the antitumor effects compared with imatinib mesylate alone. Our results identified F-AMP as a promising, repurposed drug therapy for the treatment of GISTs, with potential to be administered in combination with imatinib mesylate or for treatment of imatinib mesylate-refractory tumors. ©2014 American Association for Cancer Research.

A Comparative Analysis of Drug-Induced Hepatotoxicity in Clinically Relevant Situations

PubMed Central

Thiel, Christoph; Cordes, Henrik; Fabbri, Lorenzo; Aschmann, Hélène Eloise; Baier, Vanessa; Atkinson, Francis; Blank, Lars Mathias; Kuepfer, Lars

2017-01-01

Drug-induced toxicity is a significant problem in clinical care. A key problem here is a general understanding of the molecular mechanisms accompanying the transition from desired drug effects to adverse events following administration of either therapeutic or toxic doses, in particular within a patient context. Here, a comparative toxicity analysis was performed for fifteen hepatotoxic drugs by evaluating toxic changes reflecting the transition from therapeutic drug responses to toxic reactions at the cellular level. By use of physiologically-based pharmacokinetic modeling, in vitro toxicity data were first contextualized to quantitatively describe time-resolved drug responses within a patient context. Comparatively studying toxic changes across the considered hepatotoxicants allowed the identification of subsets of drugs sharing similar perturbations on key cellular processes, functional classes of genes, and individual genes. The identified subsets of drugs were next analyzed with regard to drug-related characteristics and their physicochemical properties. Toxic changes were finally evaluated to predict both molecular biomarkers and potential drug-drug interactions. The results may facilitate the early diagnosis of adverse drug events in clinical application. PMID:28151932

FXR: Big fish or small fry for drug-induced liver injury?

PubMed

Ballet, François

2016-02-01

By integrating network analysis and molecular modeling, a "system pharmacology" approach identified FXR as a potential off-target protein mediating non-steroidal anti-inflammatory drugs (NSAID)-induced liver injury. In vitro assays showed that NSAID are potent FXR antagonists that inhibit FXR transcriptional activity. Given the role of FXR in bile acid homeostasis, liver inflammation and cell proliferation, the data suggest that FXR antagonism could mediate, at least in part, NSAID-induced liver injury. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

High-throughput matrix screening identifies synergistic and antagonistic antimalarial drug combinations

PubMed Central

Mott, Bryan T.; Eastman, Richard T.; Guha, Rajarshi; Sherlach, Katy S.; Siriwardana, Amila; Shinn, Paul; McKnight, Crystal; Michael, Sam; Lacerda-Queiroz, Norinne; Patel, Paresma R.; Khine, Pwint; Sun, Hongmao; Kasbekar, Monica; Aghdam, Nima; Fontaine, Shaun D.; Liu, Dongbo; Mierzwa, Tim; Mathews-Griner, Lesley A.; Ferrer, Marc; Renslo, Adam R.; Inglese, James; Yuan, Jing; Roepe, Paul D.; Su, Xin-zhuan; Thomas, Craig J.

2015-01-01

Drug resistance in Plasmodium parasites is a constant threat. Novel therapeutics, especially new drug combinations, must be identified at a faster rate. In response to the urgent need for new antimalarial drug combinations we screened a large collection of approved and investigational drugs, tested 13,910 drug pairs, and identified many promising antimalarial drug combinations. The activity of known antimalarial drug regimens was confirmed and a myriad of new classes of positively interacting drug pairings were discovered. Network and clustering analyses reinforced established mechanistic relationships for known drug combinations and identified several novel mechanistic hypotheses. From eleven screens comprising >4,600 combinations per parasite strain (including duplicates) we further investigated interactions between approved antimalarials, calcium homeostasis modulators, and inhibitors of phosphatidylinositide 3-kinases (PI3K) and the mammalian target of rapamycin (mTOR). These studies highlight important targets and pathways and provide promising leads for clinically actionable antimalarial therapy. PMID:26403635

Idiosyncratic drug-induced agranulocytosis or acute neutropenia.

PubMed

Andrès, Emmanuel; Maloisel, Frédéric

2008-01-01

Idiosyncratic drug-induced agranulocytosis or acute neutropenia is an adverse event resulting in a neutrophil count of under 0.5 x 10/l. Patients with such severe neutropenia are likely to experience life-threatening and sometimes fatal infections. Over the last 20 years, the incidence of idiosyncratic drug-induced agranulocytosis or acute neutropenia has remained stable at 2.4-15.4 cases per million, despite the emergence of new causative drugs: antibiotics (beta-lactam and cotrimoxazole), antiplatelet agents (ticlopidine), antithyroid drugs, sulfasalazine, neuroleptics (clozapine), antiepileptic agents (carbamazepine), nonsteroidal anti-inflammatory agents and dipyrone. Drug-induced agranulocytosis remains a serious adverse event due to the occurrence of severe sepsis with severe deep infections (such as pneumonia), septicemia and septic shock in around two thirds of patients. In this setting, old age (>65 years), septicemia or shock, metabolic disorders such as renal failure, and a neutrophil count under 0.1 x 10/l are poor prognostic factors. Nevertheless with appropriate management using preestablished procedures, with intravenous broad-spectrum antibiotic therapy and hematopoietic growth factors, the mortality rate is currently around 5%. Given the increased life expectancy and subsequent longer exposure to drugs, as well as the development of new agents, healthcare professionals should be aware of this adverse event and its management.

Using Functional Signatures to Identify Repositioned Drugs for Breast, Myelogenous Leukemia and Prostate Cancer

PubMed Central

Shigemizu, Daichi; Hu, Zhenjun; Hung, Jui-Hung; Huang, Chia-Ling; Wang, Yajie; DeLisi, Charles

2012-01-01

The cost and time to develop a drug continues to be a major barrier to widespread distribution of medication. Although the genomic revolution appears to have had little impact on this problem, and might even have exacerbated it because of the flood of additional and usually ineffective leads, the emergence of high throughput resources promises the possibility of rapid, reliable and systematic identification of approved drugs for originally unintended uses. In this paper we develop and apply a method for identifying such repositioned drug candidates against breast cancer, myelogenous leukemia and prostate cancer by looking for inverse correlations between the most perturbed gene expression levels in human cancer tissue and the most perturbed expression levels induced by bioactive compounds. The method uses variable gene signatures to identify bioactive compounds that modulate a given disease. This is in contrast to previous methods that use small and fixed signatures. This strategy is based on the observation that diseases stem from failed/modified cellular functions, irrespective of the particular genes that contribute to the function, i.e., this strategy targets the functional signatures for a given cancer. This function-based strategy broadens the search space for the effective drugs with an impressive hit rate. Among the 79, 94 and 88 candidate drugs for breast cancer, myelogenous leukemia and prostate cancer, 32%, 13% and 17% respectively are either FDA-approved/in-clinical-trial drugs, or drugs with suggestive literature evidences, with an FDR of 0.01. These findings indicate that the method presented here could lead to a substantial increase in efficiency in drug discovery and development, and has potential application for the personalized medicine. PMID:22346740

Drug-induced lupus erythematosus.

PubMed

Marzano, A V; Tavecchio, S; Menicanti, C; Crosti, C

2014-06-01

Drug-induced lupus erythematosus (DI-LE) is defined as an entity characterized by clinical manifestations and immunopathological serum findings similar to those of idiopathic lupus but which is temporally related to drug exposure and resolves after withdrawal of the implicated drug. Similarly to idiopathic lupus, DI-LE can be divided into systemic LE, subacute cutaneous LE (SCLE), chronic cutaneous LE (CCLE) and cutaneous LE tumidus. DI-SCLE is the most frequent variant of drug-induced cutaneous LE and presents mainly with annular-polycyclic lesions; the clinical picture is often widespread, with involvement of the lower legs that are usually spared in idiopathic SCLE. ANA and anti-Ro/SSA antibodies are typically present, whereas antihistone antibodies are uncommonly found. We have recently addressed the question whether DI-SCLE differs significantly from its idiopathic counterpart by virtue of clinical features and, based on our findings, we have suggested that the frequent occurrence of malar rash and bullous, erythema multiforme-like and vasculitic manifestations can be regarded as the hallmark of DI-SCLE. In contrast, the histology is not a useful diagnostic criterion for DI-SCLE, considering that the typical pattern of lichenoid interface dermatitis is seen only in the early stage of disease and tissue eosinophilia does not represent a differentiating histopathological feature. DI-CCLE and DI-LE tumidus, albeit possibly misdiagnosed, are rarely observed and are characterized by classic discoid lesions and erythematous-oedematous plaques on sun exposed areas, respectively. Management of DI-LE is based on the discontinuation of the offending drug; topical and/or systemic corticosteroids and other immunomodulating/immunosuppressive agents should be reserved for resistant cases.

Case ascertainment and estimated incidence of drug-induced long-QT syndrome: study in Southwest France

PubMed Central

Molokhia, Mariam; Pathak, Atul; Lapeyre-Mestre, Maryse; Caturla, Laetitia; Montastruc, Jean Louis; McKeigue, Paul

2008-01-01

AIMS The aim of this study was to investigate the incidence and reporting rate of drug-induced long-QT syndrome (LQTS) in France [defined by evidence of torsades de pointes (TdP), QT prolongation and exposure to a relevant drug] and to assess feasibility of case collection for drug-induced LQTS. METHODS A retrospective population-based study was carried out in Southwest France in five institutions: three main hospitals, one private clinic and one cardiac emergency unit, searched from 1 January 1999 to 1 January 2005 (population coverage of 614 000). The study population consisted of 861 cases with International Classification of Diseases-10 diagnostic codes for ventricular tachycardia (I147.2), ventricular fibrillation (I149.0) and sudden cardiac death (I146.1) from hospital discharge summaries, supplemented by cases reported to national or regional pharmacovigilance systems, and voluntary reporting by physicians, validated according to internationally defined criteria for drug-induced LQTS. RESULTS Of 861 patients coded with arrhythmias or sudden cardiac death, there were 40 confirmed surviving acquired cases of drug-induced LQTS. We estimated that the incidence of those who survive to reach hospital drug-induced LQTS is approximately 10.9 per million annually in France (95% confidence interval 7.8, 14.8). CONCLUSIONS Many cases of drug-induced LQTS may not survive before they reach hospital, as the reporting rate for drug-induced LQTS identified through the cardiology records and also reported to pharmacovigilance systems for the Midi-Pyrenees area is 3/40 (7.5%). Using the methods outlined it is possible to assemble cases to study genetic susceptibility to drug-induced LQTS and adapt these methods more widely. WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT Drug-induced long-QT syndrome (LQTS) is a potentially fatal condition that has led to a number of postmarketing withdrawals in recent years. However, many cases may not survive long enough to reach hospital, and

Primary psychosis with comorbid drug abuse and drug-induced psychosis: Diagnostic and clinical evolution at follow up.

PubMed

Mauri, M C; Di Pace, C; Reggiori, A; Paletta, S; Colasanti, A

2017-10-01

The study reports a follow-up assessment of 48 patients with concomitant drug abuse at the first admission for psychosis. We focused on the diagnostic distinction between primary psychosis with concomitant drug abuse and drug induced psychosis, to observe whether the diagnoses are stable over time and whether the clinical course significantly differs. The study examined 25 primary psychotic disorder with comorbid drug abuse and 23 drug-induced psychotic disorder patients. Diagnostic and psychopathological assessments were made at baseline and at follow-up. Mean follow-up period was 4.96 years. Patients with comorbid Drug Abuse exhibited higher scores in the item Unusual Content of Thought at baseline than drug-induced psychotic disorder patients: 5.48 vs 4.39 while the two patients groups did not differ in any of the BPRS items evaluated at follow-up. The primary psychosis with comorbid drug abuse and the substance induced psychosis groups were similar regarding diagnostic stability, and a diagnosis of schizophrenia at follow-up occurred similarly. There was no evidence that Drug Induced psychotic patients' symptoms tend to improve more after cessation of drug abuse. An earlier age of onset was found in primary psychotic patients, particularly for patients diagnosed as affected by schizophrenia at follow up. These results might reflect the uncertainty of the distinction between Primary and Drug Induced Psychosis and the difficulties in applying the DSM IV-TR criteria for diagnosing comorbid drug use disorders and psychotic disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

MicroRNAs and Drug-induced Kidney Injury

PubMed Central

Pavkovic, Mira; Vaidya, Vishal S.

2016-01-01

Drug-induced kidney injury (DIKI) is a severe complication in hospitalized patients associated with higher probabilities of developing progressive chronic kidney disease or end-stage renal diseases. Furthermore, DIKI is a problem during preclinical and clinical phases of drug development leading to high rates of project terminations. Understanding the molecular perturbations caused by DIKI would pave the way for a new class of therapeutics to mitigate the damage. Yet, another approach to ameliorate DIKI is identifying sensitive and specific translational biomarkers that outperform the current diagnostic analytes like serum creatinine and facilitate early diagnosis. MicroRNAs (miRNAs), a class of non-coding RNAs, are increasingly being recognized to have a two-pronged approach towards DIKI management: 1) miRNAs have a regulatory role in gene expression and signaling pathways thereby making them novel interventional targets and 2) miRNAs enable diagnosis and prognosis of DIKI because of their stable presence in biofluids. In this review, apart from summarizing the literature on miRNAs in DIKI, we report small RNA sequencing results showing miRNA expression profiles at baseline in normal kidney samples from mice and humans. Additionally, we also compared the miRNA expression in biopsies of normal human kidneys to patients with acute tubular necrosis, and found 76 miRNAs significantly downregulated and 47 miRNAs upregulated (FDR adjusted p<0.05, +/−2-fold change). In summary, we highlight the transformative potential of miRNAs in therapeutics and translational medicine with a focus on drug-induced kidney damage. PMID:27126472

Drug-Induced Anaphylaxis in Latin American Countries.

PubMed

Jares, Edgardo José; Baena-Cagnani, Carlos E; Sánchez-Borges, Mario; Ensina, Luis Felipe C; Arias-Cruz, Alfredo; Gómez, Maximiliano; Cuello, Mabel Noemi; Morfin-Maciel, Blanca María; De Falco, Alicia; Barayazarra, Susana; Bernstein, Jonathan A; Serrano, Carlos; Monsell, Silvana; Schuhl, Juan; Cardona-Villa, Ricardo

2015-01-01

Information regarding the clinical features and management of drug-induced anaphylaxis (DIA) in Latin America is lacking. The objective of this study was to assess implicated medications, demographics, and treatments received for DIA in Latin American patients referred to national specialty centers for evaluation. A database previously used to compile information on drug-induced allergic reactions in 11 Latin American countries was used to identify and characterize patients presenting specifically with a clinical diagnosis of DIA. Information regarding clinical presentation, causative agent(s), diagnostic studies performed, treatment, and contributing factors associated with increased reaction severity was analyzed. There were 1005 patients evaluated for possible drug hypersensitivity reactions during the study interval, and 264 (26.3%) met criteria for DIA. DIA was more frequent in adults and in elderly females (N = 129 [76.6%] and N = 30 [75%], respectively) compared with children and/or adolescents (N = 21 [42.9%], P < .01). Severe DIA was less frequent with underlying asthma (N = 22 vs 35 [38.6% vs 61.4%], P < .05) or atopy (N = 62 vs 71 [43% vs 59% ], P < .01). Nonsteroidal anti-inflammatory drugs (NSAIDs) (N = 178 [57.8%]), beta-lactam antibiotics (N = 44 [14.3%]), and other antibiotics (N = 16 [5.2%]) were the most frequently implicated drug classes. Anaphylaxis was rated as severe in N = 133 (50.4%) and anaphylactic shock (AS) was present in N = 90 (34.1%). Epinephrine was only used in N = 73 (27.6%) overall, but in N = 70 (77.8%) of patients with AS. In Latin American patients referred for evaluation of DIA, NSAIDs and antibiotics were implicated in approximately 80% of cases. Most of these reactions were treated in the emergency department. Epinephrine was administered in only 27.6% of all cases, although more frequently for anaphylactic shock. Dissemination of anaphylaxis guidelines among emergency department physicians should be encouraged to improve

The Application of Root Mean Square Electrocardiography (RMS ECG) for the Detection of Acquired and Congenital Long QT Syndrome

PubMed Central

Lux, Robert L.; Sower, Christopher Todd; Allen, Nancy; Etheridge, Susan P.; Tristani-Firouzi, Martin; Saarel, Elizabeth V.

2014-01-01

Background Precise measurement of the QT interval is often hampered by difficulty determining the end of the low amplitude T wave. Root mean square electrocardiography (RMS ECG) provides a novel alternative measure of ventricular repolarization. Experimental data have shown that the interval between the RMS ECG QRS and T wave peaks (RTPK) closely reflects the mean ventricular action potential duration while the RMS T wave width (TW) tracks the dispersion of repolarization timing. Here, we tested the precision of RMS ECG to assess ventricular repolarization in humans in the setting of drug-induced and congenital Long QT Syndrome (LQTS). Methods RMS ECG signals were derived from high-resolution 24 hour Holter monitor recordings from 68 subjects after receiving placebo and moxifloxacin and from standard 12 lead ECGs obtained in 97 subjects with LQTS and 97 age- and sex-matched controls. RTPK, QTRMS and RMS TW intervals were automatically measured using custom software and compared to traditional QT measures using lead II. Results All measures of repolarization were prolonged during moxifloxacin administration and in LQTS subjects, but the variance of RMS intervals was significantly smaller than traditional lead II measurements. TW was prolonged during moxifloxacin and in subjects with LQT-2, but not LQT-1 or LQT-3. Conclusion These data validate the application of RMS ECG for the detection of drug-induced and congenital LQTS. RMS ECG measurements are more precise than the current standard of care lead II measurements. PMID:24454918

The application of root mean square electrocardiography (RMS ECG) for the detection of acquired and congenital long QT syndrome.

PubMed

Lux, Robert L; Sower, Christopher Todd; Allen, Nancy; Etheridge, Susan P; Tristani-Firouzi, Martin; Saarel, Elizabeth V

2014-01-01

Precise measurement of the QT interval is often hampered by difficulty determining the end of the low amplitude T wave. Root mean square electrocardiography (RMS ECG) provides a novel alternative measure of ventricular repolarization. Experimental data have shown that the interval between the RMS ECG QRS and T wave peaks (RTPK) closely reflects the mean ventricular action potential duration while the RMS T wave width (TW) tracks the dispersion of repolarization timing. Here, we tested the precision of RMS ECG to assess ventricular repolarization in humans in the setting of drug-induced and congenital Long QT Syndrome (LQTS). RMS ECG signals were derived from high-resolution 24 hour Holter monitor recordings from 68 subjects after receiving placebo and moxifloxacin and from standard 12 lead ECGs obtained in 97 subjects with LQTS and 97 age- and sex-matched controls. RTPK, QTRMS and RMS TW intervals were automatically measured using custom software and compared to traditional QT measures using lead II. All measures of repolarization were prolonged during moxifloxacin administration and in LQTS subjects, but the variance of RMS intervals was significantly smaller than traditional lead II measurements. TW was prolonged during moxifloxacin and in subjects with LQT-2, but not LQT-1 or LQT-3. These data validate the application of RMS ECG for the detection of drug-induced and congenital LQTS. RMS ECG measurements are more precise than the current standard of care lead II measurements.

Heterogeneity of ventricular repolarization in newborns with intrauterine growth restriction.

PubMed

Fouzas, Sotirios; Karatza, Ageliki A; Davlouros, Periklis A; Chrysis, Dionisios; Alexopoulos, Dimitrios; Mantagos, Stefanos; Dimitriou, Gabriel

2014-12-01

Intrauterine growth restriction (IUGR) is associated with structural and functional cardiac alterations but the electrophysiological consequences of these disturbances remain unknown. To explore the distribution of ventricular repolarization and its relation to myocardial mechanics in newborns with IUGR. STUDY DESIGN, SUBJECTS AND OUTCOME MEASUREMENTS: Conventional and tissue Doppler echocardiographic data, and electrocardiographic parameters used to describe the distribution of ventricular repolarization (dispersion of QT [QTd] and JT [JTd]), were obtained on the second (D2) and fifth (D5) postnatal day and compared between 25 IUGR newborns and 25 matched-for-gestational age controls. IUGR was associated with relative interventricular septum hypertrophy, increased left ventricular (LV) E/E' ratio and higher LV myocardial performance index (MPI). On both study days, the IUGR infants presented higher QTd and JTd compared to controls (QTd-D2: 66±20 ms vs. 36±12 ms, P<0.001; JTd-D2: 54±13 ms vs. 34±9 ms, P<0.001; QTd-D5: 61±14 ms vs. 27±12 ms, P<0.001; JTd-D5: 54±13 ms vs. 27±9 ms, P<0.001). The association between QTd and LV E/E' (D2: regression coefficient beta 0.747, R(2) 0.585; D5: beta 0.843, R(2) 0.646) and QTd and MPI (D2: beta 0.680, R(2) 0.576; D5: beta 0.698, R(2) 0.650) was also significant (P<0.001 for all analyses). Our findings suggest that IUGR is associated with electrophysiological remodeling of the neonatal heart, a process which is closely related to the underlying alterations in ventricular mechanics and might predispose to adverse electrophysiological events. Copyright © 2014 Elsevier Ltd. All rights reserved.

Timing of myocardial trpm7 deletion during cardiogenesis variably disrupts adult ventricular function, conduction, and repolarization.

PubMed

Sah, Rajan; Mesirca, Pietro; Mason, Xenos; Gibson, William; Bates-Withers, Christopher; Van den Boogert, Marjolein; Chaudhuri, Dipayan; Pu, William T; Mangoni, Matteo E; Clapham, David E

2013-07-09

Transient receptor potential (TRP) channels are a superfamily of broadly expressed ion channels with diverse physiological roles. TRPC1, TRPC3, and TRPC6 are believed to contribute to cardiac hypertrophy in mouse models. Human mutations in TRPM4 have been linked to progressive familial heart block. TRPM7 is a divalent-permeant channel and kinase of unknown function, recently implicated in the pathogenesis of atrial fibrillation; however, its function in ventricular myocardium remains unexplored. We generated multiple cardiac-targeted knockout mice to test the hypothesis that TRPM7 is required for normal ventricular function. Early cardiac Trpm7 deletion (before embryonic day 9; TnT/Isl1-Cre) results in congestive heart failure and death by embryonic day 11.5 as a result of hypoproliferation of the compact myocardium. Remarkably, Trpm7 deletion late in cardiogenesis (about embryonic day 13; αMHC-Cre) produces viable mice with normal adult ventricular size, function, and myocardial transcriptional profile. Trpm7 deletion at an intermediate time point results in 50% of mice developing cardiomyopathy associated with heart block, impaired repolarization, and ventricular arrhythmias. Microarray analysis reveals elevations in transcripts of hypertrophy/remodeling genes and reductions in genes important for suppressing hypertrophy (Hdac9) and for ventricular repolarization (Kcnd2) and conduction (Hcn4). These transcriptional changes are accompanied by action potential prolongation and reductions in transient outward current (Ito; Kcnd2). Similarly, the pacemaker current (If; Hcn4) is suppressed in atrioventricular nodal cells, accounting for the observed heart block. Trpm7 is dispensable in adult ventricular myocardium under basal conditions but is critical for myocardial proliferation during early cardiogenesis. Loss of Trpm7 at an intermediate developmental time point alters the myocardial transcriptional profile in adulthood, impairing ventricular function, conduction

A hidden Markov model to assess drug-induced sleep fragmentation in the telemetered rat.

PubMed

Diack, C; Ackaert, O; Ploeger, B A; van der Graaf, P H; Gurrell, R; Ivarsson, M; Fairman, D

2011-12-01

Drug-induced sleep fragmentation can cause sleep disturbances either via their intended pharmacological action or as a side effect. Examples of disturbances include excessive daytime sleepiness, insomnia and nightmares. Developing drugs without these side effects requires insight into the mechanisms leading to sleep disturbance. The characterization of the circadian sleep pattern by EEG following drug exposure has improved our understanding of these mechanisms and their translatability across species. The EEG shows frequent transitions between specific sleep states leading to multiple correlated sojourns in these states. We have developed a Markov model to consider the high correlation in the data and quantitatively compared sleep disturbance in telemetered rats induced by methylphenidate, which is known to disturb sleep, and of a new chemical entity (NCE). It was assumed that these drugs could either accelerate or decelerate the transitions between the sleep states. The difference in sleep disturbance of methylphenidate and the NCE were quantitated and different mechanisms of action on rebound sleep were identified. The estimated effect showed that both compounds induce sleep fragmentation with methylphenidate being fivefold more potent compared to the NCE.

A side-effect free method for identifying cancer drug targets.

PubMed

Ashraf, Md Izhar; Ong, Seng-Kai; Mujawar, Shama; Pawar, Shrikant; More, Pallavi; Paul, Somnath; Lahiri, Chandrajit

2018-04-27

Identifying effective drug targets, with little or no side effects, remains an ever challenging task. A potential pitfall of failing to uncover the correct drug targets, due to side effect of pleiotropic genes, might lead the potential drugs to be illicit and withdrawn. Simplifying disease complexity, for the investigation of the mechanistic aspects and identification of effective drug targets, have been done through several approaches of protein interactome analysis. Of these, centrality measures have always gained importance in identifying candidate drug targets. Here, we put forward an integrated method of analysing a complex network of cancer and depict the importance of k-core, functional connectivity and centrality (KFC) for identifying effective drug targets. Essentially, we have extracted the proteins involved in the pathways leading to cancer from the pathway databases which enlist real experimental datasets. The interactions between these proteins were mapped to build an interactome. Integrative analyses of the interactome enabled us to unearth plausible reasons for drugs being rendered withdrawn, thereby giving future scope to pharmaceutical industries to potentially avoid them (e.g. ESR1, HDAC2, F2, PLG, PPARA, RXRA, etc). Based upon our KFC criteria, we have shortlisted ten proteins (GRB2, FYN, PIK3R1, CBL, JAK2, LCK, LYN, SYK, JAK1 and SOCS3) as effective candidates for drug development.

Drug Induced Hearing Loss: What Is Ototoxicity?

MedlinePlus

... page please turn JavaScript on. Feature: Drug-Induced Hearing Loss What Is Ototoxicity? Past Issues / Spring 2016 ... of patients taking these drugs." "Antibiotics Caused My Hearing Loss..." Gulab Lalwani Photo Courtesy of: Gulab Lalwani ...

Stress-Induced Reinstatement of Drug Seeking: 20 Years of Progress

PubMed Central

Mantsch, John R; Baker, David A; Funk, Douglas; Lê, Anh D; Shaham, Yavin

2016-01-01

In human addicts, drug relapse and craving are often provoked by stress. Since 1995, this clinical scenario has been studied using a rat model of stress-induced reinstatement of drug seeking. Here, we first discuss the generality of stress-induced reinstatement to different drugs of abuse, different stressors, and different behavioral procedures. We also discuss neuropharmacological mechanisms, and brain areas and circuits controlling stress-induced reinstatement of drug seeking. We conclude by discussing results from translational human laboratory studies and clinical trials that were inspired by results from rat studies on stress-induced reinstatement. Our main conclusions are (1) The phenomenon of stress-induced reinstatement, first shown with an intermittent footshock stressor in rats trained to self-administer heroin, generalizes to other abused drugs, including cocaine, methamphetamine, nicotine, and alcohol, and is also observed in the conditioned place preference model in rats and mice. This phenomenon, however, is stressor specific and not all stressors induce reinstatement of drug seeking. (2) Neuropharmacological studies indicate the involvement of corticotropin-releasing factor (CRF), noradrenaline, dopamine, glutamate, kappa/dynorphin, and several other peptide and neurotransmitter systems in stress-induced reinstatement. Neuropharmacology and circuitry studies indicate the involvement of CRF and noradrenaline transmission in bed nucleus of stria terminalis and central amygdala, and dopamine, CRF, kappa/dynorphin, and glutamate transmission in other components of the mesocorticolimbic dopamine system (ventral tegmental area, medial prefrontal cortex, orbitofrontal cortex, and nucleus accumbens). (3) Translational human laboratory studies and a recent clinical trial study show the efficacy of alpha-2 adrenoceptor agonists in decreasing stress-induced drug craving and stress-induced initial heroin lapse. PMID:25976297

Identifying Drug-Drug Interactions by Data Mining: A Pilot Study of Warfarin-Associated Drug Interactions.

PubMed

Hansen, Peter Wæde; Clemmensen, Line; Sehested, Thomas S G; Fosbøl, Emil Loldrup; Torp-Pedersen, Christian; Køber, Lars; Gislason, Gunnar H; Andersson, Charlotte

2016-11-01

Knowledge about drug-drug interactions commonly arises from preclinical trials, from adverse drug reports, or based on knowledge of mechanisms of action. Our aim was to investigate whether drug-drug interactions were discoverable without prior hypotheses using data mining. We focused on warfarin-drug interactions as the prototype. We analyzed altered prothrombin time (measured as international normalized ratio [INR]) after initiation of a novel prescription in previously INR-stable warfarin-treated patients with nonvalvular atrial fibrillation. Data sets were retrieved from clinical work. Random forest (a machine-learning method) was set up to predict altered INR levels after novel prescriptions. The most important drug groups from the analysis were further investigated using logistic regression in a new data set. Two hundred and twenty drug groups were analyzed in 61 190 novel prescriptions. We rediscovered 2 drug groups having known interactions (β-lactamase-resistant penicillins [dicloxacillin] and carboxamide derivatives) and 3 antithrombotic/anticoagulant agents (platelet aggregation inhibitors excluding heparin, direct thrombin inhibitors [dabigatran etexilate], and heparins) causing decreasing INR. Six drug groups with known interactions were rediscovered causing increasing INR (antiarrhythmics class III [amiodarone], other opioids [tramadol], glucocorticoids, triazole derivatives, and combinations of penicillins, including β-lactamase inhibitors) and two had a known interaction in a closely related drug group (oripavine derivatives [buprenorphine] and natural opium alkaloids). Antipropulsives had an unknown signal of increasing INR. We were able to identify known warfarin-drug interactions without a prior hypothesis using clinical registries. Additionally, we discovered a few potentially novel interactions. This opens up for the use of data mining to discover unknown drug-drug interactions in cardiovascular medicine. © 2016 American Heart Association

Drug-induced liver injury: Do we know everything?

PubMed Central

Alempijevic, Tamara; Zec, Simon; Milosavljevic, Tomica

2017-01-01

Interest in drug-induced liver injury (DILI) has dramatically increased over the past decade, and it has become a hot topic for clinicians, academics, pharmaceutical companies and regulatory bodies. By investigating the current state of the art, the latest scientific findings, controversies, and guidelines, this review will attempt to answer the question: Do we know everything? Since the first descriptions of hepatotoxicity over 70 years ago, more than 1000 drugs have been identified to date, however, much of our knowledge of diagnostic and pathophysiologic principles remains unchanged. Clinically ranging from asymptomatic transaminitis and acute or chronic hepatitis, to acute liver failure, DILI remains a leading causes of emergent liver transplant. The consumption of unregulated herbal and dietary supplements has introduced new challenges in epidemiological assessment and clinician management. As such, numerous registries have been created, including the United States Drug-Induced Liver Injury Network, to further our understanding of all aspects of DILI. The launch of LiverTox and other online hepatotoxicity resources has increased our awareness of DILI. In 2013, the first guidelines for the diagnosis and management of DILI, were offered by the Practice Parameters Committee of the American College of Gastroenterology, and along with the identification of risk factors and predictors of injury, novel mechanisms of injury, refined causality assessment tools, and targeted treatment options have come to define the current state of the art, however, gaps in our knowledge still undoubtedly remain. PMID:28443154

Assessment of mitochondrial dysfunction-related, drug-induced hepatotoxicity in primary rat hepatocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Cong; Sekine, Shuichi, E-mail: ssekine@facult

Evidence that mitochondrial dysfunction plays a central role in drug-induced liver injury is rapidly accumulating. In contrast to physiological conditions, in which almost all adenosine triphosphate (ATP) in hepatocytes is generated in mitochondria via aerobic respiration, the high glucose content and limited oxygen supply of conventional culture systems force primary hepatocytes to generate most ATP via cytosolic glycolysis. Thus, such anaerobically poised cells are resistant to xenobiotics that impair mitochondrial function, and are not suitable to identify drugs with mitochondrial liabilities. In this study, primary rat hepatocytes were cultured in galactose-based medium, instead of the conventional glucose-based medium, and inmore » hyperoxia to improve the reliance of energy generation on aerobic respiration. Activation of mitochondria was verified by diminished cellular lactate release and increased oxygen consumption. These conditions improved sensitivity to the mitochondrial complex I inhibitor rotenone. Since oxidative stress is also a general cause of mitochondrial impairment, cells were exposed to test compounds in the presence of transferrin to increase the generation of reactive oxygen species via increased uptake of iron. Finally, 14 compounds with reported mitochondrial liabilities were tested to validate this new drug-induced mitochondrial toxicity assay. Overall, the culture of primary rat hepatocytes in galactose, hyperoxia and transferrin is a useful model for the identification of mitochondrial dysfunction-related drug-induced hepatotoxicity. - Highlights: • Drug-induced mitochondrial toxicity was evaluated using primary rat hepatocytes. • Galactose and hyperoxia could activate OXPHOS in primary rat hepatocytes. • Cells with enhanced OXPHOS exhibit improved sensitivity to mitochondrial toxins. • Transferrin potentiate mitochondrial toxicity via increased ROS production.« less

Drug-induced low blood sugar

MedlinePlus

Drug-induced low blood sugar is low blood glucose that results from taking medicine. ... Low blood sugar (hypoglycemia) is common in people with diabetes who are taking insulin or other medicines to control their diabetes. ...

Drug-Induced QTc Interval Prolongation: A Multicenter Study to Detect Drugs and Clinical Factors Involved in Every Day Practice.

PubMed

Keller, Guillermo A; Alvarez, Paulino A; Ponte, Marcelo L; Belloso, Waldo H; Bagnes, Claudia; Sparanochia, Cecilia; Gonzalez, Claudio D; Villa Etchegoyen, M Cecilia; Diez, Roberto A; Di Girolamo, Guillermo

2016-01-01

The actual prevalence of drug induced QTc prolongation in clinical practice is unknown. Our objective was to determine the occurrence and characteristics of drug-induced QT prolongation in several common clinical practices. Additionally, a subgroup of patients treated with dextropropoxyphene of particular interest for the regulatory authority was analysed. Medical history and comorbidities predisposing to QT interval prolongation were registered for 1270 patient requiring medical assistance that involved drug administration. Three ionograms and ECGs were performed: baseline, intra- and after treatment; QT interval was corrected with Bazzet formula. Among patients, 9.9% presented QTc >450/470 ms, 3% QTc > 500 ms, 12.7% ΔQTc >30 ms and 5.2% ΔQTc >60 ms. QTc prolongation associated with congestive heart failure, ischemic cardiopathy, diabetes, renal failure, arrhythmias, hypothyroidism, and bradycardia. At univariate analysis, clarithromycin, haloperidol, tramadol, amiodarone, glyceryl trinitrate, amoxicillin + clavulanic acid, amoxicillin + sulbactam, ampicillin + sulbactam, fentanyl, piperacillin + tazobactam, and diazepam prolonged QTc. Prolongation remained significantly associated with furosemide, clarithromycin, glyceryl trinitrate and betalactamase inhibitors after multivariate analysis. QT interval prolongation in everyday practice is frequent, in association to clinical factors and drugs that can be easily identified for monitoring and prevention strategies.

Withaferin-A, a steroidal lactone encapsulated mannose decorated liposomes ameliorates rheumatoid arthritis by intriguing the macrophage repolarization in adjuvant-induced arthritic rats.

PubMed

Sultana, Farhath; Neog, Manoj Kumar; Rasool, MahaboobKhan

2017-07-01

In order to develop a better therapeutic approach for the treatment of rheumatoid arthritis (RA), withaferin-A; a steroidal lactone incorporated with mannosylated liposomes (ML-WA) was administered to adjuvant induced arthritic rats in intent to target the synovial macrophages. The confocal microscopy studies showed a successful internalization of ML-WA in the primarily isolated synovial macrophages. Consequently, targeting synovial macrophages via ML-WA reduced the oxidative stress (ROS and NO), and paw edema, however, a progressive gain in the body weight was observed in AIA rats. ML-WA treatment upregulated the production of osteoprotegerin (OPG) and downregulated the release of receptor activator of nuclear factor-κB ligand (RANKL), favoring osteoclastogenesis negatively. Correspondingly, the ankle joints were found intact with no bone erosion and cartilage degradation in ML-WA treated AIA rats as evidenced by histopathological analysis. Also, synovial macrophage assessment showed that the concentration and the gene amplification of M1 macrophage mediated pro-inflammatory mediators (TNF-α, IL-1β, IL-6, MCP-1 and VEGF) were curtailed in ML-WA treated AIA rats. In contrast, anti-inflammatory cytokine (IL-10) was found abundantly released. Furthermore, the mRNA expression of the M1 surface marker (CD86) was found down regulated, whereas, M2 marker (CD163) was highly amplified in ML-WA treated synovial macrophages of arthritic rats. Cumulatively, our result signified that targeted delivery of ML-WA ameliorated the severity of inflammation and bone resorption in AIA rats via M1 to M2 macrophage repolarization. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of cardiac autonomic regulation and ventricular repolarization after off-pump coronary artery bypass grafting.

PubMed

Kalisnik, Jurij M; Avbelj, Viktor; Trobec, Roman; Ivaskovic, Daroslav; Vidmar, Gaj; Troise, Giovanni; Gersak, Borut

2006-01-01

Altered autonomic regulation precipitates cardiac arrhythmias and increases the risk of sudden cardiac death. This risk is further increased by changes in ventricular repolarization. Autonomic regulation is deranged in patients after myocardial on-pump revascularization. We aimed to clarify how off-pump coronary artery bypass grafting (CABG) affects postoperative cardiac autonomic regulation and ventricular repolarization within 4 weeks after CABG. Forty-two patients (mean age, 61.9 +/- 9.3 years; mean EURO score 2.6 +/- 1.9) were electively admitted for off-pump CABG. The electrocardiographic and respiratory waveform recordings were performed in the afternoon in the supine position for 10 minutes. Autonomic modulation was assessed using heart rate variability analysis. Power spectra were computed from 5-minute stable RR intervals using Fourier Transform analysis. Total power of spectra was defined in the range of 0.01 to 0.40 Hz, high-frequency power within 0.15 to 0.40 Hz, and low-frequency power within 0.04 to 0.15 Hz. Normalized power was defined as a ratio of power in each band/total power. The high- and low-frequency power as well as their normalized values indicated cardiac vagal and sympathetic modulation, respectively. Ventricular repolarization was assessed using QT interval, QT interval variability, and QT-RR interdependence analysis. QT intervals were determined from the beginning of the 5-minute segments. QT interval variability was evaluated by a T-wave template-matching algorithm. Pearson correlation between length of RR and QT interval was applied to study QT-RR characteristics. The results were tested for significance using the Fisher exact test, nonpaired t test, and analysis of variance; a P <.05 was considered significant. The frequency of arrhythmic events and heart rate increased from the fourth to the seventh postoperative day and returned to preoperative levels 4 weeks after CABG. Heart rate variability measures indicating autonomic

Changes in left ventricular repolarization and ion channel currents following a transient rate increase superimposed on bradycardia in anesthetized dogs.

PubMed

Rubart, M; Lopshire, J C; Fineberg, N S; Zipes, D P

2000-06-01

We previously demonstrated in dogs that a transient rate increase superimposed on bradycardia causes prolongation of ventricular refractoriness that persists for hours after resumption of bradycardia. In this study, we examined changes in membrane currents that are associated with this phenomenon. The whole cell, patch clamp technique was used to record transmembrane voltages and currents, respectively, in single mid-myocardial left ventricular myocytes from dogs with 1 week of complete AV block; dogs either underwent 1 hour of left ventricular pacing at 120 beats/min or did not undergo pacing. Pacing significantly heightened mean phase 1 and peak plateau amplitudes by approximately 6 and approximately 3 mV, respectively (P < 0.02), and prolonged action potential duration at 90% repolarization from 235+/-8 msec to 278+/-8 msec (1 Hz; P = 0.02). Rapid pacing-induced changes in transmembrane ionic currents included (1) a more pronounced cumulative inactivation of the 4-aminopyridine-sensitive transient outward K+ current, Ito, over the range of physiologic frequencies, resulting from a approximately 30% decrease in the population of quickly reactivating channels; (2) increases in peak density of L-type Ca2+ currents, I(Ca.L), by 15% to 35 % between +10 and +60 mV; and (3) increases in peak density of the Ca2+-activated chloride current, I(Cl.Ca), by 30% to 120% between +30 and +50 mV. Frequency-dependent reduction in Ito combined with enhanced I(Ca.L) causes an increase in net inward current that may be responsible for the observed changes in ventricular repolarization. This augmentation of net cation influx is partially antagonized by an increase in outward I(Ca.Cl).

Cardiac memory in patients with Wolff-Parkinson-White syndrome: noninvasive imaging of activation and repolarization before and after catheter ablation.

PubMed

Ghosh, Subham; Rhee, Edward K; Avari, Jennifer N; Woodard, Pamela K; Rudy, Yoram

2008-08-26

Cardiac memory refers to a change in ventricular repolarization induced by and persisting for minutes to months after cessation of a period of altered ventricular activation (eg, resulting from pacing or preexcitation in patients with Wolff-Parkinson-White syndrome). ECG imaging (ECGI) is a novel imaging modality for noninvasive electroanatomic mapping of epicardial activation and repolarization. Fourteen pediatric patients with Wolff-Parkinson-White syndrome and no other congenital disease, were imaged with ECGI a day before and 45 minutes, 1 week, and 1 month after successful catheter ablation. ECGI determined that preexcitation sites were consistent with sites of successful ablation in all cases to within a 1-hour arc of each atrioventricular annulus. In the preexcited rhythm, activation-recovery interval (ARI) was the longest (349+/-6 ms) in the area of preexcitation leading to high average base-to-apex ARI dispersion of 95+/-9 ms (normal is approximately 40 ms). The ARI dispersion remained the same 45 minutes after ablation, although the activation sequence was restored to normal. ARI dispersion was still high (79+/-9 ms) 1 week later and returned to normal (45+/-6 ms) 1 month after ablation. The study demonstrates that ECGI can noninvasively localize ventricular insertion sites of accessory pathways to guide ablation and evaluate its outcome in pediatric patients with Wolff-Parkinson-White syndrome. Wolff-Parkinson-White is associated with high ARI dispersion in the preexcited rhythm that persists after ablation and gradually returns to normal over a period of 1 month, demonstrating the presence of cardiac memory. The 1-month time course is consistent with transcriptional reprogramming and remodeling of ion channels.

Carbon monoxide induces cardiac arrhythmia via induction of the late Na+ current.

PubMed

Dallas, Mark L; Yang, Zhaokang; Boyle, John P; Boycott, Hannah E; Scragg, Jason L; Milligan, Carol J; Elies, Jacobo; Duke, Adrian; Thireau, Jérôme; Reboul, Cyril; Richard, Sylvain; Bernus, Olivier; Steele, Derek S; Peers, Chris

2012-10-01

Clinical reports describe life-threatening cardiac arrhythmias after environmental exposure to carbon monoxide (CO) or accidental CO poisoning. Numerous case studies describe disruption of repolarization and prolongation of the QT interval, yet the mechanisms underlying CO-induced arrhythmias are unknown. To understand the cellular basis of CO-induced arrhythmias and to identify an effective therapeutic approach. Patch-clamp electrophysiology and confocal Ca(2+) and nitric oxide (NO) imaging in isolated ventricular myocytes was performed together with protein S-nitrosylation to investigate the effects of CO at the cellular and molecular levels, whereas telemetry was used to investigate effects of CO on electrocardiogram recordings in vivo. CO increased the sustained (late) component of the inward Na(+) current, resulting in prolongation of the action potential and the associated intracellular Ca(2+) transient. In more than 50% of myocytes these changes progressed to early after-depolarization-like arrhythmias. CO elevated NO levels in myocytes and caused S-nitrosylation of the Na(+) channel, Na(v)1.5. All proarrhythmic effects of CO were abolished by the NO synthase inhibitor l-NAME, and reversed by ranolazine, an inhibitor of the late Na(+) current. Ranolazine also corrected QT variability and arrhythmias induced by CO in vivo, as monitored by telemetry. Our data indicate that the proarrhythmic effects of CO arise from activation of NO synthase, leading to NO-mediated nitrosylation of Na(V)1.5 and to induction of the late Na(+) current. We also show that the antianginal drug ranolazine can abolish CO-induced early after-depolarizations, highlighting a novel approach to the treatment of CO-induced arrhythmias.

Glucuronidation of Drugs and Drug-Induced Toxicity in Humanized UDP-Glucuronosyltransferase 1 Mice

PubMed Central

Kutsuno, Yuki; Itoh, Tomoo; Tukey, Robert H.

2014-01-01

UDP-glucuronosyltransferases (UGTs) are phase II drug-metabolizing enzymes that catalyze glucuronidation of various drugs. Although experimental rodents are used in preclinical studies to predict glucuronidation and toxicity of drugs in humans, species differences in glucuronidation and drug-induced toxicity have been reported. Humanized UGT1 mice in which the original Ugt1 locus was disrupted and replaced with the human UGT1 locus (hUGT1 mice) were recently developed. In this study, acyl-glucuronidations of etodolac, diclofenac, and ibuprofen in liver microsomes of hUGT1 mice were examined and compared with those of humans and regular mice. The kinetics of etodolac, diclofenac, and ibuprofen acyl-glucuronidation in hUGT1 mice were almost comparable to those in humans, rather than in mice. We further investigated the hepatotoxicity of ibuprofen in hUGT1 mice and regular mice by measuring serum alanine amino transferase (ALT) levels. Because ALT levels were increased at 6 hours after dosing in hUGT1 mice and at 24 hours after dosing in regular mice, the onset pattern of ibuprofen-induced liver toxicity in hUGT1 mice was different from that in regular mice. These data suggest that hUGT1 mice can be valuable tools for understanding glucuronidations of drugs and drug-induced toxicity in humans. PMID:24764149

A review of drug-induced liver injury databases.

PubMed

Luo, Guangwen; Shen, Yiting; Yang, Lizhu; Lu, Aiping; Xiang, Zheng

2017-09-01

Drug-induced liver injuries have been a major focus of current research in drug development, and are also one of the major reasons for the failure and withdrawal of drugs in development. Drug-induced liver injuries have been systematically recorded in many public databases, which have become valuable resources in this field. In this study, we provide an overview of these databases, including the liver injury-specific databases LiverTox, LTKB, Open TG-GATEs, LTMap and Hepatox, and the general databases, T3DB, DrugBank, DITOP, DART, CTD and HSDB. The features and limitations of these databases are summarized and discussed in detail. Apart from their powerful functions, we believe that these databases can be improved in several ways: by providing the data about the molecular targets involved in liver toxicity, by incorporating information regarding liver injuries caused by drug interactions, and by regularly updating the data.

In silico modeling to predict drug-induced phospholipidosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Sydney S.; Kim, Jae S.; Valerio, Luis G., E-mail: luis.valerio@fda.hhs.gov

2013-06-01

Drug-induced phospholipidosis (DIPL) is a preclinical finding during pharmaceutical drug development that has implications on the course of drug development and regulatory safety review. A principal characteristic of drugs inducing DIPL is known to be a cationic amphiphilic structure. This provides evidence for a structure-based explanation and opportunity to analyze properties and structures of drugs with the histopathologic findings for DIPL. In previous work from the FDA, in silico quantitative structure–activity relationship (QSAR) modeling using machine learning approaches has shown promise with a large dataset of drugs but included unconfirmed data as well. In this study, we report the constructionmore » and validation of a battery of complementary in silico QSAR models using the FDA's updated database on phospholipidosis, new algorithms and predictive technologies, and in particular, we address high performance with a high-confidence dataset. The results of our modeling for DIPL include rigorous external validation tests showing 80–81% concordance. Furthermore, the predictive performance characteristics include models with high sensitivity and specificity, in most cases above ≥ 80% leading to desired high negative and positive predictivity. These models are intended to be utilized for regulatory toxicology applied science needs in screening new drugs for DIPL. - Highlights: • New in silico models for predicting drug-induced phospholipidosis (DIPL) are described. • The training set data in the models is derived from the FDA's phospholipidosis database. • We find excellent predictivity values of the models based on external validation. • The models can support drug screening and regulatory decision-making on DIPL.« less

Conditioned Place Preference Induced by Licit Drugs: Establishment, Extinction, and Reinstatement

PubMed Central

Liu, Yu; Le Foll, Bernard; Liu, Yanli; Wang, Xi; Lu, Lin

2008-01-01

The conditioned place preference (CPP) model has been widely used to evaluate the rewarding effects of abused drugs, and recently, the extinction and reinstatement phases of this paradigm have been used to assess relapse to drug seeking. The vast majority of studies have focused on CPP induced by illicit drugs, such as psychostimulants and opioids. Although legal psychoactive drugs, such as ethanol, nicotine, and caffeine, are more widely used than illegal drugs, the establishment, extinction, and reinstatement of CPP produced by these licit drugs are less well understood. The present review discusses the extant research on CPP induced by legal drugs. We first describe the CPP model and discuss the behavioral procedures used to induce CPP for ethanol, nicotine, and caffeine. We then summarize the neuronal substrates that underlie CPP induced by these drugs from a genetic perspective. Finally, we draw on findings from pharmacological studies and discuss the neurotransmitters and neurohormones underlying CPP produced by ethanol, nicotine, and caffeine. PMID:19082419

Conditioned place preference induced by licit drugs: establishment, extinction, and reinstatement.

PubMed

Liu, Yu; Le Foll, Bernard; Liu, Yanli; Wang, Xi; Lu, Lin

2008-12-14

The conditioned place preference (CPP) model has been widely used to evaluate the rewarding effects of abused drugs, and recently, the extinction and reinstatement phases of this paradigm have been used to assess relapse to drug seeking. The vast majority of studies have focused on CPP induced by illicit drugs, such as psychostimulants and opioids. Although legal psychoactive drugs, such as ethanol, nicotine, and caffeine, are more widely used than illegal drugs, the establishment, extinction, and reinstatement of CPP produced by these licit drugs are less well understood. The present review discusses the extant research on CPP induced by legal drugs. We first describe the CPP model and discuss the behavioral procedures used to induce CPP for ethanol, nicotine, and caffeine. We then summarize the neuronal substrates that underlie CPP induced by these drugs from a genetic perspective. Finally, we draw on findings from pharmacological studies and discuss the neurotransmitters and neurohormones underlying CPP produced by ethanol, nicotine, and caffeine.

Ventricular fibrillation associated with early repolarization in a patient with thyroid storm.

PubMed

Ueno, Akira; Yamamoto, Takeshi; Sato, Naoki; Tanaka, Keiji

2010-11-01

We present a case of a 69-year-old male who was hospitalized for the treatment of thyroid storm due to Grave's disease, who presented with unexpected ventricular fibrillation (VF). The possible etiology was early repolarization (ER), characterized by J-point elevation in inferior and posterolateral leads, unmasked by the attenuation of beta-adrenergic effect with normalization of thyroid hormones and following the administration of a beta-blocker. Our case focuses attention on the occurrence of VF in a patient with ER during the treatment of hyperthyroidism, which to our knowledge is the first such report.

PTTG1 Attenuates Drug-Induced Cellular Senescence

PubMed Central

Tong, Yunguang; Zhao, Weijiang; Zhou, Cuiqi; Wawrowsky, Kolja; Melmed, Shlomo

2011-01-01

As PTTG1 (pituitary tumor transforming gene) abundance correlates with adverse outcomes in cancer treatment, we determined mechanisms underlying this observation by assessing the role of PTTG1 in regulating cell response to anti-neoplastic drugs. HCT116 cells devoid of PTTG1 (PTTG1−/−) exhibited enhanced drug sensitivity as assessed by measuring BrdU incorporation in vitro. Apoptosis, mitosis catastrophe or DNA damage were not detected, but features of senescence were observed using low doses of doxorubicin and TSA. The number of drug-induced PTTG1−/− senescent cells increased ∼4 fold as compared to WT PTTG1-replete cells (p<0.001). p21, an important regulator of cell senescence, was induced ∼3 fold in HCT116 PTTG1−/− cells upon doxorubicin or Trichostatin A treatment. Binding of Sp1, p53 and p300 to the p21 promoter was enhanced in PTTG1−/− cells after treatment, suggesting transcriptional regulation of p21. p21 knock down abrogated the observed senescent effects of these drugs, indicating that PTTG1 likely suppresses p21 to regulate drug-induced senescence. PTTG1 also regulated SW620 colon cancer cells response to doxorubicin and TSA mediated by p21. Subcutaneously xenografted PTTG1−/− HCT116 cells developed smaller tumors and exhibited enhanced responses to doxorubicin. PTTG1−/− tumor tissue derived from excised tumors exhibited increased doxorubicin-induced senescence. As senescence is a determinant of cell responses to anti-neoplastic treatments, these findings suggest PTTG1 as a tumor cell marker to predict anti-neoplastic treatment outcomes. PMID:21858218

Microvolt T-wave alternans and beat-to-beat variability of repolarization during early postischemic remodeling in a pig heart.

PubMed

Floré, Vincent; Claus, Piet; Antoons, Gudrun; Oosterhoff, Peter; Holemans, Patricia; Vos, Marc A; Sipido, Karin R; Willems, Rik

2011-07-01

Repolarization variability is considered to predict sudden cardiac death. T-wave alternans (TWA) has been the subject of exhaustive research, whereas beat-to-beat variability of repolarization (BVR) is a new parameter that possibly predicts proarrhythmia. How these parameters interact has not been tested. The purpose of this study was to compare TWA and BVR as predictors of proarrhythmic substrate early after myocardial infarction (MI). In nine pigs, MI was induced by 1-hour occlusion of the left anterior descending coronary artery. Cardiac magnetic resonance imaging was performed at day 21. Six sham pigs served as control. Spectral TWA was tested during right atrial pacing before induction of MI and after 21 days. BVR was calculated from 60 consecutive QT intervals. Magnetic resonance imaging showed transmural MI. TWA was negative in all pigs at clinical threshold rate and equally present in MI versus sham pigs at higher rates (170 bpm: 55% vs 50% positive TWA). In MI pigs, BVR of QT intervals increased significantly during acute ischemia (2.44 ± 0.43 ms vs 3.55 ± 0.41 ms, P <.01) and even more on day 21 (5.80 ± 1.12 ms), but it differed significantly from sham (2.14 ± 0.54 ms, P <.01). A clinical ventricular tachycardia induction protocol was positive in 2 of 8 MI pigs and in none of 6 shams. In early remodeling after MI, BVR at intrinsic heart rate was a consistent phenomenon, whereas TWA during atrial pacing or baseline QT-interval changes were not. TWA and BVR could reflect different post-MI remodeling processes. BVR may be a new technique for predicting a potentially proarrhythmic substrate in the early postinfarction period. Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

2010 drug packaging review: identifying problems to prevent errors.

PubMed

2011-06-01

Prescrire's analyses showed that the quality of drug packaging in 2010 still left much to be desired. Potentially dangerous packaging remains a significant problem: unclear labelling is source of medication errors; dosing devices for some psychotropic drugs create a risk of overdose; child-proof caps are often lacking; and too many patient information leaflets are misleading or difficult to understand. Everything that is needed for safe drug packaging is available; it is now up to regulatory agencies and drug companies to act responsibly. In the meantime, health professionals can help their patients by learning to identify the pitfalls of drug packaging and providing safe information to help prevent medication errors.

The discovery of drug-induced illness.

PubMed

Jick, H

1977-03-03

The increased use of drugs (and the concurrent increased risks of drug-induced illness) require definition of relevant research areas and strategy. For established marketed drugs, research needs depend on the magnitudes of risk of an illness from a drug and the base-line risk. With the drug risk high and the base-line risk low, the problem surfaces in premarketing studies or through the epidemic that develops after marketing. If the drug adds slightly to a high base-line risk, the effect is undetectable. When both risks are low, adverse effects can be discovered by chance, but systematic case-referent studies can speed discovery. If both risks are high, clinical trials and nonexperimental studies may be used. With both risks intermediate, systematic evaluations, especially case-referent studies are needed. Newly marketed drugs should be routinely evaluated through compulsory registration and follow-up study of the earliest users.

hERG trafficking inhibition in drug-induced lethal cardiac arrhythmia.

PubMed

Nogawa, Hisashi; Kawai, Tomoyuki

2014-10-15

Acquired long QT syndrome induced by non-cardiovascular drugs can cause lethal cardiac arrhythmia called torsades de points and is a significant problem in drug development. The prolongation of QT interval and cardiac action potential duration are mainly due to reduced physiological function of the rapidly activating voltage-dependent potassium channels encoded by human ether-a-go-go-related gene (hERG). Structurally diverse groups of drugs are known to directly inhibit hERG channel conductance. Therefore, the ability of acute hERG inhibition is routinely assessed at the preclinical stages in pharmaceutical testing. Recent findings indicated that chronic treatment with various drugs not only inhibits hERG channels but also decreases hERG channel expression in the plasma membrane of cardiomyocytes, which has become another concern in safety pharmacology. The mechanisms involve the disruption of hERG trafficking to the surface membrane or the acceleration of hERG protein degradation. From this perspective, we present a brief overview of mechanisms of drug-induced trafficking inhibition and pathological regulation. Understanding of drug-induced hERG trafficking inhibition may provide new strategies for predicting drug-induced QT prolongation and lethal cardiac arrhythmia in pharmaceutical drug development. Copyright © 2014 Elsevier B.V. All rights reserved.

The Role of Spatial Dispersion of Repolarization in Inherited and Acquired Sudden Cardiac Death Syndromes

PubMed Central

Antzelevitch, Charles

2007-01-01

This review examines the role of spatial electrical heterogeneity within ventricular myocardium on the function of the heart in health and disease. The cellular basis for transmural dispersion of repolarization (TDR) is reviewed and the hypothesis that amplification of spatial dispersion of repolarization underlies the development of life-threatening ventricular arrhythmias associated with inherited ion channelopathies is evaluated. The role of TDR in the long QT, short QT and Brugada syndromes as well as catecholaminergic polymorphic ventricular tachycardia (CPVT) are critically examined. In the long QT Syndrome, amplification of TDR is often secondary to preferential prolongation of the action potential duration (APD) of M cells, whereas in the Brugada Syndrome, it is thought to be due to selective abbreviation of the APD of right ventricular (RV) epicardium. Preferential abbreviation of APD of either endocardium or epicardium appears to be responsible for amplification of TDR in the short QT syndrome. In catecholaminergic polymorphic VT, reversal of the direction of activation of the ventricular wall is responsible for the increase in TDR. In conclusion, the long QT, short QT, Brugada and catecholaminergic polymorphic VT syndromes are pathologies with very different phenotypes and etiologies, but which share a common final pathway in causing sudden cardiac death. PMID:17586620

Screening approach for identifying candidate drugs and drug-drug interactions related to hip fracture risk in persons with Alzheimer disease.

PubMed

Tolppanen, Anna-Maija; Taipale, Heidi; Koponen, Marjaana; Tanskanen, Antti; Lavikainen, Piia; Paananen, Jussi; Tiihonen, Jari; Hartikainen, Sirpa

2017-08-01

To assess whether a "drugome-wide" screen with case-crossover design is a feasible approach for identifying candidate drugs and drug-drug interactions. All community-dwelling residents of Finland who received a clinically verified Alzheimer disease diagnosis in 2005 to 2011 and experienced incident hip fracture (HF) afterwards (N = 4851). Three scenarios were used to test the sensitivity of this approach (1) hazard period 0 to 30 and control period 31 to 61 days before HF, (2) hazard period 0 to 30 and control period 336 to 366 days before HF, and (3) hazard period 0 to 14 and control period 16 to 30 days before HF. Nine, 44, and 5 drugs were associated with increased HF risk and 8, 23, and 4 with decreased risk in scenarios 1, 2, and 3, respectively. Six drugs were identified with scenario 1 only and 54 and 1 with scenarios 2 and 3, respectively. Only six drugs (metoprolol, simvastatin, trimethoprim, codeine combinations, fentanyl, and paracetamol) were associated with HF in all scenarios, four with 1 and 2 (cefalexin, buprenorphine, olanzapine, and memantine), and one with 1 and 3 (enalapril) or 2 and 3 (ciprofloxacin). The direction of associations was the same in all/both scenarios. The interaction results were equally versatile, with hydroxocobalamin*oxazepam being the only interaction observed in all scenarios. Case-crossover analysis is a potential approach for identifying candidate drugs and drug-drug interactions associated with adverse events as it implicitly controls for fixed confounders. The results are highly dependent on applied hazard and control periods, but the choice of periods can help in targeting the analyses to different phases of drug use. Copyright © 2017 John Wiley & Sons, Ltd.

Protection against severe hypokalemia but impaired cardiac repolarization after intense rowing exercise in healthy humans receiving salbutamol.

PubMed

Atanasovska, Tania; Smith, Robert; Graff, Claus; Tran, Cao Thach; Melgaard, Jacob; Kanters, Jørgen K; Petersen, Aaron C; Tobin, Antony; Kjeldsen, Keld P; McKenna, Michael John

2018-05-10

Intense exercise induces pronounced hyperkalemia, followed by transient hypokalemia in recovery. We investigated whether the β 2 -agonist salbutamol attenuated the exercise-hyperkalemia, and exacerbated the post-exercise hypokalemia, and whether hypokalemia was associated with impaired cardiac repolarization (QT hysteresis). Eleven healthy adults participated in a randomized, counterbalanced, double-blind trial receiving either 1000 µg salbutamol (SAL) or placebo (PLAC) by inhalation. Arterial plasma potassium concentration ([K + ] a ) was measured at rest, during 3 min intense rowing exercise and 60 min recovery. QT hysteresis was calculated from ECG (n=8). [K + ] a increased above baseline during exercise (rest, 3.72{plus minus}0.7 vs end-exercise, 6.81{plus minus}1.4 mM, P<0.001, mean{plus minus}SD) and decreased rapidly during early recovery to below baseline; restoration was incomplete at 60 min post-exercise (P<0.05). [K + ] a was less during SAL than PLAC (4.39{plus minus}0.13 vs. 4.73{plus minus}0.19 mM, pooled across all times, P=0.001, treatment main effect). [K + ] a was lower after SAL than PLAC, from 2 min pre-exercise until 2.5 min during exercise, and at 50 and 60 min post-exercise (P<0.05). The post-exercise decline in [K + ] a was correlated with QT hysteresis (r=0.343, n=112, pooled data, P=0.001). Thus the decrease in [K + ] a from end-exercise by ~4 mM was associated with reduced QT hysteresis by ~75 ms. Whilst salbutamol lowered [K + ] a during exercise, no additive hypokalemic effects occurred in early recovery, suggesting there may be a protective mechanism against severe or prolonged hypokalemia after exercise when treated by salbutamol. This is important since post-exercise hypokalemia impaired cardiac repolarization, which could potentially trigger arrhythmias and sudden cardiac death in susceptible individuals with pre-existing hypokalemia and/or heart disease.

Common Genetic Variant Risk Score Is Associated With Drug-Induced QT Prolongation and Torsade de Pointes Risk: A Pilot Study.

PubMed

Strauss, David G; Vicente, Jose; Johannesen, Lars; Blinova, Ksenia; Mason, Jay W; Weeke, Peter; Behr, Elijah R; Roden, Dan M; Woosley, Ray; Kosova, Gulum; Rosenberg, Michael A; Newton-Cheh, Christopher

2017-04-04

Drug-induced QT interval prolongation, a risk factor for life-threatening ventricular arrhythmias, is a potential side effect of many marketed and withdrawn medications. The contribution of common genetic variants previously associated with baseline QT interval to drug-induced QT prolongation and arrhythmias is not known. We tested the hypothesis that a weighted combination of common genetic variants contributing to QT interval at baseline, identified through genome-wide association studies, can predict individual response to multiple QT-prolonging drugs. Genetic analysis of 22 subjects was performed in a secondary analysis of a randomized, double-blind, placebo-controlled, crossover trial of 3 QT-prolonging drugs with 15 time-matched QT and plasma drug concentration measurements. Subjects received single doses of dofetilide, quinidine, ranolazine, and placebo. The outcome was the correlation between a genetic QT score comprising 61 common genetic variants and the slope of an individual subject's drug-induced increase in heart rate-corrected QT (QTc) versus drug concentration. The genetic QT score was correlated with drug-induced QTc prolongation. Among white subjects, genetic QT score explained 30% of the variability in response to dofetilide ( r =0.55; 95% confidence interval, 0.09-0.81; P =0.02), 23% in response to quinidine ( r =0.48; 95% confidence interval, -0.03 to 0.79; P =0.06), and 27% in response to ranolazine ( r =0.52; 95% confidence interval, 0.05-0.80; P =0.03). Furthermore, the genetic QT score was a significant predictor of drug-induced torsade de pointes in an independent sample of 216 cases compared with 771 controls ( r 2 =12%, P =1×10 -7 ). We demonstrate that a genetic QT score comprising 61 common genetic variants explains a significant proportion of the variability in drug-induced QT prolongation and is a significant predictor of drug-induced torsade de pointes. These findings highlight an opportunity for recent genetic discoveries to

Chemotherapy drugs induce pyroptosis through caspase-3 cleavage of a gasdermin.

PubMed

Wang, Yupeng; Gao, Wenqing; Shi, Xuyan; Ding, Jingjin; Liu, Wang; He, Huabin; Wang, Kun; Shao, Feng

2017-07-06

Pyroptosis is a form of cell death that is critical for immunity. It can be induced by the canonical caspase-1 inflammasomes or by activation of caspase-4, -5 and -11 by cytosolic lipopolysaccharide. The caspases cleave gasdermin D (GSDMD) in its middle linker to release autoinhibition on its gasdermin-N domain, which executes pyroptosis via its pore-forming activity. GSDMD belongs to a gasdermin family that shares the pore-forming domain. The functions and mechanisms of activation of other gasdermins are unknown. Here we show that GSDME, which was originally identified as DFNA5 (deafness, autosomal dominant 5), can switch caspase-3-mediated apoptosis induced by TNF or chemotherapy drugs to pyroptosis. GSDME was specifically cleaved by caspase-3 in its linker, generating a GSDME-N fragment that perforates membranes and thereby induces pyroptosis. After chemotherapy, cleavage of GSDME by caspase-3 induced pyroptosis in certain GSDME-expressing cancer cells. GSDME was silenced in most cancer cells but expressed in many normal tissues. Human primary cells exhibited GSDME-dependent pyroptosis upon activation of caspase-3 by chemotherapy drugs. Gsdme -/- (also known as Dfna5 -/- ) mice were protected from chemotherapy-induced tissue damage and weight loss. These findings suggest that caspase-3 activation can trigger necrosis by cleaving GSDME and offer new insights into cancer chemotherapy.

UniDrug-target: a computational tool to identify unique drug targets in pathogenic bacteria.

PubMed

Chanumolu, Sree Krishna; Rout, Chittaranjan; Chauhan, Rajinder S

2012-01-01

Targeting conserved proteins of bacteria through antibacterial medications has resulted in both the development of resistant strains and changes to human health by destroying beneficial microbes which eventually become breeding grounds for the evolution of resistances. Despite the availability of more than 800 genomes sequences, 430 pathways, 4743 enzymes, 9257 metabolic reactions and protein (three-dimensional) 3D structures in bacteria, no pathogen-specific computational drug target identification tool has been developed. A web server, UniDrug-Target, which combines bacterial biological information and computational methods to stringently identify pathogen-specific proteins as drug targets, has been designed. Besides predicting pathogen-specific proteins essentiality, chokepoint property, etc., three new algorithms were developed and implemented by using protein sequences, domains, structures, and metabolic reactions for construction of partial metabolic networks (PMNs), determination of conservation in critical residues, and variation analysis of residues forming similar cavities in proteins sequences. First, PMNs are constructed to determine the extent of disturbances in metabolite production by targeting a protein as drug target. Conservation of pathogen-specific protein's critical residues involved in cavity formation and biological function determined at domain-level with low-matching sequences. Last, variation analysis of residues forming similar cavities in proteins sequences from pathogenic versus non-pathogenic bacteria and humans is performed. The server is capable of predicting drug targets for any sequenced pathogenic bacteria having fasta sequences and annotated information. The utility of UniDrug-Target server was demonstrated for Mycobacterium tuberculosis (H37Rv). The UniDrug-Target identified 265 mycobacteria pathogen-specific proteins, including 17 essential proteins which can be potential drug targets. UniDrug-Target is expected to accelerate

Associations of Drug Lipophilicity and Extent of Metabolism with Drug-Induced Liver Injury.

PubMed

McEuen, Kristin; Borlak, Jürgen; Tong, Weida; Chen, Minjun

2017-06-22

Drug-induced liver injury (DILI), although rare, is a frequent cause of adverse drug reactions resulting in warnings and withdrawals of numerous medications. Despite the research community's best efforts, current testing strategies aimed at identifying hepatotoxic drugs prior to human trials are not sufficiently powered to predict the complex mechanisms leading to DILI. In our previous studies, we demonstrated lipophilicity and dose to be associated with increased DILI risk and, and in our latest work, we factored reactive metabolites into the algorithm to predict DILI. Given the inconsistency in determining the potential for drugs to cause DILI, the present study comprehensively assesses the relationship between DILI risk and lipophilicity and the extent of metabolism using a large published dataset of 1036 Food and Drug Administration (FDA)-approved drugs by considering five independent DILI annotations. We found that lipophilicity and the extent of metabolism alone were associated with increased risk for DILI. Moreover, when analyzed in combination with high daily dose (≥100 mg), lipophilicity was statistically significantly associated with the risk of DILI across all datasets ( p < 0.05). Similarly, the combination of extensive hepatic metabolism (≥50%) and high daily dose (≥100 mg) was also strongly associated with an increased risk of DILI among all datasets analyzed ( p < 0.05). Our results suggest that both lipophilicity and the extent of hepatic metabolism can be considered important risk factors for DILI in humans, and that this relationship to DILI risk is much stronger when considered in combination with dose. The proposed paradigm allows the convergence of different published annotations to a more uniform assessment.

A physarum-inspired prize-collecting steiner tree approach to identify subnetworks for drug repositioning.

PubMed

Sun, Yahui; Hameed, Pathima Nusrath; Verspoor, Karin; Halgamuge, Saman

2016-12-05

Drug repositioning can reduce the time, costs and risks of drug development by identifying new therapeutic effects for known drugs. It is challenging to reposition drugs as pharmacological data is large and complex. Subnetwork identification has already been used to simplify the visualization and interpretation of biological data, but it has not been applied to drug repositioning so far. In this paper, we fill this gap by proposing a new Physarum-inspired Prize-Collecting Steiner Tree algorithm to identify subnetworks for drug repositioning. Drug Similarity Networks (DSN) are generated using the chemical, therapeutic, protein, and phenotype features of drugs. In DSNs, vertex prizes and edge costs represent the similarities and dissimilarities between drugs respectively, and terminals represent drugs in the cardiovascular class, as defined in the Anatomical Therapeutic Chemical classification system. A new Physarum-inspired Prize-Collecting Steiner Tree algorithm is proposed in this paper to identify subnetworks. We apply both the proposed algorithm and the widely-used GW algorithm to identify subnetworks in our 18 generated DSNs. In these DSNs, our proposed algorithm identifies subnetworks with an average Rand Index of 81.1%, while the GW algorithm can only identify subnetworks with an average Rand Index of 64.1%. We select 9 subnetworks with high Rand Index to find drug repositioning opportunities. 10 frequently occurring drugs in these subnetworks are identified as candidates to be repositioned for cardiovascular diseases. We find evidence to support previous discoveries that nitroglycerin, theophylline and acarbose may be able to be repositioned for cardiovascular diseases. Moreover, we identify seven previously unknown drug candidates that also may interact with the biological cardiovascular system. These discoveries show our proposed Prize-Collecting Steiner Tree approach as a promising strategy for drug repositioning.

Systems level mapping of metabolic complexity in Mycobacterium tuberculosis to identify high-value drug targets.

PubMed

Vashisht, Rohit; Bhat, Ashwini G; Kushwaha, Shreeram; Bhardwaj, Anshu; Brahmachari, Samir K

2014-10-11

The effectiveness of current therapeutic regimens for Mycobacterium tuberculosis (Mtb) is diminished by the need for prolonged therapy and the rise of drug resistant/tolerant strains. This global health threat, despite decades of basic research and a wealth of legacy knowledge, is due to a lack of systems level understanding that can innovate the process of fast acting and high efficacy drug discovery. The enhanced functional annotations of the Mtb genome, which were previously obtained through a crowd sourcing approach was used to reconstruct the metabolic network of Mtb in a bottom up manner. We represent this information by developing a novel Systems Biology Spindle Map of Metabolism (SBSM) and comprehend its static and dynamic structure using various computational approaches based on simulation and design. The reconstructed metabolism of Mtb encompasses 961 metabolites, involved in 1152 reactions catalyzed by 890 protein coding genes, organized into 50 pathways. By accounting for static and dynamic analysis of SBSM in Mtb we identified various critical proteins required for the growth and survival of bacteria. Further, we assessed the potential of these proteins as putative drug targets that are fast acting and less toxic. Further, we formulate a novel concept of metabolic persister genes (MPGs) and compared our predictions with published in vitro and in vivo experimental evidence. Through such analyses, we report for the first time that de novo biosynthesis of NAD may give rise to bacterial persistence in Mtb under conditions of metabolic stress induced by conventional anti-tuberculosis therapy. We propose such MPG's as potential combination of drug targets for existing antibiotics that can improve their efficacy and efficiency for drug tolerant bacteria. The systems level framework formulated by us to identify potential non-toxic drug targets and strategies to circumvent the issue of bacterial persistence can substantially aid in the process of TB drug

Epidemiology of symptomatic drug-induced long QT syndrome and Torsade de Pointes in Germany.

PubMed

Sarganas, Giselle; Garbe, Edeltraut; Klimpel, Andreas; Hering, Rolf C; Bronder, Elisabeth; Haverkamp, Wilhelm

2014-01-01

Drug-induced long QT syndrome (diLQTS) leading to Torsade de Pointes (TdP) is a potentially lethal condition, which has led to several post-marketing drug withdrawals in the past decade. The true incidence of diLQTS/TdP is largely unknown. One explanation is under-reporting of this potentially life-threatening adverse event by physicians and other medical staff to pharmacovigilance agencies. To gain more insight into the incidence of diLQTS and TdP, the Berlin Pharmacovigilance Center (PVZ-FAKOS) has actively and prospectively identified patients who developed this particular type of drug-induced adverse event. Here, the basic characteristics of the affected patients are summarized and suspected drugs are discussed. Furthermore, an extrapolation of the Berlin incidence rates to the German Standard Population is presented. Using a Berlin-wide network of 51 collaborating hospitals (>180 clinical departments), adult patients presenting with long QT syndrome (LQTS/TdP) between 2008 and 2011 were identified by active surveillance of these hospitals. Drug exposures as well as other possible risk factors were obtained from the patient's files and in a face-to-face interview with the patient. One-hundred and seventy patients of possible LQTS/TdP were reported to the Pharmacovigilance Center of whom 58 cases were confirmed in a thorough validation process. The majority (66%) of these cases were female and 60% had developed LQTS/TdP in the outpatient setting. Thirty-five (60%) of 58 confirmed cases were assessed as drug-related based on a standardized causality assessment applying the criteria of the World Health Organization. Drugs assessed as related in more than two cases were metoclopramide, amiodarone, melperone, citalopram, and levomethadone. The age-standardized incidence of diLQTS/TdP in Berlin was estimated to be 2.5 per million per year for males and 4.0 per million per year for females. While European annual reporting rates based on spontaneous reports suggest an

Glucose hypermetabolism in the thalamus of patients with drug-induced blepharospasm.

PubMed

Suzuki, Y; Kiyosawa, M; Wakakura, M; Mochizuki, M; Ishiwata, K; Oda, K; Ishii, K

2014-03-28

We examined the difference in cerebral function alterations between drug-induced blepharospasm patients and essential blepharospasm (EB) patients by using positron emission tomography with (18)F-fluorodeoxyglucose. Cerebral glucose metabolism was examined in 21 patients with drug-induced blepharospasm (5 men and 16 women; mean age, 53.1 [range, 29-78] years), 21 essential EB patients (5 men and 16 women; mean age, 53.0 [range, 33-72] years) and 24 healthy subjects (6 men and 18 women; mean age, 57.9 [range, 22-78] years) with long-term history of benzodiazepines use (drug healthy subjects). Drug-induced blepharospasm patients developed symptoms while taking benzodiazepines or thienodiazepines. Sixty-three normal volunteers (15 men and 48 women; mean age, 53.6 [range, 20-70] years) were examined as controls. Differences between the patient groups and control group were examined by statistical parametric mapping. Additionally, we defined regions of interests on both sides of the thalamus, caudate nucleus, anterior putamen, posterior putamen and primary somatosensory area. The differences between groups were tested using two-sample t-tests with Bonferroni correction for multiple comparisons. Cerebral glucose hypermetabolism on both side of the thalamus was detected in drug-induced blepharospasm, EB patients and drug healthy subjects by statistical parametric mapping. In the analysis of regions of interest, glucose metabolism in both sides of the thalamus in the drug-induced blepharospasm group was significantly lower than that in the EB group. Moreover, we observed glucose hypermetabolism in the anterior and posterior putamen bilaterally in EB group but not in drug-induced blepharospasm group and drug healthy subjects. Long-term regimens of benzodiazepines or thienodiazepines may cause down-regulation of benzodiazepine receptors in the brain. We suggest that the functional brain alteration in drug-induced blepharospasm patients is similar to that in EB patients, and

Neuroprotective Effects of Drug-Induced Therapeutic Hypothermia in Central Nervous System Diseases.

PubMed

Ma, Junwei; Wang, Yibin; Wang, Zhong; Li, Haiying; Wang, Zhimin; Chen, Gang

2017-01-01

This review article focuses on the neuroprotective effect of drug-induced hypothermia in cerebrovascular diseases and discusses its related side effects. A systematic literature search was performed using Pubmed and Embase electronic databases for a retrospective analysis. Experimental studies have shown that drug-induced hypothermia alleviates brain damage and plays a neuroprotective role, thereby reducing mortality and ameliorating neurological deficits. Therefore, drug-induced hypothermia has an important research value and is worth further consideration in the clinical setting. However, drug-induced hypothermia is also associated with side effects, such as ventricular tachycardia, ventricular fibrillation, suppressed immune function, infection, electrolyte imbalance, glucose metabolism disorders, and skeletal muscle tremor. Existing drugs with cooling effects belong to the following categories: (1) dopamine receptor agonists; (2) cannabis; (3) opioid receptors; (4) vanilloid receptors; (5) vasopressins (potent neurotensin receptor agonists); (6) thyroid drugs; (7) adenosine drugs; and (8) purine drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Rhabdomyolysis induced by antiepileptic drugs: characteristics, treatment and prognosis.

PubMed

Jiang, Wei; Wang, Xuefeng; Zhou, Shengnian

2016-01-01

Rhabdomyolysis syndrome refers to a variety of factors that affect the striated muscle cell membrane, the membrane channels and its energy supply. Most cases of rhabdomyolysis are due to direct trauma. However, infection, toxins, drugs, muscle ischemia, electrolyte imbalance, metabolic diseases, genetic diseases and abnormal body temperature can also lead to rhabdomyolysis. Epilepsy is one of the most common chronic neurological diseases. The primary long-term treatment is antiepileptic drugs (AEDs), which may cause rhabdomyolysis. This article summarizes the characteristics, treatment methods and prognosis of patients with rhabdomyolysis that is induced by antiepileptic drugs. This review is based on PubMed, EMBASE and MEDLINE searches of the literature using the keywords "epilepsy", "antiepileptic drugs","status epilepticus","rhabdomyolysis", and "antiepileptic drugs and rhabdomyolysis syndrome" as well as extensive personal clinical experience with various antiepileptic drugs. Potential relationships between antiepileptic drugs and rhabdomyolysis are discussed. Worldwide, there are approximately 50 million epilepsy patients, most of whom are treated with drugs. Reports have indicated that the majority of antiepileptic drugs on the market can cause rhabdomyolysis. Although rhabdomyolysis induced by antiepileptic drugs is a rare condition with a low incidence, this condition has serious consequences and merits attention from clinicians.

The influence of type 2 diabetes and gender on ventricular repolarization dispersion in patients with sub-clinic left ventricular diastolic dysfunction.

PubMed

Jani, Ylber; Kamberi, Ahmet; Xhunga, Sotir; Pocesta, Bekim; Ferati, Fatmir; Lala, Dali; Zeqiri, Agim; Rexhepi, Atila

2015-01-01

To assess the influence of type 2 DM and gender, on the QT dispersion, Tpeak-Tend dispersion of ventricular repolarization, in patients with sub-clinic left ventricular diastolic dysfunction of the heart. QT dispersion, that reflects spatial inhomogeneity in ventricular repolarization, Tpeak-Tend dispersion, this on the other hand reflects transmural inhomogeneity in ventricular repolarization, that is increased in an early stage of cardiomyopathy, and in patients with left ventricular diastolic dysfunction, as well. The left ventricular diastolic dysfunction, a basic characteristic of diabetic heart disease (diabetic cardiomyopathy), that developes earlier than systolic dysfunction, suggests that diastolic markers might be sensitive for early cardiac injury. It is also demonstrated that gender has complex influence on indices of myocardial repolarization abnormalities such as QT interval and QT dispersion. We performed an observational study including 300 diabetic patients with similar epidemiological-demographic characteristics recruited in our institution from May 2009 to July 2014, divided into two groups. Demographic and laboratory echocardiographic data were obtained, twelve lead resting electrocardiography, QT, QTc, Tpeak-Tend-intervals and dispersion, were determined manually, and were compared between various groups. For statistical analysis a t-test, X(2) test, and logistic regression are used according to the type of variables. A p value <0.05 was considered statistically significant for a confidence interval of 95%. QTc max. interval, QTc dispersion and Tpeak-Tend dispersion, were significantly higher in diabetic group with subclinical LV (left ventricular) diastolic dysfunction, than in diabetic group with normal left ventricular diastolic function (445.24±14.7 ms vs. 433.55±14.4 ms, P<0.000; 44.98±18.78 ms vs. 32.05±17.9 ms, P<0.000; 32.60±1.6 ms vs. 17.46±2.0 ms, P<0.02. Prolonged QTc max. interval was found in 33% of patients, indiabetic group

An Update on Drug-induced Liver Injury.

PubMed

Devarbhavi, Harshad

2012-09-01

Idiosyncratic drug-induced liver injury (DILI) is an important cause of morbidity and mortality following drugs taken in therapeutic doses. Hepatotoxicity is a leading cause of attrition in drug development, or withdrawal or restricted use after marketing. No age is exempt although adults and the elderly are at increased risk. DILI spans the entire spectrum ranging from asymptomatic elevation in transaminases to severe disease such as acute hepatitis leading to acute liver failure. The liver specific Roussel Uclaf Causality Assessment Method is the most validated and extensively used for determining the likelihood that an implicated drug caused DILI. Asymptomatic elevation in liver tests must be differentiated from adaptation. Drugs producing DILI have a signature pattern although no single pattern is characteristic. Antimicrobial and central nervous system agents including antiepileptic drugs are the leading causes of DILI worldwide. In the absence of a diagnostic test or a biomarker, the diagnosis rests on the evidence of absence of competing causes such as acute viral hepatitis, autoimmune hepatitis and others. Recent studies show that antituberculosis drugs given for active or latent disease are still a major cause of drug-induced liver injury in India and the West respectively. Presence of jaundice signifies a severe disease and entails a worse outcome. The pathogenesis is unclear and is due to a mix of host, drug metabolite and environmental factors. Research has evolved from incriminating candidate genes to genome wide analysis studies. Immediate cessation of the drug is key to prevent or minimize progressive damage. Treatment is largely supportive. N-acetylcysteine is the antidote for paracetamol toxicity. Carnitine has been tried in valproate injury whereas steroids and ursodeoxycholic acid may be used in DILI associated with hypersensitivity or cholestatic features respectively. This article provides an overview of the epidemiology, the patterns of

Drug-inducing gynaecomastia--a critical review.

PubMed

Krause, W

2012-05-01

Gynaecomastia has been associated with a large variety of drugs in the literature. However, a causal relation of the incidence of gynaecomastia to a certain drug should be considered only if sufficient and significant evidence can be obtained from the studies published. In this review, studies quoted in Medline were evaluated according to the Scottish Intercollegiate Guidelines Network (SIGN) grading system for clinical studies. Reports on 92 drugs were found in Medline in combination with gynaecomastia. An imbalance of the oestrogen/androgen ratio causes gynaecomastia. Also, prolactin has gynaecomastia-inducing properties. In 14 of the drugs quoted, the studies lead to a level of recommendation 'A'. All these drugs have been designed to interfere with the production and action of sexual hormones or of prolactin. In 25 of the drugs, the level of recommendation was 'B'. Besides those drugs in this group that have been designed for interference with the metabolism of steroid hormones or of prolactin, in drugs for acid-related disorders, diuretics, antiretroviral drugs, antimycotics, psychoanaleptics, alcohol gynaecomastia was described as an unexpected adverse effect. Studies on the association of drugs and gynaecomastia do not share a generally accepted definition of gynaecomastia; in this way, the informational value is limited. © 2011 Blackwell Verlag GmbH.

Drug induced exocytosis of glycogen in Pompe disease.

PubMed

Turner, Christopher T; Fuller, Maria; Hopwood, John J; Meikle, Peter J; Brooks, Doug A

2016-10-28

Pompe disease is caused by a deficiency in the lysosomal enzyme α-glucosidase, and this leads to glycogen accumulation in the autolysosomes of patient cells. Glycogen storage material is exocytosed at a basal rate in cultured Pompe cells, with one study showing up to 80% is released under specific culture conditions. Critically, exocytosis induction may reduce glycogen storage in Pompe patients, providing the basis for a therapeutic strategy whereby stored glycogen is redirected to an extracellular location and subsequently degraded by circulating amylases. The focus of the current study was to identify compounds capable of inducing rapid glycogen exocytosis in cultured Pompe cells. Here, calcimycin, lysophosphatidylcholine and α-l-iduronidase each significantly increased glycogen exocytosis compared to vehicle-treated controls. The most effective compound, calcimycin, induced exocytosis through a Ca 2+ -dependent mechanism, although was unable to release a pool of vesicular glycogen larger than the calcimycin-induced exocytic pore. There was reduced glycogen release from Pompe compared to unaffected cells, primarily due to increased granule size in Pompe cells. Drug induced exocytosis therefore shows promise as a therapeutic approach for Pompe patients but strategies are required to enhance the release of large molecular weight glycogen granules. Copyright © 2016. Published by Elsevier Inc.

Periodic paralysis: An unusual presentation of drug-induced hyperkalemia.

PubMed

Agrawal, Poonam; Chopra, Deepti; Patra, Surajeet K; Madaan, Himanshu

2014-01-01

Hyperkalemia is a life-threatening electrolyte abnormality. The most common cause of hyperkalemia includes renal disease and ingestion of medications. Drug-induced hyperkalemia may develop in patients with underlying renal impairment, disturbed cellular uptake of potassium load, excessive ingestion or infusion of potassium-containing substances. We report a case of "drug-induced severe hyperkalemia" presenting as periodic paralysis. A 67-year-old diabetic and hypertensive woman presented to emergency department with the complaint of intermittent episode of inability to walk for the past 5 days. Each episode lasted for 15-20 minutes and was associated with breathlessness and restlessness. There was no family history of periodic paralysis and drug history revealed that the patient was onolmesartan 20 mg per day (for past 2 years), perindopril 4 mg per day (for past 16 months), and torsemide 10 mg/day. On examination patient was found to be conscious, alert, and afebrile. Vitals were normal. Examination of cardiovascular and respiratory system did not reveal any significant finding. Blood report of the patient showed serum K+ level 8.6 mmol/l. All other investigations were within normal limits. A diagnosis of drug-induced hyperkalemia was made. Patient responded well to the symptomatic treatment. To the best of the author's knowledge, this is the first case report of drug-induced hyperkalemia presenting as periodic paralysis.

Using Social Media Data to Identify Potential Candidates for Drug Repurposing: A Feasibility Study.

PubMed

Rastegar-Mojarad, Majid; Liu, Hongfang; Nambisan, Priya

2016-06-16

Drug repurposing (defined as discovering new indications for existing drugs) could play a significant role in drug development, especially considering the declining success rates of developing novel drugs. Typically, new indications for existing medications are identified by accident. However, new technologies and a large number of available resources enable the development of systematic approaches to identify and validate drug-repurposing candidates. Patients today report their experiences with medications on social media and reveal side effects as well as beneficial effects of those medications. Our aim was to assess the feasibility of using patient reviews from social media to identify potential candidates for drug repurposing. We retrieved patient reviews of 180 medications from an online forum, WebMD. Using dictionary-based and machine learning approaches, we identified disease names in the reviews. Several publicly available resources were used to exclude comments containing known indications and adverse drug effects. After manually reviewing some of the remaining comments, we implemented a rule-based system to identify beneficial effects. The dictionary-based system and machine learning system identified 2178 and 6171 disease names respectively in 64,616 patient comments. We provided a list of 10 common patterns that patients used to report any beneficial effects or uses of medication. After manually reviewing the comments tagged by our rule-based system, we identified five potential drug repurposing candidates. To our knowledge, this is the first study to consider using social media data to identify drug-repurposing candidates. We found that even a rule-based system, with a limited number of rules, could identify beneficial effect mentions in patient comments. Our preliminary study shows that social media has the potential to be used in drug repurposing.

Predicting Drug-induced Hepatotoxicity Using QSAR and Toxicogenomics Approaches

PubMed Central

Low, Yen; Uehara, Takeki; Minowa, Yohsuke; Yamada, Hiroshi; Ohno, Yasuo; Urushidani, Tetsuro; Sedykh, Alexander; Muratov, Eugene; Fourches, Denis; Zhu, Hao; Rusyn, Ivan; Tropsha, Alexander

2014-01-01

Quantitative Structure-Activity Relationship (QSAR) modeling and toxicogenomics are used independently as predictive tools in toxicology. In this study, we evaluated the power of several statistical models for predicting drug hepatotoxicity in rats using different descriptors of drug molecules, namely their chemical descriptors and toxicogenomic profiles. The records were taken from the Toxicogenomics Project rat liver microarray database containing information on 127 drugs (http://toxico.nibio.go.jp/datalist.html). The model endpoint was hepatotoxicity in the rat following 28 days of exposure, established by liver histopathology and serum chemistry. First, we developed multiple conventional QSAR classification models using a comprehensive set of chemical descriptors and several classification methods (k nearest neighbor, support vector machines, random forests, and distance weighted discrimination). With chemical descriptors alone, external predictivity (Correct Classification Rate, CCR) from 5-fold external cross-validation was 61%. Next, the same classification methods were employed to build models using only toxicogenomic data (24h after a single exposure) treated as biological descriptors. The optimized models used only 85 selected toxicogenomic descriptors and had CCR as high as 76%. Finally, hybrid models combining both chemical descriptors and transcripts were developed; their CCRs were between 68 and 77%. Although the accuracy of hybrid models did not exceed that of the models based on toxicogenomic data alone, the use of both chemical and biological descriptors enriched the interpretation of the models. In addition to finding 85 transcripts that were predictive and highly relevant to the mechanisms of drug-induced liver injury, chemical structural alerts for hepatotoxicity were also identified. These results suggest that concurrent exploration of the chemical features and acute treatment-induced changes in transcript levels will both enrich the

Drug-Induced Liver Toxicity and Prevention by Herbal Antioxidants: An Overview

PubMed Central

Singh, Divya; Cho, William C.; Upadhyay, Ghanshyam

2016-01-01

The liver is the center for drug and xenobiotic metabolism, which is influenced most with medication/xenobiotic-mediated toxic activity. Drug-induced hepatotoxicity is common and its actual frequency is hard to determine due to underreporting, difficulties in detection or diagnosis, and incomplete observation of exposure. The death rate is high, up to about 10% for drug-induced liver damage. Endorsed medications represented >50% of instances of intense liver failure in a study from the Acute Liver Failure Study Group of the patients admitted in 17 US healing facilities. Albeit different studies are accessible uncovering the mechanistic aspects of medication prompted hepatotoxicity, we are in the dilemma about the virtual story. The expanding prevalence and effectiveness of Ayurveda and natural products in the treatment of various disorders led the investigators to look into their potential in countering drug-induced liver toxicity. Several natural products have been reported to date to mitigate the drug-induced toxicity. The dietary nature and less adverse reactions of the natural products provide them an extra edge over other candidates of supplementary medication. In this paper, we have discussed the mechanism involved in drug-induced liver toxicity and the potential of herbal antioxidants as supplementary medication. PMID:26858648

Drug-induced exanthems: correlation of allergy testing with histologic diagnosis.

PubMed

Seitz, Cornelia S; Rose, Christian; Kerstan, Andreas; Trautmann, Axel

2013-11-01

Skin biopsies are commonly performed to confirm drug-induced exanthem (DIE). However, the relevance of histologic examination in discriminating between DIE and non-DIE (NDIE) is controversial. A retrospective analysis was performed to evaluate the reliability of histologic diagnosis of DIE. In all, 91 patients with a skin biopsy specimen of an acute exanthem temporally related to a single identifiable drug underwent complete allergy testing. Their biopsy specimens were retrospectively re-evaluated by 2 dermatopathologists blinded to the original reports to test for discrimination between DIE versus NDIE. In 35 patients, non-IgE-mediated drug allergy was confirmed by allergy testing, whereas in 56 patients drug hypersensitivity could be excluded. Sensitivity of pathology reports for diagnosis of DIE reached 62.9% with a positive predictive value of 40.7%. Specificity was 41.1% with a negative predictive value of 69.7%. No significant difference in tissue eosinophilia was detected between DIE and NDIE. This was a retrospective study. Dermatopathologic evaluation of skin biopsy specimens is of limited use in differentiating between DIE and NDIE. All efforts should be made to subject these patients to thorough allergy testing for definitely confirming or ruling out drug hypersensitivity. Copyright © 2013 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Data mining reveals a network of early-response genes as a consensus signature of drug-induced in vitro and in vivo toxicity.

PubMed

Zhang, J D; Berntenis, N; Roth, A; Ebeling, M

2014-06-01

Gene signatures of drug-induced toxicity are of broad interest, but they are often identified from small-scale, single-time point experiments, and are therefore of limited applicability. To address this issue, we performed multivariate analysis of gene expression, cell-based assays, and histopathological data in the TG-GATEs (Toxicogenomics Project-Genomics Assisted Toxicity Evaluation system) database. Data mining highlights four genes-EGR1, ATF3, GDF15 and FGF21-that are induced 2 h after drug administration in human and rat primary hepatocytes poised to eventually undergo cytotoxicity-induced cell death. Modelling and simulation reveals that these early stress-response genes form a functional network with evolutionarily conserved structure and intrinsic dynamics. This is underlined by the fact that early induction of this network in vivo predicts drug-induced liver and kidney pathology with high accuracy. Our findings demonstrate the value of early gene-expression signatures in predicting and understanding compound-induced toxicity. The identified network can empower first-line tests that reduce animal use and costs of safety evaluation.

Management of Psychotropic Drug-Induced DRESS Syndrome: A Systematic Review.

PubMed

Bommersbach, Tanner J; Lapid, Maria I; Leung, Jonathan G; Cunningham, Julie L; Rummans, Teresa A; Kung, Simon

2016-06-01

Drug rash with eosinophilia and systemic symptoms (DRESS) is a severe cutaneous eruption that has been linked to several common drugs and drug categories, including antiepileptics, allopurinol, sulfonamides, and various antibiotics; however, because of a number of recent case reports linking psychotropic medications to this condition, DRESS is increasingly recognized among psychiatrists. We systematically reviewed all psychotropic drugs linked to DRESS syndrome, and this article summarizes the clinical management relevant to psychiatric professionals. A comprehensive search was performed using Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane Database of Systematic Reviews, Web of Science, Scopus, and Litt's Drug Eruption and Reaction Database for articles published in English during the past 20 years (1996-2015) using the search terms (1) psychotropic drugs OR serotonin uptake inhibitors AND DRESS or (2) psychotropic drugs AND drug reaction (or rash) eosinophilia systemic syndrome, and all article abstracts were screened for inclusion and exclusion criteria by 3 reviewers. Two independent reviewers examined the full text of 163 articles, of which 96 (25 original articles, 12 review articles, 55 case reports, and 4 letters to the editor) were included in the systematic review. We identified 1072 cases of psychotropic drug-induced DRESS, with carbamazepine, lamotrigine, phenytoin, valproate, and phenobarbital being the most implicated drugs. Based on our review of the literature, we outline management principles that include prompt withdrawal of the causative drug, hospitalization, corticosteroid therapy, and novel treatments, including intravenous immunoglobulin, cyclophosphamide, and cyclosporine, for corticosteroid-resistant DRESS. Finally, we outline strategies for treating comorbid psychiatric illness after a DRESS reaction to the psychotropic medication. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Influence of aging and chronic heart failure on temporal dispersion of myocardial repolarization.

PubMed

Piccirillo, Gianfranco; Moscucci, Federica; Pascucci, Matteo; Pappadà, Maria Antonella; D'Alessandro, Gaetana; Rossi, Pietro; Quaglione, Raffaele; Di Barba, Daniele; Barillà, Francesco; Magrì, Damiano

2013-01-01

QT and T(peak)-T(end) (Te) intervals are associated with sudden cardiac death in patients with chronic heart failure (CHF). We studied age-dependent influence on short-term temporal dispersion of these two variables in patients with postischemic CHF. We grouped 75 CHF and 53 healthy control subjects into three age subsets: ≤ 50 years, >50 years and ≤ 65 years, and >65 years. We then calculated the following indices: QT and Te variability index (QTVI and TeVI), the ratio between the short-term variability (STV) of QT or Te, and the STV of resting rate (RR) (QT/RR STV and Te/RR STV). In all different age subgroups, patients with CHF showed a higher level of QTVI than age-matched control subjects (≤ 50 years: P < 0.0001; >50 years and ≤ 65 years: P < 0.05; >65 years: P < 0.05). Patients with CHF < 50 years old also had all repolarization variability indices higher than normal age-matched controls (TeVI, P < 0.05; QT/RR STV, P < 0.05; Te/RR STV, P < 0.05), whereas we did not find any difference between the two older classes of subjects. Both QTVI (r²: 0.178, P < 0.05) and TeVI (r²: 0.433, P < 0.001) were positively related to age in normal subjects, even if the first correlation was weaker than the second one. Our data showed that QTVI could be used in all ages to evaluate repolarization temporal liability, whereas the other indices are deeply influenced by age. Probably, the age-dependent increase in QTVI was more influenced by a reduction of RR variability reported in older normal subjects.

[Drug-induced acute pancreatitis: about 10 cases].

PubMed

Maghrebi, Houcine; Rhaeim, Rami; Haddad, Anis; Makni, Amin; Mohamed, Jouini; Montasser, Kacem; Zoubeir, Ben Safta

2017-01-01

Drug-induced acute pancreatitis (AP) accounts for approximately 2% of acute pancreatitis. Its incidence is increasing, with more than 260 incriminated drugs. However, very few cases have been described in the literature due to accountability problem. We report our experience with 10 cases whose data were collected over a period of 7 years. Clinical presentation of AP was often equivocal. Ranson's score ranged from 0 to 5. We recorded 5 cases of edematous pancreatitis and 5 cases of necro-bleeding pancreatitis. These pancreatitis were often successfully treated without recurrence after discontinuation of the incriminated drug.

Drug-induced Liver Disease in Patients with Diabetes Mellitus.

PubMed

Iryna, Klyarytskaya; Helen, Maksymova; Elena, Stilidi

2015-01-01

The study presented here was accomplished to assess the course of drug-induced liver diseases in patient's rheumatoid arthritis receiving long-term methotrexate therapy. Diabetes mellitus was revealed as the most significant risk factor. The combination of diabetes mellitus with other risk factors (female sex) resulted in increased hepatic fibrosis, degree of hepatic encephalopathy and reduction of hepatic functions. The effectiveness and safety of ursodeoxycholic acid and cytolytic type-with S-Adenosyl methionine was also evaluated. 13C-MBT: 13C-methacetin breath test; ALT: alanine aminotransferase; AP: alkaline phosphatase; AST: aspartic transaminase; DILD: drug-induced liver disease; DM: diabetes mellitus; HE: hepatic encephalopathy; HFM: hepatic functional mass; SAMe: S-Adenosyl methionine; UDCA: ursodeoxycholic acid. Iryna K, Helen M, Elena S. Drug-induced Liver Disease in Patients with Diabetes Mellitus. Euroasian J Hepato-Gastroenterol 2015;5(2):83-86.

Application of metabonomics in a compound ranking study in early drug development revealing drug-induced excretion of choline into urine.

PubMed

Dieterle, Frank; Schlotterbeck, Götz; Ross, Alfred; Niederhauser, Urs; Senn, Hans

2006-09-01

Selecting drug candidates based on toxicity is an important step in early drug development. In this case study, it is shown how metabonomics is applied to a ranking study, in which drug candidates with equal pharmacological activities are selected based on least toxic side effects. The metabonomic analyses were carried out on an animal study that followed an established protocol for pilot toxicology/ranking studies in rats, however, not specifically modified for a metabonomic assessment. It is shown how conditions not specificially adopted for metabonomics investigations can significantly influence the metabolic profiles recorded by NMR. Furthermore, it is shown how the multivariate analysis of the NMR spectra identified an extreme excretion of an endogenous metabolite into urine induced by two out of the five drug candidates. The subsequent structure elucidation by two-dimensional NMR experiments and a subsequent validation by spiking experiments identified the metabolite as choline. The discussion of the mechanistic background for the excretion of choline, which is usually well-conserved in the body, results in two hypotheses of either a massive degradation of cell membranes or an inhibition of the choline oxidation. Although the validation of these hypotheses needs a follow-up study, the finding of a increased excretion of the important metabolite choline warrants exclusion of these two compounds as viable drug candidates from a metabonomics point of view.

Slow adaptation of ventricular repolarization as a cause of arrhythmia?

PubMed

Bueno-Orovio, A; Hanson, B M; Gill, J S; Taggart, P; Rodriguez, B

2014-01-01

This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems". Adaptation of the QT-interval to changes in heart rate reflects on the body-surface electrocardiogram the adaptation of action potential duration (APD) at the cellular level. The initial fast phase of APD adaptation has been shown to modulate the arrhythmia substrate. Whether the slow phase is potentially proarrhythmic remains unclear. To analyze in-vivo human data and use computer simulations to examine effects of the slow APD adaptation phase on dispersion of repolarization and reentry in the human ventricle. Electrograms were acquired from 10 left and 10 right ventricle (LV/RV) endocardial sites in 15 patients with normal ventricles during RV pacing. Activation-recovery intervals, as a surrogate for APD, were measured during a sustained increase in heart rate. Observed dynamics were studied using computer simulations of human tissue electrophysiology. Spatial heterogeneity of rate adaptation was observed in all patients. Inhomogeneity in slow APD adaptation time constants (Δτ(s)) was greater in LV than RV (Δτ(s)(LV) = 31.8 ± 13.2, Δτ(s)(RV) = 19.0 ± 12.8 s , P< 0.01). Simulations showed that altering local slow time constants of adaptation was sufficient to convert partial wavefront block to block with successful reentry. Using electrophysiological data acquired in-vivo in human and computer simulations, we identify heterogeneity in the slow phase of APD adaptation as an important component of arrhythmogenesis.

[Drug-induced fever: a diagnosis to remember].

PubMed

Vodovar, D; Le Beller, C; Lillo-Le-Louet, A; Hanslik, T; Megarbane, B

2014-03-01

Drug fever (DF) is a febrile reaction induced by a drug without additional clinical features like skin eruption. This adverse drug reaction is probably common but under diagnosed. While its outcome is generally favourable, DF generates unnecessary diagnostic procedures as well as hospitalisations or hospitalisation prolongations. Clinical presentation and biological findings are not specific. Fever is generally well tolerated but may be accompanied by general symptoms mimicking sepsis. Moderate biological disorders could be expected, including elevation or decrease in white blood cell count, eosinophilia, liver cytolysis, and increased C-reactive protein. An infection should be systematically ruled out. Clinical or biological signs of severity should question DF diagnosis. When DF is suspected, the involved drug(s) should be stopped after a reliable assessment of imputability. Antibiotics represent the most often implicated drugs. Fever disappearance after discontinuing the suspected drug is the cornerstone of DF diagnosis. Before stopping the administration of the suspected drug(s), a risk/benefit ratio assessment is necessary. Consistently, it may be complicated to stop an antimicrobial drug when treating an infection or an immunosuppressive drug if required. Copyright © 2013. Published by Elsevier SAS.

How to Identify Drug Paraphernalia

MedlinePlus

... red eyes, changes in pupil size, or eye movements Items or associations that may indicate interest in illegal drugs or drug use. Clothing, jewelry, tattoos, teen slang with drug culture messages. Websites, music, or publications that glamorize drug use. Where do ...

Cellular Mechanisms Underlying the Effects of Milrinone and Cilostazol to Suppress Arrhythmogenesis Associated with Brugada Syndrome

PubMed Central

Szél, Tamás; Koncz, István; Antzelevitch, Charles

2013-01-01

Background: Brugada syndrome is an inherited disease associated with vulnerability to ventricular tachycardia and sudden cardiac death in young adults. Milrinone and cilostazol, oral phosphodiesterase (PDE) type III inhibitors, have been shown to increase ICa and modestly increase heart rate by elevating the level of intracellular cyclic AMP. Objective: The present study examines the effectiveness of these PDE inhibitors to suppress arrhythmogenesis in an experimental model of Brugada syndrome. Methods: Action potential (AP) and ECG recordings were obtained from epicardial and endocardial sites of coronary-perfused canine right ventricular wedge preparations. The Ito agonist NS5806 (5 μM) and Ca2+ channel blocker verapamil (2 μM) were used to pharmacologically mimic Brugada phenotype. Results: The combination induced all-or-none repolarization at some epicardial sites but not others, leading to ST-segment elevation as well as an increase in both epicardial and transmural dispersion of repolarization. Under these conditions, phase 2 reentry developed as the epicardial AP dome propagated from sites where it was maintained to sites at which it was lost, generating closely coupled extrasystoles and ventricular tachycardia. Addition of the PDE inhibitor milrinone (2.5 μM) or cilostazol (5-10 μM) to the coronary perfusate restored the epicardial AP dome, reduced dispersion and abolished phase 2 reentry—induced extrasystoles and ventricular tachycardia. Conclusions: Our study identifies milrinone as a more potent alternative to cilostazol for reversing the repolarization defects responsible for the electrocardiographic and arrhythmic manifestations of Brugada syndrome. Both drugs normalize ST segment elevation, and suppress arrhythmogenesis in experimental models of Brugada syndrome. PMID:23911896

Image-based drug screen identifies HDAC inhibitors as novel Golgi disruptors synergizing with JQ1

PubMed Central

Gendarme, Mathieu; Baumann, Jan; Ignashkova, Tatiana I.; Lindemann, Ralph K.; Reiling, Jan H.

2017-01-01

The Golgi apparatus is increasingly recognized as a major hub for cellular signaling and is involved in numerous pathologies, including neurodegenerative diseases and cancer. The study of Golgi stress-induced signaling pathways relies on the selectivity of the available tool compounds of which currently only a few are known. To discover novel Golgi-fragmenting agents, transcriptomic profiles of cells treated with brefeldin A, golgicide A, or monensin were generated and compared with a database of gene expression profiles from cells treated with other bioactive small molecules. In parallel, a phenotypic screen was performed for compounds that alter normal Golgi structure. Histone deacetylase (HDAC) inhibitors and DNA-damaging agents were identified as novel Golgi disruptors. Further analysis identified HDAC1/HDAC9 as well as BRD8 and DNA-PK as important regulators of Golgi breakdown mediated by HDAC inhibition. We provide evidence that combinatorial HDACi/(+)-JQ1 treatment spurs synergistic Golgi dispersal in several cancer cell lines, pinpointing a possible link between drug-induced toxicity and Golgi morphology alterations. PMID:29074567

Identifying and Preventing Health Problems among Young Drug-Misusing Offenders

ERIC Educational Resources Information Center

Bennett, Trevor; Holloway, Katy

2008-01-01

Purpose: The purpose of this paper is to identify the health problems and treatment needs of drug-misusing offenders and to draw out the implications of the findings for health education and prevention. Design/methodology/approach: This analysis is based on data collected as part of the New English and Welsh Arrestee Drug Abuse Monitoring…

Incubation of extinction responding and cue-induced reinstatement, but not context- or drug priming-induced reinstatement, after withdrawal from methamphetamine

PubMed Central

Adhikary, Sweta; Caprioli, Daniele; Venniro, Marco; Kallenberger, Paige; Shaham, Yavin; Bossert, Jennifer M.

2016-01-01

In rats trained to self-administer methamphetamine, extinction responding in the presence of drug-associated contextual and discrete cues progressively increases after withdrawal (incubation of methamphetamine craving). The conditioning factors underlying this incubation are unknown. Here, we studied incubation of methamphetamine craving under different experimental conditions to identify factors contributing to this incubation. We also determined whether the rats’ response to methamphetamine priming incubates after withdrawal. We trained rats to self-administer methamphetamine in a distinct context (context A) for 14 days (6-h/day). Lever presses were paired with a discrete light cue. We then tested groups of rats in context A or a different non-drug context (context B) after 1 day, 1 week, or 1 month for extinction responding with or without the discrete cue. Subsequently, we tested the rats for reinstatement of drug seeking induced by exposure to contextual, discrete cue, or drug priming (0, 0.25, and 0.5 mg/kg). Operant responding in the extinction sessions in contexts A or B was higher after 1 week and 1 month of withdrawal than after 1 day; this effect was context-independent. Independent of the withdrawal period, operant responding in the extinction sessions was higher when responding led to contingent delivery of the discrete cue. After extinction, discrete cue-induced reinstatement, but not context- or drug priming-induced reinstatement, progressively increased after withdrawal. Together, incubation of methamphetamine craving, as assessed in extinction tests, is primarily mediated by time-dependent increases in non-reinforced operant responding, and this effect is potentiated by exposure to discrete, but not contextual, cues. PMID:26989042

Right precordial-directed electrocardiographical markers identify arrhythmogenic right ventricular cardiomyopathy in the absence of conventional depolarization or repolarization abnormalities.

PubMed

Cortez, Daniel; Svensson, Anneli; Carlson, Jonas; Graw, Sharon; Sharma, Nandita; Brun, Francesca; Spezzacatene, Anita; Mestroni, Luisa; Platonov, Pyotr G

2017-10-13

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) carries a risk of sudden death. We aimed to assess whether vectorcardiographic (VCG) parameters directed toward the right heart and a measured angle of the S-wave would help differentiate ARVD/C with otherwise normal electrocardiograms from controls. Task Force 2010 definite ARVD/C criteria were met for all patients. Those who did not fulfill Task Force depolarization or repolarization criteria (-ECG) were compared with age and gender-matched control subjects. Electrocardiogram measures of a 3-dimentional spatial QRS-T angle, a right-precordial-directed orthogonal QRS-T (RPD) angle, a root mean square of the right sided depolarizing forces (RtRMS-QRS), QRS duration (QRSd) and the corrected QT interval (QTc), and a measured angle including the upslope and downslope of the S-wave (S-wave angle) were assessed. Definite ARVD/C was present in 155 patients by 2010 Task Force criteria (41.7 ± 17.6 years, 65.2% male). -ECG ARVD/C patients (66 patients) were compared to 66 control patients (41.7 ± 17.6 years, 65.2% male). All parameters tested except the QRSd and QTc significantly differentiated -ECG ARVD/C from control patients (p < 0.004 to p < 0.001). The RPD angle and RtRMS-QRS best differentiated the groups. Combined, the 2 novel criteria gave 81.8% sensitivity, 90.9% specificity and odds ratio of 45.0 (95% confidence interval 15.8 to 128.2). ARVD/C disease process may lead to development of subtle ECG abnormalities that can be distinguishable using right-sided VCG or measured angle markers better than the spatial QRS-T angle, the QRSd or QTc, in the absence of Taskforce ECG criteria.

Single therapeutic and supratherapeutic doses of sacubitril/valsartan (LCZ696) do not affect cardiac repolarization.

PubMed

Langenickel, Thomas H; Jordaan, Pierre; Petruck, Jesika; Kode, Kiran; Pal, Parasar; Vaidya, Soniya; Chandra, Priya; Rajman, Iris

2016-08-01

Sacubitril/valsartan (LCZ696) is a first-in-class angiotensin receptor neprilysin inhibitor (ARNI) indicated to reduce the risk of cardiovascular death and hospitalization for heart failure in patients with chronic heart failure (NYHA class II-IV) and reduced ejection fraction. This study was aimed to evaluate the effect of single oral therapeutic (400 mg) and supratherapeutic (1200 mg) doses of LCZ696 on cardiac repolarization. This randomized double-blind crossover study in healthy male subjects compared the effect of therapeutic and supratherapeutic doses of LCZ696 with placebo and moxifloxacin 400 mg (open-label treatment) as positive control. The primary assessment was mean baseline- and placebo-corrected QTcF (∆∆QTcF; Fridericia correction). Additional assessments included the ∆∆QTcB (Bazett's correction), PR interval, QRS duration, heart rate (HR), LCZ696 pharmacokinetics, pharmacokinetic/pharmacodynamic relationships, and safety. Of the 84 subjects enrolled, 81 completed the study. The maximum upper bound of the two-sided 90 % confidence interval for ∆∆QTcF for LCZ696 400 mg and 1200 mg were <10 ms, and assay sensitivity was confirmed with moxifloxacin. No relevant treatment-emergent changes were observed in any of the ECG-derived parameters with LCZ696 or placebo, and the incidence of adverse events was comparable among the treatment groups. Single therapeutic and supratherapeutic doses of LCZ696 did not affect cardiac repolarization as defined by the E14 ICH guidelines.

Stress- and glucocorticoid-induced priming of neuroinflammatory responses: potential mechanisms of stress-induced vulnerability to drugs of abuse.

PubMed

Frank, Matthew G; Watkins, Linda R; Maier, Steven F

2011-06-01

Stress and stress-induced glucocorticoids (GCs) sensitize drug abuse behavior as well as the neuroinflammatory response to a subsequent pro-inflammatory challenge. Stress also predisposes or sensitizes individuals to develop substance abuse. There is an emerging evidence that glia and glia-derived neuroinflammatory mediators play key roles in the development of drug abuse. Drugs of abuse such as opioids, psychostimulants, and alcohol induce neuroinflammatory mediators such as pro-inflammatory cytokines (e.g. interleukin (IL)-1β), which modulate drug reward, dependence, and tolerance as well as analgesic properties. Drugs of abuse may directly activate microglial and astroglial cells via ligation of Toll-like receptors (TLRs), which mediate the innate immune response to pathogens as well as xenobiotic agents (e.g. drugs of abuse). The present review focuses on understanding the immunologic mechanism(s) whereby stress primes or sensitizes the neuroinflammatory response to drugs of abuse and explores whether stress- and GC-induced sensitization of neuroimmune processes predisposes individuals to drug abuse liability and the role of neuroinflammatory mediators in the development of drug addiction. Copyright © 2011 Elsevier Inc. All rights reserved.

14-3-3ε Boosts Bleomycin-induced DNA Damage Response by Inhibiting the Drug-Resistant Activity of MVP

PubMed Central

Tang, Siwei; Bai, Chen; Yang, Pengyuan; Chen, Xian

2013-01-01

Major vault protein (MVP) is the predominant constituent of the vault particle, the largest known ribonuclear protein complex. Although emerging evidences have been establishing the links between MVP (vault) and multidrug resistance (MDR), little is known regarding exactly how the MDR activity of MVP is modulated during cellular response to drug-induced DNA damage (DDR). Bleomycin (BLM), an anti-cancer drug, induces DNA double-stranded breaks (DSBs) and consequently triggers the cellular DDR. Due to its physiological implications in hepatocellular carcinoma (HCC) and cell fate decision, 14-3-3ε was chosen as the pathway-specific bait protein to identify the critical target(s) responsible for HCC MDR. By using LC-MS/MS-based proteomic approach, MVP was first identified in the BLM-induced 14-3-3ε interactome formed in HCC cells. Biological characterization revealed that MVP possesses specific activity to promote the resistance to the BLM-induced DDR. On the other hand, 14-3-3ε enhances BLM-induced DDR by interacting with MVP. Mechanistic investigation further revealed that 14-3-3ε, in a phosphorylation-dependent manner, binds to the phosphorylated sites at both Thr52 and Ser864 of the monomer of MVP. Consequently, the phosphorylation-dependent binding between 14-3-3ε and MVP inhibits the drug-resistant activity of MVP for an enhanced DDR to BLM treatment. Our findings provide an insight into the mechanism underlying how the BLM-induced interaction between 14-3-3ε and MVP modulates MDR, implicating novel strategy to overcome the chemotherapeutic resistance through interfering specific protein-protein interactions. PMID:23590642

β2 adrenergic receptor activation governs cardiac repolarization and arrhythmogenesis in a guinea pig model of heart failure.

PubMed

Wang, Yao; Yuan, Jiamin; Qian, Zhiyong; Zhang, Xiwen; Chen, Yanhong; Hou, Xiaofeng; Zou, Jiangang

2015-01-08

β2-AR activation increases the risk of sudden cardiac death (SCD) in heart failure (HF) patients. Non-selective β-AR blockers have greater benefits on survival than selective β1-AR blockers in chronic HF patients, indicating that β2-AR activation contributes to SCD in HF. This study investigated the role of β2-AR activation on repolarization and ventricular arrhythmia (VA) in the experimental HF model. The guinea pig HF was induced by descending aortic banding. The effective refractoriness period (ERP), corrected QT (QTc) and the incidence of VA were examined using Langendorff and programmed electrical stimulation. Ikr and APD were recorded by the whole cell patch clamp. Selective β2-AR agonist salbutamol significantly increased the incidence of VA, prolonged QTc and shortened ERP. These effects could be prevented by the selective β2-AR antagonist, ICI118551. Salbutamol prolonged APD90 and reduced Ikr in guinea pig HF myocytes. The antagonists of cAMP (Rp-cAMP) and PKA (KT5720) attenuated Ikr inhibition and APD prolongation induced by salbutamol. However, the antagonists of Gi protein (PTX) and PDE III (amrinone) showed opposite effects. This study indicates that β2-AR activation increases the incidence of VA in the experimental HF model via activation of Gs/cAMP/PKA and/or inhibition of Gi/PDE pathways.

β2 adrenergic receptor activation governs cardiac repolarization and arrhythmogenesis in a guinea pig model of heart failure

PubMed Central

Wang, Yao; Yuan, Jiamin; Qian, Zhiyong; Zhang, Xiwen; Chen, Yanhong; Hou, Xiaofeng; Zou, Jiangang

2015-01-01

β2-AR activation increases the risk of sudden cardiac death (SCD) in heart failure (HF) patients. Non-selective β-AR blockers have greater benefits on survival than selective β1-AR blockers in chronic HF patients, indicating that β2-AR activation contributes to SCD in HF. This study investigated the role of β2-AR activation on repolarization and ventricular arrhythmia (VA) in the experimental HF model. The guinea pig HF was induced by descending aortic banding. The effective refractoriness period (ERP), corrected QT (QTc) and the incidence of VA were examined using Langendorff and programmed electrical stimulation. Ikr and APD were recorded by the whole cell patch clamp. Selective β2-AR agonist salbutamol significantly increased the incidence of VA, prolonged QTc and shortened ERP. These effects could be prevented by the selective β2-AR antagonist, ICI118551. Salbutamol prolonged APD90 and reduced Ikr in guinea pig HF myocytes. The antagonists of cAMP (Rp-cAMP) and PKA (KT5720) attenuated Ikr inhibition and APD prolongation induced by salbutamol. However, the antagonists of Gi protein (PTX) and PDE III (amrinone) showed opposite effects. This study indicates that β2-AR activation increases the incidence of VA in the experimental HF model via activation of Gs/cAMP/PKA and/or inhibition of Gi/PDE pathways. PMID:25567365

Combinatorial Drug Screening Identifies Ewing Sarcoma-specific Sensitivities.

PubMed

Radic-Sarikas, Branka; Tsafou, Kalliopi P; Emdal, Kristina B; Papamarkou, Theodore; Huber, Kilian V M; Mutz, Cornelia; Toretsky, Jeffrey A; Bennett, Keiryn L; Olsen, Jesper V; Brunak, Søren; Kovar, Heinrich; Superti-Furga, Giulio

2017-01-01

Improvements in survival for Ewing sarcoma pediatric and adolescent patients have been modest over the past 20 years. Combinations of anticancer agents endure as an option to overcome resistance to single treatments caused by compensatory pathways. Moreover, combinations are thought to lessen any associated adverse side effects through reduced dosing, which is particularly important in childhood tumors. Using a parallel phenotypic combinatorial screening approach of cells derived from three pediatric tumor types, we identified Ewing sarcoma-specific interactions of a diverse set of targeted agents including approved drugs. We were able to retrieve highly synergistic drug combinations specific for Ewing sarcoma and identified signaling processes important for Ewing sarcoma cell proliferation determined by EWS-FLI1 We generated a molecular target profile of PKC412, a multikinase inhibitor with strong synergistic propensity in Ewing sarcoma, revealing its targets in critical Ewing sarcoma signaling routes. Using a multilevel experimental approach including quantitative phosphoproteomics, we analyzed the molecular rationale behind the disease-specific synergistic effect of simultaneous application of PKC412 and IGF1R inhibitors. The mechanism of the drug synergy between these inhibitors is different from the sum of the mechanisms of the single agents. The combination effectively inhibited pathway crosstalk and averted feedback loop repression, in EWS-FLI1-dependent manner. Mol Cancer Ther; 16(1); 88-101. ©2016 AACR. ©2016 American Association for Cancer Research.

Synergy testing of FDA-approved drugs identifies potent drug combinations against Trypanosoma cruzi.

PubMed

Planer, Joseph D; Hulverson, Matthew A; Arif, Jennifer A; Ranade, Ranae M; Don, Robert; Buckner, Frederick S

2014-07-01

An estimated 8 million persons, mainly in Latin America, are infected with Trypanosoma cruzi, the etiologic agent of Chagas disease. Existing antiparasitic drugs for Chagas disease have significant toxicities and suboptimal effectiveness, hence new therapeutic strategies need to be devised to address this neglected tropical disease. Due to the high research and development costs of bringing new chemical entities to the clinic, we and others have investigated the strategy of repurposing existing drugs for Chagas disease. Screens of FDA-approved drugs (described in this paper) have revealed a variety of chemical classes that have growth inhibitory activity against mammalian stage Trypanosoma cruzi parasites. Aside from azole antifungal drugs that have low or sub-nanomolar activity, most of the active compounds revealed in these screens have effective concentrations causing 50% inhibition (EC50's) in the low micromolar or high nanomolar range. For example, we have identified an antihistamine (clemastine, EC50 of 0.4 µM), a selective serotonin reuptake inhibitor (fluoxetine, EC50 of 4.4 µM), and an antifolate drug (pyrimethamine, EC50 of 3.8 µM) and others. When tested alone in the murine model of Trypanosoma cruzi infection, most compounds had insufficient efficacy to lower parasitemia thus we investigated using combinations of compounds for additive or synergistic activity. Twenty-four active compounds were screened in vitro in all possible combinations. Follow up isobologram studies showed at least 8 drug pairs to have synergistic activity on T. cruzi growth. The combination of the calcium channel blocker, amlodipine, plus the antifungal drug, posaconazole, was found to be more effective at lowering parasitemia in mice than either drug alone, as was the combination of clemastine and posaconazole. Using combinations of FDA-approved drugs is a promising strategy for developing new treatments for Chagas disease.

Synergy Testing of FDA-Approved Drugs Identifies Potent Drug Combinations against Trypanosoma cruzi

PubMed Central

Ranade, Ranae M.; Don, Robert; Buckner, Frederick S.

2014-01-01

An estimated 8 million persons, mainly in Latin America, are infected with Trypanosoma cruzi, the etiologic agent of Chagas disease. Existing antiparasitic drugs for Chagas disease have significant toxicities and suboptimal effectiveness, hence new therapeutic strategies need to be devised to address this neglected tropical disease. Due to the high research and development costs of bringing new chemical entities to the clinic, we and others have investigated the strategy of repurposing existing drugs for Chagas disease. Screens of FDA-approved drugs (described in this paper) have revealed a variety of chemical classes that have growth inhibitory activity against mammalian stage Trypanosoma cruzi parasites. Aside from azole antifungal drugs that have low or sub-nanomolar activity, most of the active compounds revealed in these screens have effective concentrations causing 50% inhibition (EC50's) in the low micromolar or high nanomolar range. For example, we have identified an antihistamine (clemastine, EC50 of 0.4 µM), a selective serotonin reuptake inhibitor (fluoxetine, EC50 of 4.4 µM), and an antifolate drug (pyrimethamine, EC50 of 3.8 µM) and others. When tested alone in the murine model of Trypanosoma cruzi infection, most compounds had insufficient efficacy to lower parasitemia thus we investigated using combinations of compounds for additive or synergistic activity. Twenty-four active compounds were screened in vitro in all possible combinations. Follow up isobologram studies showed at least 8 drug pairs to have synergistic activity on T. cruzi growth. The combination of the calcium channel blocker, amlodipine, plus the antifungal drug, posaconazole, was found to be more effective at lowering parasitemia in mice than either drug alone, as was the combination of clemastine and posaconazole. Using combinations of FDA-approved drugs is a promising strategy for developing new treatments for Chagas disease. PMID:25033456

Pulmonary and generalized lysosomal storage induced by amphiphilic drugs.

PubMed Central

Hruban, Z

1984-01-01

Administration of amphiphilic drugs to experimental animals causes formation of myelinoid bodies in many cell types, accumulation of foamy macrophages in pulmonary alveoli and pulmonary alveolar proteinosis. These changes are the result of an interaction between the drugs and phospholipids which leads to an alteration in physicochemical properties of the phospholipids. Impairment of the digestion of altered pulmonary secretions in phagosomes of macrophages results in accumulation of foam cells in pulmonary alveoli. Impairment of the metabolism of altered phospholipids removed by autophagy induces an accumulation of myelinoid bodies. The administration of amphiphilic compounds thus causes pulmonary intra-alveolar histiocytosis which is a part of a drug-induced lysosomal storage or generalized lipidosis. The accumulation of drug-lipid complexes in myelinoid bodies and in pulmonary foam cells may lead to alteration of cellular functioning and to clinical disease. Currently over 50 amphiphilic drugs are known. Unique pharmacological properties necessitate clinical use of some of these drugs. The occurrence and severity of potential clinical side effects depend on the nature of each drug, dosage and duration of treatment, simultaneous administration of other drugs and foods, individual metabolic pattern of the patient and other factors. Further studies on factors preventing and potentiating adverse effects of amphiphilic drugs are indicated. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 4. FIGURE 5. FIGURE 6. FIGURE 7. FIGURE 8. FIGURE 9. FIGURE 10. PMID:6376111

Acute organic brain syndrome due to drug-induced eosinophilia.

PubMed

Ng, S C; Lee, M K; Teh, A

1989-11-01

A 72 year old man developed acute organic brain syndrome associated with marked eosinophilia following self medication with a variety of drugs. Investigations revealed no other known causes of eosinophilia. Withdrawal of drugs resulted in dramatic drop in eosinophil count paralleled by clinical resolution of neurological problems. To our knowledge drug-induced eosinophilia has not previously been associated with acute organic brain syndrome.

Drugp-Induced Rhabdomyolysis Atlas (DIRA) for idiosyncratic adverse drug reaction management.

PubMed

Wen, Zhining; Liang, Yu; Hao, Yingyi; Delavan, Brian; Huang, Ruili; Mikailov, Mike; Tong, Weida; Li, Menglong; Liu, Zhichao

2018-06-11

Drug-induced rhabdomyolysis (DIR) is an idiosyncratic and fatal adverse drug reaction (ADR) characterized in severe muscle injuries accompanied by multiple-organ failure. Limited knowledge regarding the pathophysiology of rhabdomyolysis is the main obstacle to developing early biomarkers and prevention strategies. Given the lack of a centralized data resource to curate, organize, and standardize widespread DIR information, here we present a Drug-Induced Rhabdomyolysis Atlas (DIRA) that provides DIR-related information, including: a classification scheme for DIR based on drug labeling information; postmarketing surveillance data of DIR; and DIR drug property information. To elucidate the utility of DIRA, we used precision dosing, concomitant use of DIR drugs, and predictive modeling development to exemplify strategies for idiosyncratic ADR (IADR) management. Published by Elsevier Ltd.

Ventricular stimulus site influences dynamic dispersion of repolarization in the intact human heart

PubMed Central

Orini, Michele; Simon, Ron B.; Providência, Rui; Khan, Fakhar Z.; Segal, Oliver R.; Babu, Girish G.; Bradley, Richard; Rowland, Edward; Ahsan, Syed; Chow, Anthony W.; Lowe, Martin D.; Taggart, Peter

2016-01-01

The spatial variation in restitution properties in relation to varying stimulus site is poorly defined. This study aimed to investigate the effect of varying stimulus site on apicobasal and transmural activation time (AT), action potential duration (APD) and repolarization time (RT) during restitution studies in the intact human heart. Ten patients with structurally normal hearts, undergoing clinical electrophysiology studies, were enrolled. Decapolar catheters were placed apex to base in the endocardial right ventricle (RVendo) and left ventricle (LVendo), and an LV branch of the coronary sinus (LVepi) for transmural recording. S1–S2 restitution protocols were performed pacing RVendo apex, LVendo base, and LVepi base. Overall, 725 restitution curves were analyzed, 74% of slopes had a maximum slope of activation recovery interval (ARI) restitution (Smax) > 1 (P < 0.001); mean Smax = 1.76. APD was shorter in the LVepi compared with LVendo, regardless of pacing site (30-ms difference during RVendo pacing, 25-ms during LVendo, and 48-ms during LVepi; 50th quantile, P < 0.01). Basal LVepi pacing resulted in a significant transmural gradient of RT (77 ms, 50th quantile: P < 0.01), due to loss of negative transmural AT-APD coupling (mean slope 0.63 ± 0.3). No significant transmural gradient in RT was demonstrated during endocardial RV or LV pacing, with preserved negative transmural AT-APD coupling (mean slope −1.36 ± 1.9 and −0.71 ± 0.4, respectively). Steep ARI restitution slopes predominate in the normal ventricle and dynamic ARI; RT gradients exist that are modulated by the site of activation. Epicardial stimulation to initiate ventricular activation promotes significant transmural gradients of repolarization that could be proarrhythmic. PMID:27371682

Influence of aging and chronic heart failure on temporal dispersion of myocardial repolarization

PubMed Central

Piccirillo, Gianfranco; Moscucci, Federica; Pascucci, Matteo; Pappadà, Maria Antonella; D’Alessandro, Gaetana; Rossi, Pietro; Quaglione, Raffaele; Di Barba, Daniele; Barillà, Francesco; Magrì, Damiano

2013-01-01

Background and purpose: QT and Tpeak-Tend (Te) intervals are associated with sudden cardiac death in patients with chronic heart failure (CHF). We studied age-dependent influence on short-term temporal dispersion of these two variables in patients with postischemic CHF. Method: We grouped 75 CHF and 53 healthy control subjects into three age subsets: ≤50 years, >50 years and ≤65 years, and >65 years. We then calculated the following indices: QT and Te variability index (QTVI and TeVI), the ratio between the short-term variability (STV) of QT or Te, and the STV of resting rate (RR) (QT/RR STV and Te/RR STV). Results: In all different age subgroups, patients with CHF showed a higher level of QTVI than age-matched control subjects (≤50 years: P < 0.0001; >50 years and ≤65 years: P < 0.05; >65 years: P < 0.05). Patients with CHF < 50 years old also had all repolarization variability indices higher than normal age-matched controls (TeVI, P < 0.05; QT/RR STV, P < 0.05; Te/RR STV, P < 0.05), whereas we did not find any difference between the two older classes of subjects. Both QTVI (r2: 0.178, P < 0.05) and TeVI (r2: 0.433, P < 0.001) were positively related to age in normal subjects, even if the first correlation was weaker than the second one. Conclusion: Our data showed that QTVI could be used in all ages to evaluate repolarization temporal liability, whereas the other indices are deeply influenced by age. Probably, the age-dependent increase in QTVI was more influenced by a reduction of RR variability reported in older normal subjects. PMID:23662051

Methotrimeprazine-induced Corneal Deposits and Cataract Revealed by Urine Drug Profiling Test

PubMed Central

Kim, Seong Taeck; Kim, Joon Mo; Kim, Won Young; Choi, Gwang Ju

2010-01-01

Two schizophrenic patients who had been taking medication for a long period presented with visual disturbance of 6-month duration. Slit-lamp examination revealed fine, discrete, and brownish deposits on the posterior cornea. In addition, bilateral star-shaped anterior subcapsular lens opacities, which were dense, dust-like granular deposits, were noted. Although we strongly suspected that the patient might have taken one of the drugs of the phenothiazine family, we were unable to obtain a history of medications other than haloperidol and risperidone, which were taken for 3 yr. We performed a drug profiling test using urine samples and detected methotrimeprazine. The patient underwent surgery for anterior subcapsular lens opacities. Visual acuity improved in both eyes, but the corneal deposits remained. We report an unusual case of methotrimeprazine-induced corneal deposits and cataract in a patient with psychosis, identified by using the urine drug profiling test. PMID:21060765

Early-life experience decreases drug-induced reinstatement of morphine CPP in adulthood via microglial-specific epigenetic programming of anti-inflammatory IL-10 expression.

PubMed

Schwarz, Jaclyn M; Hutchinson, Mark R; Bilbo, Staci D

2011-12-07

A critical component of drug addiction research involves identifying novel biological mechanisms and environmental predictors of risk or resilience to drug addiction and associated relapse. Increasing evidence suggests microglia and astrocytes can profoundly affect the physiological and addictive properties of drugs of abuse, including morphine. We report that glia within the rat nucleus accumbens (NAcc) respond to morphine with an increase in cytokine/chemokine expression, which predicts future reinstatement of morphine conditioned place preference (CPP) following a priming dose of morphine. This glial response to morphine is influenced by early-life experience. A neonatal handling paradigm that increases the quantity and quality of maternal care significantly increases baseline expression of the anti-inflammatory cytokine IL-10 within the NAcc, attenuates morphine-induced glial activation, and prevents the subsequent reinstatement of morphine CPP in adulthood. IL-10 expression within the NAcc and reinstatement of CPP are negatively correlated, suggesting a protective role for this specific cytokine against morphine-induced glial reactivity and drug-induced reinstatement of morphine CPP. Neonatal handling programs the expression of IL-10 within the NAcc early in development, and this is maintained into adulthood via decreased methylation of the IL-10 gene specifically within microglia. The effect of neonatal handling is mimicked by pharmacological modulation of glia in adulthood with ibudilast, which increases IL-10 expression, inhibits morphine-induced glial activation within the NAcc, and prevents reinstatement of morphine CPP. Taken together, we have identified a novel gene × early-life environment interaction on morphine-induced glial activation and a specific role for glial activation in drug-induced reinstatement of drug-seeking behavior.

Early-Life Experience Decreases Drug-Induced Reinstatement of Morphine CPP in Adulthood via Microglial-Specific Epigenetic Programming of Anti-Inflammatory IL-10 Expression

PubMed Central

Schwarz, Jaclyn M.; Hutchinson, Mark R.; Bilbo, Staci D.

2012-01-01

A critical component of drug addiction research involves identifying novel biological mechanisms and environmental predictors of risk or resilience to drug addiction and associated relapse. Increasing evidence suggests microglia and astrocytes can profoundly affect the physiological and addictive properties of drugs of abuse, including morphine. We report that glia within the rat Nucleus Accumbens (NAcc) respond to morphine with an increase in cytokine/chemokine expression, which predicts future reinstatement of morphine conditioned place preference (CPP) following a priming dose of morphine. This glial response to morphine is influenced by early-life experience. A neonatal handling paradigm that increases the quantity and quality of maternal care significantly increases baseline expression of the anti-inflammatory cytokine IL-10 within the NAcc, attenuates morphine-induced glial activation, and prevents the subsequent reinstatement of morphine CPP in adulthood. IL-10 expression within the NAcc and reinstatement of CPP are negatively correlated, suggesting a protective role for this specific cytokine against morphine-induced glial reactivity and drug-induced reinstatement of morphine CPP. Neonatal handling programs the expression of IL-10 within the NAcc early in development, and this is maintained into adulthood via decreased methylation of the IL-10 gene specifically within microglia. The effect of neonatal handling is mimicked by pharmacological modulation of glia in adulthood with Ibudilast, which increases IL-10 expression, inhibits morphine-induced glial activation within the NAcc, and prevents reinstatement of morphine CPP. Taken together, we have identified a novel gene X early-life environment interaction on morphine-induced glial activation, and a specific role for glial activation in drug-induced reinstatement of drug-seeking behavior. PMID:22159099

Antituberculosis Drug-Induced Fixed Drug Eruption: A Case Report.

PubMed

Vaghela, Jitendra H; Nimbark, Vivek; Barvaliya, Manish; Mehta, Hita; Chavada, Bhavesh

2018-05-21

Fixed drug eruption (FDE) was caused by fixed-dose combination (FDC) of antituberculosis drugs in the form of tablet Forecox ® (rifampicin [rifampin] 225 mg + isoniazid 150 mg + pyrazinamide 750 mg + ethambutol 400 mg) in a 40-year-old male patient with a history of drug allergy. The patient developed FDE after taking the third dose of tablet Forecox ® for pulmonary tuberculosis. Tablet Forecox ® was withdrawn and the patient recovered from the reaction after 15 days of treatment for FDE. As per World Health Organization-Uppsala Monitoring Centre (WHO-UMC) and Naranjo causality assessment criteria, the association between the reaction and tablet Forecox ® was possible and probable, respectively. The reaction was moderately (Level 4b) severe according to the Modified Hartwig and Siegel scale. As there is an increased risk of allergic reaction in patients with a history of drug allergy, FDCs should not be used in order to avoid complexity in identifying the culprit drug.

Cue-Induced Craving to Paraphernalia and Drug Images in Opioid Dependence

PubMed Central

McHugh, R. Kathryn; Fulciniti, Francesca; Mashhoon, Yasmin; Weiss, Roger D.

2016-01-01

Background and Objectives Stimuli that are repeatedly paired with substance use, such as drug paraphernalia, can themselves elicit drug craving. The aim of this study was to examine whether particular cue types elicit greater craving responses than others among individuals with opioid dependence. Methods Participants seeking inpatient treatment for opioid dependence were recruited for a study of cue-induced craving. This sample (N=50), included 25 primary heroin users, 20 primary prescription opioid users, and 5 users of heroin and prescription opioids equally. Participants completed a cue reactivity task, in which images of drug-related stimuli were presented on a computer screen, each followed by a question assessing state drug craving. Results Overall, participants reported higher craving following paraphernalia stimuli relative to drug stimuli. However, this was moderated by opioid type; there was significantly higher craving in response to images of paraphernalia cues in the heroin group, and higher craving in response to drug cues in the prescription opioid group. Discussion and Conclusions These findings highlight potential differences in cue reactivity to opioid paraphernalia and drug cues, which appears to be moderated by drug type. Scientific Significance Cue-induced craving is an important factor in relapse. This study adds further to the literature on cue-induced craving in opioid dependence, suggesting that craving may vary based on both cue type and opioid type. Future studies designed to discriminate the impact of substance of abuse, route of administration, and cue type will help to further understand cue-induced craving in this population. PMID:26848719

The influence of type 2 diabetes and gender on ventricular repolarization dispersion in patients with sub-clinic left ventricular diastolic dysfunction

PubMed Central

Jani, Ylber; Kamberi, Ahmet; Xhunga, Sotir; Pocesta, Bekim; Ferati, Fatmir; Lala, Dali; Zeqiri, Agim; Rexhepi, Atila

2015-01-01

Objective: To assess the influence of type 2 DM and gender, on the QT dispersion, Tpeak-Tend dispersion of ventricular repolarization, in patients with sub-clinic left ventricular diastolic dysfunction of the heart. Background: QT dispersion, that reflects spatial inhomogeneity in ventricular repolarization, Tpeak-Tend dispersion, this on the other hand reflects transmural inhomogeneity in ventricular repolarization, that is increased in an early stage of cardiomyopathy, and in patients with left ventricular diastolic dysfunction, as well. The left ventricular diastolic dysfunction, a basic characteristic of diabetic heart disease (diabetic cardiomyopathy), that developes earlier than systolic dysfunction, suggests that diastolic markers might be sensitive for early cardiac injury. It is also demonstrated that gender has complex influence on indices of myocardial repolarization abnormalities such as QT interval and QT dispersion. Material and methods: We performed an observational study including 300 diabetic patients with similar epidemiological-demographic characteristics recruited in our institution from May 2009 to July 2014, divided into two groups. Demographic and laboratory echocardiographic data were obtained, twelve lead resting electrocardiography, QT, QTc, Tpeak-Tend-intervals and dispersion, were determined manually, and were compared between various groups. For statistical analysis a t-test, X2 test, and logistic regression are used according to the type of variables. A p value <0.05 was considered statistically significant for a confidence interval of 95%. Results: QTc max. interval, QTc dispersion and Tpeak-Tend dispersion, were significantly higher in diabetic group with subclinical LV (left ventricular) diastolic dysfunction, than in diabetic group with normal left ventricular diastolic function (445.24±14.7 ms vs. 433.55±14.4 ms, P<0.000; 44.98±18.78 ms vs. 32.05±17.9 ms, P<0.000; 32.60±1.6 ms vs. 17.46±2.0 ms, P<0.02. Prolonged QTc max

Cancer in silico drug discovery: a systems biology tool for identifying candidate drugs to target specific molecular tumor subtypes.

PubMed

San Lucas, F Anthony; Fowler, Jerry; Chang, Kyle; Kopetz, Scott; Vilar, Eduardo; Scheet, Paul

2014-12-01

Large-scale cancer datasets such as The Cancer Genome Atlas (TCGA) allow researchers to profile tumors based on a wide range of clinical and molecular characteristics. Subsequently, TCGA-derived gene expression profiles can be analyzed with the Connectivity Map (CMap) to find candidate drugs to target tumors with specific clinical phenotypes or molecular characteristics. This represents a powerful computational approach for candidate drug identification, but due to the complexity of TCGA and technology differences between CMap and TCGA experiments, such analyses are challenging to conduct and reproduce. We present Cancer in silico Drug Discovery (CiDD; scheet.org/software), a computational drug discovery platform that addresses these challenges. CiDD integrates data from TCGA, CMap, and Cancer Cell Line Encyclopedia (CCLE) to perform computational drug discovery experiments, generating hypotheses for the following three general problems: (i) determining whether specific clinical phenotypes or molecular characteristics are associated with unique gene expression signatures; (ii) finding candidate drugs to repress these expression signatures; and (iii) identifying cell lines that resemble the tumors being studied for subsequent in vitro experiments. The primary input to CiDD is a clinical or molecular characteristic. The output is a biologically annotated list of candidate drugs and a list of cell lines for in vitro experimentation. We applied CiDD to identify candidate drugs to treat colorectal cancers harboring mutations in BRAF. CiDD identified EGFR and proteasome inhibitors, while proposing five cell lines for in vitro testing. CiDD facilitates phenotype-driven, systematic drug discovery based on clinical and molecular data from TCGA. ©2014 American Association for Cancer Research.

Incubation of extinction responding and cue-induced reinstatement, but not context- or drug priming-induced reinstatement, after withdrawal from methamphetamine.

PubMed

Adhikary, Sweta; Caprioli, Daniele; Venniro, Marco; Kallenberger, Paige; Shaham, Yavin; Bossert, Jennifer M

2017-07-01

In rats trained to self-administer methamphetamine, extinction responding in the presence of drug-associated contextual and discrete cues progressively increases after withdrawal (incubation of methamphetamine craving). The conditioning factors underlying this incubation are unknown. Here, we studied incubation of methamphetamine craving under different experimental conditions to identify factors contributing to this incubation. We also determined whether the rats' response to methamphetamine priming incubates after withdrawal. We trained rats to self-administer methamphetamine in a distinct context (context A) for 14 days (6 hours/day). Lever presses were paired with a discrete light cue. We then tested groups of rats in context A or a different non-drug context (context B) after 1 day, 1 week or 1 month for extinction responding with or without the discrete cue. Subsequently, we tested the rats for reinstatement of drug seeking induced by exposure to contextual, discrete cue, or drug priming (0, 0.25 and 0.5 mg/kg). Operant responding in the extinction sessions in contexts A or B was higher after 1 week and 1 month of withdrawal than after 1 day; this effect was context-independent. Independent of the withdrawal period, operant responding in the extinction sessions was higher when responding led to contingent delivery of the discrete cue. After extinction, discrete cue-induced reinstatement, but not context- or drug priming-induced reinstatement, progressively increased after withdrawal. Together, incubation of methamphetamine craving, as assessed in extinction tests, is primarily mediated by time-dependent increases in non-reinforced operant responding, and this effect is potentiated by exposure to discrete, but not contextual, cues. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Integrated analysis of drug-induced gene expression profiles predicts novel hERG inhibitors.

PubMed

Babcock, Joseph J; Du, Fang; Xu, Kaiping; Wheelan, Sarah J; Li, Min

2013-01-01

Growing evidence suggests that drugs interact with diverse molecular targets mediating both therapeutic and toxic effects. Prediction of these complex interactions from chemical structures alone remains challenging, as compounds with different structures may possess similar toxicity profiles. In contrast, predictions based on systems-level measurements of drug effect may reveal pharmacologic similarities not evident from structure or known therapeutic indications. Here we utilized drug-induced transcriptional responses in the Connectivity Map (CMap) to discover such similarities among diverse antagonists of the human ether-à-go-go related (hERG) potassium channel, a common target of promiscuous inhibition by small molecules. Analysis of transcriptional profiles generated in three independent cell lines revealed clusters enriched for hERG inhibitors annotated using a database of experimental measurements (hERGcentral) and clinical indications. As a validation, we experimentally identified novel hERG inhibitors among the unannotated drugs in these enriched clusters, suggesting transcriptional responses may serve as predictive surrogates of cardiotoxicity complementing existing functional assays.

Integrated Analysis of Drug-Induced Gene Expression Profiles Predicts Novel hERG Inhibitors

PubMed Central

Babcock, Joseph J.; Du, Fang; Xu, Kaiping; Wheelan, Sarah J.; Li, Min

2013-01-01

Growing evidence suggests that drugs interact with diverse molecular targets mediating both therapeutic and toxic effects. Prediction of these complex interactions from chemical structures alone remains challenging, as compounds with different structures may possess similar toxicity profiles. In contrast, predictions based on systems-level measurements of drug effect may reveal pharmacologic similarities not evident from structure or known therapeutic indications. Here we utilized drug-induced transcriptional responses in the Connectivity Map (CMap) to discover such similarities among diverse antagonists of the human ether-à-go-go related (hERG) potassium channel, a common target of promiscuous inhibition by small molecules. Analysis of transcriptional profiles generated in three independent cell lines revealed clusters enriched for hERG inhibitors annotated using a database of experimental measurements (hERGcentral) and clinical indications. As a validation, we experimentally identified novel hERG inhibitors among the unannotated drugs in these enriched clusters, suggesting transcriptional responses may serve as predictive surrogates of cardiotoxicity complementing existing functional assays. PMID:23936032

Acute organic brain syndrome due to drug-induced eosinophilia.

PubMed Central

Ng, S. C.; Lee, M. K.; Teh, A.

1989-01-01

A 72 year old man developed acute organic brain syndrome associated with marked eosinophilia following self medication with a variety of drugs. Investigations revealed no other known causes of eosinophilia. Withdrawal of drugs resulted in dramatic drop in eosinophil count paralleled by clinical resolution of neurological problems. To our knowledge drug-induced eosinophilia has not previously been associated with acute organic brain syndrome. PMID:2616421

Compulsive methamphetamine taking under punishment is associated with greater cue-induced drug seeking in rats.

PubMed

Torres, Oscar V; Jayanthi, Subramanian; Ladenheim, Bruce; McCoy, Michael T; Krasnova, Irina N; Cadet, Jean Lud

2017-05-30

Methamphetamine (METH) addicts lose control over drug consumption despite suffering multiple adverse medicolegal consequences. To mimic the negative events associated with drug addiction in humans, we recently introduced a rat model of self-administration (SA) with response-contingent punishment on METH intake. These procedures allowed us to distinguish between two addiction-like phenotypes in rats, those that sustained METH taking despite negative consequences (shock-resistant, SR) and rats that significantly reduced their METH intake (shock-sensitive, SS). Here, we further developed our adverse consequence model and examined incubation of METH craving by measuring cue-induced drug seeking in SR and SS rats. Male Sprague-Dawley rats were trained to self-administer METH (0.1mg/kg/injection) or saline intravenously (i.v.) during twenty-two 9-h sessions that consisted of 3 separate 3-h sessions separated by 30min. Subsequently, rats were subjected to incremental footshocks during thirteen additional 9-h METH SA sessions performed in a fashion identical to the training phase. Cue-induced drug craving was then assessed at 2 and 21days after the footshock phase. All rats escalated their intake of METH, with both phenotypes showing similar drug taking patterns during SA training. In addition, rats that continued their METH intake despite negative consequences showed even greater cue-induced drug craving following withdrawal than the rats that reduced METH intake following negative consequences. Taken together, our adverse consequence-based model highlights the possibility of identifying rats by addiction-like phenotypes and subsequent vulnerability to relapse-like behaviors. The use of similar SA models should help in the development of better therapeutic approaches to treat different stages of METH addiction. Published by Elsevier B.V.

AgHalo: A Facile Fluorogenic Sensor to Detect Drug-Induced Proteome Stress.

PubMed

Liu, Yu; Fares, Matthew; Dunham, Noah P; Gao, Zi; Miao, Kun; Jiang, Xueyuan; Bollinger, Samuel S; Boal, Amie K; Zhang, Xin

2017-07-17

Drug-induced proteome stress that involves protein aggregation may cause adverse effects and undermine the safety profile of a drug. Safety of drugs is regularly evaluated using cytotoxicity assays that measure cell death. However, these assays provide limited insights into the presence of proteome stress in live cells. A fluorogenic protein sensor is reported to detect drug-induced proteome stress prior to cell death. An aggregation prone Halo-tag mutant (AgHalo) was evolved to sense proteome stress through its aggregation. Detection of such conformational changes was enabled by a fluorogenic ligand that fluoresces upon AgHalo forming soluble aggregates. Using 5 common anticancer drugs, we exemplified detection of differential proteome stress before any cell death was observed. Thus, this sensor can be used to evaluate drug safety in a regime that the current cytotoxicity assays cannot cover and be generally applied to detect proteome stress induced by other toxins. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Challenge for Diagnosing Acute Liver Injury with Concomitant/Sequential Exposure to Multiple Drugs: Can Causality Assessment Scales Be Utilized to Identify the Offending Drug?

PubMed Central

Lim, Roxanne; Conner, Kim; Karnsakul, Wikrom

2014-01-01

Drug-induced hepatotoxicity most commonly manifests as an acute hepatitis syndrome and remains the leading cause of drug-induced death/mortality and the primary reason for withdrawal of drugs from the pharmaceutical market. We report a case of acute liver injury in a 12-year-old Hispanic boy, who received a series of five antibiotics (amoxicillin, ceftriaxone, vancomycin, ampicillin/sulbactam, and clindamycin) for cervical lymphadenitis/retropharyngeal cellulitis. Histopathology of the liver biopsy specimen revealed acute cholestatic hepatitis. All known causes of acute liver injury were appropriately excluded and (only) drug-induced liver injury was left as a cause of his cholestasis. Liver-specific causality assessment scales such as Council for the International Organization of Medical Sciences/Roussel Uclaf Causality Assessment Method scoring system (CIOMS/RUCAM), Maria and Victorino scale, and Digestive Disease Week-Japan were applied to seek the most likely offending drug. Although clindamycin is the most likely cause by clinical diagnosis, none of causality assessment scales aid in the diagnosis. PMID:25506455

[Clinicopathologic features of drug-induced vanishing bile duct syndrome].

PubMed

Ye, L H; Wang, C K; Zhang, H C; Liu, Z Q; Zheng, H W

2017-04-20

Vanishing bile duct syndrome (VBDS) manifests as progressive destruction and disappearance of the intrahepatic bile duct caused by various factors and cholestasis. VBDS associated with drug-induced liver injury (D-VBDS) is an important etiology of VBDS, and immune disorder or immune imbalance may be the main pathogenesis. According to its clinical symptoms, serological markers, and course of the disease, D-VBDS is classified into major form and minor form, and its clinical features are based on various pathomorphological findings. Its prognosis is associated various factors including regeneration of bile duct cells, number of bile duct injuries, level and range of bile duct injury, bile duct proliferation, and compensatory shunt of bile duct branches. This disease has various clinical outcomes; most patients have good prognosis after drug withdrawal, and some patients may experience cholestatic cirrhosis, liver failure, and even death. Due to the clinical manifestation and biochemical changes are similar to the primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), it need to identify by clinical physician.

Genetic variants associated with antithyroid drug-induced agranulocytosis: a genome-wide association study in a European population.

PubMed

Hallberg, Pär; Eriksson, Niclas; Ibañez, Luisa; Bondon-Guitton, Emmanuelle; Kreutz, Reinhold; Carvajal, Alfonso; Lucena, M Isabel; Ponce, Esther Sancho; Molokhia, Mariam; Martin, Javier; Axelsson, Tomas; Yue, Qun-Ying; Magnusson, Patrik K E; Wadelius, Mia

2016-06-01

Drug-induced agranulocytosis is a potentially life-threatening adverse reaction. Genome-wide association studies (GWASs) in ethnic Chinese people in Taiwan and Hong Kong have shown an association between agranulocytosis induced by antithyroid drugs and the HLA alleles HLA-B*38:02 and HLA-DRB1*08:03. We aimed to identify genetic variants associated with antithyroid drug-induced agranulocytosis in a white European population. We did a GWAS in 234 European adults with any non-chemotherapy drug-induced agranulocytosis (absolute neutrophil count ≤0·5 × 10(9)/L [≤500/μL]) and 5170 population controls. 39 of the 234 patients had agranulocytosis that was induced by antithyroid drugs (thiamazole [methimazole], carbimazole, or propylthiouracil). After imputation and HLA allele prediction, 9 380 034 single nucleotide polymorphisms (SNPs) and 180 HLA alleles were tested for association. The genome-wide significance threshold was p<5 × 10(-8). Agranulocytosis induced by non-chemotherapy drugs in general was significantly associated with the HLA region on chromosome 6, with odds ratios (ORs) of 3·24 (95% CI 2·31-4·55, p=1·20 × 10(-11)) for HLA-B*27:05 and 3·57 (2·61-4·90, p=2·32 × 10(-15)) for the top SNP (rs114291795). Drug-specific analysis showed that the association with HLA-B*27:05 was largely driven by cases induced by antithyroid drugs. In a multiple logistic regression model, the OR for HLA-B*27:05 was 7·30 (3·81-13·96) when antithyroid drug-induced agranulocytosis was compared with population controls (p=1·91 × 10(-9)) and 16·91 (3·44-83·17) when compared with a small group of hyperthyroid controls (p=5·04 × 10(-4)). Three SNPs were strongly associated with antithyroid drug-induced agranulocytosis: rs652888 (OR 4·73, 95% CI 3·00-7·44, p=1·92 × 10(-11)) and rs199564443 (17·42, 7·38-41·12, p=7·04 × 10(-11)), which were independent of HLA-B*27:05, and rs1071816 (5·27, 3·06-9·10, p=2·35 × 10

Mechanistic Modelling of Drug-Induced Liver Injury: Investigating the Role of Innate Immune Responses.

PubMed

Shoda, Lisl Km; Battista, Christina; Siler, Scott Q; Pisetsky, David S; Watkins, Paul B; Howell, Brett A

2017-01-01

Drug-induced liver injury (DILI) remains an adverse event of significant concern for drug development and marketed drugs, and the field would benefit from better tools to identify liver liabilities early in development and/or to mitigate potential DILI risk in otherwise promising drugs. DILIsym software takes a quantitative systems toxicology approach to represent DILI in pre-clinical species and in humans for the mechanistic investigation of liver toxicity. In addition to multiple intrinsic mechanisms of hepatocyte toxicity (ie, oxidative stress, bile acid accumulation, mitochondrial dysfunction), DILIsym includes the interaction between hepatocytes and cells of the innate immune response in the amplification of liver injury and in liver regeneration. The representation of innate immune responses, detailed here, consolidates much of the available data on the innate immune response in DILI within a single framework and affords the opportunity to systematically investigate the contribution of the innate response to DILI.

Stereoselective Inhibition of the hERG1 Potassium Channel

PubMed Central

Grilo, Liliana Sintra; Carrupt, Pierre-Alain; Abriel, Hugues

2010-01-01

A growing number of drugs have been shown to prolong cardiac repolarization, predisposing individuals to life-threatening ventricular arrhythmias known as Torsades de Pointes. Most of these drugs are known to interfere with the human ether à-gogo related gene 1 (hERG1) channel, whose current is one of the main determinants of action potential duration. Prolonged repolarization is reflected by lengthening of the QT interval of the electrocardiogram, as seen in the suitably named drug-induced long QT syndrome. Chirality (presence of an asymmetric atom) is a common feature of marketed drugs, which can therefore exist in at least two enantiomers with distinct three-dimensional structures and possibly distinct biological fates. Both the pharmacokinetic and pharmacodynamic properties can differ between enantiomers, as well as also between individuals who take the drug due to metabolic polymorphisms. Despite the large number of reports about drugs reducing the hERG1 current, potential stereoselective contributions have only been scarcely investigated. In this review, we present a non-exhaustive list of clinically important molecules which display chiral toxicity that may be related to hERG1-blocking properties. We particularly focus on methadone cardiotoxicity, which illustrates the importance of the stereoselective effect of drug chirality as well as individual variations resulting from pharmacogenetics. Furthermore, it seems likely that, during drug development, consideration of chirality in lead optimization and systematic assessment of the hERG1 current block with all enantiomers could contribute to the reduction of the risk of drug-induced LQTS. PMID:21833176

Interrogation of transcriptomic changes associated with drug-induced hepatic sinusoidal dilatation in colorectal cancer.

PubMed

Jarzabek, Monika A; Proctor, William R; Vogt, Jennifer; Desai, Rupal; Dicker, Patrick; Cain, Gary; Raja, Rajiv; Brodbeck, Jens; Stevens, Dale; van der Stok, Eric P; Martens, John W M; Verhoef, Cornelis; Hegde, Priti S; Byrne, Annette T; Tarrant, Jacqueline M

2018-01-01

Drug-related sinusoidal dilatation (SD) is a common form of hepatotoxicity associated with oxaliplatin-based chemotherapy used prior to resection of colorectal liver metastases (CRLM). Recently, hepatic SD has also been associated with anti-delta like 4 (DLL4) cancer therapies targeting the NOTCH pathway. To investigate the hypothesis that NOTCH signaling plays an important role in drug-induced SD, gene expression changes were examined in livers from anti-DLL4 and oxaliplatin-induced SD in non-human primate (NHP) and patients, respectively. Putative mechanistic biomarkers of bevacizumab (bev)-mediated protection against oxaliplatin-induced SD were also investigated. RNA was extracted from whole liver sections or centrilobular regions by laser-capture microdissection (LCM) obtained from NHP administered anti-DLL4 fragment antigen-binding (F(ab')2 or patients with CRLM receiving oxaliplatin-based chemotherapy with or without bev. mRNA expression was quantified using high-throughput real-time quantitative PCR. Significance analysis was used to identify genes with differential expression patterns (false discovery rate (FDR) < 0.05). Eleven (CCL2, CCND1, EFNB2, ERG, ICAM1, IL16, LFNG, NOTCH1, NOTCH4, PRDX1, and TGFB1) and six (CDH5, EFNB2, HES1, IL16, MIK67, HES1 and VWF) candidate genes were differentially expressed in the liver of anti-DLL4- and oxaliplatin-induced SD, respectively. Addition of bev to oxaliplatin-based chemotherapy resulted in differential changes in hepatic CDH5, HEY1, IL16, JAG1, MMP9, NOTCH4 and TIMP1 expression. This work implicates NOTCH and IL16 pathways in the pathogenesis of drug-induced SD and further explains the hepato-protective effect of bev in oxaliplatin-induced SD observed in CRLM patients.

Drug-induced acne and rose pearl: similarities*

PubMed Central

Pontello Junior, Rubens; Kondo, Rogerio Nabor

2013-01-01

Drug-induced acne is a common skin condition whose classic symptoms can be similar to a rose pearl, as in the case of a male patient presenting with this condition after excessive use of a cream containing corticosteroids. PMID:24474128

Neural correlates of stress-induced and cue-induced drug craving: influences of sex and cocaine dependence.

PubMed

Potenza, Marc N; Hong, Kwang-ik Adam; Lacadie, Cheryl M; Fulbright, Robert K; Tuit, Keri L; Sinha, Rajita

2012-04-01

Although stress and drug cue exposure each increase drug craving and contribute to relapse in cocaine dependence, no previous research has directly examined the neural correlates of stress-induced and drug cue-induced craving in cocaine-dependent women and men relative to comparison subjects. Functional MRI was used to assess responses to individualized scripts for stress, drug/alcohol cue and neutral-relaxing-imagery conditions in 30 abstinent cocaine-dependent individuals (16 women, 14 men) and 36 healthy recreational-drinking comparison subjects (18 women, 18 men). Significant three-way interactions between diagnostic group, sex, and script condition were observed in multiple brain regions including the striatum, insula, and anterior and posterior cingulate. Within women, group-by-condition interactions were observed involving these regions and were attributable to relatively increased regional activations in cocaine-dependent women during the stress and, to a lesser extent, neutral-relaxing conditions. Within men, group main effects were observed involving these same regions, with cocaine-dependent men demonstrating relatively increased activation across conditions, with the main contributions from the drug and neutral-relaxing conditions. In men and women, subjective drug-induced craving measures correlated positively with corticostriatal-limbic activations. In cocaine dependence, corticostriatal-limbic hyperactivity appears to be linked to stress cues in women, drug cues in men, and neutral-relaxing conditions in both. These findings suggest that sex should be taken into account in the selection of therapies in the treatment of addiction, particularly those targeting stress reduction.

[Talc-induced pulmonary granulomas in drug addicts].

PubMed

Latartseva, L N; Kryvenko, O N

2013-01-01

Among the diseases accompanied by granuloma formation in the lung, there is so-called granulomatosis developing in injection drug users who have been long injecting suspensions of oral medications containing talc and other water insoluble fillers. 102 deaths of chronic intravenous drug users were examined; 12 of whom showed pulmonary talc-induced granulomatosis. Their morphology was studied using polarized light microscopy. The main mechanisms of thanatogenesis in lethal cases within the first hours after intravenous injection of talc-containing oral medication suspensions are explained.

Proteomic Candidate Biomarkers of Drug-Induced Nephrotoxicity in the Rat

PubMed Central

Rouse, Rodney; Siwy, Justyna; Mullen, William; Mischak, Harald; Metzger, Jochen; Hanig, Joseph

2012-01-01

Improved biomarkers of acute nephrotoxicity are coveted by the drug development industry, regulatory agencies, and clinicians. In an effort to identify such biomarkers, urinary peptide profiles of rats treated with two different nephrotoxins were investigated. 493 marker candidates were defined that showed a significant response to cis-platin comparing a cis-platin treated cohort to controls. Next, urine samples from rats that received three consecutive daily doses of 150 or 300 mg/kg gentamicin were examined. 557 potential biomarkers were initially identified; 108 of these gentamicin-response markers showed a clear temporal response to treatment. 39 of the cisplatin-response markers also displayed a clear response to gentamicin. Of the combined 147 peptides, 101 were similarly regulated by gentamicin or cis-platin and 54 could be identified by tandem mass spectrometry. Most were collagen type I and type III fragments up-regulated in response to gentamicin treatment. Based on these peptides, classification models were generated and validated in a longitudinal study. In agreement with histopathology, the observed changes in classification scores were transient, initiated after the first dose, and generally persistent over a period of 10–20 days before returning to control levels. The data support the hypothesis that gentamicin-induced renal toxicity up-regulates protease activity, resulting in an increase in several specific urinary collagen fragments. Urinary proteomic biomarkers identified here, especially those common to both nephrotoxins, may serve as a valuable tool to investigate potential new drug candidates for the risk of nephrotoxicity. PMID:22509332

Targeted Metabolomics Identifies Pharmacodynamic Biomarkers for BIO 300 Mitigation of Radiation-Induced Lung Injury.

PubMed

Jones, Jace W; Jackson, Isabel L; Vujaskovic, Zeljko; Kaytor, Michael D; Kane, Maureen A

2017-12-01

Biomarkers serve a number of purposes during drug development including defining the natural history of injury/disease, serving as a secondary endpoint or trigger for intervention, and/or aiding in the selection of an effective dose in humans. BIO 300 is a patent-protected pharmaceutical formulation of nanoparticles of synthetic genistein being developed by Humanetics Corporation. The primary goal of this metabolomic discovery experiment was to identify biomarkers that correlate with radiation-induced lung injury and BIO 300 efficacy for mitigating tissue damage based upon the primary endpoint of survival. High-throughput targeted metabolomics of lung tissue from male C57L/J mice exposed to 12.5 Gy whole thorax lung irradiation, treated daily with 400 mg/kg BIO 300 for either 2 weeks or 6 weeks starting 24 h post radiation exposure, were assayed at 180 d post-radiation to identify potential biomarkers. A panel of lung metabolites that are responsive to radiation and able to distinguish an efficacious treatment schedule of BIO 300 from a non-efficacious treatment schedule in terms of 180 d survival were identified. These metabolites represent potential biomarkers that could be further validated for use in drug development of BIO 300 and in the translation of dose from animal to human.

Antithyroid drug-induced agranulocytosis.

PubMed

Sun, Ming-Tsung; Tsai, Chen-Hao; Shih, Kuang-Chung

2009-08-01

Antithyroid drugs are widely used to treat hyperthyroidism, especially Graves' disease, but they tend to cause agranulocytosis, which increases the mortality rate. Granulocyte colony-stimulating factor decreases the duration of recovery from agranulocytosis. We retrospectively studied cases of antithyroid drug-induced agranulocytosis over the past 10 years in a northern Taiwan medical center. A clinical evaluation was conducted, including a review of complete blood cell counts and differential counts. Four cases were included in this analysis. Agranulocytosis persisted in 2 cases despite a change in therapy from propylthiouracil to methimazole. Fever, sore throat, and diarrhea were common symptoms of agranulocytosis. Initial white blood cell counts ranged from 450 to 1,710/microL. Only 1 case had a positive result from a throat swab culture (Staphylococcus aureus). Three of 4 cases received granulocyte colony-stimulating factor therapy, and the recovery time ranged from 3 to 13 days. All of the patients recovered from agranulocytosis. We concluded that: (1) conducting a routine complete blood cell count is beneficial in alerting caregivers to the possibility of agranulocytosis; (2) educating patients about the common symptoms of agranulocytosis may contribute to an early diagnosis; (3) providing granulocyte colony-stimulating factor therapy to patients results in good prognosis; and (4) monitoring for cross-reactions between drugs should be performed to prevent further episodes of agranulocytosis.

Zebrafish as model organisms for studying drug-induced liver injury

PubMed Central

Vliegenthart, A D Bastiaan; Tucker, Carl S; Del Pozo, Jorge; Dear, James W

2014-01-01

Drug-induced liver injury (DILI) is a major challenge in clinical medicine and drug development. New models are needed for predicting which potential therapeutic compounds will cause DILI in humans, and new markers and mediators of DILI still need to be identified. This review highlights the strengths and weaknesses of using zebrafish as a high-throughput in vivo model for studying DILI. Although the zebrafish liver architecture is different from that of the mammalian liver, the main physiological processes remain similar. Zebrafish metabolize drugs using similar pathways to those in humans; they possess a wide range of cytochrome P450 enzymes that enable metabolic reactions including hydroxylation, conjugation, oxidation, demethylation and de-ethylation. Following exposure to a range of hepatotoxic drugs, the zebrafish liver develops histological patterns of injury comparable to those of mammalian liver, and biomarkers for liver injury can be quantified in the zebrafish circulation. The zebrafish immune system is similar to that of mammals, but the zebrafish inflammatory response to DILI is not yet defined. In order to quantify DILI in zebrafish, a wide variety of methods can be used, including visual assessment, quantification of serum enzymes and experimental serum biomarkers and scoring of histopathology. With further development, the zebrafish may be a model that complements rodents and may have value for the discovery of new disease pathways and translational biomarkers. PMID:24773296

Screening of a Drug Library Identifies Inhibitors of Cell Intoxication by CNF1.

PubMed

Mahtal, Nassim; Brewee, Clémence; Pichard, Sylvain; Visvikis, Orane; Cintrat, Jean-Christophe; Barbier, Julien; Lemichez, Emmanuel; Gillet, Daniel

2018-04-06

Cytotoxic necrotizing factor 1 (CNF1) is a toxin produced by pathogenic strains of Escherichia coli responsible for extra-intestinal infections. CNF1 deamidates Rac1, thereby triggering its permanent activation and worsening inflammatory reactions. Activated Rac1 is prone to proteasomal degradation. There is no targeted therapy against CNF1, despite its clinical relevance. In this work we developed a fluorescent cell-based immunoassay to screen for inhibitors of CNF1-induced Rac1 degradation among 1120 mostly approved drugs. Eleven compounds were found to prevent CNF1-induced Rac1 degradation, and five also showed a protective effect against CNF1-induced multinucleation. Finally, lasalocid, monensin, bepridil, and amodiaquine protected cells from both diphtheria toxin and CNF1 challenges. These data highlight the potential for drug repurposing to fight several bacterial infections and Rac1-based diseases. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Drug induced liver injury with analysis of alternative causes as confounding variables.

PubMed

Teschke, Rolf; Danan, Gaby

2018-04-01

Drug-induced liver injury (DILI) is rare compared to the worldwide frequent acute or chronic liver diseases. Therefore, patients included in series of suspected DILI are at high risk of not having DILI, whereby alternative causes may confound the DILI diagnosis. The aim of this review is to evaluate published case series of DILI for alternative causes. Relevant studies were identified using a computerized search of the Medline database for publications from 1993 through 30 October 2017. We used the following terms: drug hepatotoxicity, drug induced liver injury, hepatotoxic drugs combined with diagnosis, causality assessment and alternative causes. Alternative causes as variables confounding the DILI diagnosis emerged in 22 published DILI case series, ranging from 4 to 47%. Among 13 335 cases of suspected DILI, alternative causes were found to be more likely in 4555 patients (34.2%), suggesting that the suspected DILI was probably not DILI. Biliary diseases such as biliary obstruction, cholangitis, choledocholithiasis, primary biliary cholangitis and primary sclerosing cholangitis were among the most missed diagnoses. Alternative causes included hepatitis B, C and E, cytomegalovirus, Epstein-Barr virus, ischemic hepatitis, cardiac hepatopathy, autoimmune hepatitis, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, and alcoholic liver disease. In more than one-third of published global DILI case series, alternative causes as published in these reports confounded the DILI diagnosis. In the future, published DILI case series should include only patients with secured DILI diagnosis, preferentially established by prospective use of scored items provided by robust diagnostic algorithms such as the updated Roussel Uclaf causality assessment method. © 2018 The British Pharmacological Society.

[Epidemiology of early repolarization pattern in Maghreb].

PubMed

Amara, W; Bouallouche, S A; Rezoug, A; Hraiech, A El; Iusuf, A; Hammoudi, N

2017-11-01

An early repolarization variant (ERV) in inferolateral leads has recently been associated with vulnerability to ventricular fibrillation. These studies have been conducted in the occidental countries. The prevalence of ERV in the population of the Maghreb is unknown. The aim of this study was to evaluate the prevalence and risk factors of ERV in a young population from Algeria. We assessed the prevalence of ERV within a population of 441 healthy subjects (mean age 25 years) using 12-lead electrocardiography. ERV was stratified by three independent cardiologists according to the J-point elevation (≥0.1mV) in the inferior, apicolateral or both leads with QRS slurring or notching. The inferolateral ERV pattern was present in 55 subjects (12.4%). A malign ERV (>2mm) was present in 5 subjects (9% of ER) and ER in inferior and lateral leads in 40% of ER. An ERV pattern was more frequently associated with young age, male, bradycardia and T wave in V1 lead. An ERV is a common finding in a healthy Algerian young population. This prevalence seems to be more important than other studies due to young age and not to a racial difference. Our population were more at risk that other studies, and we found more T waves in V1 lead in this people, due to an ethnic particularities or a phenotypic association with the Brugada syndrome. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Identifying types of drug intoxication : laboratory evaluation of a subject-examination procedure

DOT National Transportation Integrated Search

1985-05-01

The Los Angeles Police Department (LAPD) has developed a rating procedures for use in detecting drug-impaired drivers. The purpose of the rating procedures is to determine whether the driver is impaired and to identify the responsible drug class (e.g...

Evaluation of nefazodone-induced cardiotoxicity in human induced pluripotent stem cell-derived cardiomyocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Sujeong, E-mail: crystalee@gmail.com; Lee, Hyang-Ae, E-mail: hyangaelee@gmail.com; Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 110-799

2016-04-01

The recent establishment of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), which express the major cardiac ion channels and recapitulate spontaneous mechanical and electrical activities, may provide a possible solution for the lack of in vitro human-based cardiotoxicity testing models. Cardiotoxicity induced by the antidepressant nefazodone was previously revealed to cause an acquired QT prolongation by hERG channel blockade. To elucidate the cellular mechanisms underlying the cardiotoxicity of nefazodone beyond hERG, its effects on cardiac action potentials (APs) and ion channels were investigated using hiPSC-CMs with whole-cell patch clamp techniques. In a proof of principle study, we examined the effectsmore » of cardioactive channel blockers on the electrophysiological profile of hiPSC-CMs in advance of the evaluation of nefazodone. Nefazodone dose-dependently prolonged the AP duration at 90% (APD{sub 90}) and 50% (APD{sub 50}) repolarization, reduced the maximum upstroke velocity (dV/dt{sub max}) and induced early after depolarizations. Voltage-clamp studies of hiPSC-CMs revealed that nefazodone inhibited various voltage-gated ion channel currents including I{sub Kr}, I{sub Ks}, I{sub Na}, and I{sub Ca}. Among them, I{sub Kr} and I{sub Na} showed relatively higher sensitivity to nefazodone, consistent with the changes in the AP parameters. In summary, hiPSC-CMs enabled an integrated approach to evaluate the complex interactions of nefazodone with cardiac ion channels. These results suggest that hiPSC-CMs can be an effective model for detecting drug-induced arrhythmogenicity beyond the current standard assay of heterologously expressed hERG K{sup +} channels. - Highlights: • Nefazodone prolonged APD and decreased upstroke velocity of APs in hiPSC-CMs. • Nefazodone inhibited cardiac ion channels, especially I{sub Kr} and I{sub Na}, in hiPSC-CMs. • Nefazodone-induced AP changes are mainly the result of I{sub Kr} and I{sub Na

Cellular mechanisms underlying the effects of milrinone and cilostazol to suppress arrhythmogenesis associated with Brugada syndrome.

PubMed

Szél, Tamás; Koncz, István; Antzelevitch, Charles

2013-11-01

Brugada syndrome is an inherited disease associated with vulnerability to ventricular tachycardia and sudden cardiac death in young adults. Milrinone and cilostazol, oral phosphodiesterase (PDE) type III inhibitors, have been shown to increase L-type calcium channel current (ICa) and modestly increase heart rate by elevating the level of intracellular cyclic adenosine monophosphate. To examine the effectiveness of these PDE inhibitors to suppress arrhythmogenesis in an experimental model of Brugada syndrome. Action potential (AP) and electrocardiographic recordings were obtained from epicardial and endocardial sites of coronary-perfused canine right ventricular wedge preparations. The Ito agonist NS5806 (5 μM) and Ca(2+) channel blocker verapamil (2 μM) were used to pharmacologically mimic Brugada phenotype. The combination induced all-or-none repolarization at some epicardial sites but not others, leading to ST-segment elevation as well as an increase in both epicardial and transmural dispersion of repolarization. Under these conditions, phase 2 reentry developed as the epicardial AP dome propagated from sites where it was maintained to sites at which it was lost, generating closely coupled extrasystoles and ventricular tachycardia. The addition of the PDE inhibitor milrinone (2.5 μM) or cilostazol (5-10 μM) to the coronary perfusate restored the epicardial AP dome, reduced dispersion, and abolished phase 2 reentry-induced extrasystoles and ventricular tachycardia. Our study identifies milrinone as a more potent alternative to cilostazol for reversing the repolarization defects responsible for the electrocardiographic and arrhythmic manifestations of Brugada syndrome. Both drugs normalize ST-segment elevation and suppress arrhythmogenesis in experimental models of Brugada syndrome. © 2013 Heart Rhythm Society. All rights reserved.

Mechanisms of the hepatoprotective effects of tamoxifen against drug-induced and chemical-induced acute liver injuries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshikawa, Yukitaka; Miyashita, Taishi; Higuchi, Satonori

Although estrogen receptor (ER)α agonists, such as estradiol and ethinylestradiol (EE2), cause cholestasis in mice, they also reduce the degree of liver injury caused by hepatotoxicants as well as ischemia–reperfusion. The functional mechanisms of ERα have yet to be elucidated in drug-induced or chemical-induced liver injury. The present study investigated the effects of an ERα agonist, selective ER modulators (SERMs) and an ER antagonist on drug-induced and chemical-induced liver injuries caused by acetaminophen, bromobenzene, diclofenac, and thioacetamide (TA). We observed hepatoprotective effects of EE2, tamoxifen (TAM) and raloxifene pretreatment in female mice that were exposed to a variety of hepatotoxicmore » compounds. In contrast, the ER antagonist did not show any hepatoprotective effects. DNA microarray analyses suggested that monocyte to macrophage differentiation-associated 2 (Mmd2) protein, which has an unknown function, is commonly increased by TAM and RAL pretreatment, but not by pretreatment with the ER antagonist. In ERα-knockout mice, the hepatoprotective effects of TAM and the increased expression of Mmd2 mRNA were not observed in TA-induced liver injury. To investigate the function of Mmd2, the expression level of Mmd2 mRNA was significantly knocked down to approximately 30% in mice by injection of siRNA for Mmd2 (siMmd2). Mmd2 knockdown resulted in a reduction of the protective effects of TAM on TA-induced liver injury in mice. This is the first report of the involvement of ERα in drug-induced or chemical-induced liver injury. Upregulation of Mmd2 protein in the liver was suggested as the mechanism of the hepatoprotective effects of EE2 and SERMs. -- Highlights: ► Liver injury induced by drugs or chemicals was investigated in mice. ► Liver injury was suppressed by pretreatment with tamoxifen in female mice. ► Mmd2, whose function was unknown, could be a candidate gene for liver protection. ► Tamoxifen up-regulated Mmd2 m

Strategy for Identifying Repurposed Drugs for the Treatment of Cerebral Cavernous Malformation

PubMed Central

Gibson, Christopher C.; Zhu, Weiquan; Davis, Chadwick T.; Bowman-Kirigin, Jay A.; Chan, Aubrey C.; Ling, Jing; Walker, Ashley E.; Goitre, Luca; Monache, Simona Delle; Retta, Saverio Francesco; Shiu, Yan-Ting E.; Grossmann, Allie H.; Thomas, Kirk R.; Donato, Anthony J.; Lesniewski, Lisa A.; Whitehead, Kevin J.; Li, Dean Y.

2014-01-01

Background Cerebral cavernous malformation (CCM) is a hemorrhagic stroke disease affecting up to 0.5% of North Americans with no approved non-surgical treatment. A subset of patients have a hereditary form of the disease due primarily to loss-of-function mutations in KRIT1, CCM2, or PDCD10. We sought to identify known drugs that could be repurposed to treat CCM. Methods and Results We developed an unbiased screening platform based on both cellular and animal models of loss-of-function of CCM2. Our discovery strategy consisted of four steps: an automated immunofluorescence and machine-learning-based primary screen of structural phenotypes in human endothelial cells deficient in CCM2; a secondary screen of functional changes in endothelial stability in these same cells; a rapid in vivo tertiary screen of dermal microvascular leak in mice lacking endothelial Ccm2; and finally a quaternary screen of CCM lesion burden in these same mice. We screened 2,100 known drugs and bioactive compounds, and identified two candidates for further study, cholecalciferol (Vitamin D3) and tempol (a scavenger of superoxide). Each drug decreased lesion burden in a mouse model of CCM vascular disease by approximately 50%. Conclusions By identifying known drugs as potential therapeutics for CCM, we have decreased the time, cost, and risk of bringing treatments to patients. Each drug also prompts additional exploration of biomarkers of CCM disease. We further suggest that the structure-function screening platform presented here may be adapted and scaled to facilitate drug discovery for diverse loss-of-function genetic vascular disease. PMID:25486933

In silico assessment of drug safety in human heart applied to late sodium current blockers

PubMed Central

Trenor, Beatriz; Gomis-Tena, Julio; Cardona, Karen; Romero, Lucia; Rajamani, Sridharan; Belardinelli, Luiz; Giles, Wayne R; Saiz, Javier

2013-01-01

Drug-induced action potential (AP) prolongation leading to Torsade de Pointes is a major concern for the development of anti-arrhythmic drugs. Nevertheless the development of improved anti-arrhythmic agents, some of which may block different channels, remains an important opportunity. Partial block of the late sodium current (INaL) has emerged as a novel anti-arrhythmic mechanism. It can be effective in the settings of free radical challenge or hypoxia. In addition, this approach can attenuate pro-arrhythmic effects of blocking the rapid delayed rectifying K+ current (IKr). The main goal of our computational work was to develop an in-silico tool for preclinical anti-arrhythmic drug safety assessment, by illustrating the impact of IKr/INaL ratio of steady-state block of drug candidates on “torsadogenic” biomarkers. The O’Hara et al. AP model for human ventricular myocytes was used. Biomarkers for arrhythmic risk, i.e., AP duration, triangulation, reverse rate-dependence, transmural dispersion of repolarization and electrocardiogram QT intervals, were calculated using single myocyte and one-dimensional strand simulations. Predetermined amounts of block of INaL and IKr were evaluated. “Safety plots” were developed to illustrate the value of the specific biomarker for selected combinations of IC50s for IKr and INaL of potential drugs. The reference biomarkers at baseline changed depending on the “drug” specificity for these two ion channel targets. Ranolazine and GS967 (a novel potent inhibitor of INaL) yielded a biomarker data set that is considered safe by standard regulatory criteria. This novel in-silico approach is useful for evaluating pro-arrhythmic potential of drugs and drug candidates in the human ventricle. PMID:23696033

Repurposing drugs to treat l-DOPA-induced dyskinesia in Parkinson's disease.

PubMed

Johnston, Tom H; Lacoste, Alix M B; Visanji, Naomi P; Lang, Anthony E; Fox, Susan H; Brotchie, Jonathan M

2018-06-01

In this review, we discuss the opportunity for repurposing drugs for use in l-DOPA-induced dyskinesia (LID) in Parkinson's disease. LID is a particularly suitable indication for drug repurposing given its pharmacological diversity, translatability of animal-models, availability of Phase II proof-of-concept (PoC) methodologies and the indication-specific regulatory environment. A compound fit for repurposing is defined as one with appropriate human safety-data as well as animal safety, toxicology and pharmacokinetic data as found in an Investigational New Drug (IND) package for another indication. We first focus on how such repurposing candidates can be identified and then discuss development strategies that might progress such a candidate towards a Phase II clinical PoC. We discuss traditional means for identifying repurposing candidates and contrast these with newer approaches, especially focussing on the use of computational and artificial intelligence (AI) platforms. We discuss strategies that can be categorised broadly as: in vivo phenotypic screening in a hypothesis-free manner; in vivo phenotypic screening based on analogy to a related disorder; hypothesis-driven evaluation of candidates in vivo and in silico screening with a hypothesis-agnostic component to the selection. To highlight the power of AI approaches, we describe a case study using IBM Watson where a training set of compounds, with demonstrated ability to reduce LID, were employed to identify novel repurposing candidates. Using the approaches discussed, many diverse candidates for repurposing in LID, originally envisaged for other indications, will be described that have already been evaluated for efficacy in non-human primate models of LID and/or clinically. Copyright © 2018 Elsevier Ltd. All rights reserved.

Reliability of the Roussel Uclaf Causality Assessment Method for Assessing Causality in Drug-Induced Liver Injury*

PubMed Central

Rochon, James; Protiva, Petr; Seeff, Leonard B.; Fontana, Robert J.; Liangpunsakul, Suthat; Watkins, Paul B.; Davern, Timothy; McHutchison, John G.

2013-01-01

The Roussel Uclaf Causality Assessment Method (RUCAM) was developed to quantify the strength of association between a liver injury and the medication implicated as causing the injury. However, its reliability in a research setting has never been fully explored. The aim of this study was to determine test-retest and interrater reliabilities of RUCAM in retrospectively-identified cases of drug induced liver injury. The Drug-Induced Liver Injury Network is enrolling well-defined cases of hepatotoxicity caused by isoniazid, phenytoin, clavulanate/amoxicillin, or valproate occurring since 1994. Each case was adjudicated by three reviewers working independently; after an interval of at least 5 months, cases were readjudicated by the same reviewers. A total of 40 drug-induced liver injury cases were enrolled including individuals treated with isoniazid (nine), phenytoin (five), clavulanate/amoxicillin (15), and valproate (11). Mean ± standard deviation age at protocol-defined onset was 44.8 ± 19.5 years; patients were 68% female and 78% Caucasian. Cases were classified as hepatocellular (44%), mixed (28%), or cholestatic (28%). Test-retest differences ranged from −7 to +8 with complete agreement in only 26% of cases. On average, the maximum absolute difference among the three reviewers was 3.1 on the first adjudication and 2.7 on the second, although much of this variability could be attributed to differences between the enrolling investigator and the external reviewers. The test-retest reliability by the same assessors was 0.54 (upper 95% confidence limit = 0.77); the interrater reliability was 0.45 (upper 95% confidence limit = 0.58). Categorizing the RUCAM to a five-category scale improved these reliabilities but only marginally. Conclusion The mediocre reliability of the RUCAM is problematic for future studies of drug-induced liver injury. Alternative methods, including modifying the RUCAM, developing drug-specific instruments, or causality assessment based on

A prediction model of drug-induced ototoxicity developed by an optimal support vector machine (SVM) method.

PubMed

Zhou, Shu; Li, Guo-Bo; Huang, Lu-Yi; Xie, Huan-Zhang; Zhao, Ying-Lan; Chen, Yu-Zong; Li, Lin-Li; Yang, Sheng-Yong

2014-08-01

Drug-induced ototoxicity, as a toxic side effect, is an important issue needed to be considered in drug discovery. Nevertheless, current experimental methods used to evaluate drug-induced ototoxicity are often time-consuming and expensive, indicating that they are not suitable for a large-scale evaluation of drug-induced ototoxicity in the early stage of drug discovery. We thus, in this investigation, established an effective computational prediction model of drug-induced ototoxicity using an optimal support vector machine (SVM) method, GA-CG-SVM. Three GA-CG-SVM models were developed based on three training sets containing agents bearing different risk levels of drug-induced ototoxicity. For comparison, models based on naïve Bayesian (NB) and recursive partitioning (RP) methods were also used on the same training sets. Among all the prediction models, the GA-CG-SVM model II showed the best performance, which offered prediction accuracies of 85.33% and 83.05% for two independent test sets, respectively. Overall, the good performance of the GA-CG-SVM model II indicates that it could be used for the prediction of drug-induced ototoxicity in the early stage of drug discovery. Copyright © 2014 Elsevier Ltd. All rights reserved.

Drug-, toxin-, and radiation therapy-induced eosinophilic pneumonia.

PubMed

Solomon, Joshua; Schwarz, Marvin

2006-04-01

A significant number of drugs and toxins have been associated with eosinophilic pneumonia. Antibiotics and NSAID, are the most commonly reported drugs. Toxins suspected to cause eosinophilic pneumonia include cigarette smoke and illicit drugs. Drug- or toxin-induced eosinophilic pneumonia is indistinguishable from idiopathic acute or chronic eosinophilic pneumonia by clinical, radiographic, and histopathologic criteria. The diagnosis is supported by a temporal relationship to a drug or toxin. The condition usually resolves with removal from the agent and recurs with rechallenge. Treatment involves discontinuation of the offending drug or toxin and treatment with corticosteroids in severe respiratory failure. There are also mass outbreaks of eosinophilic pneumonia reported, such as the toxic-oil syndrome in 1981 and the eosinophilia-myalgia syndrome related to the ingestion of L-tryptophan in 1989. A recent report has described an outbreak of acute eosinophilic pneumonia found in soldiers in Iraq. Radiation therapy has also been associated with the development of eosinophilic pneumonia in patients receiving this treatment for breast cancer.

The analysis of QT interval and repolarization morphology of the heart in chronic exposure to lead.

PubMed

Kiełtucki, J; Dobrakowski, M; Pawlas, N; Średniawa, B; Boroń, M; Kasperczyk, S

2017-10-01

There are no common recommendations regarding electrocardiographic monitoring in occupationally exposed workers. Therefore, the present study was designed to investigate whether exposure to lead results in an increase of selected electrocardiography (ECG) pathologies, such as QT interval prolongation and repolarization disorders, in occupationally exposed workers. The study group included 180 workers occupationally exposed to lead compounds. The exposed group was divided according to the median of the mean blood lead level (PbB mean ) calculated based on a series of measurements performed during 5-year observation period (35 µg/dl) into two subgroups: low exposure (LE, PbB mean = 20.0-35.0 µg/dl) and high exposure (HE, PbB mean = 35.1-46.4 µg/dl). The control group consisted of 69 healthy workers without occupational exposure to lead. ECG evaluation included the analysis of heart rate (HR), QT interval and repolarization abnormalities. Mean QT interval was significantly greater in the exposed population than in the control group by 2%. In the HE group, mean QT interval was significantly greater than in the control group by 4% and significantly different from those noted in the LE group. Positive correlations between QT interval and lead exposure indices were also reported. Besides, there was a negative correlation between HR and blood lead level. Increased concentration of lead in the blood above 35 μg/dl is associated with the QT interval prolongation, which may trigger arrhythmias when combined with other abnormalities, such as long QT syndrome. Therefore, electrocardiographic evaluation should be a part of a routine monitoring of occupationally exposed populations.

Pharmacogenetic aspects of drug-induced torsade de pointes: potential tool for improving clinical drug development and prescribing.

PubMed

Shah, Rashmi R

2004-01-01

Drug-induced torsade de pointes (TdP) has proved to be a significant iatro-genic cause of morbidity and mortality and a major reason for the withdrawal of a number of drugs from the market in recent times. Enzymes that metabolise many of these drugs and the potassium channels that are responsible for cardiac repolarisation display genetic polymorphisms. Anecdotal reports have suggested that in many cases of drug-induced TdP, there may be a concealed genetic defect of either these enzymes or the potassium channels, giving rise to either high plasma drug concentrations or diminished cardiac repolarisation reserve, respectively. The presence of either of these genetic defects may predispose a patient to TdP, a potentially fatal adverse reaction, even at therapeutic dosages of QT-prolonging drugs and in the absence of other risk factors. Advances in pharmacogenetics of drug metabolising enzymes and pharmacological targets, together with the prospects of rapid and inexpensive genotyping procedures, promise to individualise and improve the benefit/risk ratio of therapy with drugs that have the potential to cause TdP. The qualitative and the quantitative contributions of these genetic defects in clinical cases of TdP are unclear because not all of the patients with TdP are routinely genotyped and some relevant genetic mutations still remain to be discovered. There are regulatory guidelines that recommend strategies aimed at uncovering the risk of TdP associated with new chemical entities during their development. There are also a number of guidelines that recommend integrating pharmacogenetics in this process. This paper proposes a strategy for integrating pharmacogenetics into drug development programmes to optimise association studies correlating genetic traits and endpoints of clinical interest, namely failure of efficacy or development of repolarisation abnormalities. Until pharmacogenetics is carefully integrated into all phases of development of QT-prolonging drugs

Macrophage Repolarization with Targeted Alginate Nanoparticles Containing IL-10 Plasmid DNA for the Treatment of Experimental Arthritis

PubMed Central

Jain, Shardool; Tran, Thanh-Huyen; Amiji, Mansoor

2015-01-01

In this study, we have shown for the first time the effectiveness of a non-viral gene transfection strategy to re-polarize macrophages from M1 to M2 functional sub-type for the treatment of rheumatoid arthritis (RA). An anti-inflammatory (IL-10) cytokine encoding plasmid DNA was successfully encapsulated into non-condensing alginate based nanoparticles and the surface of the nano-carriers was modified with tuftsin peptide to achieve active macrophage targeting. Enhanced localization of tuftsin-modified alginate nanoparticles was observed in the inflamed paws of arthritic rats upon intraperitoneal administration. Importantly, targeted nanoparticle treatment was successful in reprogramming macrophage phenotype balance as ~66% of total synovial macrophages from arthritic rats treated with the IL-10 plasmid DNA loaded tuftsin/alginate nanoparticles were in the M2 state compared to ~9% of macrophages in the M2 state from untreated arthritic rats. Treatment significantly reduced systemic and joint tissue pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) expression and prevented the progression of inflammation and joint damage as revealed by magnetic resonance imaging and histology. Treatment enabled animals to retain their mobility throughout the course of study, whereas untreated animals suffered from impaired mobility. Overall, this study demonstrates that targeted alginate nanoparticles loaded with IL-10 plasmid DNA can efficiently re-polarize macrophages from an M1 to an M2 state, offering a novel treatment paradigm for treatment of chronic inflammatory diseases. PMID:26004232

Cytidine deamination induced HIV-1 drug resistance

PubMed Central

Mulder, Lubbertus C. F.; Harari, Ariana; Simon, Viviana

2008-01-01

The HIV-1 Vif protein is essential for overcoming the antiviral activity of DNA-editing apolipoprotein B mRNA editing enzyme, catalytic polypeptide 3 (APOBEC3) cytidine deaminases. We show that naturally occurring HIV-1 Vif point mutants with suboptimal anti-APOBEC3G activity induce the appearance of proviruses with lamivudine (3TC) drug resistance-associated mutations before any drug exposure. These mutations, ensuing from cytidine deamination events, were detected in >40% of proviruses with partially defective Vif mutants. Transfer of drug resistance from hypermutated proviruses via recombination allowed for 3TC escape under culture conditions prohibitive for any WT viral growth. These results demonstrate that defective hypermutated genomes can shape the phenotype of the circulating viral population. Partially active Vif alleles resulting in incomplete neutralization of cytoplasmic APOBEC3 molecules are directly responsible for the generation of a highly diverse, yet G-to-A biased, proviral reservoir, which can be exploited by HIV-1 to generate viable and drug-resistant progenies. PMID:18391217

Antithyroid drug-induced agranulocytosis complicated by pneumococcal sepsis and upper airway obstruction.

PubMed

Ishimaru, Naoto; Ohnishi, Hisashi; Nishiuma, Teruaki; Doukuni, Ryota; Umezawa, Kanoko; Oozone, Sachiko; Kuramoto, Emi; Yoshimura, Sho; Kinami, Saori

2013-01-01

Streptococcus pneumoniae is a rare pathogen of sepsis in patients with antithyroid drug-induced agranulocytosis. We herein describe a case of antithyroid drug-induced agranulocytosis complicated by pneumococcal sepsis and upper airway obstruction. A 27-year-old woman who was previously prescribed methimazole for nine months presented with a four-day history of a sore throat. She nearly choked and was diagnosed with febrile agranulocytosis. She was successfully treated with intubation, intravenous antibiotics and granulocyte colony-stimulating factor. Her blood cultures yielded S. pneumoniae. Emergency airway management, treatment of sepsis and the administration of granulocyte colony-stimulating factor can improve the clinical course of antithyroid drug-induced pneumococcal sepsis in patients with airway obstruction.

The failure to detect drug-induced sensory loss in standard preclinical studies.

PubMed

Gauvin, David V; Abernathy, Matthew M; Tapp, Rachel L; Yoder, Joshua D; Dalton, Jill A; Baird, Theodore J

2015-01-01

Over the years a number of drugs have been approved for human use with limited signs of toxicity noted during preclinical risk assessment study designs but then show adverse events in compliant patients taking the drugs as prescribed within the first few years on the market. Loss or impairments in sensory systems, such as hearing, vision, taste, and smell have been reported to the FDA or have been described in the literature appearing in peer-reviewed scientific journals within the first five years of widespread use. This review highlights the interactive cross-modal compensation within sensory systems that can occur that reduces the likelihood of identifying these losses in less sentient animals used in standard preclinical toxicology and safety protocols. We provide some historical and experimental evidence to substantiate these sensory effects in and highlight the critical importance of detailed training of technicians on basic ethological, species-specific behaviors of all purpose-bred laboratory animals used in these study designs. We propose that the time, effort and cost of training technicians to be better able to identify and document very subtle changes in behavior will serve to increase the likelihood of early detection of biomarkers predictive of drug-induced sensory loss within current standard regulatory preclinical research protocols. Copyright © 2015 Elsevier Inc. All rights reserved.

Identifying genomic and developmental causes of adverse drug reactions in children

PubMed Central

Becker, Mara L; Leeder, J Steven

2011-01-01

Adverse drug reactions are a concern for all clinicians who utilize medications to treat adults and children; however, the frequency of adult and pediatric adverse drug reactions is likely to be under-reported. In this age of genomics and personalized medicine, identifying genetic variation that results in differences in drug biotransformation and response has contributed to significant advances in the utilization of several commonly used medications in adults. In order to better understand the variability of drug response in children however, we must not only consider differences in genotype, but also variation in gene expression during growth and development, namely ontogeny. In this article, recommendations for systematically approaching pharmacogenomic studies in children are discussed, and several examples of studies that investigate the genomic and developmental contribution to adverse drug reactions in children are reviewed. PMID:21121777

Alleviation by garlic of antitumor drug-induced damage to the intestine.

PubMed

Horie, T; Awazu, S; Itakura, Y; Fuwa, T

2001-03-01

Antitumour drugs such as methotrexate (MTX) and 5-fluorouracil (5-FU) induce intestinal damage. This is a serious side effect of cancer chemotherapy. The present studies examined whether or not aged garlic extract (AGE) protects against damage from these antitumor drugs. Both drugs were administered orally for 4 or 5 d to rats fed a standard laboratory diet with and without 2% AGE. The small intestinal absorption of the poorly absorbable compound, fluorescein isothiocyanate--labeled dextran (FD-4; average molecular weight, 4400) was used to evaluate the damage to the intestine using the in vitro everted intestine technique and the in situ intestinal loop technique. FD-4 absorption increased in the antitumour drug-treated rats fed the diet without garlic. Interestingly, FD-4 absorption was depressed in rats fed the diet containing AGE. These results suggest that AGE may protect the small intestine of rats from antitumour drug-induced damage.

Predicting drug-induced liver injury using ensemble learning methods and molecular fingerprints.

PubMed

Ai, Haixin; Chen, Wen; Zhang, Li; Huang, Liangchao; Yin, Zimo; Hu, Huan; Zhao, Qi; Zhao, Jian; Liu, Hongsheng

2018-05-21

Drug-induced liver injury (DILI) is a major safety concern in the drug-development process, and various methods have been proposed to predict the hepatotoxicity of compounds during the early stages of drug trials. In this study, we developed an ensemble model using three machine learning algorithms and 12 molecular fingerprints from a dataset containing 1,241 diverse compounds. The ensemble model achieved an average accuracy of 71.1±2.6%, sensitivity of 79.9±3.6%, specificity of 60.3±4.8%, and area under the receiver operating characteristic curve (AUC) of 0.764±0.026 in five-fold cross-validation and an accuracy of 84.3%, sensitivity of 86.9%, specificity of 75.4%, and AUC of 0.904 in an external validation dataset of 286 compounds collected from the Liver Toxicity Knowledge Base (LTKB). Compared with previous methods, the ensemble model achieved relatively high accuracy and sensitivity. We also identified several substructures related to DILI. In addition, we provide a web server offering access to our models (http://ccsipb.lnu.edu.cn/toxicity/HepatoPred-EL/).

Drug-Induced Nephrotoxicity and Dose Adjustment Recommendations: Agreement Among Four Drug Information Sources.

PubMed

Bicalho, Millena Drumond; Soares, Danielly Botelho; Botoni, Fernando Antonio; Reis, Adriano Max Moreira; Martins, Maria Auxiliadora Parreiras

2015-09-09

: Hospitalized patients require the use of a variety of drugs, many of which individually or in combination have the potential to cause kidney damage. The use of potentially nephrotoxic drugs is often unavoidable, and the need for dose adjustment should be evaluated. This study is aimed at assessing concordance in information on drug-induced nephrotoxicity and dose adjustment recommendations by comparing four drug information sources (DRUGDEX(®), UpToDate(®), Medscape(®) and the Brazilian Therapeutic Formulary) using the formulary of a Brazilian public hospital. A total of 218 drugs were investigated. The global Fleiss' kappa coefficient was 0.265 for nephrotoxicity (p < 0.001; CI 95%, 0.211-0.319) and 0.346 for recommendations (p < 0.001; CI 95%, 0.292-0.401), indicating fair concordance among the sources. Anti-infectives and anti-hypertensives were the main drugs cited as nephrotoxic by the different sources. There were no clear definitions for qualitative data or quantitative values for dose adjustments among the four information sources. There was no advice for dosing for a large number of the drugs in the international databases. The National Therapeutic Formulary offered imprecise dose adjustment recommendations for many nephrotoxic drugs. Discrepancies among information sources may have a clinical impact on patient care and contribute to drug-related morbidity and mortality.

[Assessment on the criminal responsibility of drug-induced mental disorders: a questionnaire survey].

PubMed

Zhang, Sheng-yu; Zhao, Hai; Tang, Tao; Guan, Wei

2014-12-01

To understand the assessment on the criminal responsibility of drug-induced mental disorders and judicial experts' opinions. The judicial experts from institutes of forensic psychiatry in Shanghai were selected. They were asked to finish a self-made questionnaire of assessment on the criminal responsibility of drug-induced mental disorders by letters and visits. Most of experts knew the special regulation, "not suitable for evaluation" towards the criminal responsibility of drug-induced mental disorders of the guideline promulgated by Ministry of Justice. Before and after the guideline was issued, no expert made a no-responsibility opinion in such cases. After the guideline was issued, some experts made a full-responsibility or limited-responsibility opinion in such cases. There was a little disagreement among the experts in the case that the crime was unrelated with mental symptoms or the criminals used drugs even though he knew it could induced insanity. But there were still many obvious disagreements among experts in the case that crime was related to such symptoms and person was no ability to debate. Most experts agreed to settle the disagreements with improved legislative perfection. Most experts are not strictly complying with the assessment guidelines during their practice, and there is still an obvious disagreement towards the criminal responsibility of drug-induced mental disorders.

Identifying anti-cancer drug response related genes using an integrative analysis of transcriptomic and genomic variations with cell line-based drug perturbations.

PubMed

Sun, Yi; Zhang, Wei; Chen, Yunqin; Ma, Qin; Wei, Jia; Liu, Qi

2016-02-23

Clinical responses to anti-cancer therapies often only benefit a defined subset of patients. Predicting the best treatment strategy hinges on our ability to effectively translate genomic data into actionable information on drug responses. To achieve this goal, we compiled a comprehensive collection of baseline cancer genome data and drug response information derived from a large panel of cancer cell lines. This data set was applied to identify the signature genes relevant to drug sensitivity and their resistance by integrating CNVs and the gene expression of cell lines with in vitro drug responses. We presented an efficient in-silico pipeline for integrating heterogeneous cell line data sources with the simultaneous modeling of drug response values across all the drugs and cell lines. Potential signature genes correlated with drug response (sensitive or resistant) in different cancer types were identified. Using signature genes, our collaborative filtering-based drug response prediction model outperformed the 44 algorithms submitted to the DREAM competition on breast cancer cells. The functions of the identified drug response related signature genes were carefully analyzed at the pathway level and the synthetic lethality level. Furthermore, we validated these signature genes by applying them to the classification of the different subtypes of the TCGA tumor samples, and further uncovered their in vivo implications using clinical patient data. Our work may have promise in translating genomic data into customized marker genes relevant to the response of specific drugs for a specific cancer type of individual patients.

Drug induced hypertension--An unappreciated cause of secondary hypertension.

PubMed

Grossman, Alon; Messerli, Franz H; Grossman, Ehud

2015-09-15

Most patients with hypertension have essential hypertension or well-known forms of secondary hypertension, such as renal disease, renal artery stenosis, or common endocrine diseases (hyperaldosteronism or pheochromocytoma). Physicians are less aware of drug induced hypertension. A variety of therapeutic agents or chemical substances may increase blood pressure. When a patient with well controlled hypertension is presented with acute blood pressure elevation, use of drug or chemical substance which increases blood pressure should be suspected. Drug-induced blood pressure increases are usually minor and short-lived, although rare hypertensive emergencies associated with use of certain drugs have been reported. Careful evaluation of prescription and non-prescription medications is crucial in the evaluation of the hypertensive individual and may obviate the need for expensive and unnecessary evaluations. Discontinuation of the offending agent will usually achieve adequate blood pressure control. When use of a chemical agent which increases blood pressure is mandatory, anti-hypertensive therapy may facilitate continued use of this agent. We summarize the therapeutic agents or chemical substances that elevate blood pressure and their mechanisms of action. Copyright © 2015 Elsevier B.V. All rights reserved.

Integrating virtual screening and biochemical experimental approach to identify potential anti-cancer agents from drug databank.

PubMed

Deka, Suman Jyoti; Roy, Ashalata; Manna, Debasis; Trivedi, Vishal

2018-06-01

Chemical libraries constitute a reservoir of pharmacophoric molecules to identify potent anti-cancer agents. Virtual screening of heterocyclic compound library in conjugation with the agonist-competition assay, toxicity-carcinogenicity analysis, and string-based structural searches enabled us to identify several drugs as potential anti-cancer agents targeting protein kinase C (PKC) as a target. Molecular modeling study indicates that Cinnarizine fits well within the PKC C2 domain and exhibits extensive interaction with the protein residues. Molecular dynamics simulation of PKC-Cinnarizine complex at different temperatures (300, 325, 350, 375, and 400[Formula: see text]K) confirms that Cinnarizine fits nicely into the C2 domain and forms a stable complex. The drug Cinnarizine was found to bind PKC with a dissociation constant Kd of [Formula: see text]M. The breast cancer cells stimulated with Cinnarizine causes translocation of PKC-[Formula: see text] to the plasma membrane as revealed by immunoblotting and immunofluorescence studies. Cinnarizine also dose dependently reduced the viability of MDAMB-231 and MCF-7 breast cancer cells with an IC[Formula: see text] of [Formula: see text] and [Formula: see text]g/mL, respectively. It is due to the disturbance of cell cycle of breast cancer cells with reduction of S-phase and accumulation of cells in G1-phase. It disturbs mitochondrial membrane potentials to release cytochrome C into the cytosol and activates caspase-3 to induce apoptosis in cancer cells. The cell death was due to induction of apoptosis involving mitochondrial pathway. Hence, the current study has assigned an additional role to Cinnarizine as an activator of PKC and potentials of the approach to identify new molecules for anti-cancer therapy. Thus, in silico screening along with biochemical experimentation is a robust approach to assign additional roles to the drugs present in the databank for anti-cancer therapy.

Drug-induced liver injury: present and future

PubMed Central

Suk, Ki Tae

2012-01-01

Liver injury due to prescription and nonprescription medications is a growing medical, scientific, and public health problem. Worldwide, the estimated annual incidence rate of drug-induced liver injury (DILI) is 13.9-24.0 per 100,000 inhabitants. DILI is one of the leading causes of acute liver failure in the US. In Korea, the annual extrapolated incidence of cases hospitalized at university hospital is 12/100,000 persons/year. Most cases of DILI are the result of idiosyncratic metabolic responses or unexpected reactions to medication. There is marked geographic variation in relevant agents; antibiotics, anticonvulsants, and psychotropic drugs are the most common offending agents in the West, whereas in Asia, 'herbs' and 'health foods or dietary supplements' are more common. Different medical circumstances also cause discrepancy in definition and classification of DILI between West and Asia. In the concern of causality assessment, the application of the Roussel Uclaf Causality Assessment Method (RUCAM) scale frequently undercounts the cases caused by 'herbs' due to a lack of previous information and incompatible time criteria. Therefore, a more objective and reproducible tool that could be used for the diagnosis of DILI caused by 'herbs' is needed in Asia. In addition, a reporting system similar to the Drug-Induced Liver Injury Network (DILIN) in the US should be established as soon as possible in Asia. PMID:23091804

Phytotherapy of nephrotoxicity-induced by cancer drugs: an updated review

PubMed Central

Heidari-Soreshjani, Saeid; Asadi-Samani, Majid; Yang, Qian; Saeedi-Boroujeni, Ali

2017-01-01

Context: Kidney is one of the vital organs maintaining homeostasis of body and thus dysfunction of kidney affects quality of life and health severely. Anticancer drugs, particularly chemotherapeutic agents, cause high toxicity leading kidney dysfunction and irreparable kidney injury. Therefore, attention has recently been paid to seeking out alternatives such as nature-based drugs that are effective but less toxic. In this regard, this systematic review article is to report and introduce the most important medicinal plants and their derivatives that are used to reduce anticancer drug-induced nephrotoxicity. Evidence Acquisitions: The word nephrotoxicity alongside the words cancer or chemotherapy in combination with some herbal terms such as medicinal plant, plants, herbs, and extracts were administered to search for relevant publications indexed in PubMed. Results: According to this study, 16 medicinal plants, 12 plant-based derivatives, and three traditional plant-based formulations were found to help control and modulate anticancer drug-induced nephrotoxicity indices. Conclusions: Anticancer drugs cause nephrotoxicity through activating pathways of oxidative stress, damage-associated molecular patterns (DAMPs) production, inflammatory processes, and cell apoptosis, while medicinal plants and their derivatives can cause reduction in nephrotoxicity and anticancer drugs side effects via their antioxidant and anti-inflammatory properties. PMID:28975109

Enhanced dispersion of repolarization explains increased arrhythmogenesis in severe versus therapeutic hypothermia.

PubMed

Piktel, Joseph S; Jeyaraj, Darwin; Said, Tamer H; Rosenbaum, David S; Wilson, Lance D

2011-02-01

Hypothermia is proarrhythmic, and, as the use of therapeutic hypothermia (TH) increases, it is critically important to understand the electrophysiological effects of hypothermia on cardiac myocytes and arrhythmia substrates. We tested the hypothesis that hypothermia-enhanced transmural dispersion of repolarization (DOR) is a mechanism of arrhythmogenesis in hypothermia. In addition, we investigated whether the degree of hypothermia, the rate of temperature change, and cooling versus rewarming would alter hypothermia-induced arrhythmia substrates. Optical action potentials were recorded from cells spanning the transmural wall of canine left ventricular wedge preparations at baseline (36°C), during cooling and during rewarming. Electrophysiological parameters were examined while varying the depth of hypothermia. On cooling to 26°C, DOR increased from 26±4 ms to 93±18 ms (P=0.021); conduction velocity decreased from 35±5 cm/s to 22±5 cm/s (P=0.010). On rewarming to 36°C, DOR remained prolonged, whereas conduction velocity returned to baseline. Conduction block and reentry was observed in all severe hypothermia preparations. Ventricular fibrillation/ventricular tachycardia was seen more during rewarming (4/5) versus cooling (2/6). In TH (n=7), cooling to 32°C mildly increased DOR (31±6 to 50±9, P=0.012), with return to baseline on rewarming and was associated with decreased arrhythmia susceptibility. Increased rate of cooling did not further enhance DOR or arrhythmogenesis. Hypothermia amplifies DOR and is a mechanism for arrhythmogenesis. DOR is directly dependent on the depth of cooling and rewarming. This provides insight into the clinical observation of a low incidence of arrhythmias in TH and has implications for protocols for the clinical application of TH.

Advantageous use of HepaRG cells for the screening and mechanistic study of drug-induced steatosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tolosa, Laia

Only a few in vitro assays have been proposed to evaluate the steatotic potential of new drugs. The present study examines the utility of HepaRG cells as a cell-based assay system for screening drug-induced liver steatosis. A high-content screening assay was run to evaluate multiple toxicity-related cell parameters in HepaRG cells exposed to 28 compounds, including drugs reported to cause steatosis through different mechanisms and non-steatotic compounds. Lipid content was the most sensitive parameter for all the steatotic drugs, whereas no effects on lipid levels were produced by non-steatotic compounds. Apart from fat accumulation, increased ROS production and altered mitochondrialmore » membrane potential were also found in the cells exposed to steatotic drugs, which indicates that all these cellular events contributed to drug-induced hepatotoxicity. These findings are of clinical relevance as most effects were observed at drug concentrations under 100-fold of the therapeutic peak plasmatic concentration. HepaRG cells showed increased lipid overaccumulation vs. HepG2 cells, which suggests greater sensitivity to drug-induced steatosis. An altered expression profile of transcription factors and the genes that code key proteins in lipid metabolism was also found in the cells exposed to drugs capable of inducing liver steatosis. Our results generally indicate the value of HepaRG cells for assessing the risk of liver damage associated with steatogenic compounds and for investigating the molecular mechanisms involved in drug-induced steatosis. - Highlights: • HepaRG cells were explored as an in vitro model to detect steatogenic potential. • Multiple toxicity-related endpoints were analysed by HCS. • HepaRG showed a greater sensitivity to drug-induced steatosis than HepG2 cells. • Changes in the expression of genes related to lipid metabolism were revealed. • HepaRG allow mechanistic understanding of liver damage induced by steatogenic drugs.« less

Mechanism of drug-induced gingival overgrowth revisited: a unifying hypothesis

PubMed Central

Brown, RS; Arany, PR

2015-01-01

Drug-induced gingival overgrowth (DIGO) is a disfiguring side effect of anti-convulsants, calcineurin inhibitors, and calcium channel blocking agents. A unifying hypothesis has been constructed which begins with cation flux inhibition induced by all three of these drug categories. Decreased cation influx of folic acid active transport within gingival fibroblasts leads to decreased cellular folate uptake, which in turn leads to changes in matrix metalloproteinases metabolism and the failure to activate collagenase. Decreased availability of activated collagenase results in decreased degradation of accumulated connective tissue which presents as DIGO. Studies supporting this hypothesis are discussed. PMID:24893951

Walking on thin ice! Identifying methamphetamine "drug mules" on digital plain radiography.

PubMed

Abdul Rashid, S N; Mohamad Saini, S B; Abdul Hamid, S; Muhammad, S J; Mahmud, R; Thali, M J; Flach, P M

2014-04-01

The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of identifying methamphetamine (MA) internal payloads in "drug mules" by plain abdominal digital radiography (DR). The study consisted of 35 individuals suspected of internal MA drug containers. A total of 59 supine digital radiographs were collected. An overall calculation regarding the diagnostic accuracy for all "drug mules" and a specific evaluation concerning the radiological appearance of drug packs as well as the rate of clearance and complications in correlation with the reader's experience were performed. The gold standard was the presence of secured drug packs in the faeces. There were 16 true-positive "drug mules" identified. DR of all drug carriers for Group 1 (forensic imaging experienced readers, n = 2) exhibited a sensitivity of 100%, a mean specificity of 76.3%, positive predictive value (PPV) of 78.5%, negative predictive value (NPV) of 100% and a mean accuracy 87.2%. Group 2 (inexperienced readers, n = 3) showed a lower sensitivity (93.7%), a mean specificity of 86%, a PPV of 86.5%, an NPV of 94.1% and a mean accuracy of 89.5%. The interrater agreement within Group 1 was 0.72 and within Group 2 averaged to 0.79, indicating a fair to very good agreement. DR is a valuable screening tool in cases of MA body packers with huge internal payloads being associated with a high diagnostic insecurity. Diagnostic insecurity on plain films may be overcome by low-dose CT as a cross-sectional imaging modality and addressed by improved radiological education in reporting drug carriers on imaging. Diagnostic signs (double-condom and halo signs) on digital plain radiography are specific in MA "drug mules", although DR is associated with high diagnostic insecurity and underreports the total internal payload.

[Viral and drug-induced liver damage in children with tuberculosis: prevalence, clinical features].

PubMed

Borzakova, S N; Aksenova, V A; Reĭzis, A R

2013-01-01

THE AIM OF THE RESEARCH: Improving the effectiveness of diagnostics and treatment of viral and drug-induced lesions of the liver (DILL) at a tuberculosis in children by identifying the frequency of their distribution, peculiarities of diagnostics and clinics. We examined 242 children in the age from 2 months to 17 years, the patients with different forms of tuberculosis. The prevalence of hepatitis in children with tuberculosis: B - 1,2%, C-0.4%, G - 4,6%, TT - 8,7%. DILL was diagnosed in 67.5% of children - TB patients, in 48% of the children with DILL an asymptomatic course of the disease was noted, however, in 54.4% of the children with DILL cytolitic syndrome was expressed (ALT> standards). The prevalence of viral hepatitis B and C among children with TB is low. The infection with viruses of hepatitis G and TT is more often, but has no significant impact as on the course of tuberculosis, and on the severity of the liver damage. Drug-induced liver damage is a dominant view of pathology of the liver in children - TB patients and is mostly asymptomatic, but with a pronounced cytolitic syndrome.

Cardiovascular safety of prokinetic agents: A focus on drug-induced arrhythmias.

PubMed

Giudicessi, J R; Ackerman, M J; Camilleri, M

2018-02-14

Gastrointestinal sensorimotor dysfunction underlies a wide range of esophageal, gastric, and intestinal motility and functional disorders that collectively constitute nearly half of all referrals to gastroenterologists. As a result, substantial effort has been dedicated toward the development of prokinetic agents intended to augment or restore normal gastrointestinal motility. However, the use of several clinically efficacious gastroprokinetic agents, such as cisapride, domperidone, erythromycin, and tegaserod, is associated with unfavorable cardiovascular safety profiles, leading to restrictions in their use. The purpose of this review is to detail the cellular and molecular mechanisms that lead commonly to drug-induced cardiac arrhythmias, specifically drug-induced long QT syndrome, torsades de pointes, and ventricular fibrillation, to examine the cardiovascular safety profiles of several classes of prokinetic agents currently in clinical use, and to explore potential strategies by which the risk of drug-induced cardiac arrhythmia associated with prokinetic agents and other QT interval prolonging medications can be mitigated successfully. © 2018 John Wiley & Sons Ltd.

Liver proteomics for therapeutic drug discovery: inhibition of the cyclophilin receptor CD147 attenuates sepsis-induced acute renal failure

PubMed Central

Dear, James W.; Leelahavanichkul, Asada; Aponte, Angel; Hu, Xuzhen; Constant, Stephanie L.; Hewitt, Stephen M.; Yuen, Peter S.T.; Star, Robert A.

2008-01-01

Objective Sepsis-induced multi-organ failure continues to have a high mortality. The liver is an organ central to the disease pathogenesis. The objective of this study was to identify the liver proteins that change in abundance with sepsis and, therefore, identify new drug targets. Design Proteomic discovery study and drug target validation Setting Research institute laboratory Subjects Three month old C57BL/6 mice Interventions We used a mouse model of sepsis based on cecal ligation and puncture (CLP) but with fluid and antibiotic resuscitation. Liver proteins that changed in abundance were identified by difference in-gel electrophoresis (DIGE). We compared liver proteins from 6 hr post-CLP to sham-operated mice (‘early proteins’) and 24 hr post-CLP with 6 hr post-CLP (‘late proteins’). Proteins that changed in abundance were identified by tandem mass spectrometry. We then inhibited the receptor for one protein and determined the effect on sepsis-induced organ dysfunction. Results The liver proteins that changed in abundance after sepsis had a range of functions such as acute phase proteins, coagulation, ER stress, oxidative stress, apoptosis, mitochondrial proteins and nitric oxide metabolism. We found that cyclophilin increased in abundance after CLP. When the receptor for this protein, CD147, was inhibited sepsis-induced renal dysfunction was reduced. There was also a significant reduction in serum cytokine production when CD147 was inhibited. Conclusion By applying proteomics to a clinically relevant mouse model of sepsis we identified a number of novel proteins that changed in abundance. The inhibition of the receptor for one of these proteins, cyclophilin, attenuated sepsis-induced acute renal failure. The application of proteomics to sepsis research can facilitate the discovery of new therapeutic targets. PMID:17944020

Photo-inducible Crosslinked Nanoassemblies for pH-Controlled Drug Release

PubMed Central

Dickerson, Matthew; Winquist, Nickolas; Bae, Younsoo

2014-01-01

Purpose To control drug release from block copolymer nanoassemblies by variation in the degree of photo-crosslinking and inclusion of acid sensitive linkers. Methods Poly(ethylene glycol)-poly(aspartate-hydrazide-cinnamate) (PEG-CNM) block copolymers were prepared and conjugated with a model drug, doxorubicin (DOX), through acid sensitive hydrazone linkers. The block copolymers formed photo-inducible, self-assembled nanoassemblies (piSNAs), which were used to produce photo-inducible crosslinked nanoassemblies (piCNAs) through UV crosslinking. The nanoassemblies were characterized to determine particle size, surface charge, pH- and crosslinking-dependent DOX release, in vitro cytotoxicity, and intracellular uptake as a function of photo-crosslinking degree. Results Nanoassemblies with varying photo-crosslinking degrees were successfully prepared while retaining particle size and surface charge. Photo-crosslinking caused no noticeable change in DOX release from the nanoassemblies at pH 7.4, but the DOX-loaded nanoassemblies modulated drug release as a function of crosslinking at pH 6.0. The nanoassemblies showed similar cytotoxicity regardless of crosslinking degrees, presumably due to the low cellular uptake and cell nucleus drug accumulation. Conclusion Photo-crosslinking is useful to control drug release from pH-sensitive block copolymer nanoassemblies as a function of crosslinking without altering the particle properties, and thus providing unique tools to investigate the pharmaceutical effects of drug release on cellular response. PMID:24254196

Drug-induced liver injury due to antibiotics.

PubMed

Björnsson, Einar S

Drug-induced liver injury (DILI) is an important differential diagnosis in patients with abnormal liver tests and normal hepatobiliary imaging. Of all known liver diseases, the diagnosis of DILI is probably one of the most difficult one to be established. In all major studies on DILI, antibiotics are the most common type of drugs that have been reported. The clinical phenotype of different types of antibiotics associated with liver injury is highly variable. Some widely used antibiotics such as amoxicillin-clavulanate have been shown to have a delayed onset on liver injury and recently cefazolin has been found to lead to liver injury 1-3 weeks after exposure of a single infusion. The other extreme is the nature of nitrofurantoin-induced liver injury, which can occur after a few years of treatment and lead to acute liver failure (ALF) or autoimmune-like reaction. Most patients with liver injury associated with use of antibiotics have a favorable prognosis. However, patients with jaundice have approximately 10% risk of death from liver failure and/or require liver transplantation. In rare instances, the hepatoxicity can lead to chronic injury and vanishing bile duct syndrome. Given, sometimes very severe consequences of the adverse liver reactions, it cannot be over emphasized that the indication for the different antibiotics should be evidence-based and symptoms and signs of liver injury from the drugs should lead to prompt cessation of therapy.

Traditional Chinese Medicine and Herb-induced Liver Injury: Comparison with Drug-induced Liver Injury.

PubMed

Jing, Jing; Teschke, Rolf

2018-03-28

Cases of suspected herb-induced liver injury (HILI) caused by herbal Traditional Chinese Medicines (TCMs) and of drug-induced liver injury (DILI) are commonly published in the scientific literature worldwide. As opposed to the multiplicity of botanical chemicals in herbal TCM products, which are often mixtures of several herbs, conventional Western drugs contain only a single synthetic chemical. It is therefore of interest to study how HILI by TCM and DILI compare with each other, and to what extent results from each liver injury type can be transferred to the other. China is among the few countries with a large population using synthetic Western drugs as well as herbal TCM. Therefore, China is well suited to studies of liver injury comparing drugs with TCM herbs. Despite some concordance, recent analyses of liver injury cases with verified causality, using the Roussel Uclaf Causality Assessment Method, revealed major differences in HILI caused by TCMs as compared to DILI with respect to the following features: HILI cases are less frequently observed as compared to DILI, have a smaller proportion of females and less unintentional rechallenge events, and present a higher rate of hepatocellular injury features. Since many results were obtained among Chinese residents who had access to and had used Western drugs and TCM herbs, such ethnic homogeneity supports the contention that the observed differences of HILI and DILI in the assessed population are well founded.

Traditional Chinese Medicine and Herb-induced Liver Injury: Comparison with Drug-induced Liver Injury

PubMed Central

Jing, Jing; Teschke, Rolf

2017-01-01

Abstract Cases of suspected herb-induced liver injury (HILI) caused by herbal Traditional Chinese Medicines (TCMs) and of drug-induced liver injury (DILI) are commonly published in the scientific literature worldwide. As opposed to the multiplicity of botanical chemicals in herbal TCM products, which are often mixtures of several herbs, conventional Western drugs contain only a single synthetic chemical. It is therefore of interest to study how HILI by TCM and DILI compare with each other, and to what extent results from each liver injury type can be transferred to the other. China is among the few countries with a large population using synthetic Western drugs as well as herbal TCM. Therefore, China is well suited to studies of liver injury comparing drugs with TCM herbs. Despite some concordance, recent analyses of liver injury cases with verified causality, using the Roussel Uclaf Causality Assessment Method, revealed major differences in HILI caused by TCMs as compared to DILI with respect to the following features: HILI cases are less frequently observed as compared to DILI, have a smaller proportion of females and less unintentional rechallenge events, and present a higher rate of hepatocellular injury features. Since many results were obtained among Chinese residents who had access to and had used Western drugs and TCM herbs, such ethnic homogeneity supports the contention that the observed differences of HILI and DILI in the assessed population are well founded. PMID:29577033

Negative electro-mechanical windows are required for drug-induced Torsades de Pointes in the anesthetized guinea pig.

PubMed

Guns, P-J; Johnson, D M; Weltens, E; Lissens, J

2012-09-01

Assessment of the propensity of novel drugs to cause proarrhythmia is essential in the drug development process. It is increasingly recognized, however, that QT prolongation alone is an imperfect surrogate marker for Torsades de Pointes (TdP) arrhythmia prediction. In the present study we investigated the behavior of a novel surrogate marker for TdP, the electro-mechanical (E-M) window, prior to triggering of TdP episodes with sympathetic stimulation after administration of a number of reference compounds. Experiments were carried out in closed chest pentobarbital anesthetized guinea pigs. Test compounds were administered intravenously together with a specific I(Ks) blocker (JNJ303; 0.2 mgkg(-1)min(-1) for 3 min) and adrenaline (0.06 mgkg(-1)min(-1) for 2 min) was applied to trigger TdP. ECG, blood- and left ventricular pressure signals were measured continuously throughout the experiments. The E-M window i.e. the duration of the mechanical systole (QLVP(end) interval) minus the duration of the electrical activity (QT interval) was assessed for individual beats. Drugs with documented TdP liability (quinidine, haloperidol, domperidone, terfenadine, moxifloxacin, ciprofloxacin and dofetilide) produced TdP in the protocol after adrenaline infusion, whereas negative control compounds (verapamil, ranolazine, amiodarone and saline) did not cause TdP arrhythmia, even though increases in repolarization times were observed. TdP were typically preceded by large (greater than -50 ms) negative electro-mechanical windows and were accompanied by aftercontractions. The present study in anesthetized guinea pigs indicates that negative E-M windows are a prerequisite for sympathetically-driven TdP induction after the administration of various agents with known proarrhythmic potential. These data are a first step in the validation of this novel protocol; however we believe that this proarrhythmia model in small animals might be a valuable additional tool in the prediction of TdP risk

Confinement-Induced Drug-Tolerance in Mycobacteria Mediated by an Efflux Mechanism

PubMed Central

Luthuli, Brilliant B.; Purdy, Georgiana E.; Balagaddé, Frederick K.

2015-01-01

Tuberculosis (TB) is the world’s deadliest curable disease, responsible for an estimated 1.5 million deaths annually. A considerable challenge in controlling this disease is the prolonged multidrug chemotherapy (6 to 9 months) required to overcome drug-tolerant mycobacteria that persist in human tissues, although the same drugs can sterilize genetically identical mycobacteria growing in axenic culture within days. An essential component of TB infection involves intracellular Mycobacterium tuberculosis bacteria that multiply within macrophages and are significantly more tolerant to antibiotics compared to extracellular mycobacteria. To investigate this aspect of human TB, we created a physical cell culture system that mimics confinement of replicating mycobacteria, such as in a macrophage during infection. Using this system, we uncovered an epigenetic drug-tolerance phenotype that appears when mycobacteria are cultured in space-confined bioreactors and disappears in larger volume growth contexts. Efflux mechanisms that are induced in space-confined growth environments contribute to this drug-tolerance phenotype. Therefore, macrophage-induced drug tolerance by mycobacteria may be an effect of confined growth among other macrophage-specific mechanisms. PMID:26295942

High-throughput drug screen identifies chelerythrine as a selective inducer of death in a TSC2-null setting.

PubMed

Medvetz, Doug; Sun, Yang; Li, Chenggang; Khabibullin, Damir; Balan, Murugabaskar; Parkhitko, Andrey; Priolo, Carmen; Asara, John M; Pal, Soumitro; Yu, Jane; Henske, Elizabeth P

2015-01-01

Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome associated with tumors of the brain, heart, kidney, and lung. The TSC protein complex inhibits the mammalian or mechanistic target of rapamycin complex 1 (mTORC1). Inhibitors of mTORC1, including rapamycin, induce a cytostatic response in TSC tumors, resulting in temporary disease stabilization and prompt regrowth when treatment is stopped. The lack of TSC-specific cytotoxic therapies represents an important unmet clinical need. Using a high-throughput chemical screen in TSC2-deficient, patient-derived cells, we identified a series of molecules antagonized by rapamycin and therefore selective for cells with mTORC1 hyperactivity. In particular, the cell-permeable alkaloid chelerythrine induced reactive oxygen species (ROS) and depleted glutathione (GSH) selectively in TSC2-null cells based on metabolic profiling. N-acetylcysteine or GSH cotreatment protected TSC2-null cells from chelerythrine's effects, indicating that chelerythrine-induced cell death is ROS dependent. Induction of heme-oxygenase-1 (HMOX1/HO-1) with hemin also blocked chelerythrine-induced cell death. In vivo, chelerythrine inhibited the growth of TSC2-null xenograft tumors with no evidence of systemic toxicity with daily treatment over an extended period of time. This study reports the results of a bioactive compound screen and the identification of a potential lead candidate that acts via a novel oxidative stress-dependent mechanism to selectively induce necroptosis in TSC2-deficient tumors. This study demonstrates that TSC2-deficient tumor cells are hypersensitive to oxidative stress-dependent cell death, and provide critical proof of concept that TSC2-deficient cells can be therapeutically targeted without the use of a rapalog to induce a cell death response. ©2014 American Association for Cancer Research.

Gene-set analysis based on the pharmacological profiles of drugs to identify repurposing opportunities in schizophrenia.

PubMed

de Jong, Simone; Vidler, Lewis R; Mokrab, Younes; Collier, David A; Breen, Gerome

2016-08-01

Genome-wide association studies (GWAS) have identified thousands of novel genetic associations for complex genetic disorders, leading to the identification of potential pharmacological targets for novel drug development. In schizophrenia, 108 conservatively defined loci that meet genome-wide significance have been identified and hundreds of additional sub-threshold associations harbour information on the genetic aetiology of the disorder. In the present study, we used gene-set analysis based on the known binding targets of chemical compounds to identify the 'drug pathways' most strongly associated with schizophrenia-associated genes, with the aim of identifying potential drug repositioning opportunities and clues for novel treatment paradigms, especially in multi-target drug development. We compiled 9389 gene sets (2496 with unique gene content) and interrogated gene-based p-values from the PGC2-SCZ analysis. Although no single drug exceeded experiment wide significance (corrected p<0.05), highly ranked gene-sets reaching suggestive significance including the dopamine receptor antagonists metoclopramide and trifluoperazine and the tyrosine kinase inhibitor neratinib. This is a proof of principle analysis showing the potential utility of GWAS data of schizophrenia for the direct identification of candidate drugs and molecules that show polypharmacy. © The Author(s) 2016.

Use of Belatacept as Alternative Immunosuppression in Three Renal Transplant Patients with De Novo Drug-Induced Thrombotic Microangiopathy

PubMed Central

Cicora, Federico; Paz, Marta; Mos, Fernando; Roberti, Javier

2013-01-01

Thrombotic microangiopathy (TMA), a severe complication of renal transplantation, is a pathological process involving microvascular occlusion, thrombocytopenia, and microangiopathic hemolytic anemia. It generally appears within the first weeks after transplantation, when immunosuppressive drugs are used at high doses. De novo TMA may also be drug-induced when calcineurin inhibitors or proliferation signal inhibitors are used. We report three cases of de novo drug-induced TMA in renal transplant patients who were managed by replacing calcineurin inhibitors or proliferation signal inhibitors with belatacept, a primary maintenance immunosuppressive drug, which blocks the CD28 costimulation pathway, preventing the activation of T lymphocytes. To identify the cause of TMA, we ruled out HUS, hepatitis C serology, HIV serology, parvovirus B19, cytomegalovirus, anti-HLA antibodies, and prolonged activated partial thromboplastin time. We suspect that the TMA was caused by the calcineurin inhibitors or proliferation signal inhibitors. Belatacept treatment was initiated at a dose of 10 mg/kg on days 1, 5, 14, 28, 60, and 90; maintenance treatment was 5 mg/kg once a month for 1 year. Belatacept, in combination with other agents, prevented graft rejection in three patients. PMID:24198835

Abacavir induces loading of novel self-peptides into HLA-B*57:01: an autoimmune model for HLA-associated drug hypersensitivity

PubMed Central

Norcross, Michael A.; Luo, Shen; Lu, Li; Boyne, Michael T.; Gomarteli, Mary; Rennels, Aaron D.; Woodcock, Janet; Margulies, David H.; McMurtrey, Curtis; Vernon, Stephen; Hildebrand, William H.; Buchli, Rico

2014-01-01

Background Abacavir drug hypersensitivity in HIV-treated patients is associated with HLA-B*57:01 expression. To understand the immunochemistry of abacavir drug reactions, we investigated the effects of abacavir on HLA-B*57:01 epitope-binding in vitro and the quality and quantity of self-peptides presented by HLA-B*57:01 from abacavir-treated cells. Design and methods An HLA-B*57:01-specific epitope-binding assay was developed to test for effects of abacavir, didanosine or flucloxacillin on self-peptide binding. To examine whether abacavir alters the peptide repertoire in HLA-B*57:01, a B-cell line secreting soluble human leucocyte antigen (sHLA) was cultured in the presence or absence of abacavir, peptides were eluted from purified human leucocyte antigen (HLA), and the peptide epitopes comparatively mapped by mass spectroscopy to identify drug-unique peptides. Results Abacavir, but not didansosine or flucloxacillin, enhanced binding of the FITC-labeled self-peptide LF9 to HLA-B*57:01 in a dose-dependent manner. Endogenous peptides isolated from abacavir-treated HLA-B*57:01 B cells showed amino acid sequence differences compared with peptides from untreated cells. Novel drug-induced peptides lacked typical carboxyl (C) terminal amino acids characteristic of the HLA-B*57:01 peptide motif and instead contained predominantly isoleucine or leucine residues. Drug-induced peptides bind to soluble HLA-B*57:01 with high affinity that was not altered by abacavir addition. Conclusion Our results support a model of drug-induced autoimmunity in which abacavir alters the quantity and quality of self-peptide loading into HLA-B*57:01. Drug-induced loading of novel self-peptides into HLA, possibly by abacavir either altering the binding cleft or modifying the peptide-loading complex, generates an array of neo-antigen peptides that drive polyclonal T-cell autoimmune responses and multiorgan systemic toxicity. PMID:22617051

Abacavir induces loading of novel self-peptides into HLA-B*57: 01: an autoimmune model for HLA-associated drug hypersensitivity.

PubMed

Norcross, Michael A; Luo, Shen; Lu, Li; Boyne, Michael T; Gomarteli, Mary; Rennels, Aaron D; Woodcock, Janet; Margulies, David H; McMurtrey, Curtis; Vernon, Stephen; Hildebrand, William H; Buchli, Rico

2012-07-17

Abacavir drug hypersensitivity in HIV-treated patients is associated with HLA-B57:01 expression. To understand the immunochemistry of abacavir drug reactions, we investigated the effects of abacavir on HLA-B57:01 epitope-binding in vitro and the quality and quantity of self-peptides presented by HLA-B57:01 from abacavir-treated cells. An HLA-B57:01-specific epitope-binding assay was developed to test for effects of abacavir, didanosine or flucloxacillin on self-peptide binding. To examine whether abacavir alters the peptide repertoire in HLA-B57:01, a B-cell line secreting soluble human leucocyte antigen (sHLA) was cultured in the presence or absence of abacavir, peptides were eluted from purified human leucocyte antigen (HLA), and the peptide epitopes comparatively mapped by mass spectroscopy to identify drug-unique peptides. Abacavir, but not didansosine or flucloxacillin, enhanced binding of the FITC-labeled self-peptide LF9 to HLA-B57:01 in a dose-dependent manner. Endogenous peptides isolated from abacavir-treated HLA-B57:01 B cells showed amino acid sequence differences compared with peptides from untreated cells. Novel drug-induced peptides lacked typical carboxyl (C) terminal amino acids characteristic of the HLA-B57:01 peptide motif and instead contained predominantly isoleucine or leucine residues. Drug-induced peptides bind to soluble HLA-B57:01 with high affinity that was not altered by abacavir addition. Our results support a model of drug-induced autoimmunity in which abacavir alters the quantity and quality of self-peptide loading into HLA-B57:01. Drug-induced loading of novel self-peptides into HLA, possibly by abacavir either altering the binding cleft or modifying the peptide-loading complex, generates an array of neo-antigen peptides that drive polyclonal T-cell autoimmune responses and multiorgan systemic toxicity.

Drug Induced Liver Injury: Can Biomarkers Assist RUCAM in Causality Assessment?

PubMed Central

Teschke, Rolf; Schulze, Johannes; Eickhoff, Axel; Danan, Gaby

2017-01-01

Drug induced liver injury (DILI) is a potentially serious adverse reaction in a few susceptible individuals under therapy by various drugs. Health care professionals facing DILI are confronted with a wealth of drug-unrelated liver diseases with high incidence and prevalence rates, which can confound the DILI diagnosis. Searching for alternative causes is a key element of RUCAM (Roussel Uclaf Causality Assessment Method) to assess rigorously causality in suspected DILI cases. Diagnostic biomarkers as blood tests would be a great help to clinicians, regulators, and pharmaceutical industry would be more comfortable if, in addition to RUCAM, causality of DILI can be confirmed. High specificity and sensitivity are required for any diagnostic biomarker. Although some risk factors are available to evaluate liver safety of drugs in patients, no valid diagnostic or prognostic biomarker exists currently for idiosyncratic DILI when a liver injury occurred. Identifying a biomarker in idiosyncratic DILI requires detailed knowledge of cellular and biochemical disturbances leading to apoptosis or cell necrosis and causing leakage of specific products in blood. As idiosyncratic DILI is typically a human disease and hardly reproducible in animals, pathogenetic events and resulting possible biomarkers remain largely undisclosed. Potential new diagnostic biomarkers should be evaluated in patients with DILI and RUCAM-based established causality. In conclusion, causality assessment in cases of suspected idiosyncratic DILI is still best achieved using RUCAM since specific biomarkers as diagnostic blood tests that could enhance RUCAM results are not yet available. PMID:28398242

Neurofeedback Effects on Evoked and Induced EEG Gamma Band Reactivity to Drug-related Cues in Cocaine Addiction

PubMed Central

Horrell, Timothy; El-Baz, Ayman; Baruth, Joshua; Tasman, Allan; Sokhadze, Guela; Stewart, Christopher; Sokhadze, Estate

2010-01-01

in a lower EEG gamma reactivity to drug-related images in a post-neurofeedback cue reactivity test. In particular, evoked gamma showed decreases in power to non-target and to a lesser extent target drug-related cues at all topographies (left, right, frontal, parietal, medial, inferior); while induced gamma power decreased globally to both target and non-target drug cues. Our findings supported our hypothesis that gamma band cue reactivity measures are sufficiently sensitive functional outcomes of neurofeedback treatment. Both evoked and induced gamma measures were found capable to detect changes in responsiveness to both target and non-target drug cues. Conclusion Our study emphasizes the utility of cognitive neuroscience methods based on EEG gamma band measures for the assessment of the functional outcomes of neurofeedback-based biobehavioral interventions for cocaine use disorders. This approach may have significant potential for identifying both physiological and clinical markers of treatment progress. The results confirmed our prediction that EEG changes achieved with neurofeedback training will be accompanied by positive EEG outcomes in a cue reactivity and clinical improvements. PMID:20976131

Drug-induced death signaling strategy rapidly predicts cancer response to chemotherapy.

PubMed

Montero, Joan; Sarosiek, Kristopher A; DeAngelo, Joseph D; Maertens, Ophélia; Ryan, Jeremy; Ercan, Dalia; Piao, Huiying; Horowitz, Neil S; Berkowitz, Ross S; Matulonis, Ursula; Jänne, Pasi A; Amrein, Philip C; Cichowski, Karen; Drapkin, Ronny; Letai, Anthony

2015-02-26

There is a lack of effective predictive biomarkers to precisely assign optimal therapy to cancer patients. While most efforts are directed at inferring drug response phenotype based on genotype, there is very focused and useful phenotypic information to be gained from directly perturbing the patient's living cancer cell with the drug(s) in question. To satisfy this unmet need, we developed the Dynamic BH3 Profiling technique to measure early changes in net pro-apoptotic signaling at the mitochondrion ("priming") induced by chemotherapeutic agents in cancer cells, not requiring prolonged ex vivo culture. We find in cell line and clinical experiments that early drug-induced death signaling measured by Dynamic BH3 Profiling predicts chemotherapy response across many cancer types and many agents, including combinations of chemotherapies. We propose that Dynamic BH3 Profiling can be used as a broadly applicable predictive biomarker to predict cytotoxic response of cancers to chemotherapeutics in vivo. Copyright © 2015 Elsevier Inc. All rights reserved.

Drug-induced abnormalities of potassium metabolism.

PubMed

Kokot, Franciszek; Hyla-Klekot, Lidia

2008-01-01

Pharmacotherapy has progressed rapidly over the last 20 years with the result that general practioners more and more often use drugs which may influence potassium metabolism at the kidney or gastrointestinal level, or the transmembrane transport of potassium at the cellular level. Potassium abnormalities may result in life-theatening clinical conditions. Hypokalemia is most frequently caused by renal loss of this electrolyte (thiazide, thiazide-like and loop diuretics, glucocorticoids) and the gastrointestinal tract (laxatives, diarrhea, vomiting, external fistula), and may be the result of an increased intracellular potassium influx induced by sympathicomimetics used mostly by patients with asthma, or by insulin overdosage in diabetic subjects. The leading symptoms of hypokalemia are skeletal and smooth muscle weakness and cardiac arrhythmias. Hyperkalemia may be caused by acute or end-stage renal failure, impaired tubular excretion of potassium (blockers of the renin-angiotensin-aldosterone system, nonsteroidal anti-inflammatory drugs, cyclosporine, antifungal drugs, potassium sparing diuretics), acidemia, and severe cellular injury (tumor lysis syndrome). Hyperkalemia may be the cause of severe injury of both skeletal and smooth muscle cells. The specific treatment counteracting hyperkalemia is a bolus injection of calcium salts and, when necessary, hemodialysis.

Use of Fall-Risk Inducing Drugs in Patients Using Anti-Parkinson Drugs (APD): A Swedish Register-Based Study.

PubMed

Haasum, Ylva; Fastbom, Johan; Johnell, Kristina

2016-01-01

Many drugs increase the risk of falls in old age. Although persons with Parkinson's disease (PD) are at increased risk of experiencing falls and fractures, the use of fall-risk inducing drugs (FRIDs) in this population has not previously been investigated. The objective of this study was to investigate the burden of use of FRIDs in older persons treated with anti-Parkinson drugs (APD; used as a proxy for PD), compared to persons without APD. We analyzed individual data on age, sex, type of housing and drug use in 1 346 709 persons aged ≥ 65 years in the Swedish Prescribed Drug Register on the date of 30 September 2008. Main outcome measure was the use of FRIDs. FRIDs were used by 79% of persons with APD and 75% of persons without APD. Persons with APD were more likely to use ≥ 1 FRIDs compared to persons without APD (adjusted OR: 1.09; 95% CI: 1.06-1-12). The association was stronger for concomitant use of ≥ 5 FRIDS (adjusted OR: 1.49; 95% CI: 1.44-1.55). The high use of FRIDs among persons with APD indicates that these patients may be at increased risk of drug-induced falls. Further studies are needed to investigate how these drugs affect the risk of falling in persons with PD.

Use of Fall-Risk Inducing Drugs in Patients Using Anti-Parkinson Drugs (APD): A Swedish Register-Based Study

PubMed Central

Haasum, Ylva; Fastbom, Johan; Johnell, Kristina

2016-01-01

Objectives Many drugs increase the risk of falls in old age. Although persons with Parkinson’s disease (PD) are at increased risk of experiencing falls and fractures, the use of fall-risk inducing drugs (FRIDs) in this population has not previously been investigated. The objective of this study was to investigate the burden of use of FRIDs in older persons treated with anti-Parkinson drugs (APD; used as a proxy for PD), compared to persons without APD. Methods We analyzed individual data on age, sex, type of housing and drug use in 1 346 709 persons aged ≥ 65 years in the Swedish Prescribed Drug Register on the date of 30 September 2008. Main outcome measure was the use of FRIDs. Results FRIDs were used by 79% of persons with APD and 75% of persons without APD. Persons with APD were more likely to use ≥ 1 FRIDs compared to persons without APD (adjusted OR: 1.09; 95% CI: 1.06-1-12). The association was stronger for concomitant use of ≥ 5 FRIDS (adjusted OR: 1.49; 95% CI: 1.44–1.55). Conclusions The high use of FRIDs among persons with APD indicates that these patients may be at increased risk of drug-induced falls. Further studies are needed to investigate how these drugs affect the risk of falling in persons with PD. PMID:27537366

Heart rate variability alters cardiac repolarization and electromechanical dynamics.

PubMed

Phadumdeo, Vrishti M; Weinberg, Seth H

2018-04-07

Heart rate continuously varies due to autonomic regulation, stochasticity in pacemaking, and circadian rhythm, collectively termed heart rate variability (HRV), during normal physiological conditions. Low HRV is clinically associated with an elevated risk of cardiac arrhythmias. Alternans, a beat-to-beat alternation in action potential duration (APD) and/or intracellular calcium (Ca) transient, is a well-known risk factor associated with cardiac arrhythmias that is typically studied under conditions of a constant pacing rate, i.e., the absence of HRV. In this study, we investigate the effects of HRV on the interplay between APD, Ca, and electromechanical properties, employing a nonlinear discrete-time map model that governs APD and intracellular Ca cycling with a stochastic pacing period. We find that HRV can decrease variation in APD and peak Ca at fast pacing rates for which alternans is present. Further, increased HRV typically disrupts the alternating pattern for both APD and peak Ca and weakens the correlation between APD and peak Ca, thus decoupling Ca-mediated instabilities from repolarization alternation. We find that the efficacy of these effects is regulated by the sarcoplasmic reticulum Ca uptake rate. Overall, these results demonstrate that HRV disrupts arrhythmogenic alternans and suggests that HRV may be a significant factor in preventing life-threatening arrhythmias. Copyright © 2018 Elsevier Ltd. All rights reserved.

Deep Phosphoproteomic Measurements Pinpointing Drug Induced Protective Mechanisms in Neuronal Cells

PubMed Central

Yu, Chengli; Gao, Jing; Zhou, Yanting; Chen, Xiangling; Xiao, Ruoxuan; Zheng, Jing; Liu, Yansheng; Zhou, Hu

2016-01-01

Alzheimer's disease (AD) is a progressive and irreversible neurological disorder that impairs the living quality of old population and even life spans. New compounds have shown potential inneuroprotective effects in AD, such as GFKP-19, a 2-pyrrolidone derivative which has been proved to enhance the memory of dysmnesia mouse. The molecular mechanisms remain to be established for these drug candidates. Large-scale phosphoproteomic approach has been evolved rapidly in the last several years, which holds the potential to provide a useful toolkit to understand cellular signaling underlying drug effects. To establish and test such a method, we accurately analyzed the deep quantitative phosphoproteome of the neuro-2a cells treated with and without GFKP-19 using triple SILAC labeling. A total of 14,761 Class I phosphosites were quantified between controls, damaged, and protected conditions using the high resolution mass spectrometry, with a decent inter-mass spectrometer reproducibility for even subtle regulatory events. Our data suggests that GFKP-19 can reverse Aβ25−35 induced phosphorylation change in neuro-2a cells, and might protect the neuron system in two ways: firstly, it may decrease oxidative damage and inflammation induced by NO via down regulating the phosphorylation of nitric oxide synthase NOS1 at S847; Secondly, it may decrease tau protein phosphorylation through down-regulating the phosphorylation level of MAPK14 at T180. All mass spectrometry data are available via ProteomeXchange with identifier PXD005312. PMID:28066266

Illicit Drug Use in a Community-Based Sample of Heterosexually Identified Emerging Adults

ERIC Educational Resources Information Center

Halkitis, Perry N.; Manasse, Ashley N.; McCready, Karen C.

2010-01-01

In this study we assess lifetime and recent drug use patterns among 261 heterosexually identified 18- to 25-year-olds through brief street intercept surveys conducted in New York City. Marijuana, hallucinogens, powder cocaine, and ecstasy were the most frequently reported drugs for both lifetime and recent use. Findings further suggest significant…

Kidney-on-a-Chip: a New Technology for Predicting Drug Efficacy, Interactions, and Drug-induced Nephrotoxicity.

PubMed

Lee, Jeonghwan; Kim, Sejoong

2018-03-08

The kidneys play a pivotal role in most drug-removal processes and are important when evaluating drug safety. Kidney dysfunction resulting from various drugs is an important issue in clinical practice and during the drug development process. Traditional in vivo animal experiments are limited with respect to evaluating drug efficacy and nephrotoxicity due to discrepancies in drug pharmacokinetics and pharmacodynamics between humans and animals, and static cell culture experiments cannot fully reflect the actual microphysiological environment in humans. A kidney-on-a-chip is a microfluidic device that allows the culture of living renal cells in 3-dimensional channels and mimics the human microphysiological environment, thus simulating the actual drug filtering, absorption, and secretion process.. In this review, we discuss recent developments in microfluidic culturing technique and describe current and future kidney-on-a-chip applications. We focus on pharmacological interactions and drug-induced nephrotoxicity, and additionally discuss the development of multi-organ chips and their possible applications. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Glucose Modulation Induces Lysosome Formation and Increases Lysosomotropic Drug Sequestration via the P-Glycoprotein Drug Transporter*

PubMed Central

Seebacher, Nicole A.; Lane, Darius J. R.; Jansson, Patric J.; Richardson, Des R.

2016-01-01

Pgp is functional on the plasma membrane and lysosomal membrane. Lysosomal-Pgp can pump substrates into the organelle, thereby trapping certain chemotherapeutics (e.g. doxorubicin; DOX). This mechanism serves as a “safe house” to protect cells against cytotoxic drugs. Interestingly, in contrast to DOX, lysosomal sequestration of the novel anti-tumor agent and P-glycoprotein (Pgp) substrate, di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT), induces lysosomal membrane permeabilization. This mechanism of lysosomal-Pgp utilization enhances cytotoxicity to multidrug-resistant cells. Consequently, Dp44mT has greater anti-tumor activity in drug-resistant relative to non-Pgp-expressing tumors. Interestingly, stressors in the tumor microenvironment trigger endocytosis for cell signaling to assist cell survival. Hence, this investigation examined how glucose variation-induced stress regulated early endosome and lysosome formation via endocytosis of the plasma membrane. Furthermore, the impact of glucose variation-induced stress on resistance to DOX was compared with Dp44mT and its structurally related analogue, di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC). These studies showed that glucose variation-induced stress-stimulated formation of early endosomes and lysosomes. In fact, through the process of fluid-phase endocytosis, Pgp was redistributed from the plasma membrane to the lysosomal membrane via early endosome formation. This lysosomal-Pgp actively transported the Pgp substrate, DOX, into the lysosome where it became trapped as a result of protonation at pH 5. Due to increased lysosomal DOX trapping, Pgp-expressing cells became more resistant to DOX. In contrast, cytotoxicity of Dp44mT and DpC was potentiated due to more lysosomes containing functional Pgp under glucose-induced stress. These thiosemicarbazones increased lysosomal membrane permeabilization and cell death. This mechanism has critical implications for drug-targeting in

Potassium channel KCNH2 K897T polymorphism and cardiac repolarization during exercise test: The Finnish Cardiovascular Study.

PubMed

Koskela, J; Laiho, J; KäHönen, M; Rontu, R; Lehtinen, R; Viik, J; Niemi, M; Niemelä, K; Kööbi, T; Turjanmaa, V; Pörsti, I; Lehtimäki, T; Nieminen, T

2008-01-01

Cardiac repolarization is regulated, in part, by the KCNH2 gene, which encodes a rapidly activating component of the delayed rectifier potassium channel. The gene expresses a functional single nucleotide polymorphism, K897T, which changes the biophysical properties of the channel. The objective of this study was to evaluate whether this polymorphism influences two indices of repolarization--the QT interval and T-wave alternans (TWA)--during different phases of a physical exercise test. The cohort consisted of 1,975 patients undergoing an exercise test during which on-line electrocardiographic data were registered. Information on coronary risk factors and medication was recorded. The 2690A>C nucleotide variation in the KCNH2 gene corresponding to the K897T amino acid change was analysed after polymerase chain reaction with allele-specific TaqMan probes. Among all subjects, the QTc intervals did not differ between the three genotype groups (p> or =0.31, RANOVA). Women with the CC genotype tended to have longer QT intervals during the exercise test, but the difference was statistically significant only at rest (p = 0.011, ANOVA). This difference was also detected when the analysis was adjusted for several factors influencing the QT interval. No statistically significant effects of the K897T polymorphism on TWA were observed among all subjects (p = 0.16, RANOVA), nor in men and women separately. The K897T polymorphism of the KCNH2 gene may not be a major genetic determinant for the TWA, but the influence of the CC genotype on QT interval deserves further research among women.

Modeling Drug- and Chemical-Induced Hepatotoxicity with Systems Biology Approaches

PubMed Central

Bhattacharya, Sudin; Shoda, Lisl K.M.; Zhang, Qiang; Woods, Courtney G.; Howell, Brett A.; Siler, Scott Q.; Woodhead, Jeffrey L.; Yang, Yuching; McMullen, Patrick; Watkins, Paul B.; Andersen, Melvin E.

2012-01-01

We provide an overview of computational systems biology approaches as applied to the study of chemical- and drug-induced toxicity. The concept of “toxicity pathways” is described in the context of the 2007 US National Academies of Science report, “Toxicity testing in the 21st Century: A Vision and A Strategy.” Pathway mapping and modeling based on network biology concepts are a key component of the vision laid out in this report for a more biologically based analysis of dose-response behavior and the safety of chemicals and drugs. We focus on toxicity of the liver (hepatotoxicity) – a complex phenotypic response with contributions from a number of different cell types and biological processes. We describe three case studies of complementary multi-scale computational modeling approaches to understand perturbation of toxicity pathways in the human liver as a result of exposure to environmental contaminants and specific drugs. One approach involves development of a spatial, multicellular “virtual tissue” model of the liver lobule that combines molecular circuits in individual hepatocytes with cell–cell interactions and blood-mediated transport of toxicants through hepatic sinusoids, to enable quantitative, mechanistic prediction of hepatic dose-response for activation of the aryl hydrocarbon receptor toxicity pathway. Simultaneously, methods are being developing to extract quantitative maps of intracellular signaling and transcriptional regulatory networks perturbed by environmental contaminants, using a combination of gene expression and genome-wide protein-DNA interaction data. A predictive physiological model (DILIsym™) to understand drug-induced liver injury (DILI), the most common adverse event leading to termination of clinical development programs and regulatory actions on drugs, is also described. The model initially focuses on reactive metabolite-induced DILI in response to administration of acetaminophen, and spans multiple biological

Application of optical action potentials in human induced pluripotent stem cells-derived cardiomyocytes to predict drug-induced cardiac arrhythmias.

PubMed

Lu, H R; Hortigon-Vinagre, M P; Zamora, V; Kopljar, I; De Bondt, A; Gallacher, D J; Smith, G

2017-09-01

Human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs) are emerging as new and human-relevant source in vitro model for cardiac safety assessment that allow us to investigate a set of 20 reference drugs for predicting cardiac arrhythmogenic liability using optical action potential (oAP) assay. Here, we describe our examination of the oAP measurement using a voltage sensitive dye (Di-4-ANEPPS) to predict adverse compound effects using hiPS-CMs and 20 cardioactive reference compounds. Fluorescence signals were digitized at 10kHz and the records subsequently analyzed off-line. Cells were exposed to 30min incubation to vehicle or compound (n=5/dose, 4 doses/compound) that were blinded to the investigating laboratory. Action potential parameters were measured, including rise time (T rise ) of the optical action potential duration (oAPD). Significant effects on oAPD were sensitively detected with 11 QT-prolonging drugs, while oAPD shortening was observed with I Ca -antagonists, I Kr -activator or ATP-sensitive K + channel (K ATP )-opener. Additionally, the assay detected varied effects induced by 6 different sodium channel blockers. The detection threshold for these drug effects was at or below the published values of free effective therapeutic plasma levels or effective concentrations by other studies. The results of this blinded study indicate that OAP is a sensitive method to accurately detect drug-induced effects (i.e., duration/QT-prolongation, shortening, beat rate, and incidence of early after depolarizations) in hiPS-CMs; therefore, this technique will potentially be useful in predicting drug-induced arrhythmogenic liabilities in early de-risking within the drug discovery phase. Copyright © 2017 Elsevier Inc. All rights reserved.

Di-22:6-bis(monoacylglycerol)phosphate: A clinical biomarker of drug-induced phospholipidosis for drug development and safety assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Nanjun; Tengstrand, Elizabeth A.; Chourb, Lisa

The inability to routinely monitor drug-induced phospholipidosis (DIPL) presents a challenge in pharmaceutical drug development and in the clinic. Several nonclinical studies have shown di-docosahexaenoyl (22:6) bis(monoacylglycerol) phosphate (di-22:6-BMP) to be a reliable biomarker of tissue DIPL that can be monitored in the plasma/serum and urine. The aim of this study was to show the relevance of di-22:6-BMP as a DIPL biomarker for drug development and safety assessment in humans. DIPL shares many similarities with the inherited lysosomal storage disorder Niemann–Pick type C (NPC) disease. DIPL and NPC result in similar changes in lysosomal function and cholesterol status that leadmore » to the accumulation of multi-lamellar bodies (myeloid bodies) in cells and tissues. To validate di-22:6-BMP as a biomarker of DIPL for clinical studies, NPC patients and healthy donors were classified by receiver operator curve analysis based on urinary di-22:6-BMP concentrations. By showing 96.7-specificity and 100-sensitivity to identify NPC disease, di-22:6-BMP can be used to assess DIPL in human studies. The mean concentration of di-22:6-BMP in the urine of NPC patients was 51.4-fold (p ≤ 0.05) above the healthy baseline range. Additionally, baseline levels of di-22:6-BMP were assessed in healthy non-medicated laboratory animals (rats, mice, dogs, and monkeys) and human subjects to define normal reference ranges for nonclinical/clinical studies. The baseline ranges of di-22:6-BMP in the plasma, serum, and urine of humans and laboratory animals were species dependent. The results of this study support the role of di-22:6-BMP as a biomarker of DIPL for pharmaceutical drug development and health care settings. - Highlights: • A reliable biomarker of drug-induced phospholipidosis (DIPL) is needed for humans. • Di-22:6-BMP is specific/sensitive for DIPL in animals as published in literatures. • The di-22:6-BMP biomarker can be validated for humans via NPC patients. �

Preventing Drug-Induced Liver Injury: How Useful Are Animal Models?

PubMed

Ballet, François

2015-01-01

Drug-induced liver injury (DILI) is the most common organ toxicity encountered in regulatory animal toxicology studies required prior to the clinical development of new drug candidates. Very few reports have evaluated the value of these studies for predicting DILI in humans. Indeed, compounds inducing liver toxicity in regulatory toxicology studies are not always correlated with a risk of DILI in humans. Conversely, compounds associated with the occurrence of DILI in phase 3 studies or after market release are often tested negative in regulatory toxicology studies. Idiosyncratic DILI is a rare event that is precipitated in an individual by the simultaneous occurrence of several critical factors. These factors may relate to the host (e.g. human leukocyte antigen polymorphism, inflammation), the drug (e.g. reactive metabolites) or the environment (e.g. diet/microbiota). This type of toxicity therefore cannot be detected in conventional animal toxicology studies. Several animal models have recently been proposed for the identification of drugs with the potential to cause idiosyncratic DILI: rats treated with lipopolysaccharide, Sod2(+/-) mice, panels of inbred mouse strains or chimeric mice with humanized livers. These models are not suitable for use in the prospective screening of new drug candidates. Humans therefore constitute the best model for predicting and assessing idiopathic DILI. © 2015 S. Karger AG, Basel.

Walking on thin ice! Identifying methamphetamine “drug mules” on digital plain radiography

PubMed Central

Abdul Rashid, S N; Mohamad Saini, S B; Abdul Hamid, S; Muhammad, S J; Mahmud, R; Thali, M J

2014-01-01

Objective: The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of identifying methamphetamine (MA) internal payloads in “drug mules” by plain abdominal digital radiography (DR). Methods: The study consisted of 35 individuals suspected of internal MA drug containers. A total of 59 supine digital radiographs were collected. An overall calculation regarding the diagnostic accuracy for all “drug mules” and a specific evaluation concerning the radiological appearance of drug packs as well as the rate of clearance and complications in correlation with the reader's experience were performed. The gold standard was the presence of secured drug packs in the faeces. Results: There were 16 true-positive “drug mules” identified. DR of all drug carriers for Group 1 (forensic imaging experienced readers, n = 2) exhibited a sensitivity of 100%, a mean specificity of 76.3%, positive predictive value (PPV) of 78.5%, negative predictive value (NPV) of 100% and a mean accuracy 87.2%. Group 2 (inexperienced readers, n = 3) showed a lower sensitivity (93.7%), a mean specificity of 86%, a PPV of 86.5%, an NPV of 94.1% and a mean accuracy of 89.5%. The interrater agreement within Group 1 was 0.72 and within Group 2 averaged to 0.79, indicating a fair to very good agreement. Conclusion: DR is a valuable screening tool in cases of MA body packers with huge internal payloads being associated with a high diagnostic insecurity. Diagnostic insecurity on plain films may be overcome by low-dose CT as a cross-sectional imaging modality and addressed by improved radiological education in reporting drug carriers on imaging. Advances in knowledge: Diagnostic signs (double-condom and halo signs) on digital plain radiography are specific in MA “drug mules”, although DR is associated with high diagnostic insecurity and underreports the total internal payload. PMID:24472728

[Hepatox: database on hepatotoxic drugs].

PubMed

Quinton, A; Latry, P; Biour, M

1993-01-01

Hepatox is a data base on the hepatotoxic drugs file published every year in Gastroentérologie Clinique et Biologique. The program was developed under Omnis 7 for Apple computers, and under Visual Basic Professional Toolkit and Code Base for IBM PC and compatibles computers. The data base includes forms of 866 drugs identified by their approved name and those of their 1,300 corresponding proprietary names in France; drugs are distributed among 104 pharmacological classes. It is possible to have instantaneously access to the card of a drug identified by its approved name. Acceding to a drug identified by its proprietary name gives a list of the approved name of its components; going from a name of this list to the correspondent card of hepatoxicity is immediate. It is easy to extract lists of drugs responsible of a type of hepatic injury, and a table of types of hepatic injuries induced by the drugs of a pharmacological class.

Drug-induced systemic lupus erythematosus in a child after 3 years of treatment with carbamazepine.

PubMed

Molina-Ruiz, Ana María; Lasanta, Begoña; Barcia, Ana; Pérez-Vega, Elisa; Requena, Luis

2017-02-01

Drug-induced lupus erythematosus (DILE) is a less severe variant of systemic lupus erythematosus (SLE) that generally resolves within weeks or months after the withdrawal of the implicated drug. DILE is unusual during childhood, with the most frequent age of presentation being at 50-70 years of age. Among different drugs, most commonly procainamide and hydralazine have been implicated as a cause of DILE. However carbamazepine (CBZ) is considered a low-risk drug and very few cases have been reported in children. We describe the case of CBZ-induced SLE in a 9-year-old girl following 3 years of CBZ therapy. This case report shows that drug-induced SLE is an important side-effect to be considered, even after long-term treatment with CBZ, and also during childhood. © 2015 The Australasian College of Dermatologists.

Analysis of the adverse reactions induced by natural product-derived drugs

PubMed Central

Zeng, Zhi-Ping; Jiang, Jian-Guo

2010-01-01

Compared with the therapeutic effects of established medicinal drugs, it is often considered that natural product-derived drugs are of a more benign nature in side-effects, which has made natural medicines become a popular form of therapy. Traditional Chinese medicine (TCM) is generally considered as being natural and harmless. TCM has been paid much more attention than before and widely used for the treatment nowadays. However, with the increasing cases of adverse drug reactions (ADRs), the ADRs induced by TCM are becoming more widely recognized. Some ADRs are sometimes even life-threatening. This article reviews literatures on ADRs induced by TCM which was published in the past 10 years. A total of 3122 cases including complete data are selected for the present analysis. From the data of the 3122 cases, statistics is carried out to the distribution of administration routes and time of the occurrence of ADRs, the prognosis of ADRs, sex and age factors, types and clinical symptoms of ADRs, and drugs involved in ADRs. In addition, occurrence and influencing factors of TCM-induced diseases are also analysed, which includes spices confusion, processing drugs improperly, toxic components, long-term medication, improper concerted application, interaction of TCM and Western medicine. It is concluded that the efficacy and toxicity of TCM, often using the compound prescription involving various plants and animals, resulted from a variety of chemical constituents, which lead to a comprehensive response in the human body. The ‘toxicity’ of TCM should be correctly recognized and reasonably utilized. PMID:20233209

Exposure to reactive intermediate-inducing drugs during pregnancy and the incident use of psychotropic medications among children.

PubMed

Tran, Yen-Hao; Groen, Henk; Bergman, Jorieke E H; Hak, Eelko; Wilffert, Bob

2017-03-01

Our study aimed to investigate the association between prenatal exposure to reactive intermediate (RI)-inducing drugs and the initiation of psychotropic medications among children. We designed a cohort study using a pharmacy prescription database. Pregnant women were considered exposed when they received a prescription of RI-inducing drugs. These drugs could be either used alone (RI+/FAA-) or combined with drugs exhibiting folic acid antagonism (FAA, RI+/FAA+). The reference group included pregnant women who did not receive any RI-inducing drugs or FAA drugs. We analyzed 4116 exposed and 30 422 reference pregnancies. The hazard ratio (HR) with 95% confidence interval (CI) was 1.27 (95%CI 1.15-1.41) for pregnancies exposed to RI-inducing drugs as a whole. Considering subgroups of RI-inducing drugs, prenatal exposure to both RI+/FAA+ and RI+/FAA- was associated with the children's initiation of psychotropic medications, HRs being 1.35 (95%CI 1.10-1.66) and 1.26 (1.13-1.41), respectively. The HRs were increased with prolonged exposure to RI-inducing drugs, especially in the first and second trimesters. In a detailed examination of the psychotropics, the incidences of receiving antimigraine preparations and psychostimulants were significantly increased for the exposed children, compared with the reference children. The incidences of receiving antipsychotics and hypnotics were also higher for the exposed children; however, the HRs did not reach significance after adjustment. We found a significantly increased incident use of psychotropic medications among children prenatally exposed to RI-inducing drugs, especially during the first and second trimesters. This suggests a detrimental effect during critical periods of brain development. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Haematopoietic growth factor in antithyroid-drug-induced agranulocytosis.

PubMed

Andrès, E; Kurtz, J E; Perrin, A E; Dufour, P; Schlienger, J L; Maloisel, F

2001-08-01

Drug-induced agranulocytosis (DIA) is often caused by antithyroid drugs. We retrospectively studied the use of granulocyte colony-stimulating factor (G-CSF) therapy in antithyroid-DIA. Data for 20 patients (10 treated with G-CSF) with antithyroid-DIA (neutrophil count <0.5x10(9)/l) were extracted from a cohort study of DIA patients (n=110). G-CSF (300 microg/day subcutaneously) was used where the neutrophil count was <0.1x10(9)/l, or the patient was aged >70 years, or there were severe features of infection or underlying disease. Mean patient age was 62 years (range 34-87); sex ratio (M/F) was 0.05. Carbimazole (n=19) and benzylthiouracile (n=1) were the causative drugs, at mean doses of 30 mg/day (range 20-60) and 100 mg/day (range 50-150), respectively, for a mean of 37 days (range 31-90). Antithyroid drugs were prescribed for Graves' disease (n=8), thyrotoxicosis related to amiodarone intake (n=6) and multinodular goitre (n=6). Clinical features included isolated fever (n=7), pneumonia (n=5), septicaemia or septic shock (n=5) and acute tonsillitis (n=3). Mean neutrophil count was 0.07+/-0.1x10(9)/l. No patient died. Mean durations of haematological recovery, antibiotic therapy and hospitalization were significantly reduced with G-CSF: 6.8+/-4 days vs. 11.6+/-5; 7.5+/-3.8 days vs. 12+/-4.5; and 7.3+/-4.8 days vs. 13+/-6.1, respectively (all p<0.05). G-CSF induced flu-like symptoms in 30% of patients, but reduced overall costs.

[Trends in drug-induced liver injury based on reports of adverse reactions to PMDA in Japan].

PubMed

Sudo, Chie; Maekawa, Keiko; Segawa, Katsunori; Hanatani, Tadaaki; Sai, Kimie; Saito, Yoshiro

2012-01-01

Reports on drug-related adverse reactions from manufacturing/distributing pharmaceutical companies or medical institutions/pharmacies are regulated under the Pharmaceutical Affairs Law of Japan, and this system is important for post-marketing safety measures. Although association between the medicine and the adverse event has not been clearly evaluated, and an incidence may be redundantly reported, this information would be useful to roughly grasp the current status of drug-related adverse reactions. In the present study, we analyzed the incidence of drug-induced liver injury by screening the open-source data publicized by the homepage of Pharmaceutical and Medical Devices Agency from 2005 to 2011 fiscal years. Major drug-classes suspected to cause general drug-induced liver injury were antineoplastics, anti-inflammatory agents/common cold drugs, chemotherapeutics including antituberculous drugs, antidiabetics, antiulcers and antiepileptics. In addition, reported cases for fulminant hepatitis were also summarized. We found that antituberculous isoniazid and antineoplastic tegafur-uracil were the top two suspected drugs. These results might deepen understanding of current situations for the drug-induced liver injury in Japan.

A probabilistic approach to identify putative drug targets in biochemical networks.

PubMed

Murabito, Ettore; Smallbone, Kieran; Swinton, Jonathan; Westerhoff, Hans V; Steuer, Ralf

2011-06-06

Network-based drug design holds great promise in clinical research as a way to overcome the limitations of traditional approaches in the development of drugs with high efficacy and low toxicity. This novel strategy aims to study how a biochemical network as a whole, rather than its individual components, responds to specific perturbations in different physiological conditions. Proteins exerting little control over normal cells and larger control over altered cells may be considered as good candidates for drug targets. The application of network-based drug design would greatly benefit from using an explicit computational model describing the dynamics of the system under investigation. However, creating a fully characterized kinetic model is not an easy task, even for relatively small networks, as it is still significantly hampered by the lack of data about kinetic mechanisms and parameters values. Here, we propose a Monte Carlo approach to identify the differences between flux control profiles of a metabolic network in different physiological states, when information about the kinetics of the system is partially or totally missing. Based on experimentally accessible information on metabolic phenotypes, we develop a novel method to determine probabilistic differences in the flux control coefficients between the two observable phenotypes. Knowledge of how differences in flux control are distributed among the different enzymatic steps is exploited to identify points of fragility in one of the phenotypes. Using a prototypical cancerous phenotype as an example, we demonstrate how our approach can assist researchers in developing compounds with high efficacy and low toxicity. © 2010 The Royal Society

Drug-induced liver injury is frequently associated with severe cutaneous adverse drug reactions: experience from two Australian tertiary hospitals.

PubMed

Fang, Wendy C; Adler, Nikki R; Graudins, Linda V; Goldblatt, Caitlin; Goh, Michelle S Y; Roberts, Stuart K; Trubiano, Jason A; Aung, Ar Kar

2018-05-01

Drug-induced liver injury (DILI) can be associated with certain cutaneous adverse drug reaction (cADR). To demonstrate the prevalence of DILI in patients with cADRs. Severity and patterns of liver injury, risk factors, causal medications and outcomes are also examined. A retrospective cohort study of patients with cADRs was conducted across two hospitals in Australia. Patients were identified through cross-linkage of multiple databases. One hundred and four patients with cADRs were identified. Of these, 33 (31.7%) had liver injury, representing 50% of patients with drug reaction with eosinophilia and systemic symptoms, and 30.2% of patients with Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). Most cases of liver injury (69.7%) were of a cholestatic/mixed pattern with severe disease in 18.2%. No significant risk factors for development of liver injury were noted, but peripheral lymphocytosis may represent a risk in patients with SJS (odds ratio, OR = 6.0, 95% confidence interval, CI: 1.8-19.7, P = 0.003). Antimicrobials were the most common class to be implicated in DILI. The median length of inpatient stay was longer in patients with liver injury compared to those without (19 vs 11 days, P = 0.002). The mortality rate in those with liver injury was 15.2% and 9.9% in those without. No patients required liver transplantation. DILI commonly occurs in patients with cADRs and is associated with longer inpatient stay. Patients with SJS/TEN and peripheral lymphocytosis appear to be at higher risk for developing associated liver injury. © 2018 Royal Australasian College of Physicians.

High Frequency of Early Repolarization and Brugada-Type Electrocardiograms in Hypercalcemia.

PubMed

Sonoda, Keiko; Watanabe, Hiroshi; Hisamatsu, Takashi; Ashihara, Takashi; Ohno, Seiko; Hayashi, Hideki; Horie, Minoru; Minamino, Tohru

2016-01-01

J wave, or early repolarization has recently been associated with an increased risk of lethal arrhythmia and sudden death, both in idiopathic ventricular fibrillation and in the general population. Hypercalcemia is one of the causes of J point and ST segment elevation, but the relationship has not been well studied. The aim of this study was to examine the effects of hypercalcemia on J point elevation. Electrocardiographic findings were compared in 89 patients with hypercalcemia and 267 age- and sex-matched healthy controls with normocalcemia. The association of J point elevation with arrhythmia events in patients with hypercalcemia was also studied. The PR interval and the QRS duration were longer in patients with hypercalcemia than in normocalcemic controls. Both the QT and the corrected QT intervals were shorter in patients with hypercalcemia compared with normocalcemic controls. Conduction disorders, ST-T abnormalities, and J point elevation were more common in patients with hypercalcemia than normocalcemic controls. Following the resolution of hypercalcemia, the frequency of J point elevation decreased to a level similar to that noted in controls. During hospitalization, no arrhythmia event occurred in patients with hypercalcemia. Hypercalcemia was associated with J point elevation. © 2015 Wiley Periodicals, Inc.

Cell proliferation in dimethylhydrazine-induced colonic adenocarcinomata following cytotoxic drug treatment.

PubMed

Tutton, P J; Barkla, D H

1978-08-25

A stathmokinetic technique was used to study cell proliferation in dimethylhydrazine-induced adenocarcinomata of rat colon following treatment with cytotoxic drugs. The rate of cell division was significantly increased three days after treatment with 5,7-dihydroxytryptamine and seven days after treatment with 5-fluorouracil. Acceleration of tumour cell proliferation following 5,7-dihydroxytryptamine treatment was inhibited by treating animals with the antiseritoninergic drug Xylamidine Tosylate. Acceleration of tumour cell proliferation following 5-fluorouracil treatment was inhibited by treating animals either with the antiseritoninergic drug BW501 or with the histamine H2-receptor blocking drug Cimetidine.

Oral administration of drugs with hypersensitivity potential induces germinal center hyperplasia in secondary lymphoid organ/tissue in Brown Norway rats, and this histological lesion is a promising candidate as a predictive biomarker for drug hypersensitivity occurrence in humans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tamura, Akitoshi, E-mail: akitoshi-tamura@ds-pharma.co.jp; Miyawaki, Izuru; Yamada, Toru

It is important to evaluate the potential of drug hypersensitivity as well as other adverse effects during the preclinical stage of the drug development process, but validated methods are not available yet. In the present study we examined whether it would be possible to develop a new predictive model of drug hypersensitivity using Brown Norway (BN) rats. As representative drugs with hypersensitivity potential in humans, phenytoin (PHT), carbamazepine (CBZ), amoxicillin (AMX), and sulfamethoxazole (SMX) were orally administered to BN rats for 28 days to investigate their effects on these animals by examinations including observation of clinical signs, hematology, determination ofmore » serum IgE levels, histology, and flow cytometric analysis. Skin rashes were not observed in any animals treated with these drugs. Increases in the number of circulating inflammatory cells and serum IgE level did not necessarily occur in the animals treated with these drugs. However, histological examination revealed that germinal center hyperplasia was commonly induced in secondary lymphoid organs/tissues in the animals treated with these drugs. In cytometric analysis, changes in proportions of lymphocyte subsets were noted in the spleen of the animals treated with PHT or CBZ during the early period of administration. The results indicated that the potential of drug hypersensitivity was identified in BN rat by performing histological examination of secondary lymphoid organs/tissues. Data obtained herein suggested that drugs with hypersensitivity potential in humans gained immune reactivity in BN rat, and the germinal center hyperplasia induced by administration of these drugs may serve as a predictive biomarker for drug hypersensitivity occurrence. - Highlights: • We tested Brown Norway rats as a candidate model for predicting drug hypersensitivity. • The allergic drugs did not induce skin rash, whereas D-penicillamine did so in the rats. • Some of allergic drugs increased

Identifying Drug-Target Interactions with Decision Templates.

PubMed

Yan, Xiao-Ying; Zhang, Shao-Wu

2018-01-01

During the development process of new drugs, identification of the drug-target interactions wins primary concerns. However, the chemical or biological experiments bear the limitation in coverage as well as the huge cost of both time and money. Based on drug similarity and target similarity, chemogenomic methods can be able to predict potential drug-target interactions (DTIs) on a large scale and have no luxurious need about target structures or ligand entries. In order to reflect the cases that the drugs having variant structures interact with common targets and the targets having dissimilar sequences interact with same drugs. In addition, though several other similarity metrics have been developed to predict DTIs, the combination of multiple similarity metrics (especially heterogeneous similarities) is too naïve to sufficiently explore the multiple similarities. In this paper, based on Gene Ontology and pathway annotation, we introduce two novel target similarity metrics to address above issues. More importantly, we propose a more effective strategy via decision template to integrate multiple classifiers designed with multiple similarity metrics. In the scenarios that predict existing targets for new drugs and predict approved drugs for new protein targets, the results on the DTI benchmark datasets show that our target similarity metrics are able to enhance the predictive accuracies in two scenarios. And the elaborate fusion strategy of multiple classifiers has better predictive power than the naïve combination of multiple similarity metrics. Compared with other two state-of-the-art approaches on the four popular benchmark datasets of binary drug-target interactions, our method achieves the best results in terms of AUC and AUPR for predicting available targets for new drugs (S2), and predicting approved drugs for new protein targets (S3).These results demonstrate that our method can effectively predict the drug-target interactions. The software package can

In vitro cytokine expression by peripheral mononuclear cells in herbal drug-induced skin eruption.

PubMed

Norisugi, Osamu; Yoshihisa, Yoko; Shimizu, Kyoko; Shimizu, Tadamichi

2014-01-01

Herbal medicine is widely used worldwide and is associated with side-effects such as skin eruptions. Herbal drugs are often produced by combining multiple crude drugs, mostly of plant origin. Determining which medi-cinal plants are associated with the herbal drugs that induce skin eruptions can therefore be difficult. This study investigated mRNA expression of several cytokines in peripheral mononuclear cells (PBMCs) from two patients with herbal drug-induced skin eruptions; one reacted to keishi-bukuryo-gan (KBG), composed of 5 medicinal plants, and the other patient reacted to senna. PBMCs (1×106) from the 2 patients were cultured for 24 h with the supernatant from the medicinal plants from KBG or senna in various concentrations, and a reverse transcription-polymerase chain reaction (RT-PCR) analysis was performed. A high mRNA level of interleukin (IL)-4 and IL-5 was detected in PBMCs stimulated by KBG and two of its components. Senna stimulated a high level of IL-4 and IL-5 mRNA levels in PBMCs from patient with senna-induced drug reaction.

iEzy-Drug: A Web Server for Identifying the Interaction between Enzymes and Drugs in Cellular Networking

PubMed Central

Min, Jian-Liang; Chou, Kuo-Chen

2013-01-01

With the features of extremely high selectivity and efficiency in catalyzing almost all the chemical reactions in cells, enzymes play vitally important roles for the life of an organism and hence have become frequent targets for drug design. An essential step in developing drugs by targeting enzymes is to identify drug-enzyme interactions in cells. It is both time-consuming and costly to do this purely by means of experimental techniques alone. Although some computational methods were developed in this regard based on the knowledge of the three-dimensional structure of enzyme, unfortunately their usage is quite limited because three-dimensional structures of many enzymes are still unknown. Here, we reported a sequence-based predictor, called “iEzy-Drug,” in which each drug compound was formulated by a molecular fingerprint with 258 feature components, each enzyme by the Chou's pseudo amino acid composition generated via incorporating sequential evolution information and physicochemical features derived from its sequence, and the prediction engine was operated by the fuzzy K-nearest neighbor algorithm. The overall success rate achieved by iEzy-Drug via rigorous cross-validations was about 91%. Moreover, to maximize the convenience for the majority of experimental scientists, a user-friendly web server was established, by which users can easily obtain their desired results. PMID:24371828

Role of metabolism in drug-induced idiosyncratic hepatotoxicity.

PubMed

Walgren, Jennie L; Mitchell, Michael D; Thompson, David C

2005-01-01

Rare adverse reactions to drugs that are of unknown etiology, or idiosyncratic reactions, can produce severe medical complications or even death in patients. Current hypotheses suggest that metabolic activation of a drug to a reactive intermediate is a necessary, yet insufficient, step in the generation of an idiosyncratic reaction. We review evidence for this hypothesis with drugs that are associated with hepatotoxicity, one of the most common types of idiosyncratic reactions in humans. We identified 21 drugs that have either been withdrawn from the U.S. market due to hepatotoxicity or have a black box warning for hepatotoxicity. Evidence for the formation of reactive metabolites was found for 5 out of 6 drugs that were withdrawn, and 8 out of 15 drugs that have black box warnings. For the other drugs, either evidence was not available or suitable studies have not been carried out. We also review evidence for reactive intermediate formation from a number of additional drugs that have been associated with idiosyncratic hepatotoxicity but do not have black box warnings. Finally, we consider the potential role that high dosages may play in these adverse reactions.

The Possible Potential Therapeutic Targets for Drug Induced Gingival Overgrowth

PubMed Central

Alitheen, Noorjahan Banu

2013-01-01

Gingival overgrowth is a side effect of certain medications. The most fibrotic drug-induced lesions develop in response to therapy with phenytoin, the least fibrotic lesions are caused by cyclosporin A, and the intermediate fibrosis occurs in nifedipine-induced gingival overgrowth. Fibrosis is one of the largest groups of diseases for which there is no therapy but is believed to occur because of a persistent tissue repair program. During connective tissue repair, activated gingival fibroblasts synthesize and remodel newly created extracellular matrix. Proteins such as transforming growth factor (TGF), endothelin-1 (ET-1), angiotensin II (Ang II), connective tissue growth factor (CCN2/CTGF), insulin-like growth factor (IGF), and platelet-derived growth factor (PDGF) appear to act in a network that contributes to the development of gingival fibrosis. Since inflammation is the prerequisite for gingival overgrowth, mast cells and its protease enzymes also play a vital role in the pathogenesis of gingival fibrosis. Drugs targeting these proteins are currently under consideration as antifibrotic treatments. This review summarizes recent observations concerning the contribution of TGF-β, CTGF, IGF, PDGF, ET-1, Ang II, and mast cell chymase and tryptase enzymes to fibroblast activation in gingival fibrosis and the potential utility of agents blocking these proteins in affecting the outcome of drug-induced gingival overgrowth. PMID:23690667

The drug-induced degradation of oncoproteins: an unexpected Achilles' heel of cancer cells?

PubMed

Ablain, Julien; Nasr, Rihab; Bazarbachi, Ali; de Thé, Hugues

2011-07-01

Many targeted therapies against cancer are aimed at inhibiting the enzymatic activity of kinases. Thus far, this approach has undoubtedly yielded significant clinical improvements, but has only rarely achieved cures. Other drugs, which selectively elicit proteasome-dependent degradation of oncoproteins, induce the loss of cancer cell self-renewal and promote cell differentiation and/or apoptosis. In acute promyelocytic leukemia, the cooperative degradation of PML/RARA by arsenic and retinoic acid cures most patients. In this condition and others, drug-induced proteolysis of oncoproteins is feasible and underlies improved clinical outcome. Several transcription factors, nuclear receptors, or fusion proteins driving cancer growth could be candidates for proteolysis-based drug-discovery programs.

Sulthiame-induced drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome.

PubMed

Fong, Choong Yi; Hashim, Nurmaira; Gan, Chin Seng; Chow, Tak Kuan; Tay, Chee Geap

2016-11-01

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare and potentially life-threatening acute drug-induced hypersensitivity reaction. Antiepileptic drugs (AEDs) predominantly aromatic AEDs are commonly reported in DRESS. To date there are no reports of sulthiame AED causing DRESS syndrome. We report a 10-year-old girl of Indian descent with AED resistant epilepsy on maintenance sodium valproate and clonazepam. Sulthiame AED was initiated to try to improve her seizure control. Five weeks after commencing sulthiame, she developed fever with a diffuse erythematous morbilliform maculopapular rash, elevated transaminases and atypical lymphocytes. At day 3 of illness, she deteriorated with worsening elevation of liver transaminases, thrombocytopenia, progression of rash, hepatosplenomegaly, pneumonitis and markedly elevated inflammatory markers. Immunomodulatory treatment of pulse methylprednisolone was given from day 7 which was associated with improvement inflammatory markers and complete resolution of rash from day 30 of illness. The diagnosis of sulthiame-induced DRESS syndrome was made based on clinical, laboratory and skin histology findings. She was HLA-B heterozygous for HLA-B ∗ 15:123 and 15:240 and HLA-A homozygous for HLA-A ∗ 11:01:09. Both these HLA-A and HLA-B typing has not been reported before in cutaneous drug reactions. This is the first reported case of sulthiame-induced DRESS syndrome. Our case expands the list of possible susceptible HLA alleles associated with cutaneous drug reactions. It also raises the awareness of possible DRESS syndrome among patients commenced on sulthiame who will require immediate discontinuation of sulthiame and consideration of prompt treatment of corticosteroids. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Drug-induced parkinsonism following chronic methamphetamine use by a patient on haloperidol decanoate.

PubMed

Matthew, Binoj J; Gedzior, Joanna S

2015-01-01

This report attempts to highlight that use of an antipsychotic and concurrent chronic use of methamphetamine can cause drug-induced parkinsonism. Methamphetamine is usually not encountered in the list of agents that induce drug-induced parkinsonism and so its consideration particularly during chronic use by a patient who is also on an antipsychotic is worthwhile because of its popularity as an illegal narcotic. This case report describes just such a case of drug-induced parkinsonism which is a subacute syndrome that mimics Parkinson's disease. Although less alarming than dystonia, it is more common, more difficult to treat and can be the cause of significant disability during maintenance treatment especially in the elderly. In most cases, symptoms are reversible in days or weeks, but occasionally, especially in the elderly, or if long-acting injectable antipsychotics are used-as in this case-symptoms may last for weeks or months. The report also illustrates the neuronal workings due to chronic methamphetamine-use and the additive effects of dopamine blockade by antipsychotics such as haloperidol. © The Author(s) 2015.

Identifying genetic loci affecting antidepressant drug response in depression using drug–gene interaction models

PubMed Central

Noordam, Raymond; Avery, Christy L; Visser, Loes E; Stricker, Bruno H

2016-01-01

Antidepressants are often only moderately successful in decreasing the severity of depressive symptoms. In part, antidepressant treatment response in patients with depression is genetically determined. However, although a large number of studies have been conducted aiming to identify genetic variants associated with antidepressant drug response in depression, only a few variants have been repeatedly identified. Within the present review, we will discuss the methodological challenges and limitations of the studies that have been conducted on this topic to date (e.g., ‘treated-only design’, statistical power) and we will discuss how specifically drug–gene interaction models can be used to be better able to identify genetic variants associated with antidepressant drug response in depression. PMID:27248517

Inhibin beta E is upregulated by drug-induced endoplasmic reticulum stress as a transcriptional target gene of ATF4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brüning, Ansgar, E-mail: ansgar.bruening@med.uni-muenchen.de; Matsingou, Christina; Brem, German Johannes

2012-10-15

Inhibins and activins are gonadal peptide hormones of the transforming growth factor-β super family with important functions in the reproductive system. By contrast, the recently identified inhibin βE subunit, primarily expressed in liver cells, appears to exert functions unrelated to the reproductive system. Previously shown downregulation of inhibin βE in hepatoma cells and anti-proliferative effects of ectopic inhibin βE overexpression indicated growth-regulatory effects of inhibin βE. We observed a selective re-expression of the inhibin βE subunit in HepG2 hepatoblastoma cells, MCF7 breast cancer cells, and HeLa cervical cancer cells under endoplasmic reticulum stress conditions induced by tunicamycin, thapsigargin, and nelfinavir.more » Analysis of XPB1 splicing and ATF4 activation revealed that inhibin βE re-expression was associated with induction of the endoplasmic reticulum stress reaction by these drugs. Transfection of an ATF4 expression plasmid specifically induced inhibin βE expression in HeLa cells and indicates inhibin βE as a hitherto unidentified target gene of ATF4, a key transcription factor of the endoplasmic reticulum stress response. Therefore, the inhibin βE subunit defines not only a new player but also a possible new marker for drug-induced endoplasmic reticulum stress. -- Highlights: ► Endoplasmic reticulum stress induces inhibin beta E expression. ► Inhibin beta E is regulated by the transcription factor ATF4. ► Inhibin beta E expression can be used as a marker for drug-induced ER stress.« less

A New Class III Antiarrhythmic Drug Niferidil Prolongs Action Potentials in Guinea Pig Atrial Myocardium via Inhibition of Rapid Delayed Rectifier.

PubMed

Abramochkin, Denis V; Kuzmin, Vladislav S; Rosenshtraukh, Leonid V

2017-12-01

A new class III antiarrhythmic drug niferidil (RG-2) has been introduced as a highly effective therapy for cases of persistent atrial fibrillation, but ionic mechanisms of its action are poorly understood. In the present study, the effects of niferidil on action potential (AP) waveform and potassium currents responsible for AP repolarization were investigated in guinea pig atrial myocardium. APs were recorded with sharp glass microelectrodes in multicellular atrial preparations. Whole-cell patch-clamp technique was used to measure K + currents in isolated myocytes. In multicellular atrial preparations, 10 -8  M niferidil effectively prolonged APs by 15.2 ± 2.8% at 90% repolarization level. However, even the highest tested concentrations, 10 -6  M and 10 -5  M failed to prolong APs more than 32.5% of control duration. The estimated concentration of niferedil for half-maximal AP prolongation was 1.13 × 10 -8  M. Among the potassium currents responsible for AP repolarization phase, I K1 was found to be almost insensitive to niferidil. However, another inward rectifier, I KACh , was effectively suppressed by micromolar concentrations of niferidil with IC 50  = 9.2 × 10 -6  M. I KATP was much less sensitive to the drug with IC 50  = 2.26 × 10 -4  M. The slow component of delayed rectifier, I Ks , also demonstrated low sensitivity to niferidil-the highest used concentration, 10 -4  M, decreased peak I Ks density to 46.2 ± 5.5% of control. Unlike I Ks , the rapid component of delayed rectifier, I Kr , appeared to be extremely sensitive to niferidil. The IC 50 was 1.26 × 10 -9  M. I Kr measured in ventricular myocytes was found to be less sensitive to niferidil with IC 50  = 3.82 × 10 -8  M. Niferidil prolongs APs in guinea pig atrial myocardium via inhibition of I Kr .

Risk of Acute Liver Failure in Patients With Drug-Induced Liver Injury: Evaluation of Hy's Law and a New Prognostic Model.

PubMed

Lo Re, Vincent; Haynes, Kevin; Forde, Kimberly A; Goldberg, David S; Lewis, James D; Carbonari, Dena M; Leidl, Kimberly B F; Reddy, K Rajender; Nezamzadeh, Melissa S; Roy, Jason; Sha, Daohang; Marks, Amy R; De Boer, Jolanda; Schneider, Jennifer L; Strom, Brian L; Corley, Douglas A

2015-12-01

Few studies have evaluated the ability of laboratory tests to predict risk of acute liver failure (ALF) among patients with drug-induced liver injury (DILI). We aimed to develop a highly sensitive model to identify DILI patients at increased risk of ALF. We compared its performance with that of Hy's Law, which predicts severity of DILI based on levels of alanine aminotransferase or aspartate aminotransferase and total bilirubin, and validated the model in a separate sample. We conducted a retrospective cohort study of 15,353 Kaiser Permanente Northern California members diagnosed with DILI from 2004 through 2010, liver aminotransferase levels above the upper limit of normal, and no pre-existing liver disease. Thirty ALF events were confirmed by medical record review. Logistic regression was used to develop prognostic models for ALF based on laboratory results measured at DILI diagnosis. External validation was performed in a sample of 76 patients with DILI at the University of Pennsylvania. Hy's Law identified patients that developed ALF with a high level of specificity (0.92) and negative predictive value (0.99), but low level of sensitivity (0.68) and positive predictive value (0.02). The model we developed, comprising data on platelet count and total bilirubin level, identified patients with ALF with a C statistic of 0.87 (95% confidence interval [CI], 0.76-0.96) and enabled calculation of a risk score (Drug-Induced Liver Toxicity ALF Score). We found a cut-off score that identified patients at high risk patients for ALF with a sensitivity value of 0.91 (95% CI, 0.71-0.99) and a specificity value of 0.76 (95% CI, 0.75-0.77). This cut-off score identified patients at high risk for ALF with a high level of sensitivity (0.89; 95% CI, 0.52-1.00) in the validation analysis. Hy's Law identifies patients with DILI at high risk for ALF with low sensitivity but high specificity. We developed a model (the Drug-Induced Liver Toxicity ALF Score) based on platelet count and

Refining adverse drug reaction signals by incorporating interaction variables identified using emergent pattern mining.

PubMed

Reps, Jenna M; Aickelin, Uwe; Hubbard, Richard B

2016-02-01

To develop a framework for identifying and incorporating candidate confounding interaction terms into a regularised cox regression analysis to refine adverse drug reaction signals obtained via longitudinal observational data. We considered six drug families that are commonly associated with myocardial infarction in observational healthcare data, but where the causal relationship ground truth is known (adverse drug reaction or not). We applied emergent pattern mining to find itemsets of drugs and medical events that are associated with the development of myocardial infarction. These are the candidate confounding interaction terms. We then implemented a cohort study design using regularised cox regression that incorporated and accounted for the candidate confounding interaction terms. The methodology was able to account for signals generated due to confounding and a cox regression with elastic net regularisation correctly ranking the drug families known to be true adverse drug reactions above those that are not. This was not the case without the inclusion of the candidate confounding interaction terms, where confounding leads to a non-adverse drug reaction being ranked highest. The methodology is efficient, can identify high-order confounding interactions and does not require expert input to specify outcome specific confounders, so it can be applied for any outcome of interest to quickly refine its signals. The proposed method shows excellent potential to overcome some forms of confounding and therefore reduce the false positive rate for signal analysis using longitudinal data. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electrophysiological characteristics and pharmacological sensitivity of two lines of human induced pluripotent stem cell derived cardiomyocytes coming from two different suppliers.

PubMed

Goineau, Sonia; Castagné, Vincent

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are increasingly used as preclinical tool for predicting drug-induced QT prolongation and arrhythmias. This study was conducted to assess the electrophysiological characteristics and the pharmacological sensitivity of two commercialized hiPSC-CMs. The baseline electrophysiological characteristics measured with a multi-electrode array (MEA) technology differ between Cor.4U and iCell 2 : higher beat rate (+32bpm) and shorter field potential duration (FPD, -201ms) for Cor.4U. The FPD lengthening after cisapride (100nM: +65% versus +18%), quinidine (10μM: +65% versus +31%), sotalol (30μM: +90% versus +47%) or flecainide (3μM: +76% versus +22%) application appeared earlier in iCell 2 as compared to Cor.4U. Arrhythmia occurrence also appeared earlier in iCell 2 as compared to Cor.4U for the 3 substances mentioned above. The FPD shortening recorded after verapamil or nifedipine application was similar in both hiPSC-CMs. In conclusion, Cor.4U and iCell 2 hiPSC-CMs are both sensitive enough to detect drug-induced delayed or shortened repolarization and arrhythmia and can provide useful predictive cardiac electrophysiology data. Arrhythmias occurred at concentrations higher than clinical free maximum plasma concentrations with an overestimation of the risk with cisapride. However, quantitative differences of baseline electrophysiological characteristics or pharmacological sensitivity of both cell types have to be considered with caution during the interpretation of data. The new chemical entities included within a given drug development program should be evaluated in hiPSC-CMs coming from a single supplier. Copyright © 2017 Elsevier Inc. All rights reserved.

Direct-to-consumer prescription drug advertising, 1989-1998. A content analysis of conditions, targets, inducements, and appeals.

PubMed

Bell, R A; Kravitz, R L; Wilkes, M S

2000-04-01

We conducted a content analysis of consumer-targeted prescription drug advertisements to explore trends in prevalence, shifts in the medical conditions for which drugs are promoted, reliance on financial and nonmonetary inducements, and appeals used to attract public interest. We collected the drug advertisements appearing in 18 consumer magazines from 1989 through 1998. Two judges independently coded each advertisement and placed it in a category pertaining to the target audience, use of inducements, and product benefits (mean kappa=0.93). We employed descriptive statistics, cross-tabulations, and curve estimation procedures. A total of 320 distinct advertisements were identified, representing 101 brands and 14 medical conditions. New advertisement and brand introductions increased dramatically during this decade. Advertisements for drugs used for dermatologic, human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS), and obstetric/gynecologic conditions were most common. Almost all of the advertisements were aimed at the potential user of the drug, not third-party intermediaries such as parents and spouses. Although most advertisements were gender-neutral, women were more likely to be exclusively targeted. One eighth of the advertisements offered a monetary incentive (eg, a rebate or money-back guarantee), and one third made an offer of additional information in printed or audio/video form. The most common appeals used were effectiveness, symptom control, innovativeness, and convenience. Consumer-directed prescription drug advertising has increased dramatically during the past decade. The pharmaceutical industry is turning to this type of advertising to generate interest in its products. Our data may be useful to physicians who want to stay abreast of the treatments that are being directly marketed to their patients.

Drug-Induced Gingival Overgrowth: The Genetic Dimension

PubMed Central

Charles, Noronha Shyam Curtis; Chavan, Rahul; Moon, Ninad Joshirao; Nalla, Srinivas; Mali, Jaydeepchandra; Prajapati, Anchal

2014-01-01

Background: Currently, the etiology of drug-induced gingival overgrowth is not entirely understood but is clearly multifactorial. Phenytoin, one of the common drugs implicated in gingival enlargement, is metabolized mainly by cytochrome P450 (CYP)2C9 and partly by CYP2C19. The CYP2C9 and CYP2C19 genes are polymorphically expressed and most of the variants result in decreased metabolism of the respective substrates. Aims: The present study was undertaken to investigate the influence of the CYP2C9*2 and *3 variant genotypes on phenytoin hydroxylation in subjects diagnosed with epilepsy from South India, thus establishing the genetic polymorphisms leading to its defective hydroxylation process. Materials and Methods: Fifteen epileptic subjects, age 9 to 60 years were included in the study. Among the study subjects, 8 were males and 7 were females. Genomic DNA was extracted from patients’ blood using Phenol-chloroform method and genotyping was done for CYP2C9 using customized TaqMan genotyping assays on a real time thermocycler, by allelic discrimination method. The genetic polymorphisms *1, *2 and *3 on CYP2C9 were selected based on their function and respective allele frequencies in Asian subcontinent among the Asian populations. Results: CYP2C9*1*2 and CYP2C9*3/*3 were identified with equal frequency in the study population. There were seven subjects with CYP2C9*1/*2 genotype (heterozygous mutant), one subject with CYP2C9*1/*1 (wild type) and seven study subjects with CYP2C9*3/*3 (homozygous mutant). Conclusion: The results obtained in the present study will be helpful in the medical prescription purposes of phenytoin, and a more personalized patient approach with its administration can be advocated. PMID:25317394

Drug-induced gingival overgrowth: the genetic dimension.

PubMed

Charles, Noronha Shyam Curtis; Chavan, Rahul; Moon, Ninad Joshirao; Nalla, Srinivas; Mali, Jaydeepchandra; Prajapati, Anchal

2014-09-01

Currently, the etiology of drug-induced gingival overgrowth is not entirely understood but is clearly multifactorial. Phenytoin, one of the common drugs implicated in gingival enlargement, is metabolized mainly by cytochrome P450 (CYP)2C9 and partly by CYP2C19. The CYP2C9 and CYP2C19 genes are polymorphically expressed and most of the variants result in decreased metabolism of the respective substrates. The present study was undertaken to investigate the influence of the CYP2C9*2 and *3 variant genotypes on phenytoin hydroxylation in subjects diagnosed with epilepsy from South India, thus establishing the genetic polymorphisms leading to its defective hydroxylation process. Fifteen epileptic subjects, age 9 to 60 years were included in the study. Among the study subjects, 8 were males and 7 were females. Genomic DNA was extracted from patients' blood using Phenol-chloroform method and genotyping was done for CYP2C9 using customized TaqMan genotyping assays on a real time thermocycler, by allelic discrimination method. The genetic polymorphisms *1, *2 and *3 on CYP2C9 were selected based on their function and respective allele frequencies in Asian subcontinent among the Asian populations. CYP2C9*1*2 and CYP2C9*3/*3 were identified with equal frequency in the study population. There were seven subjects with CYP2C9*1/*2 genotype (heterozygous mutant), one subject with CYP2C9*1/*1 (wild type) and seven study subjects with CYP2C9*3/*3 (homozygous mutant). The results obtained in the present study will be helpful in the medical prescription purposes of phenytoin, and a more personalized patient approach with its administration can be advocated.

History as a tool in identifying "new" old drugs.

PubMed

Riddle, John M

2002-01-01

To trace the history of a natural product and its use, it is necessary to identify to correct plant among around a half-million species. One must also know how and when harvest the plant and the morphology of location and extraction. Within the same species plant chemistry varies, depending upon climatic and soil conditions, stage of maturity and even diurnal factors. To all of these variations must be added the diagnostic ability of physicians and native healers (to distinguish between Hippocratically-trained Western physicians and whose knowledge is less formally taught). Seldom was a disease identified as we Know it today, but the constellations of symptoms described, when studied carefully within the framework historical setting of the culture, can be related to modern medicine. It is essential to study the historical contemporary usage data in the language in which those accounts were writTen. Translators are often philologists who are not sensitive to medical nuances. Modern readers of translated historical documents often are unaware of the precision the authors delivered in describing medical afflictions and their treatments. Natural product drugs are truly products of human knowledge. Because so many modern pharmaceuticals are manufactured synthetically we forget that once either the compound or its affinity had a home in a natural product. Over 2,500 years ago man first used a drug obtained from white willow bark, which was aspirin or acetylsalicylic acid. Today's scientists continue to be bewildered by just what aspirin's mechanisms of action are, discovering new modes of action, and how they relate to medical diagnostics. Whatever the science of aspirin, an intelligent person today takes it just as our ancestors did fo millennia. Throughout time, explanations continue to vary just as purpose of administration do as well. Nevertheless, aspirin is perceived as being beneficial. Historical in-use data can also be a factor in judging a drug's safety, since

Development of novel prediction model for drug-induced mitochondrial toxicity by using naïve Bayes classifier method.

PubMed

Zhang, Hui; Yu, Peng; Ren, Ji-Xia; Li, Xi-Bo; Wang, He-Li; Ding, Lan; Kong, Wei-Bao

2017-12-01

Mitochondrial dysfunction has been considered as an important contributing factor in the etiology of drug-induced organ toxicity, and even plays an important role in the pathogenesis of some diseases. The objective of this investigation was to develop a novel prediction model of drug-induced mitochondrial toxicity by using a naïve Bayes classifier. For comparison, the recursive partitioning classifier prediction model was also constructed. Among these methods, the prediction performance of naïve Bayes classifier established here showed best, which yielded average overall prediction accuracies for the internal 5-fold cross validation of the training set and external test set were 95 ± 0.6% and 81 ± 1.1%, respectively. In addition, four important molecular descriptors and some representative substructures of toxicants produced by ECFP_6 fingerprints were identified. We hope the established naïve Bayes prediction model can be employed for the mitochondrial toxicity assessment, and these obtained important information of mitochondrial toxicants can provide guidance for medicinal chemists working in drug discovery and lead optimization. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Framework of Knowledge Integration and Discovery for Supporting Pharmacogenomics Target Predication of Adverse Drug Events: A Case Study of Drug-Induced Long QT Syndrome.

PubMed

Jiang, Guoqian; Wang, Chen; Zhu, Qian; Chute, Christopher G

2013-01-01

Knowledge-driven text mining is becoming an important research area for identifying pharmacogenomics target genes. However, few of such studies have been focused on the pharmacogenomics targets of adverse drug events (ADEs). The objective of the present study is to build a framework of knowledge integration and discovery that aims to support pharmacogenomics target predication of ADEs. We integrate a semantically annotated literature corpus Semantic MEDLINE with a semantically coded ADE knowledgebase known as ADEpedia using a semantic web based framework. We developed a knowledge discovery approach combining a network analysis of a protein-protein interaction (PPI) network and a gene functional classification approach. We performed a case study of drug-induced long QT syndrome for demonstrating the usefulness of the framework in predicting potential pharmacogenomics targets of ADEs.

ICD-10 codes used to identify adverse drug events in administrative data: a systematic review.

PubMed

Hohl, Corinne M; Karpov, Andrei; Reddekopp, Lisa; Doyle-Waters, Mimi; Stausberg, Jürgen

2014-01-01

Adverse drug events, the unintended and harmful effects of medications, are important outcome measures in health services research. Yet no universally accepted set of International Classification of Diseases (ICD) revision 10 codes or coding algorithms exists to ensure their consistent identification in administrative data. Our objective was to synthesize a comprehensive set of ICD-10 codes used to identify adverse drug events. We developed a systematic search strategy and applied it to five electronic reference databases. We searched relevant medical journals, conference proceedings, electronic grey literature and bibliographies of relevant studies, and contacted content experts for unpublished studies. One author reviewed the titles and abstracts for inclusion and exclusion criteria. Two authors reviewed eligible full-text articles and abstracted data in duplicate. Data were synthesized in a qualitative manner. Of 4241 titles identified, 41 were included. We found a total of 827 ICD-10 codes that have been used in the medical literature to identify adverse drug events. The median number of codes used to search for adverse drug events was 190 (IQR 156-289) with a large degree of variability between studies in the numbers and types of codes used. Authors commonly used external injury (Y40.0-59.9) and disease manifestation codes. Only two papers reported on the sensitivity of their code set. Substantial variability exists in the methods used to identify adverse drug events in administrative data. Our work may serve as a point of reference for future research and consensus building in this area.

ICD-10 codes used to identify adverse drug events in administrative data: a systematic review

PubMed Central

Hohl, Corinne M; Karpov, Andrei; Reddekopp, Lisa; Stausberg, Jürgen

2014-01-01

Background Adverse drug events, the unintended and harmful effects of medications, are important outcome measures in health services research. Yet no universally accepted set of International Classification of Diseases (ICD) revision 10 codes or coding algorithms exists to ensure their consistent identification in administrative data. Our objective was to synthesize a comprehensive set of ICD-10 codes used to identify adverse drug events. Methods We developed a systematic search strategy and applied it to five electronic reference databases. We searched relevant medical journals, conference proceedings, electronic grey literature and bibliographies of relevant studies, and contacted content experts for unpublished studies. One author reviewed the titles and abstracts for inclusion and exclusion criteria. Two authors reviewed eligible full-text articles and abstracted data in duplicate. Data were synthesized in a qualitative manner. Results Of 4241 titles identified, 41 were included. We found a total of 827 ICD-10 codes that have been used in the medical literature to identify adverse drug events. The median number of codes used to search for adverse drug events was 190 (IQR 156–289) with a large degree of variability between studies in the numbers and types of codes used. Authors commonly used external injury (Y40.0–59.9) and disease manifestation codes. Only two papers reported on the sensitivity of their code set. Conclusions Substantial variability exists in the methods used to identify adverse drug events in administrative data. Our work may serve as a point of reference for future research and consensus building in this area. PMID:24222671

Drug-induced hypersensitivity syndrome associated with Epstein-Barr virus infection.

PubMed

Descamps, V; Mahe, E; Houhou, N; Abramowitz, L; Rozenberg, F; Ranger-Rogez, S; Crickx, B

2003-05-01

Association of drug-induced hypersensitivity syndrome with viral infection is debated. Human herpesvirus 6 (HHV-6) reactivation has been the most frequently reported infection associated with this syndrome. However, a case of cytomegalovirus (CMV) infection was recently described associated with anticonvulsant-induced hypersensitivity syndrome. We report a case of severe allopurinol-induced hypersensitivity syndrome with pancreatitis associated with Epstein-Barr virus (EBV) infection. Active EBV infection was demonstrated in two consecutive serum samples by the presence of anti-EBV early antigen (EA) IgM antibodies and an increase in anti-EBV EA IgG antibodies, whereas no anti-EBV nuclear antigen IgG antibodies were detected. EBV DNA was detected by polymerase chain reaction (PCR) in peripheral blood mononuclear cells. Reactivation of HHV-6 was suggested only by the presence of anti-HHV-6 IgM antibodies, but HHV-6 DNA was not detected by PCR in the serum. Other viral investigations showed previous infection (CMV, rubella, measles, parvovirus B19), immunization after vaccination (hepatitis B virus), or absence of previous infection (hepatitis C virus, human immunodeficiency virus). We suggest that EBV infection may participate in some cases, as do the other herpesviruses HHV-6 or CMV, in the development of drug-induced hypersensitivity syndrome.

Eculizumab for drug-induced de novo posttransplantation thrombotic microangiopathy: A case report.

PubMed

Safa, Kassem; Logan, Merranda S; Batal, Ibrahim; Gabardi, Steven; Rennke, Helmut G; Abdi, Reza

2015-02-01

De novo thrombotic microangiopathy (TMA) following renal transplantation is a severe complication associated with high rates of allograft failure. Several immunosuppressive agents are associated with TMA. Conventional approaches to managing this entity, such as withdrawal of the offending agent and/or plasmapheresis, often offer limited help, with high rates of treatment failure and graft loss. We herein report a case of drug induced de novo TMA successfully treated using the C5a inhibitor eculizumab in a renal transplant patient. This report highlights a potentially important role for eculizumab in settings where drug-induced de novo TMA is refractory to conventional therapies.

[Prospective study of drug-induced interstitial nephritis in eleven French nephrology units].

PubMed

Leven, Cyril; Hudier, Laurent; Picard, Sylvie; Longuet, Hélène; Lorcy, Nolwenn; Cam, Gérard; Boukerroucha, Zakaria; Dolley-Hitze, Thibault; Le Cacheux, Philippe; Halimi, Jean-Michel; Cornec Le Gall, Emilie; Hanrotel-Saliou, Catherine; Arreule, Audrey; Massad, Michel; Duveau, Agnès; Couvrat-Desvergnes, Grégoire; Renaudineau, Eric

2014-11-01

Certain medications have been associated with drug-induced acute interstitial nephritis (AIN), but few prospective studies have been published. This prospective observational study aims to record and assess incidents of drug-induced AIN observed over a period of one year in nephrology units in France. The goal is to determine which medications are involved in AIN and to expound the clinical and biological presentation, management, and evolution of AIN. Between April 2012 and April 2013, drug-associated cases of AIN were prospectively recorded in 24 patients registered in 11 nephrology units that belong to the Société de Néphrologie de l'Ouest (SNO). Data sheets, including suspected and concomitant drug(s), kidney function assessment, biological disturbances, clinical signs, histological data, management, and evolution, were collected by the Rennes Regional Pharmacovigilance Center and recorded in the French pharmacovigilance database. In order, the most frequently involved medications in the AIN cases were: vitamin K antagonists (33.3% of the cases, almost exclusively fluindione), antibiotics (20.8% of cases) non-steroidal anti-inflammatory drugs (20.8% of cases), and proton pump inhibitors (16.7% of cases). The mean delay of onset to AIN was 8.3 weeks. At the time of diagnosis, mean serum creatinine was 366 μM, higher for vitamin K antagonists (VKAs), except in the case of warfarin. During the course of an AIN event, 70% of patients had complete blood count and/or urine analysis abnormalities, 55% had clinical signs of systemic hypersensitivity, and 13% of patients had hepatic disorders. Renal biopsies were performed in 54% of patients; however, only 37% of patients requiring therapeutic anticoagulation underwent a biopsy. Suspected drugs were discontinued in all patients and the majority was treated with oral corticosteroids. Renal function often continued to be impaired after an AIN event. At baseline, 25% of patients had chronic kidney disease (CKD); after

Disease modeling and phenotypic drug screening for diabetic cardiomyopathy using human induced pluripotent stem cells.