Ekincioğlu, Aygin Bayraktar; Demirkan, Kutay
A drug’s plasma level, pharmacological effects or side effects, elimination, physicochemical properties or stability could be changed by interactions of drug-drug or drug-nutrition products in patients who receive enteral or parenteral nutritional support. As a result, patients might experience ineffective outcomes or unexpected effects of therapy (such as drug toxicity, embolism). Stability or incompatibility problems between parenteral nutrition admixtures and drugs might lead to alterations in expected therapeutic responses from drug and/or parenteral nutrition, occlusion in venous catheter or symptoms or mortality due to infusion of composed particles. Compatibilities between parenteral nutrition and drugs are not always guaranteed in clinical practice. Although the list of compatibility or incompatibilities of drugs are published for the use of clinicians in their practices, factors such as composition of parenteral nutrition admixture, drug concentration, contact time in catheter, temperature of the environment and exposure to light could change the status of compatibilities between drugs and nutrition admixtures. There could be substantial clinical changes occurring in the patient’s nutritional status and pharmacological effects of drugs due to interactions between enteral nutrition and drugs. Drug toxicity and ineffective nutritional support might occur as a result of those predictable interactions. Although administration of drugs via feeding tube is a complex and problematic route for drug usage, it is possible to minimise the risk of tube occlusion, decreased effects of drug and drug toxicity by using an appropriate technique. Therefore, it is important to consider pharmacological dosage forms of drugs while administering drugs via a feeding tube. In conclusion, since the pharmacists are well-experienced and more knowledgeable professionals in drugs and drug usage compared to other healthcare providers, it is suggested that provision of information
Kennedy, William Klugh; Jann, Michael W; Kutscher, Eric C
Atypical antipsychotics [also known as second-generation antipsychotics (SGAs)] have become a mainstay therapeutic treatment intervention for patients with schizophrenia, bipolar disorders and other psychotic conditions. These agents are commonly used with other medications--most notably, antidepressants and antiepileptic drugs. Drug interactions can take place by various pharmacokinetic, pharmacodynamic and pharmaceutical mechanisms. The pharmacokinetic profile of each SGA, especially with phase I and phase II metabolism, can allow for potentially significant drug interactions. Pharmacodynamic interactions arise when agents have comparable receptor site activity, which can lead to additive or competitive effects without alterations in measured plasma drug concentrations. Additionally, the role of drug transporters in drug interactions continues to evolve and may effect both pharmacokinetic and pharmacodynamic interactions. Pharmaceutical interactions occur when physical incompatibilities take place between agents prior to drug absorption. Approximate therapeutic plasma concentration ranges have been suggested for a number of SGAs. Drug interactions that markedly increase or decrease the concentrations of these agents beyond their ranges can lead to adverse events or diminished clinical efficacy. Most clinically significant drug interactions with SGAs occur via the cytochrome P450 (CYP) system. Many but not all drug interactions with SGAs are identified during drug discovery and pre-clinical development by employing a series of standardized in vitro and in vivo studies with known CYP inducers and inhibitors. Later therapeutic drug monitoring programmes, clinical studies and case reports offer methods to identify additional clinically significant drug interactions. Some commonly co-administered drugs with a significant potential for drug-drug interactions with selected SGAs include some SSRIs. Antiepileptic mood stabilizers such as carbamazepine and valproate, as
Caraci, Filippo; Sultana, Janet; Drago, Filippo; Spina, Edoardo
The aging world population had led to an increase in the prevalence of Alzheimer's disease (AD). The drugs used to slow down the onset of AD, galantamine, donepezil, rivastigmine and memantine, are generally well-tolerated. However, drug interactions between these drugs and other drugs are an important aspect of patient safety that should be borne in mind, particularly given the high burden of polypharmacy in the elderly. The aim of this review is to provide an updated review of clinically significant drug-drug interactions concerning drugs approved for AD. PubMed was searched for relevant keywords. No time limit was imposed but only articles in English published in peer-reviewed journals were selected. Relevant literature was also identified from the references of identified articles. Further information was obtained from drug summary of product characteristics. The major pharmacokinetic interactions identified concerned fluoxetine, paroxetine and ketoconazole when used with galantamine or donepezil. On the other hand, the major potential pharmacodynamic interactions concerned anti-dementia drugs and general anesthesia agents, anti-cholinergic drugs, conventional antipsychotics and bradycardia-inducing drugs. In clinical practice memantine shows a lower potential for pharmacodynamic drug-drug interactions (DDIs) compared to other drug classes. In conclusion, the concomitant use of anti-dementia drugs with other drugs can have variable clinical effects, making appropriate prescribing of these drugs very challenging. A simple and coherent way of presenting evidence on complex drug interaction information from heterogenous sources to clinicians is needed in order for the voluminous data available to have an impact on clinical practice.
Spina, Edoardo; Trifirò, Gianluca; Caraci, Filippo
After the introduction of selective serotonin reuptake inhibitors (SSRIs), other newer antidepressants with different mechanisms of action have been introduced in clinical practice. Because antidepressants are commonly prescribed in combination with other medications used to treat co-morbid psychiatric or somatic disorders, they are likely to be involved in clinically significant drug interactions. This review examines the drug interaction profiles of the following newer antidepressants: escitalopram, venlafaxine, desvenlafaxine, duloxetine, milnacipran, mirtazapine, reboxetine, bupropion, agomelatine and vilazodone. In general, by virtue of a more selective mechanism of action and receptor profile, newer antidepressants carry a relatively low risk for pharmacodynamic drug interactions, at least as compared with first-generation antidepressants, i.e. monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants (TCAs). On the other hand, they are susceptible to pharmacokinetic drug interactions. All new antidepressants are extensively metabolized in the liver by cytochrome P450 (CYP) isoenzymes, and therefore may be the target of metabolically based drug interactions. Concomitant administration of inhibitors or inducers of the CYP isoenzymes involved in the biotransformation of specific antidepressants may cause changes in their plasma concentrations. However, due to their relatively wide margin of safety, the consequences of such kinetic modifications are usually not clinically relevant. Conversely, some newer antidepressants may cause pharmacokinetic interactions through their ability to inhibit specific CYPs. With regard to this, duloxetine and bupropion are moderate inhibitors of CYP2D6. Therefore, potentially harmful drug interactions may occur when they are coadministered with substrates of these isoforms, especially compounds with a narrow therapeutic index. The other new antidepressants are only weak inhibitors or are not inhibitors of CYP isoforms at
Combining analgesic and psychotropic drugs can lead to pharmacodynamic and pharmacokinetic drug interactions. Under treatment with several serotonergic substances serotonin syndrome can occur, e.g., with certain opioids and antidepressant drugs. Serotonin reuptake inhibitors also affect the serotonin level in platelets, this can raise the risk for gastrointestinal bleeding especially in combination with non-steroidal antirheumatic drugs. Anticholinergic effects and sedation are common side effects of psychotropic but also analgesic drugs with possible additive results. A wide range of interactions between analgesics and psychotropics can occure during metabolism, especially via the cytochrome-P-system. The clinical relevance of warnings on drug interactions from data banks has always to be judged for the individual patient.
Vadlapatla, Ramya Krishna; Patel, Mitesh; Paturi, Durga K; Pal, Dhananjay; Mitra, Ashim K
Introduction Complete delineation of the HIV-1 life cycle has resulted in the development of several antiretroviral drugs. Twenty-five therapeutic agents belonging to five different classes are currently available for the treatment of HIV-1 infections. Advent of triple combination antiretroviral therapy has significantly lowered the mortality rate in HIV patients. However, fungal infections still represent major opportunistic diseases in immunocompromised patients worldwide. Areas covered Antiretroviral drugs that target enzymes and/or proteins indispensable for viral replication are discussed in this article. Fungal infections, causative organisms, epidemiology and preferred treatment modalities are also outlined. Finally, observed/predicted drug-drug interactions between antiretrovirals and antifungals are summarized along with clinical recommendations. Expert opinion Concomitant use of amphotericin B and tenofovir must be closely monitored for renal functioning. Due to relatively weak interactive potential with the CYP450 system, fluconazole is the preferred antifungal drug. High itraconazole doses (> 200 mg/day) are not advised in patients receiving booster protease inhibitor (PI) regimen. Posaconazole is contraindicated in combination with either efavirenz or fosamprenavir. Moreover, voriconazole is contraindicated with high-dose ritonavir-boosted PI. Echino-candins may aid in overcoming the limitations of existing antifungal therapy. An increasing number of documented or predicted drug-drug interactions and therapeutic drug monitoring may aid in the management of HIV-associated opportunistic fungal infections. PMID:24521092
Michalets, E L; Williams, C R
Cisapride, a prokinetic agent, has been used for the treatment of a number of gastrointestinal disorders, particularly gastro-oesophageal reflux disease in adults and children. Since 1993, 341 cases of ventricular arrhythmias, including 80 deaths, have been reported to the US Food and Drug Administration. Marketing of the drug has now been discontinued in the US; however, it is still available under a limited-access protocol. Knowledge of the risk factors for cisapride-associated arrhythmias will be essential for its continued use in those patients who meet the eligibility criteria. This review summarises the published literature on the pharmacokinetic and pharmacodynamic interactions of cisapride with concomitantly administered drugs, providing clinicians with practical recommendations for avoiding these potentially fatal events. Pharmacokinetic interactions with cisapride involve inhibition of cytochrome P450 (CYP) 3A4, the primary mode of elimination of cisapride, thereby increasing plasma concentrations of the drug. The macrolide antibacterials clarithromycin, erythromycin and troleandomycin are inhibitors of CYP3A4 and should not be used in conjunction with cisapride. Azithromycin is an alternative. Similarly, azole antifungal agents such as fluconazole, itraconazole and ketoconazole are CYP3A4 inhibitors and their concomitant use with cisapride should be avoided. Of the antidepressants nefazodone and fluvoxamine should be avoided with cisapride. Data with fluoxetine is controversial, we favour the avoidance of its use. Citalopram, paroxetine and sertraline are alternatives. The HIV protease inhibitors amprenavir, indinavir, nelfinavir, ritonavir and saquinavir inhibit CYP3A4. Clinical experience with cisapride is lacking but avoidance with all protease inhibitors is recommended, although saquinavir is thought to have clinically insignificant effects on CYP3A4. Delavirdine is also a CYP3A4 inhibitor and should be avoided with cisapride. We also recommend
Wang, Zhengping; Yang, Jinfu; Kirk, Christopher; Fang, Ying; Alsina, Melissa; Badros, Ashraf; Papadopoulos, Kyriakos; Wong, Alvin; Woo, Tina; Bomba, Darrin; Li, Jin; Infante, Jeffrey R
Carfilzomib, an irreversible proteasome inhibitor, has a favorable safety profile and significant antitumor activity in patients with relapsed and refractory multiple myeloma (MM). Here we summarize the clinical pharmacokinetics (PK), metabolism, and drug-drug interaction (DDI) profile of carfilzomib. The PK of carfilzomib, infused over 2-10 minutes, was evaluated in patients with solid tumors or MM. Metabolites of carfilzomib were characterized in patient plasma and urine samples. In vitro drug metabolism and DDI studies were conducted in human liver microsomes and hepatocytes. A clinical DDI study was conducted in patients with solid tumors to evaluate the effect of carfilzomib on CYP3A activity. Plasma concentrations of carfilzomib declined rapidly and in a biphasic manner after intravenous administration. The systemic half-life was short and the systemic clearance rate was higher than hepatic blood flow. Carfilzomib was cleared largely extrahepatically via peptidase cleavage and epoxide hydrolysis. Cytochrome P450-mediated metabolism played a minor role, suggesting that coadministration of P450 inhibitors or inducers is unlikely to change its PK profile. Carfilzomib showed direct and time-dependent inhibition of CYP3A in human liver microsome preparations and exposure to carfilzomib resulted in reductions in CYP3A and 1A2 gene expression in cultured human hepatocytes. However, administration of carfilzomib did not affect the PK of midazolam in patients with solid tumors, and there were no safety signals indicative of potential drug interactions. We conclude that the rapid systemic clearance and short half-life of carfilzomib limit clinically significant DDI.
Rahal, Anu; Ahmad, A H; Kumar, Amit; Mahima; Verma, Amit Kumar; Chakraborty, Sandip; Dhama, Kuldeep
Every time a drug is administered to the animal to treat an ailment, no matter whether it is acute or chronic manifestation, it usually goes together with some other prescription medicine, OTC (Over the counter) formulation, herbs or even food. All the xenobiotics such as drugs, toxins and food components as well as the endogenous compound that are formed in the animal body as a routine phenomenon exert a stimulatory or inhibitory effect on the different physiological and biochemical processes going in the body. These effects may alter the normal metabolism and/or drug transport or its efficacy drastically and thus expose the man and animals to the risk of a potentially dangerous interaction. The present review discusses these potential reactions and their mechanisms that help in navigating the hazardous combinations of drugs with other medicines, food, herbs, vitamins and minerals with confidence.
De Smet, Peter A G M
The concomitant use of conventional and herbal medicines can lead to clinically relevant herb–drug interactions. Clinical risk management offers a systematic approach to minimize the untoward consequences of these interactions by paying attention to: (i) risk identification and assessment; (ii) development and execution of risk reduction strategies; and (iii) evaluation of risk reduction strategies. This paper reviews which steps should be explored or taken in these domains to improve the clinical risk management of adverse herb–drug interactions. PMID:17116126
Carrillo Norte, Juan Antonio
In a drug interaction, the effects of one drug can be increased or decreased or a quite new effect produced by the previous, concurrent or subsequent administration of another substance, including prescription and nonprescription drugs, food, tobacco or alcohol. The effect of the interaction can be desirable, inconsequential, or adverse. The increasing number of drugs available and the increasing use of multidrug therapeutic regimens enhance the potential for drug interactions. However, in clinical practice, most interactions are not significant or rarely of significance. It is when the interaction leads to adverse consequences that it comes to the attention of the patient and physician. Interactions may occur by pharmacokinetic or pharmacodynamics mechanisms. Pharmacokinetic interactions represent the modification of one substance (the interacting substance) on the ADME processes of absorption, distribution, metabolism or excretion of a drug (the index drug). Subsequently, it may lead to changes in the concentration of the index drug at the receptor sites. Drug interactions with a pharmacodynamic basis involve actions on the same receptor or physiological systems through either synergism or antagonism. Many drug interactions can be predicted if the pharmacodynamics effects, pharmacokinetic properties and mechanisms of action of the interacting agents are known. The most obvious interactions are those producing altered pharmacokinetic of drugs with a low therapeutic index (oral anticoagulants, antidiabetic drugs, digoxin, benzodiazepines and immunosuppressant and cytotoxic drugs).
McLeod, Howard L
Although anticancer agents are one of the most toxic classes of medication prescribed today, there is relatively little information available about clinically relevant drug–drug interactions. Pharmacokinetic drug interactions have been described, including alterations in absorption, catabolism, and excretion. For example, an increased bioavailability of 6-mercaptopurine has been observed when combined with either allopurinol or methotrexate, leading to increased toxicity in some patients. Induction of etoposide or teniposide clearance by anticonvulsants has also been described, resulting in a lower systemic exposure and risk for lower anticancer activity. Alterations in elimination of methotrexate has been observed with probenecid, presumably through competition for renal secretion. There are also several examples of pharmacodynamic interactions. The combination of 5-fluorouracil plus folinic acid results in more efficient inhibition of thymidylate synthase, a finding which is now utilized routinely in the treatment of colorectal cancer. Improvements in the in vitro and early clinical testing now allow a relatively high degree of prediction of potential clinical drug interactions, prior to observations of untoward drug effects. In conclusion, drug interactions among commonly used anticancer agents have been identified. Their clinical significance can have more impact than many other classes of medications due to the narrow therapeutic index of antineoplastic agents and the potential for lethal side-effects. It is only through prospective, preclinical and early clinical evaluation that the presence of clinically significant drug interactions can be identified and the information used to provide better therapy for this significant health problem. PMID:9663808
Barranco, Vincent P
Although there are thousands of drug interactions (DIs) listed in computers and manuals, only about 10% are clinically significant. Equally disturbing is these systems fail to detect up to one third of all dangerous DIs. This update on clinically significant DIs is current through September 2005 and discusses systemic drugs important to dermatologists. In addition, 4 aspects of DIs are discussed that are helpful in replacing rote memory with a step-by-step, logical approach based on scientific evidence.
For healthcare professionals, the volume of literature available on herb-drug interactions often makes it difficult to separate experimental/potential interactions from those deemed clinically relevant. There is a need for concise and conclusive information to guide pharmacotherapy in HIV/AIDS. In t...
May, Marcus; Schindler, Christoph
Patients with type 2 diabetes mellitus often require multifactorial pharmacological treatment due to different comorbidities. An increasing number of concomitantly taken medications elevate the risk of the patient experiencing adverse drug effects or drug interactions. Drug interactions can be divided into pharmacokinetic and pharmacodynamic interactions affecting cytochrome (CYP) enzymes, absorption properties, transporter activities and receptor affinities. Furthermore, nutrition, herbal supplements, patient’s age and gender are of clinical importance. Relevant drug interactions are predominantly related to sulfonylureas, thiazolidinediones and glinides. Although metformin has a very low interaction potential, caution is advised when drugs that impair renal function are used concomitantly. With the exception of saxagliptin, dipeptidyl peptidase-4 (DPP-4) inhibitors also show a low interaction potential, but all drugs affecting the drug transporter P-glycoprotein should be used with caution. Incretin mimetics and sodium–glucose cotransporter-2 (SGLT-2) inhibitors comprise a very low interaction potential and are therefore recommended as an ideal combination partner from the clinical–pharmacologic point of view. PMID:27092232
Fasinu, Pius S; Gurley, Bill J; Walker, Larry A
For healthcare professionals, the volume of literature available on herb-drug interactions often makes it difficult to separate experimental/potential interactions from those deemed clinically relevant. There is a need for concise and conclusive information to guide pharmacotherapy in HIV/AIDS. In this review, the bases for potential interaction of medicinal herbs with specific antiretroviral drugs are presented, and several botanicals are discussed for which clinically relevant interactions in humans are established. Such studies have provided, in most cases, sufficient ground to warrant the avoidance of concurrent administration of antiretroviral (ARVs) drugs with St John's wort (Hypericum perforatum), black pepper (Piper species) and grapefruit juice. Other botanicals that require caution in the use with antiretrovirals include African potato (Hypoxis hemerocallidea), ginkgo (Ginkgo biloba), ginseng (Panax species), garlic (Allium sativum), goldenseal (Hydrastis canadensis) and kava kava (Piper methysticum). The knowledge of clinically significant herb-drug interaction will be important in order to avoid herb-induced risk of sub-therapeutic exposure to ARVs (which can lead to viral resistance) or the precipitation of toxicity (which may lead to poor compliance and/or discontinuation of antiretroviral therapy).
This article introduces fundamental concepts to guide the analysis and interpretation of drug-target interaction networks. An overview of the generation and integration of interaction networks is followed by key strategies for extracting biologically meaningful information. The article highlights how this information can enable novel translational and clinically motivated applications. Important advances for the discovery of new treatments and for the detection of adverse drug effects are discussed. Examples of applications and findings originating from cardiovascular research are presented. The review ends with a discussion of crucial challenges and opportunities.
Zhang, Rui; Cairelli, Michael J.; Fiszman, Marcelo; Rosemblat, Graciela; Kilicoglu, Halil; Rindflesch, Thomas C.; Pakhomov, Serguei V.; Melton, Genevieve B.
In this study we report on potential drug-drug interactions between drugs occurring in patient clinical data. Results are based on relationships in SemMedDB, a database of structured knowledge extracted from all MEDLINE citations (titles and abstracts) using SemRep. The core of our methodology is to construct two potential drug-drug interaction schemas, based on relationships extracted from SemMedDB. In the first schema, Drug1 and Drug2 interact through Drug1’s effect on some gene, which in turn affects Drug2. In the second, Drug1 affects Gene1, while Drug2 affects Gene2. Gene1 and Gene2, together, then have an effect on some biological function. After checking each drug pair from the medication lists of each of 22 patients, we found 19 known and 62 unknown drug-drug interactions using both schemas. For example, our results suggest that the interaction of Lisinopril, an ACE inhibitor commonly prescribed for hypertension, and the antidepressant sertraline can potentially increase the likelihood and possibly the severity of psoriasis. We also assessed the relationships extracted by SemRep from a linguistic perspective and found that the precision of SemRep was 0.58 for 300 randomly selected sentences from MEDLINE. Our study demonstrates that the use of structured knowledge in the form of relationships from the biomedical literature can support the discovery of potential drug-drug interactions occurring in patient clinical data. Moreover, SemMedDB provides a good knowledge resource for expanding the range of drugs, genes, and biological functions considered as elements in various drug-drug interaction pathways. PMID:24448204
van Leeuwen, Roelof W F; van Gelder, Teun; Mathijssen, Ron H J; Jansman, Frank G A
In the past decade, many tyrosine-kinase inhibitors have been introduced in oncology and haemato-oncology. Because this new class of drugs is extensively used, serious drug-drug interactions are an increasing risk. In this Review, we give a comprehensive overview of known or suspected drug-drug interactions between tyrosine-kinase inhibitors and other drugs. We discuss all haemato-oncological and oncological tyrosine-kinase inhibitors that had been approved by Aug 1, 2013, by the US Food and Drug Administration or the European Medicines Agency. Various clinically relevant drug interactions with tyrosine-kinase inhibitors have been identified. Most interactions concern altered bioavailability due to altered stomach pH, metabolism by cytochrome P450 isoenzymes, and prolongation of the QTc interval. To guarantee the safe use of tyrosine-kinase inhibitors, a drugs review for each patient is needed. This Review provides specific recommendations to guide haemato-oncologists, oncologists, and clinical pharmacists, through the process of managing drug-drug interactions during treatment with tyrosine-kinase inhibitors in daily clinical practice.
Bolt, H M
Metabolism of contraceptive compounds may be influenced by various drugs. Of clinical importance is induction by barbiturates, by diphenylhydantoin, and especially by rifampicin, of enzymes that are responsible for degradation of estrogens. The major target is the hepatic microsomal estrogen-2-hydroxylase (cytochrome P450 3A4). Another type of interaction of drugs with disposition and effectiveness of estrogens is impairment of their enterohepatic circulation. This may be due to absorption of biliary estrogen conjugates (e.g., by cholestyramine) or to insufficient cleavage of the conjugate by intestinal bacteria, the latter being observed after administration of antibiotics (e.g., ampicillin, neomycin). PMID:7698081
Ogawa, Ryuichi; Echizen, Hirotoshi
One may consider that drug-drug interactions (DDIs) associated with antacids is an obsolete topic because they are prescribed less frequently by medical professionals due to the advent of drugs that more effectively suppress gastric acidity (i.e. histamine H(2)-receptor antagonists [H2RAs] and proton pump inhibitors [PPIs]). Nevertheless, the use of antacids by ambulant patients may be ever increasing, because they are freely available as over-the-counter (OTC) drugs. Antacids consisting of weak basic substances coupled with polyvalent cations may alter the rate and/or the extent of absorption of concomitantly administered drugs via different mechanisms. Polyvalent cations in antacid formulations may form insoluble chelate complexes with drugs and substantially reduce their bioavailability. Clinical studies demonstrated that two classes of antibacterials (tetracyclines and fluoroquinolones) are susceptible to clinically relevant DDIs with antacids through this mechanism. Countermeasures against this type of DDI include spacing out the dosing interval - taking antacid either 4 hours before or 2 hours after administration of these antibacterials. Bisphosphonates may be susceptible to DDIs with antacids by the same mechanism, as described in the prescription information of most bisphosphonates, but no quantitative data about the DDIs are available. For drugs with solubility critically dependent on pH, neutralization of gastric fluid by antacids may alter the dissolution of these drugs and the rate and/or extent of their absorption. However, the magnitude of DDIs elicited by antacids through this mechanism is less than that produced by H2RAs or PPIs; therefore, the clinical relevance of such DDIs is often obscure. Magnesium ions contained in some antacid formulas may increase gastric emptying, thereby accelerating the rate of absorption of some drugs. However, the clinical relevance of this is unclear in most cases because the difference in plasma drug concentration
Wells, Charles; Petersen, Carolyn; Paccaly, Anne; Shoaf, Susan E.; Patil, Shiva; Geiter, Lawrence
Delamanid is a medicinal product approved for treatment of multidrug-resistant tuberculosis. Three studies were conducted to evaluate the potential drug-drug interactions between delamanid and antiretroviral drugs, including ritonavir, a strong inhibitor of CYP3A4, and selected anti-TB drugs, including rifampin, a strong inducer of cytochrome P450 (CYP) isozymes. Multiple-dose studies were conducted in parallel groups of healthy subjects. Plasma samples were analyzed for delamanid, delamanid metabolite, and coadministered drug concentrations, and pharmacokinetic (PK) parameters were determined. The magnitude of the interaction was assessed by the ratio of the geometric means and 90% confidence intervals. Coadministration of delamanid with tenofovir or efavirenz did not affect the PK characteristics of delamanid. Coadministration of Kaletra (lopinavir/ritonavir) with delamanid resulted in an approximately 25% higher delamanid area under the concentration-time curve from time 0 to the end of the dosing interval (AUCτ). Tenofovir, efavirenz, lopinavir, and ritonavir exposure were not affected by delamanid. Coadministration of delamanid with the TB drugs (ethambutol plus Rifater [rifampin, pyrazinamide, and isoniazid]) resulted in lower delamanid exposures (47 and 42% for the AUCτ and Cmax [maximum concentration of a drug in plasma] values, respectively), as well as decreased exposure of three primary metabolites (approximately 30 to 50% lower AUCτ values). Delamanid did not affect rifampin, pyrazinamide, and isoniazid exposure; the ethambutol AUCτ and Cmax values were about 25% higher with delamanid coadministration. The lack of clinically significant drug-drug interactions between delamanid and selected antiretroviral agents (including the strong CYP inhibitor ritonavir) and a combination of anti-TB drugs was demonstrated. Although there was a decrease in the delamanid concentrations when coadministered with ethambutol plus Rifater, this is likely related to
Russo, Emilio; Scicchitano, Francesca; Whalley, Benjamin J; Mazzitello, Carmela; Ciriaco, Miriam; Esposito, Stefania; Patanè, Marinella; Upton, Roy; Pugliese, Michela; Chimirri, Serafina; Mammì, Maria; Palleria, Caterina; De Sarro, Giovambattista
Hypericum perforatum (HP) belongs to the Hypericaceae family and is one of the oldest used and most extensively investigated medicinal herbs. The medicinal form comprises the leaves and flowering tops of which the primary ingredients of interest are naphthodianthrones, xanthones, flavonoids, phloroglucinols (e.g. hyperforin), and hypericin. Although several constituents elicit pharmacological effects that are consistent with HP's antidepressant activity, no single mechanism of action underlying these effects has thus far been found. Various clinical trials have shown that HP has a comparable antidepressant efficacy as some currently used antidepressant drugs in the treatment of mild/moderate depression. Interestingly, low-hyperforin-content preparations are effective in the treatment of depression. Moreover, HP is also used to treat certain forms of anxiety. However, HP can induce various cytochrome P450s isozymes and/or P-glycoprotein, of which many drugs are substrates and which are the main origin of HP-drug interactions. Here, we analyse the existing evidence describing the clinical consequence of HP-drug interactions. Although some of the reported interactions are based on findings from in vitro studies, the clinical importance of which remain to be demonstrated, others are based on case reports where causality can, in some cases, be determined to reveal clinically significant interactions that suggest caution, consideration, and disclosure of potential interactions prior to informed use of HP.
Zhang, Ping; Wang, Fei; Hu, Jianying; Sorrentino, Robert
Drug-drug interaction (DDI) is an important topic for public health, and thus attracts attention from both academia and industry. Here we hypothesize that clinical side effects (SEs) provide a human phenotypic profile and can be translated into the development of computational models for predicting adverse DDIs. We propose an integrative label propagation framework to predict DDIs by integrating SEs extracted from package inserts of prescription drugs, SEs extracted from FDA Adverse Event Reporting System, and chemical structures from PubChem. Experimental results based on hold-out validation demonstrated the effectiveness of the proposed algorithm. In addition, the new algorithm also ranked drug information sources based on their contributions to the prediction, thus not only confirming that SEs are important features for DDI prediction but also paving the way for building more reliable DDI prediction models by prioritizing multiple data sources. By applying the proposed algorithm to 1,626 small-molecule drugs which have one or more SE profiles, we obtained 145,068 predicted DDIs. The predicted DDIs will help clinicians to avoid hazardous drug interactions in their prescriptions and will aid pharmaceutical companies to design large-scale clinical trial by assessing potentially hazardous drug combinations. All data sets and predicted DDIs are available at http://astro.temple.edu/~tua87106/ddi.html.
Palleria, Caterina; Di Paolo, Antonello; Giofrè, Chiara; Caglioti, Chiara; Leuzzi, Giacomo; Siniscalchi, Antonio; De Sarro, Giovambattista; Gallelli, Luca
Drug-drug interactions (DDIs) are one of the commonest causes of medication error in developed countries, particularly in the elderly due to poly-therapy, with a prevalence of 20-40%. In particular, poly-therapy increases the complexity of therapeutic management and thereby the risk of clinically important DDIs, which can both induce the development of adverse drug reactions or reduce the clinical efficacy. DDIs can be classify into two main groups: pharmacokinetic and pharmacodynamic. In this review, using Medline, PubMed, Embase, Cochrane library and Reference lists we searched articles published until June 30 2012, and we described the mechanism of pharmacokinetic DDIs focusing the interest on their clinical implications. PMID:24516494
Podszun, Maren; Frank, Jan
Vitamin E (α-, β-, γ- and δ-tocopherol and -tocotrienol) is an essential factor in the human diet and regularly taken as a dietary supplement by many people, who act under the assumption that it may be good for their health and can do no harm. With the publication of meta-analyses reporting increased mortality in persons taking vitamin E supplements, the safety of the micronutrient was questioned and interactions with prescription drugs were suggested as one potentially underlying mechanism. Here, we review the evidence in the scientific literature for adverse vitamin E-drug interactions and discuss the potential of each of the eight vitamin E congeners to alter the activity of drugs. In summary, there is no evidence from animal models or randomised controlled human trials to suggest that the intake of tocopherols and tocotrienols at nutritionally relevant doses may cause adverse nutrient-drug interactions. Consumption of high-dose vitamin E supplements ( ≥ 300 mg/d), however, may lead to interactions with the drugs aspirin, warfarin, tamoxifen and cyclosporine A that may alter their activities. For the majority of drugs, however, interactions with vitamin E, even at high doses, have not been observed and are thus unlikely.
Lee, Caroline A; O'Connor, Meeghan A; Ritchie, Tasha K; Galetin, Aleksandra; Cook, Jack A; Ragueneau-Majlessi, Isabelle; Ellens, Harma; Feng, Bo; Taub, Mitchell E; Paine, Mary F; Polli, Joseph W; Ware, Joseph A; Zamek-Gliszczynski, Maciej J
Breast cancer resistance protein (BCRP; ABCG2) limits intestinal absorption of low-permeability substrate drugs and mediates biliary excretion of drugs and metabolites. Based on clinical evidence of BCRP-mediated drug-drug interactions (DDIs) and the c.421C>A functional polymorphism affecting drug efficacy and safety, both the US Food and Drug Administration and European Medicines Agency recommend preclinical evaluation and, when appropriate, clinical assessment of BCRP-mediated DDIs. Although many BCRP substrates and inhibitors have been identified in vitro, clinical translation has been confounded by overlap with other transporters and metabolic enzymes. Regulatory recommendations for BCRP-mediated clinical DDI studies are challenging, as consensus is lacking on the choice of the most robust and specific human BCRP substrates and inhibitors and optimal study design. This review proposes a path forward based on a comprehensive analysis of available data. Oral sulfasalazine (1000 mg, immediate-release tablet) is the best available clinical substrate for intestinal BCRP, oral rosuvastatin (20 mg) for both intestinal and hepatic BCRP, and intravenous rosuvastatin (4 mg) for hepatic BCRP. Oral curcumin (2000 mg) and lapatinib (250 mg) are the best available clinical BCRP inhibitors. To interrogate the worst-case clinical BCRP DDI scenario, study subjects harboring the BCRP c.421C/C reference genotype are recommended. In addition, if sulfasalazine is selected as the substrate, subjects having the rapid acetylator phenotype are recommended. In the case of rosuvastatin, subjects with the organic anion-transporting polypeptide 1B1 c.521T/T genotype are recommended, together with monitoring of rosuvastatin's cholesterol-lowering effect at baseline and DDI phase. A proof-of-concept clinical study is being planned by a collaborative consortium to evaluate the proposed BCRP DDI study design.
Henderson, L; Yue, Q Y; Bergquist, C; Gerden, B; Arlett, P
Aims The aim of this work is to identify the medicines which interact with the herbal remedy St John's wort (SJW), and the mechanisms responsible. Methods A systematic review of all the available evidence, including worldwide published literature and spontaneous case reports provided by healthcare professionals and regulatory authorities within Europe has been undertaken. Results A number of clinically significant interactions have been identified with prescribed medicines including warfarin, phenprocoumon, cyclosporin, HIV protease inhibitors, theophylline, digoxin and oral contraceptives resulting in a decrease in concentration or effect of the medicines. These interactions are probably due to the induction of cytochrome P450 isoenzymes CYP3A4, CYP2C9, CYP1A2 and the transport protein P-glycoprotein by constituent(s) in SJW. The degree of induction is unpredictable due to factors such as the variable quality and quantity of constituent(s) in SJW preparations. In addition, possible pharmacodynamic interactions with selective serotonin re-uptake inhibitors and serotonin (5-HT1d) receptor-agonists such as triptans used to treat migraine were identified. These interactions are associated with an increased risk of adverse reactions. Conclusions In Sweden and the UK the potential risks to patients were judged to be significant and therefore information about the interactions was provided to health care professionals and patients. The product information of the licensed medicines involved has been amended to reflect these newly identified interactions and SJW preparations have been voluntarily labelled with appropriate warnings. PMID:12392581
In vitro and in vivo laboratory data show that pomegranate juice consistently inhibits intestinal CYP2C9 and CYP3A4 enzymes. Pomegranate juice may therefore increase the bioavailability of drugs that are metabolized by these enzymes. However, studies in humans find that pomegranate juice does not increase exposure to either CYP2C9 or CYP3A4 substrates. These contradictory findings suggest that potential drug interactions identified in the laboratory may not necessarily translate into clinically significant drug interactions in humans, and hence that laboratory data are insufficient grounds upon which clinical decisions may be based.
Gharavi, Robert; Hedrich, William; Wang, Hongbing; Hassan, Hazem E
Opioid-related deaths, abuse, and drug interactions are growing epidemic problems that have medical, social, and economic implications. Drug transporters play a major role in the disposition of many drugs, including opioids; hence they can modulate their pharmacokinetics, pharmacodynamics and their associated drug-drug interactions (DDIs). Our understanding of the interaction of transporters with many therapeutic agents is improving; however, investigating such interactions with opioids is progressing relatively slowly despite the alarming number of opioids-mediated DDIs that may be related to transporters. This review presents a comprehensive report of the current literature relating to opioids and their drug transporter interactions. Additionally, it highlights the emergence of transporters that are yet to be fully identified but may play prominent roles in the disposition of opioids, the growing interest in transporter genomics for opioids, and the potential implications of opioid-drug transporter interactions for cancer treatments. A better understanding of drug transporters interactions with opioids will provide greater insight into potential clinical DDIs and could help improve opioids safety and efficacy.
Reis, Adriano Max Moreira; de Carvalho, Rhanna Emanuela Fontenele Lima; de Faria, Leila Marcia Pereira; de Oliveira, Regina Célia; Zago, Karine Santana de Azevedo; Cavelagna, Milena Ferreira; Silva, Adriano Gomes; Neto, Manoel Luis; Cassiani, Silvia Helena de Bortoli
This is a multicenter, cross-sectional retrospective study, which aimed to determine the prevalence of interactions drug-enteral nutrition (EN) in Intensive Care Units (ICU) of seven teaching hospitals in Brazil, and to analyze the clinical significance of them. Information on medications and EN administered with 24 hours and 120 hours of hospitalization were collected. For identification of drug-EN interaction was employed software Drug Reax®. It was investigated 1.124 records. Of these, 320 patients, with 24 hours of hospitalization, were on EN, and 20 (6.3%) had drug-EN interaction. Of the 504 patients with 120 hours of hospitalization, 39 (7.7%) had drug-EN interaction. The most frequent drug-EN interactions of clinical significance were phenytoin-EN, warfarin-EN and levothyroxine-EN. Drug-EN interactions may interfere with the quality and cost effectiveness of care in ICU, so it is essential that the health team has knowledge about them.
Lee, C A; Kalvass, J C; Galetin, A; Zamek-Gliszczynski, M J
The "P-glycoprotein" IC50 working group reported an 18- to 796-fold interlaboratory range in digoxin transport IC50 (inhibitor concentration achieving 50% of maximal inhibition), raising concerns about the predictability of clinical transporter-based drug-drug interactions (DDIs) from in vitro data. This Commentary describes complexities of digoxin transport, which involve both uptake and efflux processes. We caution against attributing digoxin transport IC50 specifically to P-glycoprotein (P-gp) or extending this composite uptake/efflux IC50 variability to individual transporters. Clinical digoxin interaction studies should be interpreted as evaluation of digoxin safety, not P-gp DDIs.
Schmidt, Lars E; Dalhoff, Kim
Interactions between food and drugs may inadvertently reduce or increase the drug effect. The majority of clinically relevant food-drug interactions are caused by food-induced changes in the bioavailability of the drug. Since the bioavailability and clinical effect of most drugs are correlated, the bioavailability is an important pharmacokinetic effect parameter. However, in order to evaluate the clinical relevance of a food-drug interaction, the impact of food intake on the clinical effect of the drug has to be quantified as well. As a result of quality review in healthcare systems, healthcare providers are increasingly required to develop methods for identifying and preventing adverse food-drug interactions. In this review of original literature, we have tried to provide both pharmacokinetic and clinical effect parameters of clinically relevant food-drug interactions. The most important interactions are those associated with a high risk of treatment failure arising from a significantly reduced bioavailability in the fed state. Such interactions are frequently caused by chelation with components in food (as occurs with alendronic acid, clodronic acid, didanosine, etidronic acid, penicillamine and tetracycline) or dairy products (ciprofloxacin and norfloxacin), or by other direct interactions between the drug and certain food components (avitriptan, indinavir, itraconazole solution, levodopa, melphalan, mercaptopurine and perindopril). In addition, the physiological response to food intake, in particular gastric acid secretion, may reduce the bioavailability of certain drugs (ampicillin, azithromycin capsules, didanosine, erythromycin stearate or enteric coated, and isoniazid). For other drugs, concomitant food intake may result in an increase in drug bioavailability either because of a food-induced increase in drug solubility (albendazole, atovaquone, griseofulvin, isotretinoin, lovastatin, mefloquine, saquinavir and tacrolimus) or because of the secretion of
Wagner, Alex H; Coffman, Adam C; Ainscough, Benjamin J; Spies, Nicholas C; Skidmore, Zachary L; Campbell, Katie M; Krysiak, Kilannin; Pan, Deng; McMichael, Joshua F; Eldred, James M; Walker, Jason R; Wilson, Richard K; Mardis, Elaine R; Griffith, Malachi; Griffith, Obi L
The Drug-Gene Interaction Database (DGIdb, www.dgidb.org) is a web resource that consolidates disparate data sources describing drug-gene interactions and gene druggability. It provides an intuitive graphical user interface and a documented application programming interface (API) for querying these data. DGIdb was assembled through an extensive manual curation effort, reflecting the combined information of twenty-seven sources. For DGIdb 2.0, substantial updates have been made to increase content and improve its usefulness as a resource for mining clinically actionable drug targets. Specifically, nine new sources of drug-gene interactions have been added, including seven resources specifically focused on interactions linked to clinical trials. These additions have more than doubled the overall count of drug-gene interactions. The total number of druggable gene claims has also increased by 30%. Importantly, a majority of the unrestricted, publicly-accessible sources used in DGIdb are now automatically updated on a weekly basis, providing the most current information for these sources. Finally, a new web view and API have been developed to allow searching for interactions by drug identifiers to complement existing gene-based search functionality. With these updates, DGIdb represents a comprehensive and user friendly tool for mining the druggable genome for precision medicine hypothesis generation.
Bushra, Rabia; Aslam, Nousheen; Khan, Arshad Yar
The effect of drug on a person may be different than expected because that drug interacts with another drug the person is taking (drug-drug interaction), food, beverages, dietary supplements the person is consuming (drug-nutrient/food interaction) or another disease the person has (drug-disease interaction). A drug interaction is a situation in which a substance affects the activity of a drug, i.e. the effects are increased or decreased, or they produce a new effect that neither produces on its own. These interactions may occur out of accidental misuse or due to lack of knowledge about the active ingredients involved in the relevant substances. Regarding food-drug interactions physicians and pharmacists recognize that some foods and drugs, when taken simultaneously, can alter the body's ability to utilize a particular food or drug, or cause serious side effects. Clinically significant drug interactions, which pose potential harm to the patient, may result from changes in pharmaceutical, pharmacokinetic, or pharmacodynamic properties. Some may be taken advantage of, to the benefit of patients, but more commonly drug interactions result in adverse drug events. Therefore it is advisable for patients to follow the physician and doctors instructions to obtain maximum benefits with least food-drug interactions. The literature survey was conducted by extracting data from different review and original articles on general or specific drug interactions with food. This review gives information about various interactions between different foods and drugs and will help physicians and pharmacists prescribe drugs cautiously with only suitable food supplement to get maximum benefit for the patient.
Müller, Fabian; Fromm, Martin F
Drug-drug interactions are a serious clinical issue. An important mechanism underlying drug-drug interactions is induction or inhibition of drug transporters that mediate the cellular uptake and efflux of xenobiotics. Especially drug transporters of the small intestine, liver and kidney are major determinants of the pharmacokinetic profile of drugs. Transporter-mediated drug-drug interactions in these three organs can considerably influence the pharmacokinetics and clinical effects of drugs. In this article, we focus on probe drugs lacking significant metabolism to highlight mechanisms of interactions of selected intestinal, hepatic and renal drug transporters (e.g., organic anion transporting polypeptide [OATP] 1A2, OATP2B1, OATP1B1, OATP1B3, P-gp, organic anion transporter [OAT] 1, OAT3, breast cancer resistance protein [BCRP], organic cation transporter [OCT] 2 and multidrug and toxin extrusion protein [MATE] 1). Genotype-dependent drug-drug interactions are also discussed.
Since the late 1980s, grapefruit juice has been known to affect the metabolism of certain drugs. Several serious adverse effects involving drug interactions with grapefruit juice have been published in detail. The components of grapefruit juice vary considerably depending on the variety, maturity and origin of the fruit, local climatic conditions, and the manufacturing process. No single component accounts for all observed interactions. Other grapefruit products are also occasionally implicated, including preserves, lyophylised grapefruit juice, powdered whole grapefruit, grapefruit seed extract, and zest. Clinical reports of drug interactions with grapefruit juice are supported by pharmacokinetic studies, each usually involving about 10 healthy volunteers, in which the probable clinical consequences were extrapolated from the observed plasma concentrations. Grapefruit juice inhibits CYP3A4, the cytochrome P450 isoenzyme most often involved in drug metabolism. This increases plasma concentrations of the drugs concerned, creating a risk of overdose and dose-dependent adverse effects. Grapefruit juice also inhibits several other cytochrome P450 isoenzymes, but they are less frequently implicated in interactions with clinical consequences. Drugs interacting with grapefruit and inducing serious clinical consequences (confirmed or very probable) include: immunosuppressants, some statins, benzodiazepines, most calcium channel blockers, indinavir and carbamazepine. There are large inter-individual differences in enzyme efficiency. Along with the variable composition of grapefruit juice, this makes it difficult to predict the magnitude and clinical consequences of drug interactions with grapefruit juice in a given patient. There is increasing evidence that transporter proteins such as organic anion transporters and P-glycoprotein are involved in interactions between drugs and grapefruit juice. In practice, numerous drugs interact with grapefruit juice. Although only a few
Drug-nutrient interactions are defined as physical, chemical, physiologic, or pathophysiologic relationships between a drug and a nutrient. The causes of most clinically significant drug-nutrient interactions are usually multifactorial. Failure to identify and properly manage drug-nutrient interactions can lead to very serious consequences and have a negative impact on patient outcomes. Nevertheless, with thorough review and assessment of the patient's history and treatment regimens and a carefully executed management strategy, adverse events associated with drug-nutrient interactions can be prevented. Based on the physiologic sequence of events after a drug or a nutrient has entered the body and the mechanism of interactions, drug-nutrient interactions can be categorized into 4 main types. Each type of interaction can be managed using similar strategies. The existing data that guide the clinical management of most drug-nutrient interactions are mostly anecdotal experience, uncontrolled observations, and opinions, whereas the science in understanding the mechanism of drug-nutrient interactions remains limited. The challenge for researchers and clinicians is to increase both basic and higher level clinical research in this field to bridge the gap between the science and practice. The research should aim to establish a better understanding of the function, regulation, and substrate specificity of the nutrient-related enzymes and transport proteins present in the gastrointestinal tract, as well as assess how the incidence and management of drug-nutrient interactions can be affected by sex, ethnicity, environmental factors, and genetic polymorphisms. This knowledge can help us develop a true personalized medicine approach in the prevention and management of drug-nutrient interactions.
McTigue, Michele; Murray, Brion William; Chen, Jeffrey H.; Deng, Ya-Li; Solowiej, James; Kania, Robert S.
We performed analyses of compounds in clinical development which have shown that ligand efficient-molecules with privileged physical properties and low dose are less likely to fail in the various stages of clinical testing, have fewer postapproval withdrawals, and are less likely to receive black box safety warnings. However, detailed side-by-side examination of molecular interactions and properties within single drug classes are lacking. As a class, VEGF receptor tyrosine kinase inhibitors (VEGFR TKIs) have changed the landscape of how cancer is treated, particularly in clear cell renal cell carcinoma, which is molecularly linked to the VEGF signaling axis. Despite the clear role of the molecular target, member molecules of this validated drug class exhibit distinct clinical efficacy and safety profiles in comparable renal cell carcinoma clinical studies. The first head-to-head randomized phase III comparative study between active VEGFR TKIs has confirmed significant differences in clinical performance [Rini BI, et al. (2011) Lancet 378:193–1939]. To elucidate how fundamental drug potency–efficiency is achieved and impacts differentiation within the VEGFR TKI class, we determined potencies, time dependence, selectivities, and X-ray structures of the drug–kinase complexes using a VEGFR2 TK construct inclusive of the important juxtamembrane domain. Collectively, the studies elucidate unique drug–kinase interactions that are dependent on distinct juxtamembrane domain conformations, resulting in significant potency and ligand efficiency differences. Finally, the identified structural trends are consistent with in vitro measurements, which translate well to clinical performance, underscoring a principle that may be broadly applicable to prospective drug design for optimal in vivo performance.
Yu, Jingjing; Ritchie, Tasha K; Zhou, Zhu; Ragueneau-Majlessi, Isabelle
Regulatory approval documents contain valuable information, often not published, to assess the drug-drug interaction (DDI) profile of newly marketed drugs. This analysis aimed to systematically review all drug metabolism, transport, pharmacokinetics, and DDI data available in the new drug applications and biologic license applications approved by the U.S. Food and Drug Administration in 2014, using the University of Washington Drug Interaction Database, and to highlight the significant findings. Among the 30 new drug applications and 11 biologic license applications reviewed, 35 new molecular entities (NMEs) were well characterized with regard to drug metabolism, transport, and/or organ impairment and were fully analyzed in this review. In vitro, a majority of the NMEs were found to be substrates or inhibitors/inducers of at least one drug metabolizing enzyme or transporter. In vivo, when NMEs were considered as victim drugs, 16 NMEs had at least one in vivo DDI study with a clinically significant change in exposure (area under the time-plasma concentration curve or Cmax ratio ≥2 or ≤0.5), with 6 NMEs shown to be sensitive substrates of cytochrome P450 enzymes (area under the time-plasma concentration curve ratio ≥5 when coadministered with potent inhibitors): paritaprevir and naloxegol (CYP3A), eliglustat (CYP2D6), dasabuvir (CYP2C8), and tasimelteon and pirfenidone (CYP1A2). As perpetrators, seven NMEs showed clinically significant inhibition involving both enzymes and transporters, although no clinically significant induction was observed. Physiologically based pharmacokinetic modeling and pharmacogenetics studies were used for six and four NMEs, respectively, to optimize dosing recommendations in special populations and/or multiple impairment situations. In addition, the pharmacokinetic evaluations in patients with hepatic or renal impairment provided useful quantitative information to support drug administration in these fragile populations.
KITAZAWA, FUMIAKI; KADO, YOKO; UEDA, KUMI; KOKUFU, TAKATOSHI; FUCHIDA, SHIN-ICHI; OKANO, AKIRA; HATSUSE, MAYUMI; MURAKAMI, SATOSHI; NAKAYAMA, YUKO; TAKARA, KOHJI; SHIMAZAKI, CHIHIRO
The aim of the present study was to clarify whether gastric antisecretory drugs affect the clinical efficacy and toxicity of orally administered melphalan in patients with multiple myeloma. A total of 10 patients receiving bortezomib plus oral melphalan and prednisolone (VMP) therapy between December 2011 and November 2014 were analyzed retrospectively. The patients were divided into a control group (seven patients) and a concomitant group (three patients, who were also administered with gastric antisecretory drugs). The gastric antisecretory drugs included rabeprazole sodium (two patients) and famotidine (one patient). No significant differences between the groups were observed in either the characteristics of the patients or the VMP regimen. The levels of monoclonal protein (M protein) in the control group tended to decrease (with a VMP cycle-dependency), although they were primarily stable in the concomitant group. During the second and third VMP cycles, the levels of M protein were markedly lower in the control group compared with the concomitant group. All the patients in the control group achieved a partial response, whereas those in the concomitant group exhibited stable disease. Hematological toxicity levels were revealed to be comparable between the two groups, whereas gastrointestinal toxicity was more prevalent in the control group. In conclusion, the results of the present study suggested that the clinical efficacy of melphalan may be reduced by the co-administration of gastric antisecretory drugs. This interaction may result in decreased toxicity and clinical efficacy of melphalan. PMID:26893878
Srinivas, Nuggehally R
Bosentan, an endothelin-1 (ET) receptor antagonist is an important drug for the effective management of patients with pulmonary arterial hypertension. Bosentan has a rather complicated pharmacokinetics in humans involving multiple physiological components that have a profound influence on its drug disposition. Bosentan is mainly metabolized by cytochrome P450 (CYP) 3A4 and 2C9 enzymes with the involvement of multiple transporters that control its hepatic uptake and biliary excretion. The involvement of phase 2 metabolism of bosentan is a key to have an enhanced biliary excretion of the drug-related products. While bosentan exhibits high protein binding restricting the drug from extensive distribution and significant urinary excretion, bosentan induces its own metabolism by an increased expression of CYP3A4 on repeated dosing. Due to the above properties, bosentan has the potential to display drug-drug interaction with the co-administered drugs, either being a perpetrator or a victim. The intent of this review is manifold: a) to summarize the physiological role of CYP enzymes and hepatic-biliary transporters; b) to discuss the mechanism(s) involved in the purported liver injury caused by bosentan; c) to tabulate the numerous clinical drug-drug interaction studies involving the physiological interplay with CYP and/or transporters; d) to provide some perspectives on dosing strategy of bosentan.
Kam, Hye Jin; Kim, Jeong Ah; Cho, InSook; Kim, Yoon; Park, Rae Woong
There exist limitations in both commercial and in-house clinical decision support systems (CDSSs) and issues related to the integration of different knowledge sources and CDSSs. We chose Standard-based Shareable Active Guideline Environment (SAGE) as a new architecture with knowledge integration and a centralized knowledge base which includes authoring/management functions and independent CDSS, and applied it to Drug-Drug Interaction (DDI) CDSS. The aim of this study was to evaluate the feasibility of the newly integrated DDI alerting CDSS into a real world hospital information system involving construction of an integrated CDSS derived from two heterogeneous systems and their knowledge sets. The proposed CDSS was successfully implemented and compensated for the weaknesses of the old CDSS from knowledge integration and management, and its applicability in actual situations was verified. Although the DDI CDSS was constructed as an example case, the new CDS architecture might prove applicable to areas of CDSSs.
Robertson, Sarah M; Luo, Xia; Dubey, Neeraj; Li, Chonghua; Chavan, Ajit B; Gilmartin, Geoffrey S; Higgins, Mark; Mahnke, Lisa
Ivacaftor is approved in the USA for the treatment of cystic fibrosis (CF) in patients with a G551D-CFTR mutation or one of eight other CFTR mutations. A series of in vitro experiments conducted early in the development of ivacaftor indicated ivacaftor and metabolites may have the potential to inhibit cytochrome P450 (CYP) 2C8, CYP2C9, CYP3A, and CYP2D6, as well as P-glycoprotein (P-gp). Based on these results, a series of clinical drug-drug interaction (DDI) studies were conducted to evaluate the effect of ivacaftor on sensitive substrates of CYP2C8 (rosiglitazone), CYP3A (midazolam), CYP2D6 (desipramine), and P-gp (digoxin). In addition, a DDI study was conducted to evaluate the effect of ivacaftor on a combined oral contraceptive, as this is considered an important comedication in CF patients. The results indicate ivacaftor is a weak inhibitor of CYP3A and P-gp, but has no effect on CYP2C8 or CYP2D6. Ivacaftor caused non-clinically significant increases in ethinyl estradiol and norethisterone exposure. Based on these results, caution and appropriate monitoring are recommended when concomitant substrates of CYP2C9, CYP3A and/or P-gp are used during treatment with ivacaftor, particularly drugs with a narrow therapeutic index, such as warfarin.
Fontes-Carvalho, Ricardo; Albuquerque, Aníbal
Recent studies have raised the concern that proton pump inhibitors (PPIs) could potentially interfere with clopidogrel antiplatelet effect. This association is frequent in clinical practice and is recommended by recent consensus guidelines in patients taking dual antiplatelet therapy to prevent gastrointestinal (GI) bleeding. Clopidogrel is a pro-drug which needs to be metabolized into its active metabolite, by cytochrome P450, especially by CYP2C19 isoenzyme. Various PPIs can inhibit CYP2C19, which could possibly decrease clopidogrel bioactivation process and, therefore, its antiplatelet effect. Various platelet function studies have shown that omeprazol can significantly decrease clopidogrel inhibitory effect on platelet P2Y12 receptor, leading to an increase in the number of patients who are "nonresponders" to clopidogrel. These pharmacokinetic studies also shown that this is not probably a class effect of PPIs, because they are metabolized to varying degrees by CYP2C19. The clinical impact of these observations remains uncertain, because various observational studies have shown conflicting results, and remains to demonstrate if PPIs can really increase the risk of cardiovascular events in patients taking clopidogrel. In this review we will discuss the pharmacokinetic basis underlying this drug interaction, the effect of different PPIs on platelet function tests and we will analyze in detail the potential clinical implications of using this association, both on cardiovascular and gastrointestinal events. Until further data is available, some clinical strategies can be recommended: (1) individual gastrointestinal risk assessment, with PPIs administration only to patients on dual anti-platelet therapy with additional GI risk factors; (2) preferential use of PPIs that have shown less interference with clopidogrel efficacy; (3) wide separation of PPI and clopidogrel dosing to minimize the risk of interaction (PPI may be given before breakfast and clopidogrel at
Armstrong, Scott C; Cozza, Kelly L
Pharmacokinetic drug-drug interactions with codeine, dihydrocodeine, hydrocodone, oxycodone, and buprenorphine are reviewed in this column. These compounds have a very similar chemical structure to morphine. Unlike morphine, which is metabolized chiefly through conjugation reactions with uridine diphosphate glucuronosyl transferase (UGT) enzymes, these five drugs are metabolized both through oxidative reactions by the cytochrome P450 (CYP450) enzyme and conjugation by UGT enzymes. There is controversy as to whether codeine, dihydrocodeine, and hydrocodone are actually prodrugs requiring activation by the CYP450 2D6 enzyme or UGT enzymes. Oxycodone and buprenorphine, however, are clearly not prodrugs and are metabolized by the CYP450 2D6 and 3A4 enzymes, respectively. Knowledge of this metabolism assists in the understanding for the potential of drug-drug interactions with these drugs. This understanding is important so that clinicians can choose the proper dosages for analgesia and anticipate potential drug-drug interactions.
Nichols, Alice I.; Preskorn, Sheldon H.
Objective: The avoidance of adverse drug-drug interactions (DDIs) is a high priority in terms of both the US Food and Drug Administration (FDA) and the individual prescriber. With this perspective in mind, this article illustrates the process for assessing the risk of a drug (example here being desvenlafaxine) causing or being the victim of DDIs, in accordance with FDA guidance. Data Sources/Study Selection: DDI studies for the serotonin-norepinephrine reuptake inhibitor desvenlafaxine conducted by the sponsor and published since 2009 are used as examples of the systematic way that the FDA requires drug developers to assess whether their new drug is either capable of causing clinically meaningful DDIs or being the victim of such DDIs. In total, 8 open-label studies tested the effects of steady-state treatment with desvenlafaxine (50–400 mg/d) on the pharmacokinetics of cytochrome (CYP) 2D6 and/or CYP 3A4 substrate drugs, or the effect of CYP 3A4 inhibition on desvenlafaxine pharmacokinetics. The potential for DDIs mediated by the P-glycoprotein (P-gp) transporter was assessed in in vitro studies using Caco-2 monolayers. Data Extraction: Changes in area under the plasma concentration-time curve (AUC; CYP studies) and efflux (P-gp studies) were reviewed for potential DDIs in accordance with FDA criteria. Results: Desvenlafaxine coadministration had minimal effect on CYP 2D6 and/or 3A4 substrates per FDA criteria. Changes in AUC indicated either no interaction (90% confidence intervals for the ratio of AUC geometric least-squares means [GM] within 80%–125%) or weak inhibition (AUC GM ratio 125% to < 200%). Coadministration with ketoconazole resulted in a weak interaction with desvenlafaxine (AUC GM ratio of 143%). Desvenlafaxine was not a substrate (efflux ratio < 2) or inhibitor (50% inhibitory drug concentration values > 250 μM) of P-gp. Conclusions: A 2-step process based on FDA guidance can be used first to determine whether a pharmacokinetically mediated
Abbasi Nazari, Mohammad; Salamzadeh, Jamshid; Hajebi, Giti; Gilbert, Benjamin
Drug-food interactions can increase or decrease drug effects, resulting in therapeutic failure or toxicity. Activities that reduce these interactions play an important role for clinical pharmacists. This study was planned and performed in order to determine the role of clinical pharmacist in the prevention of absorption drug-food interactions through educating the nurses in a teaching hospital affiliated to Shahid Beheshti University of Medical Sciences, Tehran, Iran. The rate of interactions was determined using direct observation methods before and after the nurse training courses in four wards including gastrointestinal-liver, endocrine, vascular surgery and nephrology. Training courses consisted of the nurse attendance lecture delivered by a clinical pharmacist which included receiving information pamphlets. Total incorrect drug administration fell down from 44.6% to 31.5%. The analysis showed that the rate of absorption drug-food interactions significantly decreased after the nurse training courses (p < 0.001). Clinical pharmacist can play an important role in nurse training as an effective method to reduce drug-food interactions in hospitals.
Mouly, Stéphane; Lloret-Linares, Célia; Sellier, Pierre-Olivier; Sene, Damien; Bergmann, J-F
An interaction of drug with food, herbs, and dietary supplements is usually the consequence of a physical, chemical or physiologic relationship between a drug and a product consumed as food, nutritional supplement or over-the-counter medicinal plant. The current educational review aims at reminding to the prescribing physicians that the most clinically relevant drug-food interactions may not be strictly limited to those with grapefruit juice and with the Saint John's Wort herbal extract and may be responsible for changes in drug plasma concentrations, which in turn decrease efficacy or led to sometimes life-threatening toxicity. Common situations handled in clinical practice such as aging, concomitant medications, transplant recipients, patients with cancer, malnutrition, HIV infection and those receiving enteral or parenteral feeding may be at increased risk of drug-food or drug-herb interactions. Medications with narrow therapeutic index or potential life-threatening toxicity, e.g., the non-steroidal anti-inflammatory drugs, opioid analgesics, cardiovascular medications, warfarin, anticancer drugs and immunosuppressants may be at risk of significant drug-food interactions to occur. Despite the fact that considerable effort has been achieved to increase patient' and doctor's information and ability to anticipate their occurrence and consequences in clinical practice, a thorough and detailed health history and dietary recall are essential for identifying potential problems in order to optimize patient prescriptions and drug dosing on an individual basis as well as to increase the treatment risk/benefit ratio.
Long, Amanda J.; Annes, William F.; Witcher, Jennifer W.; Knadler, Mary Pat; Ayan-Oshodi, Mosun A.; Mitchell, Malcolm I.; Leese, Phillip; Hillgren, Kathleen M.
Despite peptide transporter 1 (PEPT1) being responsible for the bioavailability for a variety of drugs, there has been little study of its potential involvement in drug-drug interactions. Pomaglumetad methionil, a metabotropic glutamate 2/3 receptor agonist prodrug, utilizes PEPT1 to enhance absorption and bioavailability. In vitro studies were conducted to guide the decision to conduct a clinical drug interaction study and to inform the clinical study design. In vitro investigations determined the prodrug (LY2140023 monohydrate) is a substrate of PEPT1 with Km value of approximately 30 µM, whereas the active moiety (LY404039) is not a PEPT1 substrate. In addition, among the eight known PEPT1 substrates evaluated in vitro, valacyclovir was the most potent inhibitor (IC50 = 0.46 mM) of PEPT1-mediated uptake of the prodrug. Therefore, a clinical drug interaction study was conducted to evaluate the potential interaction between the prodrug and valacyclovir in healthy subjects. No effect of coadministration was observed on the pharmacokinetics of the prodrug, valacyclovir, or either of their active moieties. Although in vitro studies showed potential for the prodrug and valacyclovir interaction via PEPT1, an in vivo study showed no interaction between these two drugs. PEPT1 does not appear to easily saturate because of its high capacity and expression in the intestine. Thus, a clinical interaction at PEPT1 is unlikely even with a compound with high affinity for the transporter. PMID:27895114
Greupink, Rick; Schreurs, Marieke; Benne, Marina S; Huisman, Maarten T; Russel, Frans G M
We studied if the clinical pharmacokinetics and drug-drug interactions (DDIs) of the sulfonylurea-derivative glibenclamide can be simulated via a physiologically-based pharmacokinetic modeling approach. To this end, a glibenclamide PBPK-model was build in Simcyp using in vitro physicochemical and biotransformation data of the drug, and was subsequently optimized using plasma disappearance data observed after i.v. administration. The model was validated against data observed after glibenclamide oral dosing, including DDIs. We found that glibenclamide pharmacokinetics could be adequately modeled if next to CYP metabolism an active hepatic uptake process was assumed. This hepatic uptake process was subsequently included in the model in a non-mechanistic manner. After an oral dose of 0.875 mg predicted Cmax and AUC were 39.7 (95% CI:37.0-42.7)ng/mL and 108 (95% CI: 96.9-120)ng/mLh, respectively, which is in line with observed values of 43.6 (95% CI: 37.7-49.5)ng/mL and 133 (95% CI: 107-159)ng/mLh. For a 1.75 mg oral dose, the predicted and observed values were 82.5 (95% CI:76.6-88.9)ng/mL vs 91.1 (95% CI: 67.9-115.9) for Cmax and 224 (95% CI: 202-248) vs 324 (95% CI: 197-451)ng/mLh for AUC, respectively. The model correctly predicted a decrease in exposure after rifampicin pre-treatment. An increase in glibenclamide exposure after clarithromycin co-treatment was predicted, but the magnitude of the effect was underestimated because part of this DDI is the result of an interaction at the transporter level. Finally, the effects of glibenclamide and fluconazol co-administration were simulated. Our simulations indicated that co-administration of this potent CYP450 inhibitor will profoundly increase glibenclamide exposure, which is in line with clinical observations linking the glibenclamide-fluconazol combination to an increased risk of hypoglycemia. In conclusion, glibenclamide pharmacokinetics and its CYP-mediated DDIs can be simulated via PBPK-modeling. In addition, our
Gufford, Brandon T; Chen, Gang; Vergara, Ana G; Lazarus, Philip; Oberlies, Nicholas H; Paine, Mary F
Women at high risk of developing breast cancer are prescribed selective estrogen response modulators, including raloxifene, as chemoprevention. Patients often seek complementary and alternative treatment modalities, including herbal products, to supplement prescribed medications. Milk thistle preparations, including silibinin and silymarin, are top-selling herbal products that may be consumed by women taking raloxifene, which undergoes extensive first-pass glucuronidation in the intestine. Key constituents in milk thistle, flavonolignans, were previously shown to be potent inhibitors of intestinal UDP-glucuronosyl transferases (UGTs), with IC50s ≤ 10 μM. Taken together, milk thistle preparations may perpetrate unwanted interactions with raloxifene. The objective of this work was to evaluate the inhibitory effects of individual milk thistle constituents on the intestinal glucuronidation of raloxifene using human intestinal microsomes and human embryonic kidney cell lysates overexpressing UGT1A1, UGT1A8, and UGT1A10, isoforms highly expressed in the intestine that are critical to raloxifene clearance. The flavonolignans silybin A and silybin B were potent inhibitors of both raloxifene 4'- and 6-glucuronidation in all enzyme systems. The Kis (human intestinal microsomes, 27-66 µM; UGT1A1, 3.2-8.3 µM; UGT1A8, 19-73 µM; and UGT1A10, 65-120 µM) encompassed reported intestinal tissue concentrations (20-310 µM), prompting prediction of clinical interaction risk using a mechanistic static model. Silibinin and silymarin were predicted to increase raloxifene systemic exposure by 4- to 5-fold, indicating high interaction risk that merits further evaluation. This systematic investigation of the potential interaction between a widely used herbal product and chemopreventive agent underscores the importance of understanding natural product-drug interactions in the context of cancer prevention.
So-Ngern, Apichot; Montakantikul, Preecha; Manosuthi, Weerawat
We conducted a cross sectional study of the outpatient medical records of 1000 HIV-infected patients receiving antiretroviral therapy (ART) in 2011 to determine the incidence of clinically significant drug interactions (CSDI). The severities of the CSDI were graded following the Micromedex" 2.0 database and the Department of Health and Human Services (DHHS) 2012 HIV treatment guidelines. Three hundred thirty-five patients (34%) had 554 episodes of CSDI. Of which 337 episodes (61%), 163 episodes (29%) and 54 episodes (10%) had grades 2, 3 and 4 severity CSDI, respectively. The CSDI were caused by protease inhibitor (PI)-based drug regimens in 79%, by efavirenz-based regimens in 34% and by nevirapine-based regimens in 10% (p<0.001). The three most common grade 4 CSDI were: a PI with simvastatin (n=24), simvastatin with gemfibrozil (n=24) and didanosine with allopurinol (n=2). The three most common grade 3 CSDI were: a PI with a statin drug except simvastatin (n=56), fenofibrate with a statin drug (n=28) and amlodipine with simvastatin (n=14). On multivariate analysis, risk factors associated with CSDI were: receiving a PI-based regimen (OR 14.44; 95% CI: 9.10-22.88), having dyslipidemia (OR 3.94; 95% CI: 1.89-8.21), having >5 items prescribed at a time (OR 1.80; 95% CI: 1.23-2.63), seeing a doctor >4 times a year (OR 1.72; 95% CI: 1.20-2.46), having hypertension (OR 0.60; 95% CI: 0.37-0.98), having a duration of receiving ART of >5 years (OR 0.46; 95% CI: 0.28-0.77) and having a CD4 count of >200 cells/mm3 (OR 0.46; 95%CI: 0.26-0.84). CSDI were common among HIV-infected patients receiving ARV in our outpatient clinic. Patients having a low CD, count, having dyslipidemia, receiving PI-based ART, having a frequent number of visits per year and having a large number of items prescribed at each visit had a greater chance of a CSDI.
Vilar, Santiago; Friedman, Carol; Hripcsak, George
Drug-drug interactions (DDIs) constitute an important concern in drug development and postmarketing pharmacovigilance. They are considered the cause of many adverse drug effects exposing patients to higher risks and increasing public health system costs. Methods to follow-up and discover possible DDIs causing harm to the population are a primary aim of drug safety researchers. Here, we review different methodologies and recent advances using data mining to detect DDIs with impact on patients. We focus on data mining of different pharmacovigilance sources, such as the US Food and Drug Administration Adverse Event Reporting System and electronic health records from medical institutions, as well as on the diverse data mining studies that use narrative text available in the scientific biomedical literature and social media. We pay attention to the strengths but also further explain challenges related to these methods. Data mining has important applications in the analysis of DDIs showing the impact of the interactions as a cause of adverse effects, extracting interactions to create knowledge data sets and gold standards and in the discovery of novel and dangerous DDIs.
He, Jiake; Yu, Yang; Prasad, Bhagwat; Chen, Xijing; Unadkat, Jashvant D
An unusual, but clinically significant, digoxin (DIG)-bupropion (BUP) drug interaction (DDI), in which BUP increased DIG renal clearance by 80% is reported. To investigate the mechanism(s) of this unusual DDI, first the effect of BUP, its circulating metabolites or their combination on [(3) H]-DIG transport by cells expressing human P-gp or human OATP4C1 was determined. Second, the study asked whether this DDI could be replicated in the rat so that it could be used to conduct mechanistic studies. Then, the effect of BUP and its rat metabolites on [(3) H]-DIG transport were tested by cells expressing rat Oatp4c1. Bupropion and its metabolites had no effect on human P-gp mediated transepithelial transport of [(3) H]-DIG. Bupropion and hydroxybupropion (HBUP) significantly stimulated H-OATP4C1 mediated transport of [(3) H]-DIG. In addition, BUP cocktail (BUP plus its metabolites) significantly increased the H-OATP4C1 mediated transport of [(3) H]-DIG, and partially reversed the inhibition by 100 µm DIG. However, erythro-hydrobupropion (EBUP) and threo-hydrobupropion (TBUP) did not affect the [(3) H]-DIG uptake by H-OATP4C1 cells. Bupropion administration significantly increased digoxin renal clearance in rats. Surprisingly, bupropion significantly inhibited r-Oatp4c1 mediated transport of [(3) H]-DIG at clinically relevant unbound plasma concentrations of BUP or those observed in the rat study, while HBUP or TBUP did not. These data support our hypothesis that at clinically relevant plasma concentrations, bupropion and its metabolites activate H-OATP4C1 mediated DIG tubular secretion, and could possibly explain the increase in digoxin renal clearance produced by bupropion. While bupropion increased digoxin renal clearance in the rat, it appeared to do so by inhibiting r-Oatp4c1-mediated digoxin renal reabsorption.
Caccia, Silvio; Pasina, Luca; Nobili, Alessandro
Unexpected drug interactions have led to the withdrawal of many drugs, raising concern about the gap between what is known at the time of approval and the risk of serious effects in the longer term, particularly in high-risk populations generally excluded from drug development. This is because the majority of drug interaction studies are done using in vitro methods, or in healthy young volunteers who may not reflect the complexity of patients, and the settings in which the drug will be used in clinical practice. Pre-marketing interaction studies should therefore be designed to make information easily accessible and clinically transferable. They should be adequate in terms of sample size, population, comorbidity, phenotyping and/or genotyping, end-points and outcome measures, and conducted in conditions of dose, route and timing of co-administration that reproduce the proposed therapeutic indications of the new drug. Although young volunteers have the advantage of minimizing some confounding effects introduced by diseases or polypharmacy, patients drawn from populations for whom the drug is intended would be more relevant and accurate, providing the studies are feasible and safe.
Choi, Jong Hwan; Ko, Chang Mann
Natural foods and vegetal supplements have recently become increasingly popular for their roles in medicine and as staple foods. This has, however, led to the increased risk of interaction between prescribed drugs and the bioactive ingredients contained in these foods. These interactions range from pharmacokinetic interactions (absorption, distribution, metabolism, and excretion influencing blood levels of drugs) to pharmacodynamic interactions (drug effects). In a quantitative respect, these interactions occur mainly during metabolism. In addition to the systemic metabolism that occurs mainly in the liver, recent studies have focused on the metabolism in the gastrointestinal tract endothelium before absorption. Inhibition of metabolism causes an increase in the blood levels of drugs and could have adverse reactions. The food-drug interactions causing increased blood levels of drugs may have beneficial or detrimental therapeutic effects depending on the intensity and predictability of these interactions. It is therefore important to understand the potential interactions between foods and drugs should and the specific outcomes of such interactions.
Goodchild, Jason H; Donaldson, Mark
One of the few cases reported in the literature, this article reviews the case of a 66-year-old man who developed an elevated international normalized ratio and sustained clinically significant bleeding as a result of a drug-drug interaction between warfarin and amoxicillin. Given the popularity of these medications, it is surprising that these reports are not more commonplace, and there is a concern that the lack of reports may result in practitioners overlooking the significance of this possible complication. Although the mechanism for this interaction is not fully known, it is suspected that a decrease in vitamin K-producing gut flora, with resulting vitamin K deficiency, is the most likely contributing factor. An objective causality assessment revealed that this adverse drug event, secondary to the warfarin and amoxicillin interaction, was probable.
Mohutsky, Michael; Hall, Stephen D
This chapter describes the types of irreversible inhibition of drug-metabolizing enzymes and the methods commonly employed to quantify the irreversible inhibition and subsequently predict the extent and time course of clinically important drug-drug interactions.
Derks, Michael; Abt, Markus; Phelan, Mary
AIMS Dalcetrapib, which targets cholesteryl ester transfer protein activity, is in development for prevention of cardiovascular events. Because dalcetrapib will likely be prescribed with other lipid-modifying therapies such as ezetimibe, a study was performed to investigate potential pharmacokinetic interactions between dalcetrapib and ezetimibe. Lipids changes and tolerability were secondary endpoints. METHODS Co-administration of dalcetrapib 900 mg (higher than the phase III dose) with ezetimibe was investigated in a three period, three treatment crossover study in healthy males: 7 days of dalcetrapib, 7 days of dalcetrapib plus ezetimibe, 7 days of ezetimibe alone. A full pharmacokinetic profile was performed on day 7 of each treatment. RESULTS Co-administration of dalcetrapib with ezetimibe was associated with minimal changes in dalcetrapib exposure compared with dalcetrapib alone. Least squares mean ratio (LSMR) (90% confidence interval) was 93.6 (87.1, 100.7) for AUC(0,24 h) and 99.0 (85.2, 115.0) for Cmax. Ezetimibe exposure was reduced with co-administration of ezetimibe with dalcetrapib compared with ezetimibe alone: LSMR 80.3 (74.6, 86.4) for AUC(0,24 h) and 88.9 (80.9, 99.9) for Cmax for total ezetimibe. High-density lipoprotein cholesterol increases associated with co-administration of dalcetrapib with ezetimibe (+29.8%) were comparable with those with dalcetrapib alone (+25.6%), while the reduction in low-density lipoprotein cholesterol with co-administration (−35.9%) was greater than with ezetimibe alone (−20.9%). Dalcetrapib was generally well tolerated when administered alone and when co-administered with ezetimibe. CONCLUSION Co-administration of dalcetrapib with ezetimibe was not associated with clinically significant changes in pharmacokinetic parameters or tolerability and did not diminish the lipid effects of either drug. PMID:21175438
Drug-drug interactions (DDI) are a major topic in programs for continuous medical education (CME). Many physicians are afraid of being trapped into charges of malpractice; however, DDI cannot be avoided in many cases. They belong to routine medical practice and it is often impossible to avoid them. Moreover, they do not just occur between drugs but between any kind of foreign substance (xenobiotica), such as food (e.g. grapefruit juice, broccoli, barbecue) as well as legal (e.g. tobacco smoke, caffeine and alcohol) and illegal drugs. Therefore, the medical challenge is not just to avoid any interaction. Instead the physician faces the question of how to proceed with drug treatment in the presence of such interactions. Based on the medical education a physician has to judge first of all whether there is a risk for interactions in the prescription being planned for an individual patient. The classification of interactions proposed in this article (PD1-PD4, PK1-PK3) might help as a sort of check list. For more detailed information the physician can then consult one of the many databases available on the internet, such as PSIAConline (http://www.psiac.de) and MediQ (http://www.mediq.ch). Pharmacokinetic interactions can be easily assessed, monitored and controlled by therapeutic drug monitoring (TDM). Besides these tools it is important to keep in mind that nobody knows everything; even physicians do not know everything. So take pride in asking someone who might help and for this purpose AGATE offers a drug information service AID (http://www.amuep-agate.de). Just good for nothing, without being based on any kind of medical approach are computer programs that judge prescriptions without taking into account a patient's individual peculiarities. In case these types of programs produce red exclamation marks or traffic lights to underline their judgment, they might even work in a contrapuntal way by just eliciting insecurity and fear.
Saab, Yolande B; Zeenny, Rony; Ramadan, Wijdan H
Purpose Response to clopidogrel varies widely with nonresponse rates ranging from 4% to 30%. A reduced function of the gene variant of the CYP2C19 has been associated with lower drug metabolite levels, and hence diminished platelet inhibition. Drugs that alter CYP2C19 activity may also mimic genetic variants. The aim of the study is to investigate the cumulative effect of CYP2C19 gene polymorphisms and drug interactions that affects clopidogrel dosing, and apply it into a new clinical-pharmacogenetic algorithm that can be used by clinicians in optimizing clopidogrel-based treatment. Method Clopidogrel dose optimization was analyzed based on two main parameters that affect clopidogrel metabolite area under the curve: different CYP2C19 genotypes and concomitant drug intake. Clopidogrel adjusted dose was computed based on area under the curve ratios for different CYP2C19 genotypes when a drug interacting with CYP2C19 is added to clopidogrel treatment. A clinical-pharmacogenetic algorithm was developed based on whether clopidogrel shows 1) expected effect as per indication, 2) little or no effect, or 3) clinical features that patients experience and fit with clopidogrel adverse drug reactions. Results The study results show that all patients under clopidogrel treatment, whose genotypes are different from *1*1, and concomitantly taking other drugs metabolized by CYP2C19 require clopidogrel dose adjustment. To get a therapeutic effect and avoid adverse drug reactions, therapeutic dose of 75 mg clopidogrel, for example, should be lowered to 6 mg or increased to 215 mg in patients with different genotypes. Conclusion The implementation of clopidogrel new algorithm has the potential to maximize the benefit of clopidogrel pharmacological therapy. Clinicians would be able to personalize treatment to enhance efficacy and limit toxicity. PMID:26445541
Herman, R J
Drug interactions commonly occur in patients receiving treatment with multiple medications. Most interactions remain unrecognized because drugs, in general, have a wide margin of safety or because the extent of change in drug levels is small when compared with the variation normally seen in clinical therapy. All drug interactions have a pharmacokinetic or pharmacodynamic basis and are predictable given an understanding of the pharmacology of the drugs involved. Drugs most liable to pose problems are those having concentration-dependent toxicity within, or close to, the therapeutic range; those with steep dose-response curves; those having high first-pass metabolism or those with a single, inhibitable route of elimination. Knowing which drugs possess these intrinsic characteristics, together with a knowledge of hepatic P-450 metabolism and common enzyme-inducing and enzyme-inhibiting drugs, can greatly assist physicians in predicting interactions that may be clinically relevant. This article reviews the pharmacology of drug interactions that can occur with hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) to illustrate the scope of the problem and the ways in which physicians may manage this important therapeutic class of drugs. PMID:10584091
Corti, N; Taegtmeyer, A B
Most medicines are taken with breakfast which is usually unproblematic and has the advantage of improving adherence through establishment of a daily routine. However, due to alterations in absorption from the gastrointestinal tract, there are a number of medicines that either lose (such as bisphosphonates) or gain (such as albendazole) efficacy if taken together with food. Food components can also affect drug-metabolising enzymes and even cause drug toxicity (alcohol and grapefruit juice are notable examples). Conversely, drugs such as monoamine oxidase inhibitors can inhibit the metabolism of tyramine in tyramine-rich foods and lead to adverse circulatory reactions. These and other examples of when the ingestion of medication together with food can cause clinically relevant problems are discussed in this article.
Kroiss, Matthias; Quinkler, Marcus; Lutz, Werner K; Allolio, Bruno; Fassnacht, Martin
Mitotane [1-(2-chlorophenyl)-1-(4-chlorophenyl)-2,2-dichloroethane, (o,p'-DDD)] is the only drug approved for the treatment for adrenocortical carcinoma (ACC) and has also been used for various forms of glucocorticoid excess. Through still largely unknown mechanisms, mitotane inhibits adrenal steroid synthesis and adrenocortical cell proliferation. Mitotane increases hepatic metabolism of cortisol, and an increased replacement dose of glucocorticoids is standard of care during mitotane treatment. Recently, sunitinib, a multityrosine kinase inhibitor (TKI), has been found to be rapidly metabolized by CYP3A4 during mitotane treatment, indicating clinically relevant drug interactions with mitotane. We here summarize the current evidence concerning mitotane-induced changes in hepatic monooxygenase expression, list drugs potentially affected by mitotane-related CYP3A4 induction and suggest alternatives. For example, using standard doses of macrolide antibiotics is unlikely to reach sufficient plasma levels, making fluoroquinolones in many cases a superior choice. Similarly, statins such as simvastatin are metabolized by CYP3A4, whereas others like pravastatin are not. Importantly, in the past, several clinical trials using cytotoxic drugs but also targeted therapies in ACC yielded disappointing results. This lack of antineoplastic activity may be explained in part by insufficient drug exposure owing to enhanced drug metabolism induced by mitotane. Thus, induction of CYP3A4 by mitotane needs to be considered in the design of future clinical trials in ACC.
Franco, D; Henao, Y; Monsalve, M; Gutiérrez, F; Hincapie, J; Amariles, P
Objetivo: Realizar una revisión estructurada sobre interacciones medicamentosas de los hipolipemiantes y valorar su relevancia clínica. Método: Revisión estructurada de interacciones medicamentosas con hipolipemiantes en humanos, en PubMed/Medline de artículos publicados sin restricción de idioma, con acceso a texto completo hasta junio 30 de 2012. La búsqueda se realizó con los siguientes terminos Mesh: Drug Interactions, Lipid Regulating Agents, Herb-Drug Interactions, Food-Drug Interactions y Hypolipidemic Agents (Pharmacological Action). La información se complementó con artículos considerados importantes. Por último, se utilizó un método para evaluar la relevancia clínica de la interacción, basado en la probabilidad de ocurrencia y en la gravedad del efecto de la interacción. Resultados: Se obtuvieron 849 publicaciones, de las cuales se seleccionaron 243 referencias, en las los que se identificaron 189 interacciones. De ellas 33 fueron valoradas como de riesgo muy alto (nivel 1) y 42 de riesgo alto (nivel 2), asociadas fundamentalmente al aumento del riesgo de rabdomiólisis. La inhibición enzimática de la CYP450 fue el mecanismo más común de las interacciones. Conclusiones. En los pacientes en tratamiento con hipolipemiantes, de las interacciones identificadas 60,3% (128/189) son clínicamente relevantes (riesgo muy alto o alto), asociadas principalmente a la aparición de rabdomiólisis. La mayoría de dichas interacciones son atribuidas al uso simultáneo de reconocidos inhibidores de la CYP3A4. Por ello, las estatinas metabolizadas por la CYP3A4 (simvastatina, lovastatina y atorvastatina) son las que más interacciones de relevancia clínica presentan.
Le Jeunne, C; Hugues, F C
Elderly people are particularly at risk for drug interactions, for several reasons. They are the part of the population who consume the most drugs: over 75 years the mean number of drugs on a prescription is 5.6. As they suffer from various associated diseases, they see several medical specialists, each of them adding a new prescription to the others. Self-prescriptions complicate the problem because they are rarely mentioned. Changes in pharmacokinetics in the elderly tend to increase blood concentrations of drugs. Elderly people suffer from altered homeostatic mechanisms to compensate for adverse drug effects. As a whole, such individuals are more exposed to the side effects of drugs. The drugs most often involved in these interactions are diuretics, non-steroidal anti-inflammatory drugs, benzodiazepines, antiarrhythmics, cardiac glycosides, antihypertensive drugs, oral antidiabetics and antalgics. The clinical accidents most often occurring with these drug interactions are: malaise, orthostatic hypotension, loss of conciousness, amnesia, confusion, renal insufficiency, digestive problems. Since elderly people are less likely to recover easily, this problem of drug interaction should be looked for systematically.
Fahmi, Odette A; Maurer, Tristan S; Kish, Mary; Cardenas, Edwin; Boldt, Sherri; Nettleton, David
Although approaches to the prediction of drug-drug interactions (DDIs) arising via time-dependent inactivation have recently been developed, such approaches do not account for simple competitive inhibition or induction. Accordingly, these approaches do not provide accurate predictions of DDIs arising from simple competitive inhibition (e.g., ketoconazole) or induction of cytochromes P450 (e.g., phenytoin). In addition, methods that focus upon a single interaction mechanism are likely to yield misleading predictions in the face of mixed mechanisms (e.g., ritonavir). As such, we have developed a more comprehensive mathematical model that accounts for the simultaneous influences of competitive inhibition, time-dependent inactivation, and induction of CYP3A in both the liver and intestine to provide a net drug-drug interaction prediction in terms of area under the concentration-time curve ratio. This model provides a framework by which readily obtained in vitro values for competitive inhibition, time-dependent inactivation and induction for the precipitant compound as well as literature values for f(m) and F(G) for the object drug can be used to provide quantitative predictions of DDIs. Using this model, DDIs arising via inactivation (e.g., erythromycin) continue to be well predicted, whereas those arising via competitive inhibition (e.g., ketoconazole), induction (e.g., phenytoin), and mixed mechanisms (e.g., ritonavir) are also predicted within the ranges reported in the clinic. This comprehensive model quantitatively predicts clinical observations with reasonable accuracy and can be a valuable tool to evaluate candidate drugs and rationalize clinical DDIs.
Choi, Jong Hwan; Ko, Chang Mann
Natural foods and vegetal supplements have recently become increasingly popular for their roles in medicine and as staple foods. This has, however, led to the increased risk of interaction between prescribed drugs and the bioactive ingredients contained in these foods. These interactions range from pharmacokinetic interactions (absorption, distribution, metabolism, and excretion influencing blood levels of drugs) to pharmacodynamic interactions (drug effects). In a quantitative respect, these interactions occur mainly during metabolism. In addition to the systemic metabolism that occurs mainly in the liver, recent studies have focused on the metabolism in the gastrointestinal tract endothelium before absorption. Inhibition of metabolism causes an increase in the blood levels of drugs and could have adverse reactions. The food-drug interactions causing increased blood levels of drugs may have beneficial or detrimental therapeutic effects depending on the intensity and predictability of these interactions. It is therefore important to understand the potential interactions between foods and drugs should and the specific outcomes of such interactions. PMID:28261555
Youdim, Kuresh A; Zayed, Aref; Dickins, Maurice; Phipps, Alex; Griffiths, Michelle; Darekar, Amanda; Hyland, Ruth; Fahmi, Odette; Hurst, Susan; Plowchalk, David R; Cook, Jack; Guo, Feng; Obach, R Scott
AIMS The aim of this study was to explore and optimize the in vitro and in silico approaches used for predicting clinical DDIs. A data set containing clinical information on the interaction of 20 Pfizer compounds with ketoconazole was used to assess the success of the techniques. METHODS The study calculated the fraction and the rate of metabolism of 20 Pfizer compounds via each cytochrome P450. Two approaches were used to determine fraction metabolized (fm); 1) by measuring substrate loss in human liver microsomes (HLM) in the presence and absence of specific chemical inhibitors and 2) by measuring substrate loss in individual cDNA expressed P450s (also referred to as recombinant P450s (rhCYP)) The fractions metabolized via each CYP were used to predict the drug–drug interaction due to CYP3A4 inhibition by ketoconazole using the modelling and simulation software SIMCYP®. RESULTS When in vitro data were generated using Gentest supersomes, 85% of predictions were within two-fold of the observed clinical interaction. Using PanVera baculosomes, 70% of predictions were predicted within two-fold. In contrast using chemical inhibitors the accuracy was lower, predicting only 37% of compounds within two-fold of the clinical value. Poorly predicted compounds were found to either be metabolically stable and/or have high microsomal protein binding. The use of equilibrium dialysis to generate accurate protein binding measurements was especially important for highly bound drugs. CONCLUSIONS The current study demonstrated that the use of rhCYPs with SIMCYP® provides a robust in vitro system for predicting the likelihood and magnitude of changes in clinical exposure of compounds as a consequence of CYP3A4 inhibition by a concomitantly administered drug. WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT Numerous retrospective analyses have shown the utility of in vitro systems for predicting potential drug–drug interactions (DDIs). Prediction of DDIs from in vitro data is commonly
Agrawal, A.; Agarwal, S. K.; Kaleekal, T.; Gupta, Y. K.
Patients on dialysis have an increased incidence of tuberculosis (TB). Rifampicin, a first-line antitubercular therapy (ATT) drug, is a potent inducer of hepatic cytochrome P450 (CYP). There is potential for pharmacokinetic interaction between rifampicin and anti-hypertensives that are CYP substrates: amlodipine and metoprolol. Therefore, hypertensive patients receiving rifampicin-based ATT are at risk for worsening of hypertension. However, this hypothesis has not yet been systematically studied. In this prospective study, hypertensive CKD 5D patients with TB were followed after rifampicin initiation. Blood pressure (BP) was ≤140/90 mmHg with stable anti-HT requirement at inclusion. Serum amlodipine, metoprolol, and prazosin levels were estimated by high-performance liquid chromatography at baseline and 3, 7, 10, and 14 days after rifampicin initiation. BP and anti-HT requirement were monitored for 2 weeks or until stabilization. All 24 patients in the study had worsening of hypertension after rifampicin and 83.3% required increase in drugs to maintain BP <140/90 mmHg. Serial amlodipine levels were estimated in 16 patients; metoprolol and prazosin in four patients each. Drug levels declined by >50% in all patients and became undetectable in 50-75%. Drug requirement increased from 4.5 ± 3.6 to 8.5 ± 6.4 units (P < 0.0001). Mean time to first increase in dose was 6.5 ± 3.6 days. Eleven (46%) patients experienced a hypertensive crisis at 9.1 ± 3.8 days. Three of them had a hypertensive emergency with acute pulmonary edema. In two patients, rifampicin had to be discontinued to achieve BP control. In conclusion, rifampicin caused a significant decrease in blood levels of commonly used anti hypertensives. This decrease in levels correlated well with worsening of hypertension. Thus, we suggest very close BP monitoring in CKD patients after rifampicin initiation. PMID:27795624
Zhou, Yi-Ting; Yu, Lu-Shan; Zeng, Su; Huang, Yu-Wen; Xu, Hui-Min; Zhou, Quan
Background Coadministration of 1,4-dihydropyridine calcium channel blockers (DHP-CCBs) with statins (or 3-hydroxy-3-methylglutaryl-coenzyme A [HMG-CoA] reductase inhibitors) is common for patients with hypercholesterolemia and hypertension. To reduce the risk of myopathy, in 2011, the US Food and Drug Administration (FDA) Drug Safety Communication set a new dose limitation for simvastatin, for patients taking simvastatin concomitantly with amlodipine. However, there is no such dose limitation for atorvastatin for patients receiving amlodipine. The combination pill formulation of amlodipine/atorvastatin is available on the market. There been no systematic review of the pharmacokinetic drug–drug interaction (DDI) profile of DHP-CCBs with statins, the underlying mechanisms for DDIs of different degree, or the corresponding management of clinical risk. Methods The relevant literature was identified by performing a PubMed search, covering the period from January 1987 to September 2013. Studies in the field of drug metabolism and pharmacokinetics that described DDIs between DHP-CCB and statin or that directly compared the degree of DDIs associated with cytochrome P450 (CYP)3A4-metabolized statins or DHP-CCBs were included. The full text of each article was critically reviewed, and data interpretation was performed. Results There were three circumstances related to pharmacokinetic DDIs in the combined use of DHP-CCB and statin: 1) statin is comedicated as the precipitant drug (pravastatin–nimodipine and lovastatin–nicardipine); 2) statin is comedicated as the object drug (isradipine–lovastatin, lacidipine–simvastatin, amlodipine–simvastatin, benidipine-simvastatin, azelnidipine– simvastatin, lercanidipine–simvastatin, and amlodipine–atorvastatin); and 3) mutual interactions (lercanidipine–fluvastatin). Simvastatin has an extensive first-pass effect in the intestinal wall, whereas atorvastatin has a smaller intestinal first-pass effect. The interaction
Morrelli, Howard F.; Melmon, Kenneth L.
Drug interactions are important causes of both unexpected toxic and therapeutic effects. Adverse reactions due to drug interaction are proportional to the number of drugs given and the duration of administration. Although drug interactions may be beneficial, they are most often recognized when they increase mortality or morbidity. The frequency of adverse drug interactions in clinical practice makes it mandatory for physicians to know the drugs and mechanisms involved. A drug may potentiate or antagonize the effects of another drug by direct chemical or physical combination, by altering gastrointestinal absorption, by influencing metabolism, transport, or renal clearance, by changing the activity of a drug at its receptor site, or by modifying the patient's response to the drug by a variety of means. This article stresses the importance of avoiding multible drug therapy. When such treatment is unavoidable, patients must be carefully observed for evidence of intensified or diminished drug effect. Only this permits the detection and prevention of untoward drug interactions. PMID:4881984
Nishimura, Adam A.; Shirts, Brian H.; Salama, Joseph; Smith, Joe W.; Devine, Beth; Tarczy-Hornoch, Peter
Objective To determine if physicians find clinical decision support alerts for pharmacogenomic drug-gene interactions useful and assess their perceptions of usability aspects that impact usefulness. Materials and Methods 52 physicians participated in an online simulation and questionnaire involving a prototype alert for the clopidogrel and CYP2C19 drug-gene interaction. Results Only 4% of participants stated they would override the alert. 92% agreed that the alerts were useful. 87% found the visual interface appropriate, 91% felt the timing of the alert was appropriate and 75% were unfamiliar with the specific drug-gene interaction. 80% of providers preferred the ability to order the recommended medication within the alert. Qualitative responses suggested that supplementary information is important, but should be provided as external links, and that the utility of pharmacogenomic alerts depends on the broader ecosystem of alerts. Principal Conclusions Pharmacogenomic alerts would be welcomed by many physicians, can be built with minimalist design principles, and are appropriately placed at the end of the prescribing process. Since many physicians lack familiarity with pharmacogenomics but have limited time, information and educational resources within the alert should be carefully selected and presented in concise ways. PMID:26642939
Fahmi, Odette A; Shebley, Mohamad; Palamanda, Jairam; Sinz, Michael W; Ramsden, Diane; Einolf, Heidi J; Chen, Liangfu; Wang, Hongbing
Drug-drug interactions (DDIs) due to CYP2B6 induction have recently gained prominence and clinical induction risk assessment is recommended by regulatory agencies. This work aimed to evaluate the potency of CYP2B6 versus CYP3A4 induction in vitro and from clinical studies and to assess the predictability of efavirenz versus bupropion as clinical probe substrates of CYP2B6 induction. The analysis indicates that the magnitude of CYP3A4 induction was higher than CYP2B6 both in vitro and in vivo. The magnitude of DDIs caused by induction could not be predicted for bupropion with static or dynamic models. On the other hand, the relative induction score, net effect, and physiologically based pharmacokinetics SimCYP models using efavirenz resulted in improved DDI predictions. Although bupropion and efavirenz have been used and are recommended by regulatory agencies as clinical CYP2B6 probe substrates for DDI studies, CYP3A4 contributes to the metabolism of both probes and is induced by all reference CYP2B6 inducers. Therefore, caution must be taken when interpreting clinical induction results because of the lack of selectivity of these probes. Although in vitro-in vivo extrapolation for efavirenz performed better than bupropion, interpretation of the clinical change in exposure is confounded by the coinduction of CYP2B6 and CYP3A4, as well as the increased contribution of CYP3A4 to efavirenz metabolism under induced conditions. Current methods and probe substrates preclude accurate prediction of CYP2B6 induction. Identification of a sensitive and selective clinical substrate for CYP2B6 (fraction metabolized > 0.9) is needed to improve in vitro-in vivo extrapolation for characterizing the potential for CYP2B6-mediated DDIs. Alternative strategies and a framework for evaluating the CYP2B6 induction risk are proposed.
Concurrent use of herbs may mimic, magnify, or oppose the effect of drugs. Plausible cases of herb-drug interactions include: bleeding when warfarin is combined with ginkgo (Ginkgo biloba), garlic (Allium sativum), dong quai (Angelica sinensis), or danshen (Salvia miltiorrhiza); mild serotonin syndrome in patients who mix St John's wort (Hypericum perforatum) with serotonin-reuptake inhibitors; decreased bioavailability of digoxin, theophylline, cyclosporin, and phenprocoumon when these drugs are combined with St John's wort; induction of mania in depressed patients who mix antidepressants and Panax ginseng; exacerbation of extrapyramidal effects with neuroleptic drugs and betel nut (Areca catechu); increased risk of hypertension when tricyclic antidepressants are combined with yohimbine (Pausinystalia yohimbe); potentiation of oral and topical corticosteroids by liquorice (Glycyrrhiza glabra); decreased blood concentrations of prednisolone when taken with the Chinese herbal product xaio chai hu tang (sho-salko-to); and decreased concentrations of phenytoin when combined with the Ayurvedic syrup shankhapushpi. Anthranoid-containing plants (including senna [Cassia senna] and cascara [Rhamnus purshiana]) and soluble fibres (including guar gum and psyllium) can decrease the absorption of drugs. Many reports of herb-drug interactions are sketchy and lack laboratory analysis of suspect preparations. Health-care practitioners should caution patients against mixing herbs and pharmaceutical drugs.
Ripp, Sharon L; Mills, Jessica B; Fahmi, Odette A; Trevena, Kristen A; Liras, Jennifer L; Maurer, Tristan S; de Morais, Sonia M
Cytochrome P4503A4 (CYP3A4) is the principal drug-metabolizing enzyme in human liver. Drug-drug interactions (DDIs) caused by induction of CYP3A4 can result in decreased exposure to coadministered drugs, with potential loss of efficacy. Immortalized hepatocytes (Fa2N-4 cells) have been proposed as a tool to identify CYP3A4 inducers. The purpose of the current studies was to characterize the effect of known inducers on CYP3A4 in Fa2N-4 cells, and to determine whether these in vitro data could reliably project the magnitude of DDIs caused by induction. Twenty-four compounds were chosen for these studies, based on previously published data using primary human hepatocytes. Eighteen compounds had been shown to be positive for induction, and six compounds had been shown to be negative for induction. In Fa2N-4 cells, all 18 positive controls produced greater than 2-fold maximal CYP3A4 induction, and all 6 negative controls produced less than 1.5-fold maximal CYP3A4 induction. Subsequent studies were conducted to determine the relationship between in vitro induction data and in vivo induction response. The approach was to relate in vitro induction data (E(max) and EC(50) values) with efficacious free plasma concentrations to calculate a relative induction score. This score was then correlated with decreases in area under the plasma concentration versus time curve values for coadministered CYP3A4 object drugs (midazolam or ethinylestradiol) from previously published clinical DDI studies. Excellent correlations (r(2) values >0.92) were obtained, suggesting that Fa2N-4 cells can be used for identification of inducers as well as prediction of the magnitude of clinical DDIs.
Spinelli, Tulla; Calcagnile, Selma; Lanzarotti, Corinna; Rossi, Giorgia; Cox, David; Kashef, Kimia
Neurokinin-1 (NK1) receptor antagonists (RAs) are commonly coadministered with serotonin (5-HT3) RAs (e.g. palonosetron (PALO)) to prevent chemotherapy-induced nausea/vomiting. Netupitant/palonosetron (NEPA), an oral fixed combination of netupitant (NETU)—a new NK1 RA—and PALO, is currently under development. In vitro data suggest that NETU inhibits CYP3A4 and is a substrate for and weak inhibitor of P-glycoprotein (P-gp). This review evaluates potential drug–drug interactions between NETU or NEPA and CYP3A4 substrates/inducers/inhibitors or P-gp substrates in healthy subjects. Pharmacokinetic (PK) parameters were evaluated for each drug when NETU was coadministered with PALO (single doses) and when single doses of NETU or NEPA were coadministered with CYP3A4 substrates (erythromycin (ERY), midazolam (MID), dexamethasone (DEX), or oral contraceptives), inhibitors (ketoconazole (KETO)), or inducers (rifampicin (RIF)), or a P-gp substrate (digoxin (DIG)). Results showed no relevant PK interactions between NETU and PALO. Coadministration of NETU increased MID and ERY exposure and significantly increased DEX exposure in a dose-dependent manner; NETU exposure was unaffected. NEPA coadministration had no clinically significant effect on oral contraception, although levonorgestrel exposure increased. NETU exposure increased after coadministration of NEPA with KETO and decreased after coadministration with RIF; PALO exposure was unaffected. NETU coadministration did not influence DIG exposure. In conclusion, there were no clinically relevant interactions between NETU and PALO, or NEPA and oral contraceptives (based on levonorgestrel and ethinylestradiol exposure). Coadministration of NETU or NEPA with CYP3A4 inducers/inhibitors/substrates should be done with caution. Dose reduction is recommended for DEX. Dose adjustments are not needed for NETU coadministration with P-gp substrates. PMID:25998320
Laki, Szilvia; Kalapos-Kovács, Bernadett; Antal, István; Klebovich, Imre
Drug interaction is a process during which a drug's fate in the body or its pharmacological properties are altered by an influencing factor. The extent of the drug interaction's effect can vary. The interaction could result from the modulation by another drug, food, alcohol, caffeine, narcotics, a drug influencing absorption or smoking. Moreover, transporter interactions with smoking could also have a major impact on many drug's efficacy. Clinically relevant drug interactions with smoking were classified in terms of their effect: pharmacokinetic, pharmacodynamic and transporter interactions. Policyclic aromatic carbohydrates, found in cigarette smoke, have enzyme inducing properties. The interaction affects mainly the hepatic isoenzyme CYP1A2. Interactions caused by smoking have an effect on all drugs being substrates of and therefore metabolised by CYP1A2. Pharmacokinetic alteration can also occur during the absorption, distribution and elimination process. The pharmacodynamic interactions are mainly caused by the effects of nicotine, a cigarette smoke component. Through interactions, smoking could also modify the activity of transporter proteins, altering this way the ADME properties of many drugs. Since smoking is one of the deadliest artefact in the history of human civilisation, identifying drug interactions with smoking is the physician's and pharmacist's major responsibility and task. Moreover, it is necessary to identify the patient's smoking habits during a medical treatment. This review aims to investigate the main types of drug interactions (PK/PD), identify factors influencing the activity of CYP enzymes and transporters, and also summarize the mechanisms of the most important drug interactions with smoking and their clinically relevant consequences (Table II-VI.). Drugs, with effects somehow altered by smoking-interactions, have been studied.
Goey, Andrew K L; Mooiman, Kim D; Beijnen, Jos H; Schellens, Jan H M; Meijerman, Irma
The use of complementary and alternative medicines (CAM) by cancer patients is increasing. Concomitant use of CAM and anticancer drugs could lead to serious safety issues in patients. CAM have the potential to cause pharmacokinetic interactions with anticancer drugs, leading to either increased or decreased plasma levels of anticancer drugs. This could result in unexpected toxicities or a reduced efficacy. Significant pharmacokinetic interactions have already been shown between St. John's Wort (SJW) and the anticancer drugs imatinib and irinotecan. Most pharmacokinetic CAM-drug interactions, involve drug metabolizing cytochrome P450 (CYP) enzymes, in particular CYP3A4. The effect of CAM on CYP3A4 activity and expression can be assessed in vitro. However, no data have been reported yet regarding the relevance of these in vitro data for the prediction of CAM-anticancer drug interactions in clinical practice. To address this issue, a literature research was performed to evaluate the relevance of in vitro data to predict clinical effects of CAM frequently used by cancer patients: SJW, milk thistle, garlic and Panax ginseng (P. ginseng). Furthermore, in clinical studies the sensitive CYP3A4 substrate probe midazolam is often used to determine pharmacokinetic interactions. Results of these clinical studies with midazolam are used to predict pharmacokinetic interactions with other drugs metabolized by CYP3A4. Therefore, this review also explored whether clinical trials with midazolam are useful to predict clinical pharmacokinetic CAM-anticancer drug interactions. In vitro data of SJW have shown CYP3A4 inhibition after short-term exposure and induction after long-term exposure. In clinical studies using midazolam or anticancer drugs (irinotecan and imatinib) as known CYP3A4 substrates in combination with SJW, decreased plasma levels of these drugs were observed, which was expected as a consequence of CYP3A4 induction. For garlic, no effect on CYP3A4 has been shown in vitro
Cheng, Yaofeng; Ma, Li; Chang, Shu-Ying; Humphreys, W Griffith; Li, Wenying
Asunaprevir (ASV), daclatasvir (DCV), and beclabuvir (BCV) are three drugs developed for the treatment of chronic hepatitis C virus infection. Here, we evaluated the CYP3A4 induction potential of each drug, as well as BCV-M1 (the major metabolite of BCV), in human hepatocytes by measuring CYP3A4 mRNA alteration. The induction responses were quantified as induction fold (mRNA fold change) and induction increase (mRNA fold increase), and then fitted with four nonlinear regression algorithms. Reversible inhibition and time-dependent inhibition (TDI) on CYP3A4 activity were determined to predict net drug-drug interactions (DDIs). All four compounds were CYP3A4 inducers and inhibitors, with ASV demonstrating TDI. The curve-fitting results demonstrated that fold increase is a better assessment to determine kinetic parameters for compounds inducing weak responses. By summing the contribution of each inducer, the basic static model was able to correctly predict the potential for a clinically meaningful induction signal for single or multiple perpetrators, but with over prediction of the magnitude. With the same approach, the mechanistic static model improved the prediction accuracy of DCV and BCV when including both induction and inhibition effects, but incorrectly predicted the net DDI effects for ASV alone or triple combinations. The predictions of ASV or the triple combination could be improved by only including the induction and reversible inhibition but not the ASV CYP3A4 TDI component. Those results demonstrated that static models can be applied as a tool to help project the DDI risk of multiple perpetrators using in vitro data.
Wu, Heng-Yi; Chiang, Chien-Wei; Li, Lang
In order to understand the mechanisms of drug-drug interaction (DDI), the study of pharmacokinetics (PK), pharmacodynamics (PD), and pharmacogenetics (PG) data are significant. In recent years, drug PK parameters, drug interaction parameters, and PG data have been unevenly collected in different databases and published extensively in literature. Also the lack of an appropriate PK ontology and a well-annotated PK corpus, which provide the background knowledge and the criteria of determining DDI, respectively, lead to the difficulty of developing DDI text mining tools for PK data collection from the literature and data integration from multiple databases.To conquer the issues, we constructed a comprehensive pharmacokinetics ontology. It includes all aspects of in vitro pharmacokinetics experiments, in vivo pharmacokinetics studies, as well as drug metabolism and transportation enzymes. Using our pharmacokinetics ontology, a PK corpus was constructed to present four classes of pharmacokinetics abstracts: in vivo pharmacokinetics studies, in vivo pharmacogenetic studies, in vivo drug interaction studies, and in vitro drug interaction studies. A novel hierarchical three-level annotation scheme was proposed and implemented to tag key terms, drug interaction sentences, and drug interaction pairs. The utility of the pharmacokinetics ontology was demonstrated by annotating three pharmacokinetics studies; and the utility of the PK corpus was demonstrated by a drug interaction extraction text mining analysis.The pharmacokinetics ontology annotates both in vitro pharmacokinetics experiments and in vivo pharmacokinetics studies. The PK corpus is a highly valuable resource for the text mining of pharmacokinetics parameters and drug interactions.
Albaugh, Daniel R; Fullenwider, Cody L; Fisher, Michael B; Hutzler, J Matthew
The current studies assessed the utility of freshly plated hepatocytes, cryopreserved plated hepatocytes, and cryopreserved plated HepaRG cells for the estimation of inactivation parameters k(inact) and K(I) for CYP3A. This was achieved using a subset of CYP3A time-dependent inhibitors (fluoxetine, verapamil, clarithromycin, troleandomycin, and mibefradil) representing a range of potencies. The estimated k(inact) and K(I) values for each time-dependent inhibitor were compared with those obtained using human liver microsomes and used to estimate the magnitude of clinical pharmacokinetic drug-drug interaction (DDI). The inactivation kinetic parameter, k(inact), was most consistent across systems tested for clarithromycin, verapamil, and troleandomycin, with a high k(inact) of 0.91 min(-1) observed for mibefradil in HepaRG cells. The apparent K(I) estimates derived from the various systems displayed a range of variability from 3-fold for clarithromycin (5.4-17.7 μM) to 6-fold for verapamil (1.9-12.6 μM). In general, the inactivation kinetic parameters derived from the cell systems tested fairly replicated what was observed in time-dependent inhibition studies using human liver microsomes. Despite some of the observed differences in inactivation kinetic parameters, the estimated DDIs derived from each of the tested systems generally agreed with the clinically reported DDI within approximately 2-fold. In addition, a plated cell approach offered the ability to conduct longer primary incubations (greater than 30 min), which afforded improved ability to identify the weak time-dependent inhibitor fluoxetine. Overall, results from these studies suggest that in vitro inactivation parameters generated from plated cell systems may be a practical approach for identifying time-dependent inhibitors and for estimating the magnitude of clinical DDIs.
Menon, M K; Clark, W G; Vivonia, C
Pretreatment (IP) of mice with (-) baclofen, muscimol, 4,5,6,7-tetrahydroisoxazolo (S,4-c) pyridin-3-ol hydrate (THIP), aminooxyacetic acid (AOAA) or gamma-acetylenic GABA caused a dose-dependent inhibition of thelocomotor stimulant effect of phencyclidine (PCP, 8 mg/kg). Although (-) baclofen was found to be the most effective PCP antagonist, its (+) isomer was inactive. The maximum blocking effect of AOAA was seen in animals treated 3 and 6 hr earlier. Except for gamma-acetylenic GABA, none of these drugs significantly blocked the locomotor stimulant effect of d-amphetamine (3 mg/kg, IP). Diazepam reduced d-amphetamine response, but failed to influence PCP-induced stimulation. The locomotor stimulant effect of PCP, unlike that of d-amphetamine, may be the result of a specific GABA antagonistic effect at certain dopamine-rich areas of the brain. It seems that (-) baclofen may prove to be useful in the management of PCP intoxication. Administration of higher doses of PCP (20 and 50 mg/kg) in mice pretreated with (-) baclofen resulted in the development of surgical anesthesia manifested as the loss of a) righting reflex, b) pain sensation and c) corneal reflex. The duration of the general anesthetic response was found to be a function of the doses of both (-) baclofen and PCP. The possible use of (-) baclofen as an adjuvant to general anesthetic is discussed.
Yin, Hang; Flynn, Aaron D.
The majority of therapeutics target membrane proteins, accessible on the surface of cells, to alter cellular signaling. Cells use membrane proteins to transduce signals into cells, transport ions and molecules, bind the cell to a surface or substrate, and catalyze reactions. Newly devised technologies allow us to drug conventionally “undruggable” regions of membrane proteins, enabling modulation of protein–protein, protein–lipid, and protein–nucleic acid interactions. In this review, we survey the state of the art in high-throughput screening and rational design in drug discovery, and we evaluate the advances in biological understanding and technological capacity that will drive pharmacotherapy forward against unorthodox membrane protein targets. PMID:26863923
Lai, Yurong; Mandlekar, Sandhya; Shen, Hong; Holenarsipur, Vinay K; Langish, Robert; Rajanna, Prabhakar; Murugesan, Senthilkumar; Gaud, Nilesh; Selvam, Sabariya; Date, Onkar; Cheng, Yaofeng; Shipkova, Petia; Dai, Jun; Humphreys, William G; Marathe, Punit
In the present study, an open-label, three-treatment, three-period clinical study of rosuvastatin (RSV) and rifampicin (RIF) when administered alone and in combination was conducted in 12 male healthy subjects to determine if coproporphyrin I (CP-I) and coproporphyrin III (CP-III) could serve as clinical biomarkers for organic anion transporting polypeptide 1B1 (OATP1B1) and 1B3 that belong to the solute carrier organic anion gene subfamily. Genotyping of the human OATP1B1 gene was performed in all 12 subjects and confirmed absence of OATP1B1*5 and OATP1B1*15 mutations. Average plasma concentrations of CP-I and CP-III prior to drug administration were 0.91 ± 0.21 and 0.15 ± 0.04 nM, respectively, with minimum fluctuation over the three periods. CP-I was passively eliminated, whereas CP-III was actively secreted from urine. Administration of RSV caused no significant changes in the plasma and urinary profiles of CP-I and CP-III. RIF markedly increased the maximum plasma concentration (Cmax) of CP-I and CP-III by 5.7- and 5.4-fold (RIF) or 5.7- and 6.5-fold (RIF+RSV), respectively, as compared with the predose values. The area under the plasma concentration curves from time 0 to 24 h (AUC0-24h) of CP-I and CP-III with RIF and RSV increased by 4.0- and 3.3-fold, respectively, when compared with RSV alone. In agreement with this finding, Cmax and AUC0-24h of RSV increased by 13.2- and 5.0-fold, respectively, when RIF was coadministered. Collectively, we conclude that CP-I and CP-III in plasma and urine can be appropriate endogenous biomarkers specifically and reliably reflecting OATP inhibition, and thus the measurement of these molecules can serve as a useful tool to assess OATP drug-drug interaction liabilities in early clinical studies.
Jang, Graham; Kaufman, Allegra; Lee, Edward; Hamilton, Lisa; Hutton, Shauna; Egbuna, Ogo; Padhi, Desmond
Drug–disease interactions involving therapeutic proteins that target cytokines and potentially impact cytochrome P450 (CYP) enzymes have been of increased interest to drug regulatory agencies and industry sponsors in recent years. This parallel-group open-label study evaluated the effects of the monoclonal antibody denosumab, an inhibitor of the cytokine RANKL, on the pharmacokinetics of the probe CYP3A4 substrate midazolam in postmenopausal women with osteoporosis. The pharmacokinetics of a 2 mg oral dose of midazolam was evaluated on days 1 and 16. Subjects in Group A received a 60 mg subcutaneous dose of denosumab on day 2, 2 weeks before the second midazolam dose, while subjects in Group B did not. For Group A (n = 17), point estimates for the ratio of least square means for midazolam exposures based on maximum observed plasma concentration (Cmax) and areas under the plasma concentration–time curve (AUCs) on day 16 versus day 1 ranged from 1.02 to 1.04 and 90% confidence intervals were within 0.80–1.25. No period effect was observed for Group B (n = 8). Midazolam and denosumab coadministration was safe and well tolerated. Inhibition of the cytokine RANKL by denosumab does not affect CYP3A4 in postmenopausal women with osteoporosis and will not alter the pharmacokinetics of drugs metabolized by this enzyme. These results are consistent with data suggesting that RANKL does not impact markers of inflammation and represent the first clinical data demonstrating a lack of effect on CYP3A4 of a therapeutic protein that is a cytokine modulator. PMID:25505582
Staltari, Orietta; Leporini, Christian; Caroleo, Benedetto; Russo, Emilio; Siniscalchi, Antonio; De Sarro, Giovambattista; Gallelli, Luca
With the advances in antiretroviral (ARV) therapy, patients with Human Immunodeficiency Virus (HIV) infection are living longer, however, some patients encounter co- morbidities which sometimes require treatment. Therefore, during the treatment with ARV drugs these patients could take several recreational drugs (e.g. amphetamines, hallucinogenes, opiates, or alcohol) with a possible development of drug-drug interactions (DDIs). In particular, Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs/NtRTIs) are mainly excreted through the kidney and are not substrates of the cytochrome P450 or P-glycoprotein, therefore the DDIs during this treatment are minimal. In contrast, the other ARV drugs (i.e. non-nucleoside reversetranscriptase inhibitors, Protease inhibitors, Integrase inhibitors, chemokine receptor 5 antagonists and HIV-fusion inhibitors) are an important class of antiretroviral medications that are frequent components of HAART regimens but show several DDIs related to interaction with the cytochrome P450 or P-glycoprotein. In this paper we will review data concerning the possibility of DDI in HIV patients treated with ARV and taking recreational drugs.
Patel, Risha I.; Beckett, Robert D.
Objective The research sought to evaluate seven drug information resources, specifically designed for analyzing drug interactions for scope, completeness, and ease of use, and determine the consistency of content among the seven resources. Methods A cross-sectional study was conducted where 100 drug-drug and drug-dietary supplement interactions were analyzed using 7 drug information resources: Lexicomp Interactions module, Micromedex Drug Interactions, Clinical Pharmacology Drug Interaction Report, Facts & Comparisons eAnswers, Stockley's Drug Interactions (10th edition), Drug Interactions Analysis and Management (2014), and Drug Interaction Facts (2015). The interaction sample was developed based on published resources and peer input. Two independent reviewers gathered data for each interaction from each of the 7 resources using a common form. Results Eighty-two drug-drug and 18 drug-dietary supplement interactions were analyzed. Scope scores were higher for Lexicomp Interactions (97.0%), Clinical Pharmacology Drug Interaction Report (97.0%), and Micromedex Drug Interactions (93.0%) compared to all other resources (p<0.05 for each comparison). Overall completeness scores were higher for Micromedex Drug Interactions (median 5, interquartile range [IQR] 4 to 5) compared to all other resources (p<0.01 for each comparison) and were higher for Lexicomp Interactions (median 4, IQR 4 to 5), Facts & Comparisons eAnswers (median 4, IQR 4 to 5), and Drug Interaction Facts (4, IQR 4 to 5) compared to all other resources, except Micromedex (p<0.05 for each comparison). Ease of use, in terms of time to locate information and time to gather information, was similar among resources. Consistency score was higher for Micromedex (69.9%) compared to all other resources (p<0.05 for each comparison). Conclusions Clinical Pharmacology Drug Interaction Report, Lexicomp Interactions, and Micromedex Drug Interactions scored highest in scope. Micromedex Drug Interactions and Lexicomp
Schneider, Elena K; Huang, Johnny X; Carbone, Vincenzo; Baker, Mark; Azad, Mohammad A K; Cooper, Matthew A; Li, Jian; Velkov, Tony
Ivacaftor is a novel cystic fibrosis (CF) transmembrane conductance regulator (CFTR) potentiator that improves the pulmonary function for patients with CF bearing a G551D CFTR-protein mutation. Because ivacaftor is highly bound (>97%) to plasma proteins, there is the strong possibility that co-administered CF drugs may compete for the same plasma protein binding sites and impact the free drug concentration. This, in turn, could lead to drastic changes in the in vivo efficacy of ivacaftor and therapeutic outcomes. This biochemical study compares the binding affinity of ivacaftor and co-administered CF drugs for human serum albumin (HSA) and α1 -acid glycoprotein (AGP) using surface plasmon resonance and fluorimetric binding assays that measure the displacement of site-selective probes. Because of their ability to strongly compete for the ivacaftor binding sites on HSA and AGP, drug-drug interactions between ivacaftor are to be expected with ducosate, montelukast, ibuprofen, dicloxacillin, omeprazole, and loratadine. The significance of these plasma protein drug-drug interactions is also interpreted in terms of molecular docking simulations. This in vitro study provides valuable insights into the plasma protein drug-drug interactions of ivacaftor with co-administered CF drugs. The data may prove useful in future clinical trials for a staggered treatment that aims to maximize the effective free drug concentration and clinical efficacy of ivacaftor.
Hansen, J M; Christensen, L K
The effect of the oral sulphonylurea hypoglycaemic drugs may be influenced by a large number of other drugs. Some of these combinations (e.g. phenylbutazone, sulphaphenazole) may result in cases of severe hypoglycaemic collapse. Tolbutamide and chlorpropamide should never be given to a patient without a prior careful check of which medicaments are already being given. Similarly, no drug should be given to a diabetic treated with tolbutamide and chlorpropamide without consideration of the possibility of interaction phenomena.
Investigational small-molecule drug selectively suppresses constitutive CYP2B6 activity at the gene transcription level: physiologically based pharmacokinetic model assessment of clinical drug interaction risk.
Zamek-Gliszczynski, Maciej J; Mohutsky, Michael A; Rehmel, Jessica L F; Ke, Alice B
The glycogen synthase kinase-3 inhibitor LY2090314 specifically impaired CYP2B6 activity during in vitro evaluation of cytochrome P450 (P450) enzyme induction in human hepatocytes. CYP2B6 catalytic activity was significantly decreased following 3-day incubation with 0.1-10 μM LY2090314, on average by 64.3% ± 5.0% at 10 μM. These levels of LY2090314 exposure were not cytotoxic to hepatocytes and did not reduce CYP1A2 and CYP3A activities. LY2090314 was not a time-dependent CYP2B6 inhibitor, did not otherwise inhibit enzyme activity at concentrations ≤10 μM, and was not metabolized by CYP2B6. Thus, mechanism-based inactivation or other direct interaction with the enzyme could not explain the observed reduction in CYP2B6 activity. Instead, LY2090314 significantly reduced CYP2B6 mRNA levels (Imax = 61.9% ± 1.4%; IC50 = 0.049 ± 0.043 μM), which were significantly correlated with catalytic activity (r(2) = 0.87, slope = 0.77; Imax = 57.0% ± 10.8%, IC50 = 0.057 ± 0.027 μM). Direct inhibition of constitutive androstane receptor by LY2090314 is conceptually consistent with the observed CYP2B6 transcriptional suppression (Imax = 100.0% ± 10.8% and 57.1% ± 2.4%; IC50 = 2.5 ± 1.2 and 2.1 ± 0.4 μM for isoforms 1 and 3, respectively) and may be sufficiently extensive to overcome the weak but potent activation of pregnane X receptor by ≤10 μM LY2090314 (19.3% ± 2.2% of maximal rifampin response, apparent EC50 = 1.2 ± 1.1 nM). The clinical relevance of these findings was evaluated through physiologically based pharmacokinetic model simulations. CYP2B6 suppression by LY2090314 is not expected clinically, with a projected <1% decrease in hepatic enzyme activity and <1% decrease in hydroxybupropion exposure following bupropion coadministration. However, simulations showed that observed CYP2B6 suppression could be clinically relevant for a drug with different pharmacokinetic properties from LY2090314.
Greim, Julie A; Shek, Caroline; Jones, Linda; Macauley, Robert; Paterno, Marilyn; Blumenfeld, Barry H; Kuperman, Gilad
According to the Institute of Medicine's (IOM) 1999 report To Err is Human: Building a safer Health System, "medical errors kill some 44,000-98,0001 people in U.S. hospitals each year. Partners HealthCare System (PHS) is a large integrated delivery network in Boston, MA, which has as a goal improving patient care by preventing adverse drug events (ADE) and reducing medication errors enterprise-wide. PHS has developed a drug-drug Interaction (DDI) detection feature, for the suite of clinical applications currently used by its two major teaching institutions, Brigham & Women's Hospital (BWH) and Mass General Hospital (MGH). The following clinical applications will be using this drug-drug interaction feature: NICU Order Entry (OE) at BWH, MGH OE for pediatrics and adults, the Partners outpatient medical record, The LMR, and BICS OE at BWH.
Fahmi, Odette A; Hurst, Susan; Plowchalk, David; Cook, Jack; Guo, Feng; Youdim, Kuresh; Dickins, Maurice; Phipps, Alex; Darekar, Amanda; Hyland, Ruth; Obach, R Scott
Cytochrome P450 3A4 (CYP3A4) is the most important enzyme in drug metabolism and because it is the most frequent target for pharmacokinetic drug-drug interactions (DDIs) it is highly desirable to be able to predict CYP3A4-based DDIs from in vitro data. In this study, the prediction of clinical DDIs for 30 drugs on the pharmacokinetics of midazolam, a probe substrate for CYP3A4, was done using in vitro inhibition, inactivation, and induction data. Two DDI prediction approaches were used, which account for effects at both the liver and intestine. The first was a model that simultaneously combines reversible inhibition, time-dependent inactivation, and induction data with static estimates of relevant in vivo concentrations of the precipitant drug to provide point estimates of the average magnitude of change in midazolam exposure. This model yielded a success rate of 88% in discerning DDIs with a mean -fold error of 1.74. The second model was a computational physiologically based pharmacokinetic model that uses dynamic estimates of in vivo concentrations of the precipitant drug and accounts for interindividual variability among the population (Simcyp). This model yielded success rates of 88 and 90% (for "steady-state" and "time-based" approaches, respectively) and mean -fold errors of 1.59 and 1.47. From these findings it can be concluded that in vivo DDIs for CYP3A4 can be predicted from in vitro data, even when more than one biochemical phenomenon occurs simultaneously.
Troisi, Joseph R.
Drug abuse remains costly. Drug-related cues can evoke cue-reactivity and craving, contributing to relapse. The Pavlovian extinction-based cue-exposure therapy (CET) has not been very successful in treating drug abuse. A functional operant analysis of complex rituals involved in CET is outlined and reinterpreted as an operant heterogeneous chain maintained by observing responses, conditioned reinforcers, and discriminative stimuli. It is further noted that operant functions are not predicated on Pavlovian processes but can be influenced by them in contributing to relapse; several empirical studies from the animal and human literature highlight this view. Cue-reactivity evoked by Pavlovian processes is conceptualized as an operant establishing/motivating operation. CET may be more effective in incorporating an operant-based approach that takes into account the complexity of Pavlovian–operant interaction. Extinction of the operant chain coupled with the shaping of alternative behaviors is proposed as an integrated therapy. It is proposed that operant-based drug abuse treatments (contingency management, voucher programs, and the therapeutic work environment) might consider incorporating cue-reactivity, as establishing/motivating operations, to increase long-term success—a hybrid approach based on Pavlovian–operant interaction. PMID:25346551
Hromadkova, L; Soukup, T; Vlcek, J
Despite the fact that biological treatments are very promising, classical immunosuppressants, antimalarial drugs and glucocorticosteroids are still very important and widely used in practice. Although drug interactions can have fatal consequences, few studies have reviewed drug interactions of these classical drugs used in rheumatology, and very few guidelines are available on this subject. Therefore, this report summarizes important interactions of immunosuppressants, antimalarial drugs and glucocorticosteroids with drugs commonly used in internal medicine. In the present study, more than 300 interactions were retrieved from the Micromedex ® database. The selection was reduced to the interactions rated as moderate, major or contraindicated. The selected interactions were further checked against PubMed ®, MEDLINE ®, InfoPharm Compendium of Drug Interactions and Summaries of Product Characteristics. For each interaction, its nature, mechanism, onset and clinical severity were indicated, documentation quality was rated and recommendations for clinical practice were formulated. Twenty significant interactions that we rated as moderate, severe and very severe were identified. Interacting drugs were warfarin, fluoroquinolones, azole antifungals, co-trimoxazole, proton pump inhibitors, amiodarone, cholestyramine, activated carbon, allopurinol, angiotensin-converting enzyme inhibitors, statins, digoxin, iron, aluminium and magnesium salts, and hepatotoxic and nephrotoxic agents.
Pellegrino, Paolo; Clementi, Emilio; Capuano, Annalisa; Radice, Sonia
Vaccines are safe and efficacious in reducing the burden of several serious infections affecting children and adults. Due to their efficacy, vaccines are often administered in patients with chronic diseases, likely to be under poly-therapy. Because of several case reports indicating changes in drug metabolism after vaccination, the hypothesis of an interaction between vaccines and specific drugs has been put forward. These interactions are conceivably of great concern, especially in patients treated with molecules characterised by a narrow therapeutic index. Herein, we review and systematise the available evidence on vaccine-drug interactions. The picture that emerges indicates that reduction in the activity of specific CYPs following vaccination may occur, most likely via interferon γ overproduction, and for specific drugs such as anticonvulsivant and theophylline may have significant clinical relevance. Clinical interaction between vaccines and drugs that are metabolised by cytochromes uninfluenced by INFγ levels, such as warfarin, are instead unlikely to happen. Further studies are however needed to gain a complete picture of vaccine-drug interactions and define their relevance in terms of possible negative clinical impact.
Becker, Daniel E.
Autonomic drugs are used clinically to either imitate or inhibit the normal functions of the sympathetic and parasympathetic nervous systems. A large number of additional drug classes also interact with these systems to produce a stunning number of possible side effects. This article reviews the basic function of the autonomic nervous system and the various drug classes that act within these neural synapses. PMID:23241039
Pelliccia, Francesco; Rollini, Fabiana; Marazzi, Giuseppe; Greco, Cesare; Gaudio, Carlo; Angiolillo, Dominick J
The combination of aspirin and the thienopyridine clopidogrel is a cornerstone in the prevention of atherothrombotic events. These two agents act in concert to ameliorate the prothrombotic processes stimulated by plaque rupture and vessel injury complicating cardiovascular disease. Guidelines recommend the use of clopidogrel in patients with acute coronary syndromes and in those undergoing percutaneous coronary intervention, and the drug remains the most utilized P2Y12 receptor inhibitor despite the fact that newer antiplatelet agents are now available. In recent years, numerous studies have shown inconsistency in the efficacy of clopidogrel to prevent atherothrombotic events. Studies of platelet function testing have shown variability in the response to clopidogrel. One of the major reason for this phenomenon lies in the interaction between clopidogrel and other drugs that may affect clopidogrel absorption, metabolism, and ultimately its antiplatelet action. Importantly, these drug-drug interactions have prognostic implications, since patients with high on-treatment platelet reactivity associated with reduced clopidogrel metabolism have an increased risk of ischemia. Previous systematic reviews have focused on drug-drug interactions between clopidogrel and specific pharmacologic classes, such as proton pump inhibitors, calcium channel blockers, and statins. However, more recent pieces of scientific evidence show that clopidogrel may also interact with newer drugs that are now available for the treatment of cardiovascular patients. Accordingly, the aim of this review is to highlight and discuss recent data on drug-drug interactions between clopidogrel and third-generation proton pump inhibitors, pantoprazole and lansoprazole, statins, pitavastatin, and antianginal drug, ranolazine.
Aman, Syed Faisal; Hassan, Fouzia; Naqvi, Baqar S; Hasan, Syed Muhammmad Farid
Medicines can treat and alleviate many diseases provided that they must be taken properly to ensure that they are safe and useful. One issue related with the medicines is that whether to take on empty stomach or with food. The present work gives information regarding food-drug interactions that were studied by collecting seventy five prescriptions from various hospitals. In most of the collected prescriptions, food-drug interactions were detected using the literature available. It was also found that only few studies have been carried out so far on the effect of food on drug disposition in the Asian population. Thus more studies on food-drug interactions particularly in the local population is recommended in order to determine the effect of food and food components on drug disposition and to the kinetics of the drugs which has not yet well highlighted in this part of the world.
Xu, Jingyu; Wang, Panpan; Yang, Hong; Li, Yinghong; Yu, Chunyan; Tian, Yubin
Kinase is one of the most productive classes of established targets, but the majority of approved drugs against kinase were developed only for cancer. Intensive efforts were therefore exerted for releasing its therapeutic potential by discovering new therapeutic area. Kinases in clinical trial could provide great opportunities for treating various diseases. However, no systematic comparison between system profiles of established targets and those of clinical trial ones was conducted. The reveal of probable difference or shift of trend would help to identify key factors defining druggability of established targets. In this study, a comparative analysis of system profiles of both types of targets was conducted. Consequently, the systems profiles of the majority of clinical trial kinases were identified to be very similar to those of established ones, but percentages of established targets obeying the system profiles appeared to be slightly but consistently higher than those of clinical trial targets. Moreover, a shift of trend in the system profiles from the clinical trial to the established targets was identified, and popular kinase targets were discovered. In sum, this comparative study may help to facilitate the identification of the druggability of established drug targets by their system profiles and drug-target interaction networks. PMID:27547755
The effect of drugs such as glucocorticoids and thyroid extract on calcium metabolism is unknown. However, several other medications affect the excretion and intestinal absorption of calcium. A controlled study was carried out to investigate these aspects. Urinary calcium was determined for 3 months during the long-term intake of the antituberculous drug isoniazid (INH) and of the antibiotic tetracycline. The effect of the diuretics furosemide and hydrochlorothiazide, of several aluminum-containing antacids, of thyroid extract and of corticosteroids was also studied. Metabolic balances of calcium, phosphorus, magnesium and zinc were determined, as well as the intestinal absorption of calcium using Ca 47. Plasma levels, urinary and fecal excretions of Ca 47 were determined. All drugs tested increased urinary calcium except for the diuretic hydrochlorothiazide. Regarding the effect of corticosteroids: the intestinal absorption of calcium was unchanged after the short-term use and was very high after long-term use. The studies have shown that several commonly used drugs induce an increase in urinary calcium excretion which may contribute to calcium loss, if this increase persists for prolonged periods of time. Urinary excretions of phosphorus, magnesium and zinc increased in some of the studies.
Lal, Ritu; Sukbuntherng, Juthamas; Luo, Wendy; Vicente, Virna; Blumenthal, Robin; Ho, Judy; Cundy, Kenneth C
AIM Gabapentin enacarbil, a transported prodrug of gabapentin, provides sustained, dose-proportional exposure to gabapentin. Unlike gabapentin, the prodrug is absorbed throughout the intestinal tract by high-capacity nutrient transporters, including mono-carboxylate transporter-1 (MCT-1). Once absorbed, gabapentin enacarbil is rapidly hydrolyzed to gabapentin, which is subsequently excreted by renal elimination via organic cation transporters (OCT2). To examine the potential for drug–drug interactions at these two transporters, the pharmacokinetics of gabapentin enacarbil were evaluated in healthy adults after administration alone or in combination with either naproxen (an MCT-1 substrate) or cimetidine (an OCT2 substrate). METHODS Subjects (n= 12 in each study) received doses of study drug until steady state was achieved; 1200 mg gabapentin enacarbil each day, followed by either naproxen (500 mg twice daily) or cimetidine (400 mg four times daily) followed by the combination. RESULTS When gabapentin enacarbil was co-administered with naproxen, gabapentin Css,max increased by, on average, 8% and AUC by, on average, 13%. When gabapentin enacarbil was co-administered with cimetidine, gabapentin AUCss increased by 24% and renal clearance of gabapentin decreased. Co-administration with gabapentin enacarbil did not affect naproxen or cimetidine exposure. Gabapentin enacarbil was generally well tolerated. CONCLUSIONS No gabapentin enacarbil dose adjustment is needed with co-administration of naproxen or cimetidine. PMID:20573085
... HIV Treatment Services HIV Treatment What is a Drug Interaction? (Last updated 3/13/2017; last reviewed ... taking or plan to take. What is a drug interaction? A drug interaction is a reaction between ...
Gurley, Bill J; Swain, Ashley; Williams, D Keith; Barone, Gary; Battu, Sunil K
Concomitant administration of botanical supplements with drugs that are P-glycoprotein (P-gp) substrates may produce clinically significant herb-drug interactions. This study evaluated the effects of St. John's wort and Echinacea on the pharmacokinetics of digoxin, a recognized P-gp substrate. Eighteen healthy volunteers were randomly assigned to receive a standardized St. John's wort (300 mg three times daily) or Echinacea (267 mg three times daily) supplement for 14 days, followed by a 30-day washout period. Subjects were also randomized to receive rifampin (300 mg twice daily, 7 days) and clarithromycin (500 mg twice daily, 7 days) as positive controls for P-gp induction and inhibition, respectively. Digoxin (Lanoxin 0.25 mg) was administered orally before and after each supplementation and control period. Serial digoxin plasma concentrations were obtained over 24 h and analyzed by chemiluminescent immunoassay. Comparisons of area under the curve (AUC)((0-3)), AUC((0-24)), elimination half-life, and maximum serum concentration were used to assess the effects of St. John's wort, Echinacea, rifampin, and clarithromycin on digoxin disposition. St. John's wort and rifampin both produced significant reductions (p < 0.05) in AUC((0-3)), AUC((0-24)), and C(max), while clarithromycin increased these parameters significantly (p < 0.05). Echinacea supplementation did not affect digoxin pharmacokinetics. Clinically significant P-gp-mediated herb-drug interactions are more likely to occur with St. John's wort than with Echinacea.
Bogetti-Salazar, Michele; González-González, Cesar; Juárez-Cedillo, Teresa; Sánchez-García, Sergio; Rosas-Carrasco, Oscar
OBJECTIVE: To identify the main severe potential drug-drug interactions in older adults with dementia and to examine the factors associated with these interactions. METHOD: This was a cross-sectional study. The enrolled patients were selected from six geriatrics clinics of tertiary care hospitals across Mexico City. The patients had received a clinical diagnosis of dementia based on the current standards and were further divided into the following two groups: those with severe drug-drug interactions (contraindicated/severe) (n=64) and those with non-severe drug-drug interactions (moderate/minor/absent) (n=117). Additional socio-demographic, clinical and caregiver data were included. Potential drug-drug interactions were identified using Micromedex Drug Reax 2.0® database. RESULTS: A total of 181 patients were enrolled, including 57 men (31.5%) and 124 women (68.5%) with a mean age of 80.11±8.28 years. One hundred and seven (59.1%) patients in our population had potential drug-drug interactions, of which 64 (59.81%) were severe/contraindicated. The main severe potential drug-drug interactions were caused by the combinations citalopram/anti-platelet (11.6%), clopidogrel/omeprazole (6.1%), and clopidogrel/aspirin (5.5%). Depression, the use of a higher number of medications, dementia severity and caregiver burden were the most significant factors associated with severe potential drug-drug interactions. CONCLUSIONS: Older people with dementia experience many severe potential drug-drug interactions. Anti-depressants, antiplatelets, anti-psychotics and omeprazole were the drugs most commonly involved in these interactions. Despite their frequent use, anti-dementia drugs were not involved in severe potential drug-drug interactions. The number and type of medications taken, dementia severity and depression in patients in addition to caregiver burden should be considered to avoid possible drug interactions in this population. PMID:26872079
Diaconu, Camelia Harapu; Cuciureanu, Magdalena; Vlase, L; Cuciureanu, Rodica
Food-drug interactions are increasingly recognized as important clinical events which may change significantly the bioavailability of oral administrated drugs. Grapefruit juice (GFJ) demonstrated multiple interactions with drugs leading to loss of the therapeutic effects or increased side-effects. GFJ decreases pre-systemic metabolism through a) competitive or mechanism-based inhibition of gut wall CYP3A4 isoenzymes and b) P-glycoprotein (P-gp), c) multidrug resistance protein-2 (MRP2) or d) organic anion-transporting polypeptide (OATP) inhibition. Although, GFJ presents high amounts of flavonoids (e.g. naringin, naringenin), furanocoumarins (e.g. 6',7'-dihydroxybergamottin, bergamottin) are the main chemicals involved in the pharmacokinetic interactions. As compounds of GFJ show additive or synergistic effects, all the major furanocoumarins are necessary for the maximal inhibitory effect. Also, related citrus fruits (sweeties, pummelo and sour orange) or various plants containing furanocoumarins may present pharmacological interactions, yet to be discovered.
Virtual Clinical Trial Toward Polytherapy Safety Assessment: Combination of Physiologically Based Pharmacokinetic/Pharmacodynamic-Based Modeling and Simulation Approach With Drug-Drug Interactions Involving Terfenadine as an Example.
Wiśniowska, Barbara; Polak, Sebastian
A Quantitative Systems Pharmacology approach was utilized to predict the cardiac consequences of drug-drug interaction (DDI) at the population level. The Simcyp in vitro-in vivo correlation and physiologically based pharmacokinetic platform was used to predict the pharmacokinetic profile of terfenadine following co-administration of the drug. Electrophysiological effects were simulated using the Cardiac Safety Simulator. The modulation of ion channel activity was dependent on the inhibitory potential of drugs on the main cardiac ion channels and a simulated free heart tissue concentration. ten Tusscher's human ventricular cardiomyocyte model was used to simulate the pseudo-ECG traces and further predict the pharmacodynamic consequences of DDI. Consistent with clinical observations, predicted plasma concentration profiles of terfenadine show considerable intra-subject variability with recorded Cmax values below 5 ng/mL for most virtual subjects. The pharmacokinetic and pharmacodynamic effects of inhibitors were predicted with reasonable accuracy. In all cases, a combination of the physiologically based pharmacokinetic and physiology-based pharmacodynamic models was able to differentiate between the terfenadine alone and terfenadine + inhibitor scenario. The range of QT prolongation was comparable in the clinical and virtual studies. The results indicate that mechanistic in vitro-in vivo correlation can be applied to predict the clinical effects of DDI even without comprehensive knowledge on all mechanisms contributing to the interaction.
de Boer, Alie; van Hunsel, Florence; Bast, Aalt
Food supplements and herbal products are increasingly popular amongst consumers. This leads to increased risks of interactions between prescribed drugs and these products containing bioactive ingredients. From 1991 up to 2014, 55 cases of suspected adverse drug reactions due to concomitant intake of health-enhancing products and drugs were reported to Lareb, the Netherlands Pharmacovigilance Centre. An overview of these suspected interactions is presented and their potential mechanisms of action are described. Mainly during the metabolism of xenobiotics and due to the pharmacodynamics effects interactions seem to occur, which may result in adverse drug reactions. Where legislation is seen to distinct food and medicine, legislation concerning these different bioactive products is less clear-cut. This can only be resolved by increasing the molecular knowledge on bioactive substances and their potential interactions. Thereby potential interactions can be better understood and prevented on an individual level. By considering the dietary pattern and use of bioactive substances with prescribed medication, both health professionals and consumers will be increasingly aware of interactions and these interactive adverse effects can be prevented.
Yin, Jia; Wang, Joanne
The kidney is a vital organ for the elimination of therapeutic drugs and their metabolites. Renal drug transporters, which are primarily located in the renal proximal tubules, play an important role in tubular secretion and reabsorption of drug molecules in the kidney. Tubular secretion is characterized by high clearance capacities, broad substrate specificities, and distinct charge selectivity for organic cations and anions. In the past two decades, substantial progress has been made in understanding the roles of transporters in drug disposition, efficacy, toxicity and drug-drug interactions (DDIs). In the kidney, several transporters are involved in renal handling of organic cation (OC) and organic anion (OA) drugs. These transporters are increasingly recognized as the target for clinically significant DDIs. This review focuses on the functional characteristics of major human renal drug transporters and their involvement in clinically significant DDIs.
Poirier, T I; Giudici, R A
Drug Master 89 was evaluated using general and specific criteria. The installation process, ease of learning, and ease of use were rated excellent. The technical support, scope of coverage, and overall clinical performance were rated good. The quality of the clinical documentation and frequency of updates were fair, while the quality of the user documentation was poor. The program is valuable to the clinical dietician because of the comprehensiveness of its dietary and food interactions data base. For the practicing pharmacist, it performs reasonably well but other available programs are better values.
Hodel, M; Genné, D
Antibiotics are widely prescribed in medical practice. Many of them induce or are subject to interactions that may diminish their anti-infectious efficiency or elicit toxic effects. Food intake can influence the effectiveness of an antibiotic. Certain antibiotics can lower the effectiveness of oral contraception. Oral anticoagulation can be influenced to a great extent by antibiotics and controls are necessary. Interactions are also possible via enzymatic induction or inhibition of cytochromes. The use of an interaction list with substrates of cytochromes enables to anticipate. Every new prescription should consider a possible drug or food interaction.
Ghalib, Mohammed; Chaudhary, Imran; Goel, Sanjay
Background Drug interactions in oncology are common place and largely ignored as we tolerate high thresholds of ‘toxic’ drug responses in these patients. However, in the era of ‘targeted’ or seemingly ‘less toxic’ therapy, these interactions are more commonly flagged and contribute significantly towards poor ‘quality of life’ and medical fatalities. Objective This review and opinion article focuses on alteration of chemotherapeutic pharmacokinetic profiles by drug interactions in the setting of polypharmacy. The assumption is that the drugs, with changes in their pharmacokinetics, will contribute towards changes in their pharmacodynamics. Methods The examples cited for such drug–drug interactions are culled from published literature with an emphasis on those interactions that have been well characterized at the molecular level. Results Although very few drug interaction studies have been performed on approved oncology based drugs, it is clear that drugs whose pharmacokinetics profiles are closely related to their pharmacodynamics will indeed result in clinically important drug interactions. Some newer mechanisms are described that involve interactions at the level of gene transcription, whereby, drug metabolism is significantly altered. However, for any given drug interaction, there does not seem to be a comprehensive model describing interactions. Conclusions Mechanisms based drug interactions are plentiful in oncology; however, there is an absolute lack of a comprehensive model that would predict drug–drug interactions. PMID:19239394
Context: Drug-drug interactions(DDIs) are significant but avoidable causes of iatrogenic morbidity and hospital admission. Aim: To detect potential drug-drug interactions among medications received by hypertensive patients. Materials and Methods: Patients of both sex and all adult age groups, who were attending medicine out -patient department (OPD) of a tertiary care teaching rural hospital since last six months and were being prescribed antihypertensive drug/s for essential hypertension, were selected for the study. Hypertensive patient with co-morbities diabetes mellitus, ischemic heart diseases, congestive heart failure, and chronic renal diseases were also included in the study. Potential drug drug interactions were checked with medscape drug interaction software. Results: With the help of medscape drug interaction software, 71.50% prescriptions were identified having atleast one drug-drug interaction. Total 918 DDIs were found in between 58 drug pairs. 55.23% DDIs were pharmacodynamic, 4.79% pharmacokinetic type of DDIs. 32.24% DDIs were found affecting serum potassium level. 95.42% DDIs were found significant type of DDIs. Drug drug interaction between atenolol & amlodipine was the most common DDI (136) followed by metoprolol and amlodine (88) in this study. Atenolol and amlodipine ( 25.92%) was the most common drugs to cause DDIs in our study. Conclusion: We detected a significant number of drug drug interaction in hypertensive patients. These interactions were between antihypertensive agents or between hypertensive and drug for co-morbid condition. PMID:25584241
Prakash, Chandra; Zuniga, Baltazar; Song, Chung Seog; Jiang, Shoulei; Cropper, Jodie; Park, Sulgi; Chatterjee, Bandana
Orally delivered small-molecule therapeutics are metabolized in the liver and intestine by phase I and phase II drug-metabolizing enzymes (DMEs), and transport proteins coordinate drug influx (phase 0) and drug/drug-metabolite efflux (phase III). Genes involved in drug metabolism and disposition are induced by xenobiotic-activated nuclear receptors (NRs), i.e. PXR (pregnane X receptor) and CAR (constitutive androstane receptor), and by the 1α, 25-dihydroxy vitamin D3-activated vitamin D receptor (VDR), due to transactivation of xenobiotic-response elements (XREs) present in phase 0-III genes. Additional NRs, like HNF4-α, FXR, LXR-α play important roles in drug metabolism in certain settings, such as in relation to cholesterol and bile acid metabolism. The phase I enzymes CYP3A4/A5, CYP2D6, CYP2B6, CYP2C9, CYP2C19, CYP1A2, CYP2C8, CYP2A6, CYP2J2, and CYP2E1 metabolize >90% of all prescription drugs, and phase II conjugation of hydrophilic functional groups (with/without phase I modification) facilitates drug clearance. The conjugation step is mediated by broad-specificity transferases like UGTs, SULTs, GSTs. This review delves into our current understanding of PXR/CAR/VDR-mediated regulation of DME and transporter expression, as well as effects of single nucleotide polymorphism (SNP) and epigenome (specified by promoter methylation, histone modification, microRNAs, long non coding RNAs) on the expression of PXR/CAR/VDR and phase 0-III mediators, and their impacts on variable drug response. Therapeutic agents that target epigenetic regulation and the molecular basis and consequences (overdosing, underdosing, or beneficial outcome) of drug-drug/drug-food/drug-herb interactions are also discussed. Precision medicine requires understanding of a drug's impact on DME and transporter activity and their NR-regulated expression in order to achieve optimal drug efficacy without adverse drug reactions. In future drug screening, new tools such as humanized mouse models and
Greenblatt, David J
Medications used to treat human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections present a special challenge with respect to the management of potential and actual drug-drug interactions (DDIs). The HIV and HCV treatments may interact with each other, and also interact with drugs of abuse and/or with medications used to treat substance abuse. Possible mechanisms of these DDIs generally include induction or inhibition of activity/expression of human cytochromes P450, glucuronosyl transferases, or energy-dependent transport proteins. These DDIs can be complex and time-dependent in nature. Because time and resources available for new drug development are necessarily limited, not all potential DDIs can be evaluated via clinical pharmacokinetic studies in the course of development of HIV, HCV, and substance abuse treatments. Strategies are needed to refine existing in vitro models and screening techniques to allow more efficient targeting of resources to those clinical studies having the highest impact in terms of enhancing medication effectiveness and patient safety.
Dürrbeck, A; Nenoff, P
The allylamine terbinafine is the probably most frequently prescribed systemic antifungal agent in Germany for the treatment of dermatomycoses and onychomycoses. According to the German drug law, terbinafine is approved for patients who are 18 years and older; however, this antifungal agent is increasingly used off-label for treatment of onychomycoses and tinea capitis in children. Terbinafine is associated with only a few interactions with other drugs, which is why terbinafine can generally be used without problems in older and multimorbid patients. Nevertheless, some potential interactions of terbinafine with certain drug substances are known, including substances of the group of antidepressants/antipsychotics and some cardiovascular drugs. Decisive for the relevance of interactions is-along with the therapeutic index of the substrate and the possible alternative degradation pathways-the genetically determined type of metabolism. When combining terbinafine with tricyclic antidepressants or selective serotonin reuptake inhibitors and serotonin/noradrenalin reuptake inhibitors, the clinical response and potential side effects must be monitored. Problematic is the use of terbinafine with simultaneous treatment with tamoxifen. The administration of potent CYP2D6 inhibitors leads to a diminished efficacy of tamoxifen because one of its most important active metabolites-endoxifen-is not sufficiently available. Therefore, combination of tamoxifen and terbinafine should be avoided. In conclusion, the number of substances which are able to cause clinically relevant interactions in case of simultaneously administration with terbinafine is clear and should be manageable in the dermatological office with adequate monitoring.
Prakash, Chandra; Zuniga, Baltazar; Song, Chung Seog; Jiang, Shoulei; Cropper, Jodie; Park, Sulgi; Chatterjee, Bandana
Orally delivered small-molecule therapeutics are metabolized in the liver and intestine by phase I and phase II drug-metabolizing enzymes (DMEs), and transport proteins coordinate drug influx (phase 0) and drug/drug-metabolite efflux (phase III). Genes involved in drug metabolism and disposition are induced by xenobiotic-activated nuclear receptors (NRs), i.e. PXR (pregnane X receptor) and CAR (constitutive androstane receptor), and by the 1α, 25-dihydroxy vitamin D3-activated vitamin D receptor (VDR), due to transactivation of xenobiotic-response elements (XREs) present in phase 0-III genes. Additional NRs, like HNF4-α, FXR, LXR-α play important roles in drug metabolism in certain settings, such as in relation to cholesterol and bile acid metabolism. The phase I enzymes CYP3A4/A5, CYP2D6, CYP2B6, CYP2C9, CYP2C19, CYP1A2, CYP2C8, CYP2A6, CYP2J2, and CYP2E1 metabolize >90% of all prescription drugs, and phase II conjugation of hydrophilic functional groups (with/without phase I modification) facilitates drug clearance. The conjugation step is mediated by broad-specificity transferases like UGTs, SULTs, GSTs. This review delves into our current understanding of PXR/CAR/VDR-mediated regulation of DME and transporter expression, as well as effects of single nucleotide polymorphism (SNP) and epigenome (specified by promoter methylation, histone modification, microRNAs, long non coding RNAs) on the expression of PXR/CAR/VDR and phase 0-III mediators, and their impacts on variable drug response. Therapeutic agents that target epigenetic regulation and the molecular basis and consequences (overdosing, underdosing, or beneficial outcome) of drug-drug/drug-food/drug-herb interactions are also discussed. Precision medicine requires understanding of a drug’s impact on DME and transporter activity and their NR-regulated expression in order to achieve optimal drug efficacy without adverse drug reactions. In future drug screening, new tools such as humanized mouse models and
Shaik, Abdul Naveed; Bohnert, Tonika; Williams, David A; Gan, Lawrence L; LeDuc, Barbara W
The anticoagulant drug warfarin and the lipid-lowering statin drugs are commonly co-administered to patients with cardiovascular diseases. Clinically significant drug-drug interactions (DDIs) between these drugs have been recognized through case studies for many years, but the biochemical mechanisms causing these interactions have not been explained fully. Previous theories include kinetic alterations in cytochrome P-450-mediated drug metabolism or disturbances of drug-protein binding, leading to anticoagulant activity of warfarin; however, neither the enantioselective effects on warfarin metabolism nor the potential disruption of drug transporter function have been well investigated. This study investigated the etiology of the DDIs between warfarin and statins. Liquid chromatography-mass spectrometry methods were developed and validated to quantify racemic warfarin, 6 of its hydroxylated metabolites, and pure enantiomers of warfarin; these methods were applied to study the role of different absorption, distribution, metabolism, and excretion properties, leading to DDIs. Plasma protein binding displacement of warfarin was performed in the presence of statins using equilibrium dialysis method. Substrate kinetics of warfarin and pure enantiomers were performed with human liver microsomes to determine the kinetic parameters (Km and Vmax) for the formation of all 6 hydroxywarfarin metabolites, inhibition of warfarin metabolism in the presence of statins, was determined. Uptake transport studies of warfarin were performed using overexpressing HEK cell lines and efflux transport using human adenocarcinoma colonic cell line cells. Fluvastatin significantly displaced plasma protein binding of warfarin and pure enantiomers; no other statin resulted in significant displacement of warfarin. All the statins that inhibited the formation of 10-hydroxywarfarin, atorvastatin, pitavastatin, and simvastatin were highly potent compared to other statins; in contrast, only fluvastatin
Ötles, Semih; Senturk, Ahmet
Although it is well known and identified that drug-drug interactions exist, the recognition of importance of food and drug interactions to practice has been growing much slower. On the other hand, drug-food/nutrient interactions continue to grow with the common use of medications. Beside the awareness of this type of interactions, food-drug interaction studies are critical to evaluate appropriate dosing, timing, and formulation of new drug candidates. Drug-food interactions take place mechanistically due to altered intestinal transport and metabolism, or systemic distribution, metabolism and excretion. In addition, some people have greater risk of food and drug interactions who have a poor diet, have serious health problems, childrens and pregnant women. In this article, basic informations about importance, classifications, transporters and enzymes of drug and nutrient interaction are given and some specific examples of both drug and nutrients and influences on each other are included.
Scott, Stuart A; Obeng, Aniwaa Owusu; Hulot, Jean-Sébastien
Introduction Non-aspirin antiplatelet agents (e.g., clopidogrel, prasugrel, ticagrelor) are commonly prescribed for the prevention of recurrent cardiovascular events among patients with acute coronary syndromes (ACS) and/or those undergoing percutaneous coronary intervention (PCI). In addition, combination therapy with proton pump inhibitors (PPIs) is often recommended to attenuate gastrointestinal bleeding risk, particularly during dual antiplatelet therapy (DAPT) with clopidogrel and aspirin. Importantly, a pharmacological interaction between clopidogrel and some PPIs has been proposed based on mutual CYP450-dependent metabolism, but available evidence is inconsistent. Areas covered This article provides an overview of the currently approved antiplatelet agents and PPIs, including their metabolic pathways. Additionally, the CYP450 isoenzyme at the center of the drug interaction, CYP2C19, is described in detail, and the available evidence on both the potential pharmacological interaction and influence on clinical outcomes are summarized and evaluated. Expert opinion Although concomitant DAPT and PPI use reduces clopidogrel active metabolite levels and ex vivo-measured platelet inhibition, the influence of the drug interaction on clinical outcomes has been conflicting and largely reported from non-randomized observational studies. Despite this inconsistency, a clinically important interaction cannot be definitively excluded, particularly among patient subgroups with higher overall cardiovascular risk and potentially among CYP2C19 loss-of-function allele carriers. PMID:24205916
Bolhuis, Mathieu S.; Panday, Prashant N.; Pranger, Arianna D.; Kosterink, Jos G. W.; Alffenaar, Jan-Willem C.
Like any other drug, antimicrobial drugs are prone to pharmacokinetic drug interactions. These drug interactions are a major concern in clinical practice as they may have an effect on efficacy and toxicity. This article provides an overview of all published pharmacokinetic studies on drug interactions of the commonly prescribed antimicrobial drugs oxazolidinones, rifamycines, macrolides, fluoroquinolones, and beta-lactams, focusing on systematic research. We describe drug-food and drug-drug interaction studies in humans, affecting antimicrobial drugs as well as concomitantly administered drugs. Since knowledge about mechanisms is of paramount importance for adequate management of drug interactions, the most plausible underlying mechanism of the drug interaction is provided when available. This overview can be used in daily practice to support the management of pharmacokinetic drug interactions of antimicrobial drugs. PMID:24309312
Bolhuis, Mathieu S; Panday, Prashant N; Pranger, Arianna D; Kosterink, Jos G W; Alffenaar, Jan-Willem C
Like any other drug, antimicrobial drugs are prone to pharmacokinetic drug interactions. These drug interactions are a major concern in clinical practice as they may have an effect on efficacy and toxicity. This article provides an overview of all published pharmacokinetic studies on drug interactions of the commonly prescribed antimicrobial drugs oxazolidinones, rifamycines, macrolides, fluoroquinolones, and beta-lactams, focusing on systematic research. We describe drug-food and drug-drug interaction studies in humans, affecting antimicrobial drugs as well as concomitantly administered drugs. Since knowledge about mechanisms is of paramount importance for adequate management of drug interactions, the most plausible underlying mechanism of the drug interaction is provided when available. This overview can be used in daily practice to support the management of pharmacokinetic drug interactions of antimicrobial drugs.
Espinosa-Jovel, Camilo A; Sobrino-Mejía, Fidel E
Drug-resistant epilepsy, is a condition defined by the International League Against Epilepsy as persistent seizures despite having used at least two appropriate and adequate antiepileptic drug treatments. Approximately 20-30% of patients with epilepsy are going to be resistant to antiepileptic drugs, with different patterns of clinical presentation, which are related to the biological basis of this disease (de novo resistance, relapsing-remitting and progressive). Drug resistant epilepsy, impacts negatively the quality of life and significantly increases the risk of premature death. From the neurobiological point of view, this medical condition is the result of the interaction of multiple variables related to the underlying disease, drug interactions and proper genetic aspects of each patient. Thanks to advances in pharmacogenetics and molecular biology research, currently some hypotheses may explain the cause of this condition and promote the study of new therapeutic options. Currently, overexpression of membrane transporters such as P-glycoprotein, appears to be one of the most important mechanisms in the development of drug resistant epilepsy. The objective of this review is to deepen the general aspects of this clinical condition, addressing the definition, epidemiology, differential diagnosis and the pathophysiological bases.
Blassmann, Ute; Roehr, Anka C; Frey, Otto R; Koeberer, Andreas; Briegel, Josef; Huge, Volker; Vetter-Kerkhoff, Cornelia
Linezolid is a valuable treatment option for treating infections caused by multi-resistant gram-positive pathogens. Lack of effective linezolid levels due to the co-administration of rifampicin has been described in healthy subjects. However, the clinical significance of this potential drug interaction (DI) for critically ill patients is still unclear. This was a retrospective analysis of 3 critically ill patients with the combination therapy of linezolid and rifampicin or rifampicin pre-treatment. Despite increasing the dose of linezolid, the majority of observed linezolid trough concentrations in all 3 patients were below 2 mg/l. Furthermore, linezolid trough concentrations remained below 2 mg/l after discontinuation of rifampicin. This potential DI between linezolid and rifampicin could lead to treatment failure. Therefore, we strongly recommend that linezolid serum concentrations be monitored in patients with rifampicin co-administration or rifampicin pretreatment.
dos Santos, Wendel Mombaque; Secoli, Silvia Regina; Padoin, Stela Maris de Mello
ABSTRACT Objective: to investigate potential drug-drug interactions (PDDI) in patients with HIV infection on antiretroviral therapy. Methods: a cross-sectional study was conducted on 161 adults with HIV infection. Clinical, socio demographic, and antiretroviral treatment data were collected. To analyze the potential drug interactions, we used the software Micromedex(r). Statistical analysis was performed by binary logistic regression, with a p-value of ≤0.05 considered statistically significant. Results: of the participants, 52.2% were exposed to potential drug-drug interactions. In total, there were 218 potential drug-drug interactions, of which 79.8% occurred between drugs used for antiretroviral therapy. There was an association between the use of five or more medications and potential drug-drug interactions (p = 0.000) and between the time period of antiretroviral therapy being over six years and potential drug-drug interactions (p < 0.00). The clinical impact was prevalent sedation and cardiotoxicity. Conclusions: the PDDI identified in this study of moderate and higher severity are events that not only affect the therapeutic response leading to toxicity in the central nervous and cardiovascular systems, but also can interfere in tests used for detection of HIV resistance to antiretroviral drugs. PMID:27878224
Rathbun, R. Chris; Liedtke, Michelle D.
Antiretrovirals are prone to drug-drug and drug-food interactions that can result in subtherapeutic or supratherapeutic concentrations. Interactions between antiretrovirals and medications for other diseases are common due to shared metabolism through cytochrome P450 (CYP450) and uridine diphosphate glucuronosyltransferase (UGT) enzymes and transport by membrane proteins (e.g., p-glycoprotein, organic anion-transporting polypeptide). The clinical significance of antiretroviral drug interactions is reviewed, with a focus on new and investigational agents. An overview of the mechanistic basis for drug interactions and the effect of individual antiretrovirals on CYP450 and UGT isoforms are provided. Interactions between antiretrovirals and medications for other co-morbidities are summarized. The role of therapeutic drug monitoring in the detection and management of antiretroviral drug interactions is also briefly discussed. PMID:24309307
Cheng, Judy W M; Frishman, William H; Aronow, Wilbert S
Cytochrome P (CYP) 450 is a superfamily of hemoproteins that play an important role in the metabolism of steroid hormones, fatty acids, and many medications. Many agents used for management of cardiovascular diseases are substrates, inhibitors, or inducers of CYP450 enzymes.When two agents that are substrates, inhibitors, or inducers of CYP450 are administered together, drug interactions with significant clinical consequences may occur. This review discusses CYP450-mediated cardiovascular drug interactions as well as noncardiovascular drug interactions that produced significant cardiovascular side effects. The principles in predicting drug interactions are also discussed.
Tannenbaum, Cara; Sheehan, Nancy L
Concomitant administration of multiple drugs can lead to unanticipated drug interactions and resultant adverse drug events with their associated costs. A more thorough understanding of the different cytochrome P450 isoenzymes and drug transporters has led to new methods to try to predict and prevent clinically relevant drug interactions. There is also an increased recognition of the need to identify the impact of pharmacogenetic polymorphisms on drug interactions. More stringent regulatory requirements have evolved for industry to classify cytochrome inhibitors and inducers, test the effect of drug interactions in the presence of polymorphic enzymes, and evaluate multiple potentially interacting drugs simultaneously. In clinical practice, drug alert software programs have been developed. This review discusses drug interaction mechanisms and strategies for screening and minimizing exposure to drug interactions. We also provide future perspectives for reducing the risk of clinically significant drug interactions. PMID:24745854
Skin is the most frequent target of drug reactions that are reported, may be because they are easily detected. Most (probably more than 90%) are related to drug hypersensitivity, i.e. an individually tailored, unexpected effect mediated by a drug specific activation of the immune response. The clinical presentation of "drug eruptions" is highly variable, from the most common transient and benign erythema that occurs 6-9 days after the introduction of a new drug in 1 to 3 % of users to the most severe forms, that fortunately affect less than 1/10,000 users. Even though there are some overlapping or unclassifiable cases, it is important for clinicians to recognize and categorize severe cutaneous adverse reactions/SCAR (bullous fixed drug eruptions/bFDE, acute generalized exanthematous pustulosis/AGEP, drug reaction with eosinophilia and systemic symptoms/DRESS, Stevens-Johnson syndrome/SJS, toxic epidermal necrolysis/TEN). First they must suspect rapidly that an unusual eruption with high fever and severe constitutional symptoms is caused by a medication and not by an infection. Second they have to look for involvement of organs that differ according to the type of reaction. Third they can determine a prognosis, the mortality rate being virtually 0 for bFDE, 5% for AGEP, 10% for "hypersensitivity syndrome"/DRESS and 25% for SJS or TEN. In addition if some medications are "usual suspects" for all types (e.g. anticonvulsants), some other are more specific of a given pattern (pristinamycine, hydroxychloroquine, diltiazem for AGEP, minocycline for DRESS, anti-infectious sulfonamides, allopurinol for epidermal necrolysis). The "phenotypic" diversity of the final expression drug reactions can be explained by the engagement of a variety of cytokines and inflammatory cells and by regulatory mechanisms. For example, memory cytotoxic T-Cells are key effectors in both localized blisters of bFDE and in extensive blisters of epidermal necrolysis.
Goyal, Parveen; Goyal, Kumud; Vijaya Kumar, Sengodan Gurusamy; Singh, Ajit; Katare, Om Prakash; Mishra, Dina Nath
Liposomes have been widely investigated since 1970 as drug carriers for improving the delivery of therapeutic agents to specific sites in the body. As a result, numerous improvements have been made, thus making this technology potentially useful for the treatment of certain diseases in the clinics. The success of liposomes as drug carriers has been reflected in a number of liposome-based formulations, which are commercially available or are currently undergoing clinical trials. The current pharmaceutical preparations of liposome-based therapeutic systems mainly result from our understanding of lipid-drug interactions and liposome disposition mechanisms. The insight gained from clinical use of liposome drug delivery systems can now be integrated to design liposomes that can be targeted on tissues, cells or intracellular compartments with or without expression of target recognition molecules on liposome membranes. This review is mainly focused on the diseases that have attracted most attention with respect to liposomal drug delivery and have therefore yielded most progress, namely cancer, antibacterial and antifungal disorders. In addition, increased gene transfer efficiencies could be obtained by appropriate selection of the gene transfer vector and mode of delivery.
Ochs, Christopher; Zheng, Ling; Gu, Huanying; Perl, Yehoshua; Geller, James; Kapusnik-Uner, Joan; Zakharchenko, Aleksandr
The National Drug File - Reference Terminology (NDF-RT) is a large and complex drug terminology. NDF-RT provides important information about clinical drugs, e.g., their chemical ingredients, mechanisms of action, dosage form and physiological effects. Within NDF-RT such information is represented using tens of thousands of roles. It is difficult to comprehend large, complex terminologies like NDF-RT. In previous studies, we introduced abstraction networks to summarize the content and structure of terminologies. In this paper, we introduce the Ingredient Abstraction Network to summarize NDF-RT's Chemical Ingredients and their associated drugs. Additionally, we introduce the Aggregate Ingredient Abstraction Network, for controlling the granularity of summarization provided by the Ingredient Abstraction Network. The Ingredient Abstraction Network is used to support the discovery of new candidate drug-drug interactions (DDIs) not appearing in First Databank, Inc.'s DDI knowledgebase.
Ginkgo biloba leaf extracts (GLEs) are popular herbal remedies for the treatment of Alzheimer's dementia, tinnitus, vertigo and peripheral arterial disease. As GLEs are taken regularly by older people who are likely to also use multiple other drugs for the treatment of, e.g. hypertension, diabetes, rheumatism or heart failure, potential herb-drug interactions are of interest. Preclinical studies of high doses/concentrations of GLEs of varying quality and standardization hinted at both an inhibition and induction of metabolic enzymes and transporters. However, in humans, positive in vitro-findings could not be replicated in vivo. At maximum recommended doses of 240 mg/day, a clinically relevant interaction potential of the standardized GLE EGb 761 could not be shown. GLE doses higher than the recommended ones led to a weak induction of the CYP2C19-mediated omeprazole 5-hydroxylation, and a weak inhibition of the CYP3A4-mediated midazolam 1'-hydroxylation, respectively. Also, the regular intake of a poorly characterized GLE at a dose of 360 mg/day slightly increased the bioavailability of talinolol, a substrate of P-glycoprotein and various organic anion-transporting polypeptides. Thus, regarding pharmacokinetic herb-drug interactions, the intake of the standardized GLE, EGb 761, together with synthetic drugs appears to be safe as long as daily doses up to 240 mg are consumed. If this applies to other extracts prepared according to the European Pharmacopoeia remains uncertain. Also, a relevant potential for drug interactions cannot be excluded for poorly standardized GLEs used in many food supplements.
Mechanisms and evaluation of pharmacokinetic drug interactions are discussed in general, including mechanisms beyond the hepatic phase-I reactions, and especially for the example of proton pump inhibitors (PPI), preferentially omeprazole. Particular attention is paid to the use of PPI as self-prescribed drugs. The sequelae of pharmacokinetic drug interactions can be serious. However, only the evidence of clinical consequences will convert such an interaction from a laboratory finding into a possible adverse effect. Without this, interacting drugs can still be co-administered if the specific characteristics of the concerned drugs, quantitative aspects of the interaction, and especially severity and frequency of possible clinical correlates are taken into consideration. It is encouraging that the laboratory findings reported for the PPI--in vitro or ex vivo from volunteer studies--have hardly found equivalents in clinical consequences. As of today, this is also true of the widely discussed interaction with clopidogrel. Regarding the safety of use of PPI as self-prescribed drugs, it also needs to be emphasized that a sizable number of interactions reported for omeprazole and/or pantoprazole were observed at higher dose levels than the 20 mg licensed for self medication. In conjunction with the temporal limitation of PPI self-prescription (14 days), it can be expected that pharmacokinetic drug interactions will generally be no critical factor in the usage of PPI in self-medication. However clinically relevant interactions can occur, e.g. when PPI are combined with extracts from St. John's wort, methotrexat or some inhibitors of HIV-protease with pH-dependent absorption.
Nieber, Karen; Kraft, Karin
In recent popular publications as well as in widely used information websites directed to cancer patients, valerian is claimed to have a potential of adverse interactions with anticancer drugs. This questions its use as a safe replacement for, for example, benzodiazepines. A review on the interaction potential of preparations from valerian root (Valeriana officinalis L. root) was therefore conducted. A data base search and search in a clinical drug interaction data base were conducted. Thereafter, a systematic assessment of publications was performed. Seven in vitro studies on six CYP 450 isoenzymes, on p-glycoprotein, and on two UGT isoenzymes were identified. However, the methodological assessment of these studies did not support their suitability for the prediction of clinically relevant interactions. In addition, clinical studies on various valerian preparations did not reveal any relevant interaction potential concerning CYP 1A2, 2D6, 2E1, and 3A4. Available animal and human pharmacodynamic studies did not verify any interaction potential. The interaction potential of valerian preparations therefore seems to be low and thereby without clinical relevance. We conclude that there is no specific evidence questioning their safety, also in cancer patients. PMID:25093031
Barbanoj, M J; Antonijoan, R M; Riba, J; Valle, M; Romero, S; Jané, F
A drug interaction refers to an event in which the usual pharmacological effect of a drug is modified by other factors, most frequently additional drugs. When two drugs are administered simultaneously, or within a short time of each other, an interaction can occur that may increase or decrease the intended magnitude or duration of the effect of one or both drugs. Drugs may interact on a pharmaceutical, pharmacokinetic or pharmacodynamic basis. Pharmacodynamic interactions arise when the alteration of the effects occurs at the site of action. This is a wide field where not only interactions between different drugs are considered but also drug and metabolites (midazolam/alpha-hydroxy-midazolam), enantiomers (ketamine), as well as phenomena such as tolerance (nordiazepam) and sensitization (diazepam). Pharmacodynamic interactions can result in antagonism or synergism and can originate at a receptor level (antagonism, partial agonism, down-regulation, up-regulation), at an intraneuronal level (transduction, uptake), or at an interneuronal level (physiological pathways). Alternatively, psychotropic drug interactions assessed through quantitative pharmaco-EEG can be viewed according to the broad underlying objective of the study: safety-oriented (ketoprofen/theophylline, lorazepam/diphenhydramine, granisetron/haloperidol), strictly pharmacologically-oriented (benzodiazepine receptors), or broadly neuro-physiologically-oriented (diazepam/buspirone). Methodological issues are stressed, particularly drug plasma concentrations, dose-response relationships and time-course of effects (fluoxetine/buspirone), and unsolved questions are addressed (yohimbine/caffeine, hydroxizyne/alcohol).
Lucca, Jisha M; Ramesh, Madhan; Parthasarathi, Gurumurthy; Raman, Rajesh
Drug interactions are known to play a significant role in the incidence of adverse drug reactions (ADRs) both in the community and in hospitals. Both the newer atypical antipsychotics and their more traditional counterparts are subject to drug - drug interactions amongst themselves, with other psychotropics, and with the agents used in the treatment of various physical ailments. The most common interactions encountered in clinical practice are pharmacodynamic in nature. It is well established that antipsychotic drugs reduce the efficacy of levodopa in parkinson's disease by blockade of dopamine receptors in the corpus striatum. The case reported here illustrates a common pharmacodynamic drug interaction of haloperidol with levodopa in a 60-year-old female patient.
In the introduction the author points out the importance, mechanism and consequence of interactions between oral contraceptives and other drugs. The interactions between certain drugs with different pharmacological action and the contraceptive tablets which decrease or increase the contraceptive effect as well as the drugs whose effect may be influenced by the contraceptive tablets have been discussed. Cases in which only a few data refer to, or no clinical proof supports interaction, are also mentioned. According to interactions observed until present in women taking Anteovin, the recommended measures to be taken in these cases have been described. Finally it has been emphasized that the knowledge of interactions between drugs is just as important in family planning counselling as is when prescribing other drug treatments.
Zhang, L; Wu, F; Lee, S C; Zhao, H; Zhang, L
Absorption of an orally administered drug with pH-dependent solubility may be altered when it is coadministered with a gastric acid-reducing agent (ARA). Assessing a drug's potential for pH-dependent drug-drug interactions (DDIs), considering study design elements for such DDI studies, and interpreting and communicating study results in the drug labeling to guide drug dosing are important for drug development. We collected pertinent information related to new molecular entities approved from January 2003 to May 2013 by the US Food and Drug Administration for which clinical DDI studies with ARAs were performed. On the basis of assessments of data on pH solubility and in vivo DDIs with ARAs, we proposed a conceptual framework for assessing the need for clinical pH-dependent DDI studies for weak base drugs (WBDs). Important study design considerations include selection of ARAs and timing of dosing of an ARA relative to the WBD in a DDI study. Labeling implications for drugs having DDIs with ARAs are also illustrated.
Ekstein, Dana; Tirosh, Matanya; Eyal, Yonatan; Eyal, Sara
Interactions of antiepileptic drugs (AEDs) with other substances may lead to adverse effects and treatment failure. To avoid such interactions, clinicians often rely on drug interaction compendia. Our objective was to compare the concordance for twenty-two AEDs among three drug interaction compendia (Micromedex, Lexi-Interact, and Clinical Pharmacology) and the US Food and Drug Administration-approved product labels. For each AED, the overall concordance among data sources regarding existence of interactions and their classification was poor, with less than twenty percent of interactions listed in all four sources. Concordance among the three drug compendia decreased with the fraction of the drug excreted unchanged and was greater for established inducers of hepatic drug-metabolizing enzymes than for the drugs that are not inducers (R-square=0.83, P<0.01). For interactions classified as contraindications, major, and severe, concordance among the four data sources was, in most cases, less than 30%. Prescribers should be aware of the differences between drug interaction sources of information for both older AEDs and newer AEDs, in particular for those AEDs which are not involved in hepatic enzyme-mediated interactions.
Scheen, André J
This review describes the current knowledge on drug-drug and food-drug interactions with repaglinide and nateglinide. These two meglitinide derivatives, commonly called glinides, have been developed for improving insulin secretion of patients with type 2 diabetes mellitus. They are increasingly used either in monotherapy or in combination with other oral antihyperglycaemic agents for the treatment of type 2 diabetes. Compared with sulfonylureas, glinides have been shown to (i) provide a better control of postprandial hyperglycaemia, (ii) overcome some adverse effects, such as hypoglycaemia, and (iii) have a more favourable safety profile, especially in patients with renal failure. The meal-related timing of administration of glinides and the potential influence of food and meal composition on their bioavailability may be important. In addition, some food components (e.g. grapefruit juice) may cause pharmacokinetic interactions. Because glinides are metabolised via cytochrome P450 (CYP) 3A4 isoenzyme, they are indeed exposed to pharmacokinetic interactions. In addition to CYP3A4, repaglinide is metabolised via CYP2C8, while nateglinide metabolism also involves CYP2C9. Furthermore, both compounds and their metabolites may undergo specialised transport/uptake in the intestine, another source of pharmacokinetic interactions. Clinically relevant drug-drug interactions are those that occur when glinides are administered together with other glucose-lowering agents or compounds widely coadministered to diabetic patients (e.g. lipid-lowering agents), with drugs that are known to induce (risk of lower glinide plasma levels and thus of deterioration of glucose control) or inhibit (risk of higher glinide plasma levels leading to hypoglycaemia) CYP isoenzymes concerned in their metabolism, or with drugs that have a narrow efficacy : toxicity ratio. Pharmacokinetic interactions reported in the literature appear to be more frequent and more important with repaglinide than with
Tallarida, Ronald J
This review has 2 parts. Part I deals with isobolographic procedures that are traditionally applied to the joint action of agonists that individually produce overtly similar effects. Special attention is directed to newer computational procedures that apply to agonists with dissimilar concentration-effect curves. These newer procedures are consistent with the isobolographic methods introduced and used by Loewe, however, the present communications provides the needed graphical and mathematical detail. A major aim is distinguishing super and sub-addictive interactions from those that are simply additive. The detection and measurement of an interaction is an important step in exploring drug mechanism and is also important clinically. Part II discusses a new use of isoboles that is applicable to a single drug or chemical whose effect is mediated by 2 or more receptor subtypes. This application produces a metric that characterizes the interaction between the receptor subtypes. The expansion of traditional isobolographic theory to this multi-receptor situation follows from the newer approaches for 2-drug combination analysis in Part I. This topic leads naturally to a re-examination of competitive antagonism and the classic Schild plot. In particular, it is shown here that the Schild plot in the multi-receptor case is not necessarily linear with unit slope. Both parts of this review emphasize the quantitative aspects rather than the many drugs that have been analyzed with isobolographic methods. The mathematical exposition is rather elementary and is further aided by several graphs. An appendix is included for the reader interested in the mathematical details.
Wu, Heng-Yi; Chiang, Chien-Wei; Li, Lang
In order to understand the mechanisms of drug–drug interaction (DDI), the study of pharmacokinetics (PK), pharmacodynamics (PD), and pharmacogenetics (PG) data are significant. In recent years, drug PK parameters, drug interaction parameters, and PG data have been unevenly collected in different databases and published extensively in literature. Also the lack of an appropriate PK ontology and a well-annotated PK corpus, which provide the background knowledge and the criteria of determining DDI, respectively, lead to the difficulty of developing DDI text mining tools for PK data collection from the literature and data integration from multiple databases. To conquer the issues, we constructed a comprehensive pharmacokinetics ontology. It includes all aspects of in vitro pharmacokinetics experiments, in vivo pharmacokinetics studies, as well as drug metabolism and transportation enzymes. Using our pharmacokinetics ontology, a PK corpus was constructed to present four classes of pharmacokinetics abstracts: in vivo pharmacokinetics studies, in vivo pharmacogenetic studies, in vivo drug interaction studies, and in vitro drug interaction studies. A novel hierarchical three-level annotation scheme was proposed and implemented to tag key terms, drug interaction sentences, and drug interaction pairs. The utility of the pharmacokinetics ontology was demonstrated by annotating three pharmacokinetics studies; and the utility of the PK corpus was demonstrated by a drug interaction extraction text mining analysis. The pharmacokinetics ontology annotates both in vitro pharmacokinetics experiments and in vivo pharmacokinetics studies. The PK corpus is a highly valuable resource for the text mining of pharmacokinetics parameters and drug interactions. PMID:24788261
Fugh-Berman, Adriane; Ernst, E
Aims The aim of this systematic review was to assess the published clinical evidence on interactions between herbal and conventional drugs. Methods Four electronic databases were searched for case reports, case series or clinical trials of such interactions. The data were extracted and validated using a scoring system for interaction probability. Results One hundred and eight cases of suspected interactions were found. 68.5% were classified as ‘unable to be evaluated’, 13% as ‘well-documented’ and 18.5% as ‘possible’ interactions. Warfarin was the most common drug (18 cases) and St John's wort the most common herb (54 cases) involved. Conclusion Herb–drug interactions undoubtedly do occur and may put individuals at risk. However our present knowledge is incomplete and more research is urgently needed. PMID:11736868
Wanwimolruk, Sompon; Phopin, Kamonrat; Prachayasittikul, Virapong
To date, a number of significant herbal drug interactions have their origins in the alteration of cytochrome P450 (CYP) activity by various phytochemicals. Among the most noteworthy are those involving St. John's wort and drugs metabolized by human CYP3A4 enzyme. This review article is the continued work from our previous article (Part 1) published in this journal (Wanwimolruk and Prachayasittikul, 2014[ref:133]). This article extends the scope of the review to six more herbs and updates information on herbal drug interactions. These include black cohosh, ginseng, grape seed extract, green tea, kava, saw palmetto and some important Chinese medicines are also presented. Even though there have been many studies to determine the effects of herbs and herbal medicines on the activity of CYP, most of them were in vitro and in animal studies. Therefore, the studies are limited in predicting the clinical relevance of herbal drug interactions. It appeared that the majority of the herbal medicines have no clear effects on most of the CYPs examined. For example, the existing clinical trial data imply that black cohosh, ginseng and saw palmetto are unlikely to affect the pharmacokinetics of conventional drugs metabolized by human CYPs. For grape seed extract and green tea, adverse herbal drug interactions are unlikely when they are concomitantly taken with prescription drugs that are CYP substrates. Although there were few clinical studies on potential CYP-mediated interactions produced by kava, present data suggest that kava supplements have the ability to inhibit CYP1A2 and CYP2E1 significantly. Therefore, caution should be taken when patients take kava with CYP1A2 or CYP2E1 substrate drugs as it may enhance their therapeutic and adverse effects. Despite the long use of traditional Chinese herbal medicines, little is known about the potential drug interactions with these herbs. Many popularly used Chinese medicines have been shown in vitro to significantly change the
Kellick, Kenneth A; Bottorff, Michael; Toth, Peter P; The National Lipid Association's Safety Task Force
The statins are widely used worldwide to reduce risk for cardiovascular events in both the primary and secondary prevention settings. Although generally quite safe, the statins can be associated with a variety of serious side adverse effects, including myalgia, myopathy, and changes in plasma enzymes of hepatic origin. Although rare, the most serious of these is rhabdomyolysis. Several drugs can interfere with the metabolism and disposal of the statins, thereby increasing risk for adverse events. It is important that clinicians treating patients with statins be aware of the potential for drug-drug interactions between each statin and specific other drugs and take measures to prevent them. The prediction of potential drug-drug interactions derives from basic pharmacokinetic principles. Certain drug interactions are predicted by measuring the effect of interacting drugs on blood plasma concentrations of the statin. Individual patient variations resulting in part from polymorphisms in the metabolizing enzymes confound some of these predictions. Based on these known effects, a new classification for predicting statin drug interactions is proposed. This report discusses likely prescription and nonprescription interactions as well as potential alternatives for special populations.
Wanwimolruk, Sompon; Prachayasittikul, Virapong
It is well recognized that herbal supplements or herbal medicines are now commonly used. As many patients taking prescription medications are concomitantly using herbal supplements, there is considerable risk for adverse herbal drug interactions. Such interactions can enhance the risk for an individual patient, especially with regard to drugs with a narrow therapeutic index such as warfarin, cyclosporine A and digoxin. Herbal drug interactions can alter pharmacokinetic or/and pharmacodynamic properties of administered drugs. The most common pharmacokinetic interactions usually involve either the inhibition or induction of the metabolism of drugs catalyzed by the important enzymes, cytochrome P450 (CYP). The aim of the present article is to provide an updated review of clinically relevant metabolic CYP-mediated drug interactions between selected herbal supplements and prescription drugs. The commonly used herbal supplements selected include Echinacea, Ginkgo biloba, garlic, St. John's wort, goldenseal, and milk thistle. To date, several significant herbal drug interactions have their origins in the alteration of CYP enzyme activity by various phytochemicals. Numerous herbal drug interactions have been reported. Although the significance of many interactions is uncertain but several interactions, especially those with St. John’s wort, may have critical clinical consequences. St. John’s wort is a source of hyperforin, an active ingredient that has a strong affinity for the pregnane xenobiotic receptor (PXR). As a PXR ligand, hyperforin promotes expression of CYP3A4 enzymes in the small intestine and liver. This in turn causes induction of CYP3A4 and can reduce the oral bioavailability of many drugs making them less effective. The available evidence indicates that, at commonly recommended doses, other selected herbs including Echinacea, Ginkgo biloba, garlic, goldenseal and milk thistle do not act as potent or moderate inhibitors or inducers of CYP enzymes. A good
Psychotropic drugs (antidepressants, antimanic drugs, antipsychotics, analgesic opioids, and others) are among the most frequently used medicines. Between these drugs and magnesium there are pharmacokinetic and pharmacodynamic interactions. Erythrocyte magnesium is decreased in patients with severe major depression (MD) vs normal subjects (44 +/- 2.7 mg/L in MD group vs 59.1 +/- 3.2 mg/L in control group, p < 0.01). Therapy with sertraline, 150 mg/day p.o. -21 days or with amitryptiline 3 x 25 mg/day p.o. 28 days increases significantly erythrocyte concentration of magnesium (56.9 +/- 5.22 mg/L after sertraline vs 44 +/- 2.7 mg/L before sertraline, p < 0.01). In patients with acute paranoid schizophrenia, erythrocyte magnesium concentration is decreased vs healthy subjects. Haloperidol, 8 mg/day, p.o. for 21 days or risperidone, 6 mg/day p.o. for 21 days have increased significantly erythrocyte magnesium concentration (46.21 +/- 3.1 mg/L before haloperidol and 54.6 +/- 2.7 mg/L after haloperidol, p < 0.05). Antimanic drugs (mood stabilizers) as carbamazepine, 600 mg/day, p.o., 4 weeks and sodium valproate, 900 mg/day p.o., 4 weeks, increased significantly magnesium in patients with bipolar disorder type I. Increased magnesium status positively correlated with enhancement of the clinical state. The existent data sustain the idea that an increase of erythrocyte magnesium is involved in the mechanism of action of some psychotropic drugs. Magnesium supply decreased the intensity of morphine-induced physical drug dependence. In heroin addicts, the plasma magnesium concentration is decreased.
Yu, Jingjing; Ritchie, Tasha K; Mulgaonkar, Aditi; Ragueneau-Majlessi, Isabelle
The aim of the present work was to perform a systematic review of drug metabolism, transport, pharmacokinetics, and DDI data available in the NDAs approved by the FDA in 2013, using the University of Washington Drug Interaction Database, and to highlight significant findings. Among 27 NMEs approved, 22 (81%) were well characterized with regard to drug metabolism, transport, or organ impairment, in accordance with the FDA drug interaction guidance (2012) and were fully analyzed in this review. In vitro, a majority of the NMEs were found to be substrates or inhibitors/inducers of at least one drug metabolizing enzyme or transporter. However, in vivo, only half (n = 11) showed clinically relevant drug interactions, with most related to the NMEs as victim drugs and CYP3A being the most affected enzyme. As perpetrators, the overall effects for NMEs were much less pronounced, compared with when they served as victims. In addition, the pharmacokinetic evaluation in patients with hepatic or renal impairment provided useful information for further understanding of the drugs' disposition.
With the degree of polypharmacy currently practiced in the field of oncology, there are undoubtedly many drug interactions. In the present study the influence of "non-cytotoxic" drugs on anticancer drugs is discussed, but not the reverse. Not only is the augmentation (reversal of multidrug resistance) or the reduction of antitumor properties of cytotoxic drugs observed, but also cytostatic activities of "non-cytotoxic" drugs themselves. Examples are calmodulin inhibitors such as phenothiazines and tricyclic antidepressants. Interactions may also increase side effects of cytostatic drugs or even neutralize the antitumoral activity. To ensure that interactions are not overlooked, all medicaments being administered should be listed. It is, however, not feasible yet to determine serum concentrations of all the drugs given to the patient. The antitumor activity of supportive care could be evaluated in randomized studies (e.g. cytostatic drugs +/- antidepressants).
Martinbiancho, Jacqueline; Zuckermann, Joice; Dos Santos, Luciana; Silva, Mariane M.
Introduction The expected therapeutic response may be affected by the presence of drug interactions. With the high number of reports on new drug interactions, it has been difficult for health professionals to keep constantly updated. For this reason, computer systems have helped identify such interactions. Objectives To verify the rate and profile of drug interactions in medical prescriptions to hospitalized pediatric patients. Methods A descriptive study investigated prescriptions to hospitalized pediatric patients. The study included patients between 0 and 12 years old, containing 4 or more drugs in their prescriptions. The analysis of interaction and incompatibility possibilities in prescribed drugs used Micromedex / Drug-Reax® program. Results From 2005 to 2006, 3,170 patients were investigated, and 11,181 prescriptions were analyzed, a mean value of 3.5 prescriptions/patient. In total, 6,857 drug interactions were found, which corresponds to 1.9 interaction/prescription. Among them, relevance to ampicillin and gentamicin, found in 220 (3.2%) prescriptions. In total, 2,411 drug incompatibilities in via y were found, a mean value of 0.5/prescription, with emphasis on vancomycin and cefepime, found in 243 (10.0%) prescriptions. Conclusion The presence of drug interactions is a permanent risk in hospitals. This way, the utilization of computer programs, pharmacotherapy monitoring of patients and the pharmacist presence in the multidisciplinary team are some manners of contributing to hospitalized patients’ treatment. PMID:25170352
Sprouse, Alyssa A; van Breemen, Richard B
The use of botanical dietary supplements has grown steadily over the last 20 years despite incomplete information regarding active constituents, mechanisms of action, efficacy, and safety. An important but underinvestigated safety concern is the potential for popular botanical dietary supplements to interfere with the absorption, transport, and/or metabolism of pharmaceutical agents. Clinical trials of drug-botanical interactions are the gold standard and are usually carried out only when indicated by unexpected consumer side effects or, preferably, by predictive preclinical studies. For example, phase 1 clinical trials have confirmed preclinical studies and clinical case reports that St. John's wort (Hypericum perforatum) induces CYP3A4/CYP3A5. However, clinical studies of most botanicals that were predicted to interact with drugs have shown no clinically significant effects. For example, clinical trials did not substantiate preclinical predictions that milk thistle (Silybum marianum) would inhibit CYP1A2, CYP2C9, CYP2D6, CYP2E1, and/or CYP3A4. Here, we highlight discrepancies between preclinical and clinical data concerning drug-botanical interactions and critically evaluate why some preclinical models perform better than others in predicting the potential for drug-botanical interactions. Gaps in knowledge are also highlighted for the potential of some popular botanical dietary supplements to interact with therapeutic agents with respect to absorption, transport, and metabolism.
Chen, Yin-Ying; Wu, Ping; Wang, Jie
Drug clinical trial is an important link in the chain of new drug research and development. The results of drug discovery and development directly depend on the extent of standardization of clinical trials. Therefore, improving the quality of drug clinical trials is of great importance, and drug clinical trial institutions play a crucial role in the quality management of drug clinical trials. After years of development, the overall level of drug clinical trials has advanced rapidly in China, and a large number of clinical trials of traditional Chinese medicine have also been carried out. However, there is still a big gap between our country and developed countries. Therefore, for the construction and management of Chinese drug clinical trial institutions, there is still a long way to go. This study aims to analyze the current development of drug clinical trial institutions in China and explore the existing problems from three aspects, including current situations of institutional organization and management, regional and professional distributions, and quality control. And some suggestions are put forward finally, including support of traditional Chinese medicine, introduction of drug-risk management system, and construction of information management.
Pathak, Jyotishman; Kiefer, Richard C; Chute, Christopher G
By nature, healthcare data is highly complex and voluminous. While on one hand, it provides unprecedented opportunities to identify hidden and unknown relationships between patients and treatment outcomes, or drugs and allergic reactions for given individuals, representing and querying large network datasets poses significant technical challenges. In this research, we study the use of Semantic Web and Linked Data technologies for identifying drug-drug interaction (DDI) information from publicly available resources, and determining if such interactions were observed using real patient data. Specifically, we apply Linked Data principles and technologies for representing patient data from electronic health records (EHRs) at Mayo Clinic as Resource Description Framework (RDF), and identify potential drug-drug interactions (PDDIs) for widely prescribed cardiovascular and gastroenterology drugs. Our results from the proof-of-concept study demonstrate the potential of applying such a methodology to study patient health outcomes as well as enabling genome-guided drug therapies and treatment interventions.
Pathak, Jyotishman; Kiefer, Richard C.; Chute, Christopher G.
By nature, healthcare data is highly complex and voluminous. While on one hand, it provides unprecedented opportunities to identify hidden and unknown relationships between patients and treatment outcomes, or drugs and allergic reactions for given individuals, representing and querying large network datasets poses significant technical challenges. In this research, we study the use of Semantic Web and Linked Data technologies for identifying drug-drug interaction (DDI) information from publicly available resources, and determining if such interactions were observed using real patient data. Specifically, we apply Linked Data principles and technologies for representing patient data from electronic health records (EHRs) at Mayo Clinic as Resource Description Framework (RDF), and identify potential drug-drug interactions (PDDIs) for widely prescribed cardiovascular and gastroenterology drugs. Our results from the proof-of-concept study demonstrate the potential of applying such a methodology to study patient health outcomes as well as enabling genome-guided drug therapies and treatment interventions. PMID:23920643
Tatonetti, Nicholas P; Ye, Patrick P; Daneshjou, Roxana; Altman, Russ B
Adverse drug events remain a leading cause of morbidity and mortality around the world. Many adverse events are not detected during clinical trials before a drug receives approval for use in the clinic. Fortunately, as part of postmarketing surveillance, regulatory agencies and other institutions maintain large collections of adverse event reports, and these databases present an opportunity to study drug effects from patient population data. However, confounding factors such as concomitant medications, patient demographics, patient medical histories, and reasons for prescribing a drug often are uncharacterized in spontaneous reporting systems, and these omissions can limit the use of quantitative signal detection methods used in the analysis of such data. Here, we present an adaptive data-driven approach for correcting these factors in cases for which the covariates are unknown or unmeasured and combine this approach with existing methods to improve analyses of drug effects using three test data sets. We also present a comprehensive database of drug effects (Offsides) and a database of drug-drug interaction side effects (Twosides). To demonstrate the biological use of these new resources, we used them to identify drug targets, predict drug indications, and discover drug class interactions. We then corroborated 47 (P < 0.0001) of the drug class interactions using an independent analysis of electronic medical records. Our analysis suggests that combined treatment with selective serotonin reuptake inhibitors and thiazides is associated with significantly increased incidence of prolonged QT intervals. We conclude that confounding effects from covariates in observational clinical data can be controlled in data analyses and thus improve the detection and prediction of adverse drug effects and interactions.
Yang, Feng; Zhang, Yao; Liang, Hong
Human serum albumin (HSA) is an abundant plasma protein, which attracts great interest in the pharmaceutical industry since it can bind a remarkable variety of drugs impacting their delivery and efficacy and ultimately altering the drug's pharmacokinetic and pharmacodynamic properties. Additionally, HSA is widely used in clinical settings as a drug delivery system due to its potential for improving targeting while decreasing the side effects of drugs. It is thus of great importance from the viewpoint of pharmaceutical sciences to clarify the structure, function, and properties of HSA-drug complexes. This review will succinctly outline the properties of binding site of drugs in IIA subdomain within the structure of HSA. We will also give an overview on the binding characterization of interactive association of drugs to human serum albumin that may potentially lead to significant clinical applications.
Silverstone, T; Goodall, E
One way of gaining a greater understanding of the central mechanisms underlying hunger and the regulation of feeding behaviour in humans is to examine the actions and interactions on hunger and food intake of drugs with known or presumed pharmacological modes of action. To this end we have undertaken a number of studies which fall into three main categories: the mechanisms by which amphetamine anorexia is induced; the possible role of endogenous opioids in feeding; the action of amino acids thought to be involved in the regulation of feeding. In this field the potential for cross-fertilization between basic scientists working with laboratory animals and clinical scientists working with human subjects exists. For example, the clinical pharmacologist has been able to test out hypotheses on human subjects which could only have been developed using laboratory animals. Furthermore, using human subjects it is possible to extend the field of inquiry into an exploration of the subjective dimensions of appetite and hunger.
Rodrigues, Márcio; Alves, Gilberto; Abrantes, João; Falcão, Amílcar
Fucus vesiculosus is a seaweed claimed to be useful for obesity management. Therefore, considering the relationship between obesity and cardiovascular diseases, this work aimed to assess the potential for an herb-drug interaction among a standardized F. vesiculosus extract (GMP certificate) and amiodarone (a narrow therapeutic index drug) in rats. In a first pharmacokinetic study, rats were simultaneously co-administered with a single-dose of F. vesiculosus (575 mg/kg, p.o.) and amiodarone (50 mg/kg, p.o.); in a second study, rats were pre-treated during 14 days with F. vesiculosus (575 mg/kg/day, p.o.) and received amiodarone (50 mg/kg, p.o.) on the 15th day. Rats of the control groups received the corresponding volume of vehicle. After analysis of the pharmacokinetic data it deserves to be highlighted the significant decrease in the peak plasma concentration of amiodarone (55.4%) as well as the reduction of systemic exposure to the parent drug (~30%) following the simultaneous co-administration of F. vesiculosus extract and amiodarone. This paper reports, for the first time, the herb-drug interaction between F. vesiculosus and amiodarone, which determined a considerable decrease on amiodarone bioavailability in rats. Therefore, the therapeutic efficacy of amiodarone may be compromised by the concurrent administration of herbal slimming medicines/dietary supplements containing F. vesiculosus.
Kales, A; Scharf, M B; Soldatos, C R; Bixler, E O
The most thorough and clinically relevant approach to hypnotic drug evaluation is one that balances the strengths and weaknesses of clinical trials and sleep laboratory evaluations. Advantages of clinical trials include the ability to evaluate large numbers of subjects and specific target groups and to thoroughly assess and quantify a drug's side effects, whereas sleep laboratory studies are very limited in all of these areas. Sleep laboratory studies however provide a rigorous, precise, and comprehensive profile of a drug's activity since there is more control over experimental variables and measurements are objective as well as continuous throughout the night. These benefits offset the shortcomings of clinical trials, which include a lack of objective measurements, less control over experimental variables, failure to evaluate a drug's effectiveness with continued use, and inattention to drug interaction and withdrawal effect. Several basic principles derived from sleep laboratory findings have been incorporated into both the clinical trials and sleep laboratory evaluations recommended in the new FDA Guidelines for the Clinical Evaluation of Hypnotic Drugs. These principles include provision for adequate baseline and withdrawal periods, use of multiple consecutive drug nights to assess a drug's effectiveness with continued use, and inclusion of an adequate washout period when a cross-over design is used. The guidelines do not emphasize either clinical trials or sleep laboratory studies at the expense of each other, but rather stress their complementary utilization.
Chen, Jiezhong; Raymond, Kenneth
Rifampicin, an important drug in the treatment of tuberculosis, is used extensively despite its broad effects on drug-drug interactions, creating serious problems. The clinical importance of such interactions includes autoinduction leading to suboptimal or failed treatment. The concomitantly administered effects of rifampicin on other drugs can result in their altered metabolism or transportation that are metabolised by cytochromes P450 or transported by p-glycoprotein in the gastrointestinal tract and liver. This review paper summarises recent findings with emphases on the molecular mechanisms used to explain these broad drug-drug interactions. In general, rifampicin can act on a pattern: rifampicin activates the nuclear pregnane X receptor that in turn affects cytochromes P450, glucuronosyltransferases and p-glycoprotein activities. This pattern of action may explain many of the rifampicin inducing drug-drug interactions. However, effects through other mechanisms have also been reported and these make any explanation of such drug-drug interactions more complex. PMID:16480505
Chen, Jiezhong; Raymond, Kenneth
Rifampicin, an important drug in the treatment of tuberculosis, is used extensively despite its broad effects on drug-drug interactions, creating serious problems. The clinical importance of such interactions includes autoinduction leading to suboptimal or failed treatment. The concomitantly administered effects of rifampicin on other drugs can result in their altered metabolism or transportation that are metabolised by cytochromes P450 or transported by p-glycoprotein in the gastrointestinal tract and liver. This review paper summarises recent findings with emphases on the molecular mechanisms used to explain these broad drug-drug interactions. In general, rifampicin can act on a pattern: rifampicin activates the nuclear pregnane X receptor that in turn affects cytochromes P450, glucuronosyltransferases and p-glycoprotein activities. This pattern of action may explain many of the rifampicin inducing drug-drug interactions. However, effects through other mechanisms have also been reported and these make any explanation of such drug-drug interactions more complex.
Newton, David W
Whose job is it to protect patients from harm from drug instabilities and incompatibilities and other aspects of clinical pharmaceutics? Pharmacists are better educated via multiple required general and organic chemistry prerequisite and professional curricula medicinal chemistry and pharmaceutics courses. Therefore, no healthcare professional other than pharmacists are nicknamed drug experts or are better formally educated to master drug chemistry in the bottle (i.e., injection stability and compatibility/incompatibility clinical pharmaceutics) as a prerequisite for drug administration to cause safe and effective drug chemistry in the body (i.e., clinical pharmacokinetics and pharmacology). To be a patient's last chance for safe and effective drug therapy requires terminal control by pharmacists over identification, retrieval, preparation, labeling, and counseling or instruction of drug therapy.
Rama, Mylapuram; Viswanathan, Gayathri; Acharya, Leelavathi D; Attur, R P; Reddy, P N; Raghavan, S V
Polypharmacy is common in drug prescriptions of chronic kidney disease patients. A study of the prescription patterns of drugs with potential interactions would be of interest to prevent drug related adverse events. A prospective observational study of six months (Dec 2009-May 2010) was carried out among the chronic kidney disease patients admitted to the nephrology ward of a South Indian tertiary care hospital. The pattern and rates of drug-drug interactions seen in the prescriptions of these patients was studied. Among the 205 prescriptions included, a total of 474 interactions were reported, making 2.7 interactions per prescription with incidence rates of 76.09%. Around 19.62% of interactions were of major severity. Most common interactions were found between ascorbic acid and cyanocobalamine (12.45%), clonidine and metoprolol (3.80%) respectively. Hypo or hypertension (31.65%), decreased drug efficacy (29.11%) and hypo or hyperglycemia (14.14%), were the most commonly reported clinical outcomes of the drug interactions. Cardiovascular drugs (calcium channel blockers and beta blockers; 52%) constitute the major class of drugs involved in interactions. As most of the interactions had a delayed onset, long term follow-up is essential to predict the clinically significant outcomes of these interactions. Hence, drug interactions are commonly seen in the prescriptions of chronic kidney disease patients which can lead to serious adverse events if not detected early. Need for collaboration with a clinical pharmacist and electronic surveillance, which are absent in developing countries like India, is emphatic.
Chan, Lingtak-Neander; Anderson, Gail D
Ethanol (alcohol) is one of the most widely used legal drugs in the world. Ethanol is metabolized by alcohol dehydrogenase (ADH) and the cytochrome P450 (CYP) 2E1 drug-metabolizing enzyme that is also responsible for the biotransformation of xenobiotics and fatty acids. Drugs that inhibit ADH or CYP2E1 are the most likely theoretical compounds that would lead to a clinically significant pharmacokinetic interaction with ethanol, which include only a limited number of drugs. Acute ethanol primarily alters the pharmacokinetics of other drugs by changing the rate and extent of absorption, with more limited effects on clearance. Both acute and chronic ethanol use can cause transient changes to many physiologic responses in different organ systems such as hypotension and impairment of motor and cognitive functions, resulting in both pharmacokinetic and pharmacodynamic interactions. Evaluating drug interactions with long-term use of ethanol is uniquely challenging. Specifically, it is difficult to distinguish between the effects of long-term ethanol use on liver pathology and chronic malnutrition. Ethanol-induced liver disease results in decreased activity of hepatic metabolic enzymes and changes in protein binding. Clinical studies that include patients with chronic alcohol use may be evaluating the effects of mild cirrhosis on liver metabolism, and not just ethanol itself. The definition of chronic alcohol use is very inconsistent, which greatly affects the quality of the data and clinical application of the results. Our study of the literature has shown that a significantly higher volume of clinical studies have focused on the pharmacokinetic interactions of ethanol and other drugs. The data on pharmacodynamic interactions are more limited and future research addressing pharmacodynamic interactions with ethanol, especially regarding the non-central nervous system effects, is much needed.
Lin, Christine; Shi, Julianne; Moore, Amanda; Khetani, Salman R
Accurate prediction of in vivo hepatic drug clearance using in vitro assays is important to properly estimate clinical dosing regimens. Clearance of low-turnover compounds is especially difficult to predict using short-lived suspensions of unpooled primary human hepatocytes (PHHs) and functionally declining PHH monolayers. Micropatterned cocultures (MPCCs) of PHHs and 3T3-J2 fibroblasts have been shown previously to display major liver functions for several weeks in vitro. In this study, we first characterized long-term activities of major cytochrome P450 enzymes in MPCCs created from unpooled cryopreserved PHH donors. MPCCs were then used to predict the clearance of 26 drugs that exhibit a wide range of turnover rates in vivo (0.05-19.5 ml/min per kilogram). MPCCs predicted 73, 92, and 96% of drug clearance values for all tested drugs within 2-fold, 3-fold, and 4-fold of in vivo values, respectively. There was good correlation (R(2) = 0.94, slope = 1.05) of predictions between the two PHH donors. On the other hand, suspension hepatocytes and conventional monolayers created from the same donor had significantly reduced predictive capacity (i.e., 30-50% clearance values within 4-fold of in vivo), and were not able to metabolize several drugs. Finally, we modulated drug clearance in MPCCs by inducing or inhibiting P450s. Rifampin-mediated CYP3A4 induction increased midazolam clearance by 73%, while CYP3A4 inhibition with ritonavir decreased midazolam clearance by 79%. Similarly, quinidine-mediated CYP2D6 inhibition reduced clearance of dextromethorphan and desipramine by 71 and 22%, respectively. In conclusion, MPCCs created using cryopreserved unpooled PHHs can be used for drug clearance predictions and to model drug-drug interactions.
Summary Phase-1 (also known as “First-in-Man”) clinical trials initiate the early clinical development of possible new medicines. Patient participation in this early phase of clinical trials is rather limited. After successful phase 1 trials, further phase 2 and phase 3 clinical trials in patients may lead to a marketing authorization. In the first 15 years of the European Union Orphan Drug Directive, 4.5% of the orphan drug applications were authorized. However, for many of these orphan drugs, no phase 1 studies were required, as these products were already well known pharmaceutical substances, with a clearly defined pharmacological profile. Furthermore, for 19 orphan drugs, already authorized by the European Medicines Agency (EMA), the original rare indication was extended to another rare disease and no phase 1 trials were needed. Phase 1 studies need to be performed in a sufficient number of volunteers even for medicinal products intended for a very limited number of patients. PMID:28357178
Bradstreet, Thomas E.; Panebianco, Deborah L.
This article focuses on a two treatment, two period, two treatment sequence crossover drug interaction study of a new drug and a standard oral contraceptive therapy. Both normal theory and distribution-free statistical analyses are provided along with a notable amount of graphical insight into the dataset. For one of the variables, the decision on…
Wang, Yi-Xiang; Deng, Min
Medical imaging can help answer key questions that arise during the drug development process. The role of medical imaging in new drug clinical trials includes identification of likely responders; detection and diagnosis of lesions and evaluation of their severity; and therapy monitoring and follow-up. Nuclear imaging techniques such as PET can be used to monitor drug pharmacokinetics and distribution and study specific molecular endpoints. In assessing drug efficacy, imaging biomarkers and imaging surrogate endpoints can be more objective and faster to measure than clinical outcomes, and allow small group sizes, quick results and good statistical power. Imaging also has important role in drug safety monitoring, particularly when there is no other suitable biomarkers available. Despite the long history of radiological sciences, its application to the drug development process is relatively recent. This review highlights the processes, opportunities, and challenges of medical imaging in new drug development.
Samojlik, Isidora; Petković, Stojan; Stilinović, Nebojša; Vukmirović, Saša; Mijatović, Vesna; Božin, Biljana
Aniseed (Pimpinella anisum L., Apiaceae) and its essential oil (EO) have been widely used. Because there are some data about the impact of aniseed EO on drug effects, this survey aimed to assess the potential of pharmacokinetic herb-drug interaction between aniseed EO and acetaminophen and caffeine in mice. The chemical analysis (gas chromatography-mass spectrometry) of aniseed EO has confirmed trans-anethole (87.96%) as the main component. The pharmacokinetic studies of intraperitoneally (i.p.) and orally applied acetaminophen (200 mg/kg) and caffeine (20 mg/kg) were performed in mice after 5 days of oral treatment with human equivalent dose of aniseed EO (0.3 mg/kg/day). The analysis of pharmacokinetic data showed that in the group treated by aniseed EO, the significant decrease in the peak plasma concentration of acetaminophen after oral application (p = 0.024) was revealed when compared with control group and the reduction of systemic exposure to the drug after oral application (74 ± 32% vs. 85 ± 35% in the control) was noted. The bioavailability of orally applied caffeine was also significantly decreased (p = 0.022) after the EO treatment in comparison with the control (57 ± 24% vs. 101 ± 29%). Therefore, the compromised therapeutic efficacy of acetaminophen and caffeine during the usage of aniseed EO preparations should be considered.
Udrescu, Lucreţia; Sbârcea, Laura; Topîrceanu, Alexandru; Iovanovici, Alexandru; Kurunczi, Ludovic; Bogdan, Paul; Udrescu, Mihai
Analyzing drug-drug interactions may unravel previously unknown drug action patterns, leading to the development of new drug discovery tools. We present a new approach to analyzing drug-drug interaction networks, based on clustering and topological community detection techniques that are specific to complex network science. Our methodology uncovers functional drug categories along with the intricate relationships between them. Using modularity-based and energy-model layout community detection algorithms, we link the network clusters to 9 relevant pharmacological properties. Out of the 1141 drugs from the DrugBank 4.1 database, our extensive literature survey and cross-checking with other databases such as Drugs.com, RxList, and DrugBank 4.3 confirm the predicted properties for 85% of the drugs. As such, we argue that network analysis offers a high-level grasp on a wide area of pharmacological aspects, indicating possible unaccounted interactions and missing pharmacological properties that can lead to drug repositioning for the 15% drugs which seem to be inconsistent with the predicted property. Also, by using network centralities, we can rank drugs according to their interaction potential for both simple and complex multi-pathology therapies. Moreover, our clustering approach can be extended for applications such as analyzing drug-target interactions or phenotyping patients in personalized medicine applications. PMID:27599720
Honig, P K; Gillespie, B K
The use and availability of over-the-counter (OTC) medication is increasing. Although regulatory agencies take care to assure than nonprescription medications are safe and effective, these drugs still have the potential to have clinically significant interactions with prescription medicines. The major classes of OTC medication to be considered in this light include antacids, histamine H2 receptor antagonists, NSAIDs, cough and cold preparations and the antiasthma products. Healthcare providers and patients/consumers should be educated regarding possible drug interactions, patient drug regimens should be simplified where possible, and all therapeutic failures and adverse reactions should be investigated with regard to the potential contribution of OTC drug products. Regulatory agencies and pharmaceutical manufacturers should ensure that nonprescription drug labelling is complete and intelligible to meet these objectives. Consideration should be given to improving the postmarketing surveillance of OTC medications.
Luna, Daniel; Otero, Carlos; Almerares, Alfredo; Stanziola, Enrique; Risk, Marcelo; González Bernaldo de Quirós, Fernán
The utilization of decision support systems, in the point of care, to alert drug-drug interactions has been shown to improve quality of care. Still, the use of these systems has not been as expected, it is believed, because of the difficulties in their knowledge databases; errors in the generation of the alerts and the lack of a suitable design. This study expands on the development of alerts using participatory design techniques based on user centered design process. This work was undertaken in three stages (inquiry, participatory design and usability testing) it showed that the use of these techniques improves satisfaction, effectiveness and efficiency in an alert system for drug-drug interactions, a fact that was evident in specific situations such as the decrease of errors to meet the specified task, the time, the workload optimization and users overall satisfaction in the system.
Pichler, Werner J; Adam, Jacqueline; Watkins, Stephen; Wuillemin, Natascha; Yun, James; Yerly, Daniel
Small chemicals like drugs tend to bind to proteins via noncovalent bonds, e.g. hydrogen bonds, salt bridges or electrostatic interactions. Some chemicals interact with other molecules than the actual target ligand, representing so-called 'off-target' activities of drugs. Such interactions are a main cause of adverse side effects to drugs and are normally classified as predictable type A reactions. Detailed analysis of drug-induced immune reactions revealed that off-target activities also affect immune receptors, such as highly polymorphic human leukocyte antigens (HLA) or T cell receptors (TCR). Such drug interactions with immune receptors may lead to T cell stimulation, resulting in clinical symptoms of delayed-type hypersensitivity. They are assigned the 'pharmacological interaction with immune receptors' (p-i) concept. Analysis of p-i has revealed that drugs bind preferentially or exclusively to distinct HLA molecules (p-i HLA) or to distinct TCR (p-i TCR). P-i reactions differ from 'conventional' off-target drug reactions as the outcome is not due to the effect on the drug-modified cells themselves, but is the consequence of reactive T cells. Hence, the complex and diverse clinical manifestations of delayed-type hypersensitivity are caused by the functional heterogeneity of T cells. In the abacavir model of p-i HLA, the drug binding to HLA may result in alteration of the presenting peptides. More importantly, the drug binding to HLA generates a drug-modified HLA, which stimulates T cells directly, like an allo-HLA. In the sulfamethoxazole model of p-i TCR, responsive T cells likely require costimulation for full T cell activation. These findings may explain the similarity of delayed-type hypersensitivity reactions to graft-versus-host disease, and how systemic viral infections increase the risk of delayed-type hypersensitivity reactions.
Levy, Ilana; Attias, Samuel; Ben-Arye, Eran; Goldstein, Lee; Schiff, Elad
Dietary and herbal supplements (DHS) are widely used in the general population, including during hospitalization. Yet, their potential interactions with prescription drugs have seldom been delineated among inpatients. We aimed to evaluate potentially dangerous interactions of DHS with prescribed medications among inpatients. This was a cross-sectional prospective study involving a cohort of patients hospitalized in 12 departments of a public academic medical center (Bnai Zion Medical Center, Haifa, Israel) from 2009 to 2014. DHS users were determined via a questionnaire. The Natural Medicine database was used to search for potential DHS-drug interactions for identified DHS, and the clinical significance was evaluated using Lexi-interact online interaction analysis. Medical files were assessed for documentation of DHS use. Univariate and multivariate logistic regression analyses were used to characterize potential risk factors for DHS-drug interactions. Of 927 patients consenting to answer the questionnaire, 458 (49 %) reported DHS use. Of these, 215 (47 %) had at least one potential interaction during hospitalization (759 interactions). Of these interactions, 116 (15 %) were potentially clinically significant. Older age [OR = 1.02 (1.01-1.04), p = 0.002], males [OR = 2.11 (1.35-3.29), p = 0.001] and increased number of used DHS [OR = 4.28 (2.28-8.03), p < 0.001] or drugs [OR = 1.95 (1.17-3.26), p = 0.011] were associated with potential interactions in DHS users. Physicians documented only 16.5 % of DHS involved in these interactions in patients' medical files. In conclusion, a substantial number of inpatients use DHS with potential interactions with concomitant medications. Medical staff should be aware of this, question patients on DHS usage and check for such interactions.
Rodríguez-Fragoso, Lourdes; Martínez-Arismendi, José Luis; Orozco-Bustos, Danae; Reyes-Esparza, Jorge; Torres, Eliseo; Burchiel, Scott W
It has been well established that complex mixtures of phytochemicals in fruits and vegetables can be beneficial for human health. Moreover, it is becoming increasingly apparent that phytochemicals can influence the pharmacological activity of drugs by modifying their absorption characteristics through interactions with drug transporters as well as drug-metabolizing enzyme systems. Such effects are more likely to occur in the intestine and liver, where high concentrations of phytochemicals may occur. Alterations in cytochrome P450 and other enzyme activities may influence the fate of drugs subject to extensive first-pass metabolism. Although numerous studies of nutrient-drug interactions have been published and systematic reviews and meta-analyses of these studies are available, no generalizations on the effect of nutrient-drug interactions on drug bioavailability are currently available. Several publications have highlighted the unintended consequences of the combined use of nutrients and drugs. Many phytochemicals have been shown to have pharmacokinetic interactions with drugs. The present review is limited to commonly consumed fruits and vegetables with significant beneficial effects as nutrients and components in folk medicine. Here, we discuss the phytochemistry and pharmacokinetic interactions of the following fruit and vegetables: grapefruit, orange, tangerine, grapes, cranberry, pomegranate, mango, guava, black raspberry, black mulberry, apple, broccoli, cauliflower, watercress, spinach, tomato, carrot, and avocado. We conclude that our knowledge of the potential risk of nutrient-drug interactions is still limited. Therefore, efforts to elucidate potential risks resulting from food-drug interactions should be intensified in order to prevent undesired and harmful clinical consequences.
Volmer, Daisy; Hartikainen, Sirpa; Zharkovsky, Alexander
In Estonia, HMG-CoA reductase inhibitors are widely used to modify lipid levels but there are no current data on additional medicines prescribed alongside the statins. The aim of this study was to identify the frequency of potential clinically relevant interactions at a national level among an outpatient population treated with statins between January and June 2008, based on the prescription database of the Estonian Health Insurance Fund. This retrospective prevalence study included 203,646 outpatients aged 50 years or older, of whom 29,367 received statin therapy. The study analysed individuals who had used at least one prescription medicine for a minimum of 7 days concomitantly with statins. Potential drug interactions were analysed using Epocrates online, Stockley’s Drug Interactions, and the drug interaction database developed in Estonia. Statins metabolised by the CYP3A4 isoenzyme were prescribed to 64% of all statin users. Medicines known to have potentially clinically significant interactions with statins were prescribed to 4.6% of patients. The drugs prescribed concomitantly most often with simvastatin were warfarin (5.7%) and amiodarone (3.9%), whereas digoxin (1.2%) and ethinylestradiol (2%) were prescribed with atorvastatin. Potential interactions were not detected in the treatment regimens of rosuvastatin, pravastatin, and fluvastatin users. PMID:28352703
Vilar, Santiago; Uriarte, Eugenio; Santana, Lourdes; Lorberbaum, Tal; Hripcsak, George; Friedman, Carol; Tatonetti, Nicholas P
Drug-drug interactions (DDIs) are a major cause of adverse drug effects and a public health concern, as they increase hospital care expenses and reduce patients’ quality of life. DDI detection is, therefore, an important objective in patient safety, one whose pursuit affects drug development and pharmacovigilance. In this article, we describe a protocol applicable on a large scale to predict novel DDIs based on similarity of drug interaction candidates to drugs involved in established DDIs. the method integrates a reference standard database of known DDIs with drug similarity information extracted from different sources, such as 2D and 3D molecular structure, interaction profile, target and side-effect similarities. the method is interpretable in that it generates drug interaction candidates that are traceable to pharmacological or clinical effects. We describe a protocol with applications in patient safety and preclinical toxicity screening. the time frame to implement this protocol is 5–7 h, with additional time potentially necessary, depending on the complexity of the reference standard DDI database and the similarity measures implemented. PMID:25122524
Johne, A; Gerloff, T; Mai, I
Implementation of the European Directive 2001/20/EC led to the inclusion of definitions for clinical trial and non-interventional trial in German Drug Law. Other terms, such as non-commercial clinical trial, single patient use, post marketing surveillance and public health study are less well defined. This article explains the various terms by comparing their differences and similarities.
... drugs, devices, and biologics; as well as inspections of clinical investigators, IRBs, and research... HUMAN SERVICES Food and Drug Administration Food and Drug Administration Clinical Trial Requirements, Compliance, and Good Clinical Practice; Public Workshop AGENCY: Food and Drug Administration, HHS....
Tsai, Jui-Kang; Lin, Wen-Kuo; Lung, For-Wey
This study aimed to explore the relationship between dosage of paliperidone and drug attitude, and also clarify the factors associated with drug attitude, using Intention-to-Treat (ITT) analysis. Three hundred thirty-one patients diagnosed with schizophrenia, who prescribed paliperidone between April 2008 and April 2009, from 10 hospitals in Taiwan were enrolled. By structural equation modeling, inpatient/outpatient status associated with occupation status, sex, and score on the Clinical Global Impression-Severity (CGIS) Scale. The score on the Personal and Social Performance (PSP) Scale associated with occupation status, inpatient/outpatient status, and the score on the CGIS Scale. The scores on the DAI-10 associated with the score on the PSP Scale and age. Good drug attitude and medication adherence significantly related to good social interaction. We should enhance the drug attitude and medication adherence of patients with schizophrenia who have poor social interaction to improve the outcome of schizophrenia.
Récoché, Isabelle; Rousseau, Vanessa; Bourrel, Robert; Lapeyre-Mestre, Maryse; Chebane, Leila; Despas, Fabien; Montastruc, Jean-Louis; Bondon-Guitton, Emmanuelle
Abstract Many patients treated with imatinib, used in cancer treatment, are using several other drugs that could interact with imatinib. Our aim was to study all the drug–drug interactions (DDIs) observed in patients treated with imatinib. We performed 2 observational studies, between the 1st January 2012 and the 31st August 2015 in the Midi-Pyrénées area (South Western France), using the French health insurance reimbursement database and then the French Pharmacovigilance Database (FPVD). A total of 544 patients received at least 1 reimbursement for imatinib. Among them, 486 (89.3%) had at least 1 drug that could potentially interact with imatinib. Paracetamol was the most frequent drug involved (77.4%). Proton pump inhibitors, dexamethasone and levothyroxine, were found in >10% of patients. In the FPVD, among a total of 25 reports of ADRs with imatinib recorded in the Midi-Pyrénées area, 10 (40%) had potential DDIs with imatinib. Imatinib was most frequently prescribed by hospital physicians and drugs interacting with imatinib, by general practitioners. Our study showed that at least 40% of the patients treated with imatinib were at risk of DDIs and that all prescribers must be cautious with DDIs in patients treated with imatinib. During imatinib treatment, we particularly recommend to limit the dose of paracetamol at 1300 mg per day, to avoid the use of dexamethasone, and to double the dose of levothyroxine. PMID:27749579
Eyal, Sara; Rasaby, Sivan; Ekstein, Dana
People with epilepsy (PWE) may use prescription and over-the-counter (OTC) drugs for the treatment of concomitant diseases. Combinations of these drugs, as well as dietary supplements, with antiepileptic drugs (AEDs) may lead to reduced control of seizures and of coexisting medical conditions and increased risk of adverse drug reactions (ADRs). The aims of this study were to obtain comprehensive lists of medications, dietary supplements, botanicals, and specific food components used by adult PWE and to evaluate the potential for interactions involving AEDs and patients' awareness of such potential interactions. We conducted a prospective, questionnaire-based study of PWE attending the Hadassah-Hebrew University Epilepsy Clinic over a period of 7months. The questionnaire interview included the listing of medications, medicinal herbs, dietary supplements, and specific food components consumed and the knowledge of potential drug-drug interactions (DDIs), and it was conducted by a pharmacist. Drug-drug interactions were analyzed via the Micromedex online database. Out of 179 patients who attended the clinic over the study period, we interviewed 73 PWE, of which 71 were included in our final analysis. The mean number of AEDs consumed per subject was 1.7 (SD: 0.8, range: 1-4). Forty (56%) subjects were also treated with other prescription and/or OTC medications, and thirty-four (48%) took dietary supplements. Drug families most prone to DDIs involving AEDs included antipsychotic agents, selective serotonin reuptake inhibitors, and statins. Two-thirds of study participants (67%) knew that DDIs may lead to ADRs, but only half (56%) were aware of the potential for reduced seizure control. Only 44% always reported treatment with AEDs to medical professionals. This study provides for the first time a comprehensive picture of prescription and OTC drugs and food supplements used by PWE. Despite a considerable potential for DDIs involving AEDs, patient awareness is limited
Huang, Shiew-Mei; Lesko, Lawrence J
Serious drug-drug interactions have contributed to recent U.S. market withdrawals and also recent nonapprovals of a few new molecular entities. Many of these interactions involved the inhibition or induction of metabolizing enzymes and efflux transporters, resulting in altered systemic exposure and adverse drug reactions or loss of efficacy. In addition to drug-drug interactions, drug-dietary supplement and drug-citrus fruit interactions, among others, could also cause adverse drug reactions or loss of efficacy and are important issues to consider in the evaluation of new drug candidates. This commentary reviews (1). the current understanding of the mechanistic basis of these interactions, (2). issues to consider in the interpretation of study results, and (3). recent labeling examples to illustrate the translation of study results to information useful for patients and health care providers.
Drug craving has re-emerged as a relevant and important construct in the pathophysiology of addiction with its inclusion in DSM-V as a key clinical symptom of addictive disorders. This renewed focus has been due in part to the recent neurobiological evidence on craving-related neural activation and clinical evidence supporting its association with drug use, relapse, and recovery processes. This review covers the neurobiology of drug craving and relapse risk with a primary focus on cocaine addiction and a secondary emphasis on alcohol addiction. A conceptualization of drug craving on the continuum of healthy desire and compulsive seeking, and the associated neurobiological adaptations associated with the development of an increased craving/wanting state is presented. Altered dopamine neurochemistry as well as disrupted prefrontal control and hyperactive striatal-limbic responses in experiencing drug cues, stress, drug intake and in basal relaxed states are identified as neurobiological signatures that predict drug craving and drug use. Thus, the clinical and neurobiological features of the craving/wanting state are presented with specific attention to alterations in these cortico-limbic-striatal and prefrontal self-control circuits that predict drug craving and relapse risk. The methodological challenges that need to be addressed to further develop the evolving conceptual approach to the neuroscience of drug craving is presented, with a focus on identification and validation of biomarkers associated with the craving state and treatment approaches that may be of benefit in reversing the neurobiological adaptations associated with drug craving to improve treatment outcomes in addiction.
Aronson, Jeffrey K
Anecdotal reports contribute 30% of the literature on adverse drug reactions and interactions. However, the quality of such reports has not been uniformly high. Standardized reporting of clinical studies is of increasing interest, including the CARE guidelines on reporting anecdotal cases in general. Although there are guidelines on evaluating and managing drug-drug interactions, there are none recommending methods for reporting suspected drug interactions. Here, based on published guidelines for reporting suspected adverse drug reactions, I propose a checklist for reporting details of suspected drug interactions, the REporting Anecdotal Drug Interactions (READI) checklist, hoping to stimulate discussion and improve reporting of suspected drug interactions. The checklist includes items relating, among others, to the patient affected, the drugs involved, and the outcome.
Alvim, Mariana Macedo; da Silva, Lidiane Ayres; Leite, Isabel Cristina Gonçalves; Silvério, Marcelo Silva
Objective To evaluate the incidence of potential drug-drug interactions in an intensive care unit of a hospital, focusing on antimicrobial drugs. Methods This cross-sectional study analyzed electronic prescriptions of patients admitted to the intensive care unit of a teaching hospital between January 1 and March 31, 2014 and assessed potential drug-drug interactions associated with antimicrobial drugs. Antimicrobial drug consumption levels were expressed in daily doses per 100 patient-days. The search and classification of the interactions were based on the Micromedex® system. Results The daily prescriptions of 82 patients were analyzed, totaling 656 prescriptions. Antimicrobial drugs represented 25% of all prescription drugs, with meropenem, vancomycin and ceftriaxone being the most prescribed medications. According to the approach of daily dose per 100 patient-days, the most commonly used antimicrobial drugs were cefepime, meropenem, sulfamethoxazole + trimethoprim and ciprofloxacin. The mean number of interactions per patient was 2.6. Among the interactions, 51% were classified as contraindicated or significantly severe. Highly significant interactions (clinical value 1 and 2) were observed with a prevalence of 98%. Conclusion The current study demonstrated that antimicrobial drugs are frequently prescribed in intensive care units and present a very high number of potential drug-drug interactions, with most of them being considered highly significant. PMID:26761473
Chauvin, Benoit; Drouot, Sylvain; Barrail-Tran, Aurélie; Taburet, Anne-Marie
The HMG-CoA reductase inhibitors are a class of drugs also known as statins. These drugs are effective and widely prescribed for the treatment of hypercholesterolemia and prevention of cardiovascular morbidity and mortality. Seven statins are currently available: atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin and simvastatin. Although these drugs are generally well tolerated, skeletal muscle abnormalities from myalgia to severe lethal rhabdomyolysis can occur. Factors that increase statin concentrations such as drug-drug interactions can increase the risk of these adverse events. Drug-drug interactions are dependent on statins' pharmacokinetic profile: simvastatin, lovastatin and atorvastatin are metabolized through cytochrome P450 (CYP) 3A, while the metabolism of the other statins is independent of this CYP. All statins are substrate of organic anion transporter polypeptide 1B1, an uptake transporter expressed in hepatocyte membrane that may also explain some drug-drug interactions. Many HIV-infected patients have dyslipidemia and comorbidities that may require statin treatment. HIV-protease inhibitors (HIV PIs) are part of recommended antiretroviral treatment in combination with two reverse transcriptase inhibitors. All HIV PIs except nelfinavir are coadministered with a low dose of ritonavir, a potent CYP3A inhibitor to improve their pharmacokinetic properties. Cobicistat is a new potent CYP3A inhibitor that is combined with elvitegravir and will be combined with HIV-PIs in the future. The HCV-PIs boceprevir and telaprevir are both, to different extents, inhibitors of CYP3A. This review summarizes the pharmacokinetic properties of statins and PIs with emphasis on their metabolic pathways explaining clinically important drug-drug interactions. Simvastatin and lovastatin metabolized through CYP3A have the highest potency for drug-drug interaction with potent CYP3A inhibitors such as ritonavir- or cobicistat-boosted HIV-PI or the
An, Bo; Lin, Yu-Shan; Brodsky, Barbara
Collagen is a major component in a wide range of drug delivery systems and biomaterial applications. Its basic physical and structural properties, together with its low immunogenicity and natural turnover, are keys to its biocompatibility and effectiveness. In addition to its material properties, the collagen triple-helix interacts with a large number of molecules that trigger biological events. Collagen interactions with cell surface receptors regulate many cellular processes, while interactions with other ECM components are critical for matrix structure and remodeling. Collagen also interacts with enzymes involved in its biosynthesis and degradation, including matrix metalloproteinases. Over the past decade, much information has been gained about the nature and specificity of collagen interactions with its partners. These studies have defined collagen sequences responsible for binding and the high-resolution structures of triple-helical peptides bound to its natural binding partners. Strategies to target collagen interactions are already being developed, including the use of monoclonal antibodies to interfere with collagen fibril formation and the use of triple-helical peptides to direct liposomes to melanoma cells. The molecular information about collagen interactions will further serve as a foundation for computational studies to design small molecules that can interfere with specific interactions or target tumor cells. Intelligent control of collagen biological interactions within a material context will expand the effectiveness of collagen-based drug delivery.
Ochs, Christopher; Zheng, Ling; Gu, Huanying; Perl, Yehoshua; Geller, James; Kapusnik-Uner, Joan; Zakharchenko, Aleksandr
The National Drug File – Reference Terminology (NDF-RT) is a large and complex drug terminology. NDF-RT provides important information about clinical drugs, e.g., their chemical ingredients, mechanisms of action, dosage form and physiological effects. Within NDF-RT such information is represented using tens of thousands of roles. It is difficult to comprehend large, complex terminologies like NDF-RT. In previous studies, we introduced abstraction networks to summarize the content and structure of terminologies. In this paper, we introduce the Ingredient Abstraction Network to summarize NDF-RT’s Chemical Ingredients and their associated drugs. Additionally, we introduce the Aggregate Ingredient Abstraction Network, for controlling the granularity of summarization provided by the Ingredient Abstraction Network. The Ingredient Abstraction Network is used to support the discovery of new candidate drug-drug interactions (DDIs) not appearing in First Databank, Inc.’s DDI knowledgebase. PMID:26958234
Sprouse, Alyssa A.
The use of botanical dietary supplements has grown steadily over the last 20 years despite incomplete information regarding active constituents, mechanisms of action, efficacy, and safety. An important but underinvestigated safety concern is the potential for popular botanical dietary supplements to interfere with the absorption, transport, and/or metabolism of pharmaceutical agents. Clinical trials of drug–botanical interactions are the gold standard and are usually carried out only when indicated by unexpected consumer side effects or, preferably, by predictive preclinical studies. For example, phase 1 clinical trials have confirmed preclinical studies and clinical case reports that St. John’s wort (Hypericum perforatum) induces CYP3A4/CYP3A5. However, clinical studies of most botanicals that were predicted to interact with drugs have shown no clinically significant effects. For example, clinical trials did not substantiate preclinical predictions that milk thistle (Silybum marianum) would inhibit CYP1A2, CYP2C9, CYP2D6, CYP2E1, and/or CYP3A4. Here, we highlight discrepancies between preclinical and clinical data concerning drug–botanical interactions and critically evaluate why some preclinical models perform better than others in predicting the potential for drug–botanical interactions. Gaps in knowledge are also highlighted for the potential of some popular botanical dietary supplements to interact with therapeutic agents with respect to absorption, transport, and metabolism. PMID:26438626
Li, Li; Wu, Zunyou; Cao, Xiaobin; Zhang, Linglin
This study examines provider-client interactions in the context of methadone maintenance treatment (MMT) in China. Service providers were recruited from six methadone clinics. A total of 41 providers were enrolled in the study and participated in an assessment from February to March 2010. Descriptive and multiple regression analyses were performed. Providers with a higher level of negative attitude toward drug users were less likely than others to interact with clients. Female providers were less likely to have negative attitudes toward drug users as compared with their male counterparts. Doctors were more likely than others to have negative attitudes toward drug users. Knowledge of MMT was not related to either negative attitude toward drug users or to provider-client interaction. The findings indicate an urgent need to address the issue of provider attitudes, which can impact interactions with clients and influence efforts to maintain treatment retention and outcomes for drug users.
Froestl, Wolfgang; Muhs, Andreas; Pfeifer, Andrea
Cognitive enhancers (nootropics) are drugs to treat cognition deficits in patients suffering from Alzheimer's disease, schizophrenia, stroke, attention deficit hyperactivity disorder, or aging. Cognition refers to a capacity for information processing, applying knowledge, and changing preferences. It involves memory, attention, executive functions, perception, language, and psychomotor functions. The term nootropics was coined in 1972 when memory enhancing properties of piracetam were observed in clinical trials. In the meantime, hundreds of drugs have been evaluated in clinical trials or in preclinical experiments. To classify the compounds, a concept is proposed assigning drugs to 18 categories according to their mechanism(s) of action, in particular drugs interacting with receptors, enzymes, ion channels, nerve growth factors, re-uptake transporters, antioxidants, metal chelators, and disease-modifying drugs meaning small molecules, vaccines, and monoclonal antibodies interacting with amyloid-β and tau. For drugs, whose mechanism of action is not known, they are either classified according to structure, e.g., peptides, or their origin, e.g., natural products. The review covers the evolution of research in this field over the last 25 years.
Froestl, Wolfgang; Muhs, Andreas; Pfeifer, Andrea
Cognitive enhancers (nootropics) are drugs to treat cognition deficits in patients suffering from Alzheimer's disease, schizophrenia, stroke, attention deficit hyperactivity disorder, or aging. Cognition refers to a capacity for information processing, applying knowledge, and changing preferences. It involves memory, attention, executive functions, perception, language, and psychomotor functions. The term nootropics was coined in 1972 when memory enhancing properties of piracetam were observed in clinical trials. In the meantime, hundreds of drugs have been evaluated in clinical trials or in preclinical experiments. To classify the compounds, a concept is proposed assigning drugs to 19 categories according to their mechanism(s) of action, in particular drugs interacting with receptors, enzymes, ion channels, nerve growth factors, re-uptake transporters, antioxidants, metal chelators, and disease modifying drugs meaning small molecules, vaccines, and monoclonal antibodies interacting with amyloid-β and tau. For drugs whose mechanism of action is not known, they are either classified according to structure, e.g., peptides, or their origin, e.g., natural products. This review covers the evolution of research in this field over the last 25 years.
... authority of FDA and to facilitate interaction with FDA representatives. The program will focus on the... provide those engaged in FDA-regulated (human) clinical trials with information on a number of topics... community a high priority to help ensure the quality of FDA-regulated drugs and devices. The workshop...
Ekins, Sean; Clark, Alex M; Wright, Stephen H
The past decade has seen increased numbers of studies publishing ligand-based computational models for drug transporters. Although they generally use small experimental data sets, these models can provide insights into structure-activity relationships for the transporter. In addition, such models have helped to identify new compounds as substrates or inhibitors of transporters of interest. We recently proposed that many transporters are promiscuous and may require profiling of new chemical entities against multiple substrates for a specific transporter. Furthermore, it should be noted that virtually all of the published ligand-based transporter models are only accessible to those involved in creating them and, consequently, are rarely shared effectively. One way to surmount this is to make models shareable or more accessible. The development of mobile apps that can access such models is highlighted here. These apps can be used to predict ligand interactions with transporters using Bayesian algorithms. We used recently published transporter data sets (MATE1, MATE2K, OCT2, OCTN2, ASBT, and NTCP) to build preliminary models in a commercial tool and in open software that can deliver the model in a mobile app. In addition, several transporter data sets extracted from the ChEMBL database were used to illustrate how such public data and models can be shared. Predicting drug-drug interactions for various transporters using computational models is potentially within reach of anyone with an iPhone or iPad. Such tools could help prioritize which substrates should be used for in vivo drug-drug interaction testing and enable open sharing of models.
Mouly, S; Morgand, M; Lopes, A; Lloret-Linares, C; Bergmann, J-F
Orally administered medications may interact with various fruits, vegetables, herbal medicines, functional foods or dietary supplements. Drug-food interactions, which are mostly unknown from prescribers, including internists, may be responsible for changes in drug plasma concentrations, which may decrease efficacy or led to sometimes life-threatening toxicity. Aging, concomitant medications, transplant recipients, patients with cancer, malnutrition, HIV infection and those receiving enteral or parenteral feeding are at increased risk of drug-food interactions. This review focused on the most clinically relevant drug-food interactions, including those with grapefruit juice, Saint-John's Wort, enteral or parenteral nutrition, their respective consequences in the clinical setting in order to provide thoughtful information for internists in their routine clinical practice. Specific clinical settings are also detailed, such as the Ramadan or multiple medications especially in elderly patients. Drug-food interactions are also presented with respect to the main therapeutic families, including the non-steroidal anti-inflammatory drugs, analgesics, cardiovascular medications, warfarin as well as new oral anticoagulants, anticancer drugs and immunosuppressant medications. Considerable effort has been achieved to a better understanding of food-drug interactions and increase clinicians' ability to anticipate their occurrence and consequences in clinical practice. Describing the frequency of relevant food-drug interactions in internal medicine is paramount in order to optimize patient care and drug dosing on an individual basis as well as to increase patients and doctors information.
Spina, Edoardo; Santoro, Vincenza
This article summarized the available knowledge on clinically relevant drug interactions of vortioxetine, a new antidepressant with a “multimodal” serotonergic mechanism of action, recently approved for the treatment of major depressive disorder. Although information is still limited and mainly based on studies performed in healthy volunteers, vortioxetine appears to have a favorable drug interaction profile. Concerning the potential for pharmacokinetic drug interactions, vortioxetine has little to no effect on various cytochrome P450 (CYP) isoforms and therefore is not expected to markedly affect plasma concentrations of other medications metabolized by these enzymes. This is a major advantage when compared to other antidepressants which are known to inhibit the activity of one or more CYP isoforms. On the other hand, dosage adjustments may be required when vortioxetine is coadministered with strong CYP2D6 inhibitors or broad-spectrum CYP inducers. Vortioxetine carries a relatively low risk for pharmacodynamic drug interactions, at least as compared to first-generation antidepressants. Like other antidepressants enhancing serotonergic activity, vortioxetine is associated with a potential risk of serotonin syndrome when used in combination with other serotonergic agents. Based on all available clinical data, vortioxetine has no increased risk of serotonin syndrome when used without other serotoninergic agents and at therapeutic doses.
Tragni, Elena; Casula, Manuela; Pieri, Vasco; Favato, Giampiero; Marcobelli, Alberico; Trotta, Maria Giovanna; Catapano, Alberico Luigi
The use of multiple medications is becoming more common, with a correspondingly increased risk of untoward effects and drug-related morbidity and mortality. We aimed at estimating the prevalence of prescription of relevant potentially interacting drugs and at evaluating possible predictors of potentially interacting drug exposure. We retrospectively analyzed data on prescriptions dispensed from January 2004 to August 2005 to individuals of two Italian regions with a population of almost 2.1 million individuals. We identified 27 pairs of potentially interacting drugs by examining clinical relevance, documentation, and volume of use in Italy. Subjects who received at least one prescription of both drugs were selected. Co-prescribing denotes “two prescriptions in the same day”, and concomitant medication “the prescription of two drugs with overlapping coverage”. A logistic regression analysis was conducted to examine the predictors of potential Drug-Drug Interaction (pDDIs). 957,553 subjects (45.3% of study population) were exposed to at least one of the drugs/classes of the 27 pairs. Overall, pDDIs occurred 2,465,819 times. The highest rates of concomitant prescription and of co-prescription were for ACE inhibitors+NSAIDs (6,253 and 4,621/100,000 plan participants). Considering concomitance, the male/female ratio was <1 in 17/27 pairs (from 0.31 for NSAIDs-ASA+SSRI to 0.74 for omeprazole+clopidogrel). The mean age was lowest for methotrexate pairs (+omeprazole, 59.9 years; +NSAIDs-ASA, 59.1 years) and highest for digoxin+verapamil (75.4 years). In 13/27 pairs, the mean ages were ≥70 years. On average, subjects involved in pDDIs received ≥10 drugs. The odds of exposure were more frequently higher for age ≥65 years, males, and those taking a large number of drugs. A substantial number of clinically important pDDIs were observed, particularly among warfarin users. Awareness of the most prevalent pDDIs could help practitioners in preventing concomitant use
Khalsa, Jag H; Talal, Andrew H; Morse, Gene
Substance use and pharmacologic treatment of co-occurring infections such as human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are associated with many adverse consequences including pharmacokinetic and pharmacodynamic drug-drug interactions (DDIs). The National Institute on Drug Abuse sponsored a 2-day conference on DDIs at which clinicians/scientists from government, academia, and the pharmaceutical industry presented the most current research findings to formulate a comprehensive overview of DDIs. Specific topics discussed included drug metabolism; drug interactions between medications used in the treatment of HIV, HCV, and substance use disorders; intrahepatic concentrations and methods of assessment of drugs in liver disease of varying etiologies and degrees of impairment; and minimally invasive sampling techniques for the assessment of intrahepatic drug concentrations, viral replication, and changes in gene expression in response to treatment. Finally, the speakers identified research targets and priorities on DDIs. Areas of emphasis included development of diagnostic assays for drug concentration assessment in different organs, an enhanced understanding of factors responsible for alterations in drug metabolism and excretion, and establishment of clinical trials and work groups to study DDIs. Our long-term objective is to broaden investigation in the field of DDIs in substance users.
Johnson, S A; Luu, N T; Herbst, T A; Knapp, R; Lutz, D; Arai, A; Rogers, G A; Lynch, G
Tests were made for interactions between antipsychotic drugs and compounds that enhance synaptic currents mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid-type glutamate receptors ("ampakines"). Typical and atypical antipsychotic drugs decreased methamphetamine-induced hyperactivity in rats; the effects of near or even subthreshold doses of the antipsychotics were greatly enhanced by the ampakines. Interactions between the ampakine CX516 and low doses of different antipsychotics were generally additive and often synergistic. The ampakine did not exacerbate neuroleptic-induced catalepsy, indicating that the interaction between the different pharmacological classes was selective. These results suggest that positive modulators of cortical glutamatergic systems may be useful adjuncts in treating schizophrenia.
... Medications Anticoagulants and Drug-Food Interactions Anticoagulants and Drug-Food Interactions Make an Appointment Ask a Question ... care provider before making the change. Anticoagulants and Medicine There are many medicines that can interact with ...
The predictable pharmacokinetic drug interaction between clozapine and rifampicin is listed in most standard reference texts but little detail is given or emphasis on its clinical significance. The interaction is based on theoretical knowledge of both drugs; to date just two case reports have been published. This article describes a third case demonstrating the significance of this interaction. This was potentially devastating for the patient who required an extended psychiatric admission. The enzyme induction was so potent that the dose of clozapine had to be increased approximately sixfold. Careful management of this significant interaction is essential for effective patient care. PMID:27280037
Dworacka, Marzena; Nowocień, Tamara
The occurence of pharmacokinetic drug-to-drug interactions is the serious clinical problem in the course of pharmacotherapy of infections. Its essential part is the influence of such interactions on the effectiveness and safety of antimicrobial therapy. The aim of study was to present, the most significant on clinical hand, examples of interactions and their mechanisms between antimicrobial agents and other drugs on stages of absorption, distribution, biotransformation and elimination, leading to the decreased antimicrobial activity and ineffective pharmacotherapy or to the increased antimicrobial activity and to the increased risk of adverse effects due to agents used for anti-infectious pharmacotherapy.
Ouwerkerk-Mahadevan, Sivi; Snoeys, Jan; Peeters, Monika; Beumont-Mauviel, Maria; Simion, Alexandru
Simeprevir is an NS3/4A protease inhibitor approved for the treatment of hepatitis C infection, as a component of combination therapy. Simeprevir is metabolized by the cytochrome P450 (CYP) system, primarily CYP3A, and is a substrate for several drug transporters, including the organic anion transporting polypeptides (OATPs). It is susceptible to metabolic drug-drug interactions with drugs that are moderate or strong CYP3A inhibitors (e.g. ritonavir and erythromycin) or CYP3A inducers (e.g. rifampin and efavirenz); coadministration of these drugs may increase or decrease plasma concentrations of simeprevir, respectively, and should be avoided. Clinical studies have shown that simeprevir is a mild inhibitor of CYP1A2 and intestinal CYP3A but does not inhibit hepatic CYP3A. The effects of simeprevir on these enzymes are of clinical relevance only for narrow-therapeutic-index drugs that are metabolized solely by these enzymes (e.g. oral midazolam). Simeprevir does not have a clinically relevant effect on the pharmacokinetics of rilpivirine, tacrolimus, oral contraceptives and several other drugs metabolized by CYP enzymes. Simeprevir is a substrate and inhibitor of the transporters P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and OATP1B1/3. Cyclosporine is an inhibitor of OATP1B1/3, BCRP and P-gp, and a mild inhibitor of CYP3A; cyclosporine causes a significant increase in simeprevir plasma concentrations, and coadministration is not recommended. Clinical studies have demonstrated increases in coadministered drug concentrations for drugs that are substrates of the OATP1B1/3, BRCP (e.g. rosuvastatin) and P-gp (e.g. digoxin) transporters; these drugs should be administered with dose titration and or/close monitoring.
Pal, Dhananjay; Mitra, Ashim K
P-glycoprotein (P-gp), multiple drug resistance associated proteins (MRPs), and cytochrome P450 3A4 together constitute a highly efficient barrier for many orally absorbed drugs. Multidrug regimens and corresponding drug-drug interactions are known to cause many adverse drug reactions and treatment failures. Available literature, clinical reports, and in vitro studies from our laboratory indicate that many drugs are substrates for both P-gp and CYP3A4. Our primary hypothesis is that transport and metabolism of protease inhibitors (PIs) and NNRTIs will be altered when administered in combination with azole antifungals, macrolide, fluroquinolone antibiotics, statins, cardiovascular agents, immune modulators, and recreational drugs [benzodiazepines, cocaine, lysergic acid dithylamide (LSD), marijuana, amphetamine (Meth), 3,4-methylenedioxymethamphetamine (MDMA), and opiates] due to efflux, and/or metabolism at cellular targets. Therefore, such drug combinations could be a reason for the unexpected and unexplainable therapeutic outcomes. A number of clinical reports on drug interaction between PIs and other classes (macrolide antibiotics, azole antifungals, cholesterol lowering statins, cardiovascular medicines, and immunomodulators) are discussed in this article. MDCKII-MDR1 was employed as an in vitro model to evaluate the effects of antiretrovirals, azole antifungals, macrolide, and fluroquinolone antibiotics on efflux transporters. Ketoconazole (50 muM) enhanced the intracellular concentration of (3)H ritonavir. The inhibitory effects of ketoconazole and MK 571 on the efflux of (3)H ritonavir were comparable. An additive effect was observed with simultaneous incorporation of ketoconazole and MK 571. Results of (3)H ritonavir uptake studies were confirmed with transcellular transport studies. Several fluroquinolones were also evaluated on P-gp-mediated efflux of (3)H cyclosporin and 14C erythromycin. These in vitro studies indicate that grepafloxacin, levofloxacin
Lathrop, Julia Tait; Jeffery, Douglas A; Shea, Yvonne R; Scholl, Peter F; Chan, Maria M
Mass spectrometry-based in vitro diagnostic devices that measure proteins and peptides are underutilized in clinical practice, and none has been cleared or approved by the Food and Drug Administration (FDA) for marketing or for use in clinical trials. One way to increase their utilization is through enhanced interactions between the FDA and the clinical mass spectrometry community to improve the validation and regulatory review of these devices. As a reference point from which to develop these interactions, this article surveys the FDA's regulation of mass spectrometry-based devices, explains how the FDA uses guidance documents and standards in the review process, and describes the FDA's previous outreach to stakeholders. Here we also discuss how further communication and collaboration with the clinical mass spectrometry communities can identify opportunities for the FDA to provide help in the development of mass spectrometry-based devices and enhance their entry into the clinic.
Vilar, Santiago; Lorberbaum, Tal; Hripcsak, George; Tatonetti, Nicholas P
Identification of Drug-Drug Interactions (DDIs) is a significant challenge during drug development and clinical practice. DDIs are responsible for many adverse drug effects (ADEs), decreasing patient quality of life and causing higher care expenses. DDIs are not systematically evaluated in pre-clinical or clinical trials and so the FDA U. S. Food and Drug Administration relies on post-marketing surveillance to monitor patient safety. However, existing pharmacovigilance algorithms show poor performance for detecting DDIs exhibiting prohibitively high false positive rates. Alternatively, methods based on chemical structure and pharmacological similarity have shown promise in adverse drug event detection. We hypothesize that the use of chemical biology data in a post hoc analysis of pharmacovigilance results will significantly improve the detection of dangerous interactions. Our model integrates a reference standard of DDIs known to cause arrhythmias with drug similarity data. To compare similarity between drugs we used chemical structure (both 2D and 3D molecular structure), adverse drug side effects, chemogenomic targets, drug indication classes, and known drug-drug interactions. We evaluated the method on external reference standards. Our results showed an enhancement of sensitivity, specificity and precision in different top positions with the use of similarity measures to rank the candidates extracted from pharmacovigilance data. For the top 100 DDI candidates, similarity-based modeling yielded close to twofold precision enhancement compared to the proportional reporting ratio (PRR). Moreover, the method helps in the DDI decision making through the identification of the DDI in the reference standard that generated the candidate.
The use of herbal supplements in the US has increased dramatically in recent years. These products are not regulated by the Food and Drug Administration (FDA) with the same scrutiny as conventional drugs. Patients who use herbal supplements often do so in conjunction with conventional drugs. This article is a review of potential adverse interactions between some of the commonly used herbal supplements and analgesic drugs. Non-steroidal anti-inflammatory drugs (NSAIDs), particularly aspirin, have the potential to interact with herbal supplements that are known to possess antiplatelet activity (ginkgo, garlic, ginger, bilberry, dong quai, feverfew, ginseng, turmeric, meadowsweet and willow), with those containing coumarin (chamomile, motherworth, horse chestnut, fenugreek and red clover) and with tamarind, enhancing the risk of bleeding. Acetaminophen may also interact with ginkgo and possibly with at least some of the above herbs to increase the risk of bleeding. Further, the incidences of hepatotoxicity and nephrotoxicity may be augmented by acetaminophen when concomitantly used with the potentially hepatotoxic herbs Echinacea and kava, and with herbs containing salicylate (willow, meadowsweet), respectively. The concomitant use of opioid analgesics with the sedative herbal supplements, valerian, kava and chamomile, may lead to increased central nervous system (CNS) depression. The analgesic effect of opioids may also be inhibited by ginseng. It is suggested that health-care professionals should be more aware of the potential adverse interactions between herbal supplements and analgesic drugs, and take appropriate precautionary measures to avoid their possible occurrences. However, as most of the interaction information available is based on individual case reports, animal studies and in vitro data, further research is needed to confirm and assess the clinical significance of these potential interactions.
... HUMAN SERVICES Food and Drug Administration Food and Drug Administration Clinical Trial Requirements, Compliance, and Good Clinical Practice; Public Workshop AGENCY: Food and Drug Administration, HHS. ACTION: Notice of public workshop. The Food and Drug Administration (FDA), Baltimore District Office,...
Azole antifungal agents are frequently used in hematopoietic stem cell and solid organ transplant recipients for prevention or treatment of invasive fungal infections. However, because of metabolism by or substrate activity for various isoenzymes of the cytochrome P450 system and/or P-glycoprotein, azole antifungals have the potential to interact with many of the drugs commonly used in these patient populations. Thus, to identify drug interactions that may result between azole antifungals and other drugs, we conducted a literature search of the MEDLINE database (1966-December 2009) for English-language articles on drug interaction studies involving the azole antifungal agents fluconazole, itraconazole, voriconazole, and posaconazole. Another literature search between each of the azoles and the immunosuppressants cyclosporine, tacrolimus, and sirolimus, as well as the corticosteroids methylprednisolone, dexamethasone, prednisolone, and prednisone, was also conducted. Concomitant administration of azoles and immunosuppressive agents may cause clinically significant drug interactions resulting in extreme immunosuppression or toxicity. The magnitude and duration of an interaction between azoles and immunosuppressants are not class effects of the azoles, but differ between drug combinations and are subject to interpatient variability. Drug interactions in the transplant recipient receiving azole therapy may also occur with antibiotics, chemotherapeutic agents, and acid-suppressive therapies, among other drugs. Initiation of an azole antifungal in transplant recipients nearly ensures a drug-drug interaction, but often these drugs are required. Management of these interactions first involves knowledge of the potential drug interaction, appropriate dosage adjustments when necessary, and therapeutic or clinical monitoring at an appropriate point in therapy to assess the drug-drug interaction (e.g., immunosuppressive drug concentrations, signs and symptoms of toxicity
Liu, Shengyu; Tang, Buzhou; Chen, Qingcai; Wang, Xiaolong
Drug-drug interaction (DDI) extraction as a typical relation extraction task in natural language processing (NLP) has always attracted great attention. Most state-of-the-art DDI extraction systems are based on support vector machines (SVM) with a large number of manually defined features. Recently, convolutional neural networks (CNN), a robust machine learning method which almost does not need manually defined features, has exhibited great potential for many NLP tasks. It is worth employing CNN for DDI extraction, which has never been investigated. We proposed a CNN-based method for DDI extraction. Experiments conducted on the 2013 DDIExtraction challenge corpus demonstrate that CNN is a good choice for DDI extraction. The CNN-based DDI extraction method achieves an F-score of 69.75%, which outperforms the existing best performing method by 2.75%. PMID:26941831
I report here an elderly woman receiving perphenazine together with terbinafine. After 1 week of terbinafine treatment she experienced extrapyramidal symptoms and, in particular, akathisia. Her symptoms did not disappear for 6 weeks, and so at 2 weeks prior to this most recent admission she had stopped taking terbinafine. However, these symptoms persisted for 3 weeks after discontinuing terbinafine. It is well known that terbinafine inhibits CYP2D6 and that perphenazine is metabolized mainly by CYP2D6. Thus, when terbinafine and perphenazine are coadministrated, the subsequent increase in the concentration of perphenazine may induce extrapyramidal symptoms. Thus, terbinafine therapy may be associated with the induction and persistence of extrapyramidal symptoms, including akathisia. This case report emphasizes the importance of monitoring drug-drug interactions in patients undergoing terbinafine and perphenazine therapy.
Palatini, Pietro; De Martin, Sara
Inhibition and induction of drug-metabolizing enzymes are the most frequent and dangerous drug-drug interactions. They are an important cause of serious adverse events that have often resulted in early termination of drug development or withdrawal of drugs from the market. Management of such interactions by dose adjustment in clinical practice is extremely difficult because of the wide interindividual variability in their magnitude. This review examines the genetic, physiological, and environmental factors responsible for this variability, focusing on an important but so far neglected cause of variability, liver functional status. Clinical studies have shown that liver disease causes a reduction in the magnitude of interactions due to enzyme inhibition, which is proportional to the degree of liver function impairment. The effect of liver dysfunction varies quantitatively according to the nature, reversible or irreversible, of the inhibitory interaction. The magnitude of reversible inhibition is more drastically reduced and virtually vanishes in patients with advanced hepatocellular insufficiency. Two mechanisms, in order of importance, are responsible for this reduction: decreased hepatic uptake of the inhibitory drug and reduced enzyme expression. The extent of irreversible inhibitory interactions is only partially reduced, as it is only influenced by the decreased expression of the inhibited enzyme. Thus, for appropriate clinical management of inhibitory drug interactions, both the liver functional status and the mechanism of inhibition must be taken into consideration. Although the inducibility of drug-metabolizing enzymes in liver disease has long been studied, very conflicting results have been obtained, mainly because of methodological differences. Taken together, the results of early animal and human studies indicated that enzyme induction is substantially preserved in compensated liver cirrhosis, whereas no definitive conclusion as to whether it is
Misiak, Majus; Mantegazza, Francesco; Beretta, Giovanni L
DNA damaging agents including anthracyclines, camptothecins and platinum drugs are among most frequently used drugs in the chemotherapeutic routine. Due to their relatively low selectivity for cancer cells, administration of these drugs is associated with adverse side effects, inherent genotoxicity with risk of developing secondary cancers. Development of new drugs, which could be spared of these drawbacks and characterize by improved antitumor efficacy, remains challenging yet vitally important task. These properties are in large part dictated by the selectivity of interaction between the drug and DNA and in this way the studies aimed at elucidating the complex interactions between ligand and DNA represent a key step in the drug development. Studies of the drug-DNA interactions encompass determination of DNA sequence specificity and mode of DNA binding as well as kinetic, dynamic and structural parameters of binding. Here, we consider the types of interactions between small molecule ligands and polynucleotides, how they are affected by DNA sequence and structure, and what is their significance for the antitumor activity. Based on this knowledge, we discuss the wide array of experimental techniques available to researchers for studying drug-DNA interactions, which include absorption and emission spectroscopies, NMR, magnetic and optical tweezers or atomic force microscopy. We show, using the clinical and experimental anticancer drugs as examples, how these methods provide various types of information and at the same time complement each other to provide full picture of drug- DNA interaction and aid in the development of new drugs.
Spanakis, Marios; Spanakis, Emmanouil G; Kondylakis, Haridimos; Sfakianakis, Stelios; Genitsaridi, Irini; Sakkalis, Vangelis; Tsiknakis, Manolis; Marias, Kostas
Personalized healthcare systems support the provision of timely and appropriate information regarding healthcare options and treatment alternatives. Especially for patients that receive multi-drug treatments a key issue is the minimization of the risk of adverse effects due to drug-drug interactions (DDIs). DDIs may be the result of doctor prescribed drugs but also due to self-medication of conventional drugs, alternative medicines, food habits, alcohol or smoking. It is therefore crucial for personalized health systems, apart from assisting physicians for optimal prescription practices, to also provide appropriate information for individual users for drug-drug interactions or similar information regarding risks for modulation of the ensuing treatment. In this manuscript we describe a DDI service including drug-food, drug-herb and other lifestyle-related factors, developed in the context of a personalized patient empowerment platform. The solution enables guidance to patients for their medication on how to reduce the risk of unwanted drug interactions and side effects in a seamless and transparent way. We present and analyze the implemented services and provide examples on using an alerting service to identify potential DDIs in two different chronic diseases, congestive heart failure and osteoarthritis.
Schulden, Jeffrey D; Lopez, Marsha F; Compton, Wilson M
Research on the epidemiology of illicit drug use disorders provides continued critical insights into the distribution and determinants of drug use and drug use disorders in the United States. This research serves as a foundation for understanding the etiology of these disorders, helping to disentangle the complex interrelationship of developmental, genetic, and environmental risk and protective factors. Building on an understanding of this research in substance abuse epidemiology, it is important for clinicians to understand the unique trends in drug use in the overall communities that they serve and the unique risk factors for given individuals. The generally high prevalence of substance use disorders, along with their high comorbidity with other psychiatric disorders and with the HIV epidemic, make prevention, evaluation, and referral for treatment for drug abuse an important part of routine clinical practice in a range of clinical settings, including primary care, psychiatric, and emergency department settings. Ongoing efforts to ensure insurance coverage parity for the treatment of mental health and substance use disorders offer the promise of continued improvements in the integration and availability of such services in the broader US health care system.
Coondoo, Arijit; Chattopadhyay, Chandan
A drug interaction is a process by which a drug or any other substance interacts with another drug and affects its activity by increasing or decreasing its effect, causing a side effect or producing a new effect unrelated to the effect of either. Interactions may be of various types-drug-drug interactions, drug-food interactions, drug-medical condition interactions, or drug-herb interactions. Interactions may occur by single or multiple mechanisms. They may occur in vivo or in vitro (pharmaceutical reactions). In vivo interactions may be further subdivided into pharmacodynamic or pharmacokinetic reactions. Topical drug interactions which may be agonistic or antagonistic may occur between two drugs applied topically or between a topical and a systemic drug. Topical drug-food interaction (for example, grape fruit juice and cyclosporine) and drug-disease interactions (for example, topical corticosteroid and aloe vera) may also occur. It is important for the dermatologist to be aware of such interactions to avoid complications of therapy in day-to-day practice.
The classical definition of clinical pharmacology is the study or the knowledge of the effects of drugs in humans. The activities of a clinical pharmacologist can vary from country to country, usually ranging from involvement in clinical trials, especially fundamental pharmacodynamic studies, to studies of pharmacokinetics and drug metabolism, to pharmacogenetics. Most clinical pharmacologists outside industry are in hospitals or university hospitals and research centres. In addition to research, this implies teaching of clinical pharmacology, and interacting with other medical staff: in the field of research, giving advice on clinical trials methodology and often managing a therapeutic drug monitoring centre. Some clinical pharmacologists have clinical departments with beds or consulting offices. Can there be another role for the clinical pharmacologist that would increase his or her usefulness for the medical community? Adverse drug reactions (ADRs) are remarkably complex events, related to drug effects, patient characteristics (background diseases, genetics), and drug/disease interactions. Evaluation of ADRs requires understanding of drug mechanisms and interactions, and of disease diagnostics, especially in the discussion of alternative diagnoses. This implies expertise as a pharmacologist and a clinician. In addition, because not all adverse reactions or interactions are in the Summary of Product Characteristics, and because problems arise long before they report in the literature, it is necessary for the clinical pharmacologist to have knowledge of ongoing regulatory processes, in addition to having access to the published literature. Helping clinicians cope with individual patient problems will also improve the clinical pharmacologist's integration into the healthcare process.
Li, Lang; Yu, Menggang; Chin, Raymond; Lucksiri, Aroonrut; Flockhart, David A; Hall, Stephen D
In drug-drug interaction (DDI) research, a two drug interaction is usually predicted by individual drug pharmacokinetics (PK). Although subject-specific drug concentration data from clinical PK studies on inhibitor/inducer or substrate's PK are not usually published, sample mean plasma drug concentrations and their standard deviations have been routinely reported. In this paper, an innovative DDI prediction method based on a three-level hierarchical Bayesian meta-analysis model is developed. The first level model is a study-specific sample mean model; the second level model is a random effect model connecting different PK studies; and all priors of PK parameters are specified in the third level model. A Monte Carlo Markov chain (MCMC) PK parameter estimation procedure is developed, and DDI prediction for a future study is conducted based on the PK models of two drugs and posterior distributions of the PK parameters. The performance of Bayesian meta-analysis in DDI prediction is demonstrated through a ketoconazole-midazolam example. The biases of DDI prediction are evaluated through statistical simulation studies. The DDI marker, ratio of area under the concentration curves, is predicted with little bias (less than 5 per cent), and its 90 per cent credible interval coverage rate is close to the nominal level. Sensitivity analysis is conducted to justify prior distribution selections.
Park, Kyunghyun; Kim, Docyong; Ha, Suhyun; Lee, Doheon
As pharmacodynamic drug-drug interactions (PD DDIs) could lead to severe adverse effects in patients, it is important to identify potential PD DDIs in drug development. The signaling starting from drug targets is propagated through protein-protein interaction (PPI) networks. PD DDIs could occur by close interference on the same targets or within the same pathways as well as distant interference through cross-talking pathways. However, most of the previous approaches have considered only close interference by measuring distances between drug targets or comparing target neighbors. We have applied a random walk with restart algorithm to simulate signaling propagation from drug targets in order to capture the possibility of their distant interference. Cross validation with DrugBank and Kyoto Encyclopedia of Genes and Genomes DRUG shows that the proposed method outperforms the previous methods significantly. We also provide a web service with which PD DDIs for drug pairs can be analyzed at http://biosoft.kaist.ac.kr/targetrw. PMID:26469276
Tari, Luis; Anwar, Saadat; Liang, Shanshan; Cai, James; Baral, Chitta
Motivation: Identifying drug–drug interactions (DDIs) is a critical process in drug administration and drug development. Clinical support tools often provide comprehensive lists of DDIs, but they usually lack the supporting scientific evidences and different tools can return inconsistent results. In this article, we propose a novel approach that integrates text mining and automated reasoning to derive DDIs. Through the extraction of various facts of drug metabolism, not only the DDIs that are explicitly mentioned in text can be extracted but also the potential interactions that can be inferred by reasoning. Results: Our approach was able to find several potential DDIs that are not present in DrugBank. We manually evaluated these interactions based on their supporting evidences, and our analysis revealed that 81.3% of these interactions are determined to be correct. This suggests that our approach can uncover potential DDIs with scientific evidences explaining the mechanism of the interactions. Contact: firstname.lastname@example.org PMID:20823320
Staudinger, Jeff L; Ding, Xunshan; Lichti, Kristin
The pregnane X receptor (PXR, NR1I2) is a member of the nuclear receptor superfamily that is activated by a myriad of compounds and natural products in clinical use. Activation of PXR represents the basis for several clinically important drug-drug interactions. Although PXR activation has undesirable effects in patients on combination therapy, it also mediates the hepatoprotective effects exhibited by some herbal remedies. This review focuses on PXR activation by natural products and the potential therapeutic opportunities presented. In particular, the biological effects of St. John's Wort, gugulipid, kava kava, Coleus forskolii, Hypoxis, Sutherlandia, qing hao, wu wei zi, gan cao and other natural products are discussed. The impact of these natural products on drug metabolism and hepatoprotection is highlighted in the context of activation and antagonism of PXR.
Cokol, Murat; Weinstein, Zohar B.; Yilancioglu, Kaan; Tasan, Murat; Doak, Allison; Cansever, Dilay; Mutlu, Beste; Li, Siyang; Rodriguez-Esteban, Raul; Akhmedov, Murodzhon; Guvenek, Aysegul; Cokol, Melike; Cetiner, Selim; Giaever, Guri; Iossifov, Ivan; Nislow, Corey; Shoichet, Brian; Roth, Frederick P.
SUMMARY One drug may suppress the effects of another. Although knowledge of drug suppression is vital to avoid efficacy-reducing drug interactions or discover countermeasures for chemical toxins, drug-drug suppression relationships have not been systematically mapped. Here, we analyze the growth response of Saccharomyces cerevisiae to anti-fungal compound (“drug”) pairs. Among 440 ordered drug pairs, we identified 94 suppressive drug interactions. Using only pairs not selected on the basis of their suppression behavior, we provide an estimate of the prevalence of suppressive interactions between anti-fungal compounds as 17%. Analysis of the drug suppression network suggested that Bromopyruvate is a frequently suppressive drug and Staurosporine is a frequently suppressed drug. We investigated potential explanations for suppressive drug interactions, including chemogenomic analysis, coaggregation, and pH effects, allowing us to explain the interaction tendencies of Bromopyruvate. PMID:24704506
Han, X; Quinney, S K; Wang, Z; Zhang, P; Duke, J; Desta, Z; Elmendorf, J S; Flockhart, D A; Li, L
Myopathy is a group of muscle diseases that can be induced or exacerbated by drug-drug interactions (DDIs). We sought to identify clinically important myopathic DDIs and elucidate their underlying mechanisms. Five DDIs were found to increase the risk of myopathy based on analysis of observational data from the Indiana Network of Patient Care. Loratadine interacted with simvastatin (relative risk 95% confidence interval [CI] = [1.39, 2.06]), alprazolam (1.50, 2.31), ropinirole (2.06, 5.00), and omeprazole (1.15, 1.38). Promethazine interacted with tegaserod (1.94, 4.64). In vitro investigation showed that these DDIs were unlikely to result from inhibition of drug metabolism by CYP450 enzymes or from inhibition of hepatic uptake via the membrane transporter OATP1B1/1B3. However, we did observe in vitro synergistic myotoxicity of simvastatin and desloratadine, suggesting a role in loratadine-simvastatin interaction. This interaction was epidemiologically confirmed (odds ratio 95% CI = [2.02, 3.65]) using the data from the US Food and Drug Administration Adverse Event Reporting System.
DeVane, C Lindsay
The development of paroxetine hydrochloride began in the late 1970s. An abundance of data have been accumulated from clinical investigations demonstrating the efficacy of paroxetine in the treatment of major depression and anxiety disorders. The published literature contains a substantial amount of supportive data documenting the safety, tolerability, and pharmacokinetic and pharmacodynamic properties of paroxetine. The role of paroxetine in clinically significant drug-drug interactions, especially involving metabolic inhibitory effects on the substrates of cytochrome p450 2D6, has long been suspected, but only isolated cases provide any evidence. Published data for widespread patient morbidity from drug interactions with paroxetine are almost nonexistent. Considerations of the pharmacokinetic properties of paroxetine support a rationale for the development of new dosage forms that maintain the efficacy yet improve the tolerability profile of the selective serotonin reuptake inhibitors. Paroxetine controlled-release is an enteric-coated formulation with release features that may enhance clinical outcome by modifying absorption-related pharmacokinetics, improving tolerability, and maintaining therapeutic benefits
Peralta-Pedrero, María Luisa; Valdivia-Ibarra, Francisco Javier; Hernández-Manzano, Mario; Medina-Beltrán, Gustavo Rodrigo; Cordero-Guillén, Miguel Angel; Baca-Zúñiga, José; Cruz-Avelar, Agles; Aguilar-Salas, Ismael; Avalos-Mejía, Annia Marisol
The process of prescribing a medication is complex and includes: deciding whether it is indicated, choosing the best option, determining the dose and the appropriate management scheme to the physiological condition of the patient, and monitoring effectiveness and toxicity. We have to inform patients about the expected side effects and indications for requesting a consultation. Specific clinical questions were designed based on the acronym PICOST. The search was made in the specific websites of clinical practice guidelines, was limited to the population of older adults, in English or Spanish. We used 10 related clinical practice guidelines, eight systematic reviews and five meta-analyses. Finally, we made a search of original articles or clinical reviews for specific topics. The development and validation of clinical practice guidelines for "rational drug prescriptions in the elderly" is intended to promote an improvement in the quality of prescription through the prevention and detection of inappropriate prescribing in the elderly and, as a result of this, a decrease in the adverse events by drugs, deterioration of health of patients and expenditure of resources.
Nakanishi, Takeo; Tamai, Ikumi
Oral bioavailability (F) is determined as fraction of the drug dose absorbed through the gastrointestinal membranes (Fa), the unmetabolized fraction of the absorbed dose that passes through the gut into the portal blood (Fg), and the hepatic first pass availability (Fh), namely F is expressed as the product of Fa, Fg and Fh (F = Fa.Fg.Fh). Current evidence suggests that transporter proteins play a role in intestinal absorption and hepatobiliary clearance of drugs. Among those transporters, this review will focus on PEPT1 and OATP2B1 as influx transporter and p-glycoprotein (P-gp) and BCRP as efflux transporter in intestinal epithelial cells, and on OATP1B1 and 1B3 as influx transporter and MRP2 as efflux transporter in hepatocytes, respectively, because drug-drug (DDI) and -food (DFI) interactions on these transporter are considered to affect bioavailability of their substrate drugs. DDI and DFI may reduce systemic exposure to drug by blocking influx transporters in intestine, but increase it by modulating influx and efflux transporters in liver and efflux transporters in intestines. Namely, drug disposition and efficacy are likely affected by DDI and DFI, resulting in treatment failures or increase in adverse effect. Therefore, it is of significantly importance to understand precise mechanism of DDI and DFI. This review will present information about transporter-based DDI and DFI in the processes of intestinal absorption and hepatic clearance of drugs, and discuss about their clinical implication.
Gillman, P K
New data on the pharmacology of tricyclic antidepressants (TCAs), their affinities for human cloned CNS receptors and their cytochrome P450 enzyme inhibition profiles, allow improved deductions concerning their effects and interactions and indicate which of the TCAs are the most useful. The relative toxicity of TCAs continues to be more precisely defined, as do TCA interactions with selective serotonin reuptake inhibitors (SSRIs). TCA interactions with monoamine oxidase inhibitors (MAOIs) have been, historically, an uncertain and difficult question, but are now well understood, although this is not reflected in the literature. The data indicate that nortriptyline and desipramine have the most pharmacologically desirable characteristics as noradrenaline reuptake inhibitors (NRIs), and as drugs with few interactions that are also safe when coadministered with either MAOIs or SSRIs. Clomipramine is the only available antidepressant drug that has good evidence of clinically relevant serotonin and noradrenaline reuptake inhibition (SNRI). These data assist drug selection for monotherapy and combination therapy and predict reliably how and why pharmacodynamic and pharmacokinetic interactions occur. In comparison, two newer drugs proposed to have SNRI properties, duloxetine and venlafaxine, may have insufficient NRI potency to be effective SNRIs. Combinations such as sertraline and nortriptyline may therefore offer advantages over drugs like venlafaxine that have fixed ratios of SRI/NRI effects that are not ideal. However, no TCA/SSRI combination is sufficiently safe to be universally applicable without expert knowledge. Standard texts (e.g. the British National Formulary) and treatment guidelines would benefit by taking account of these new data and understandings. PMID:17471183
Nanda, Kavita; Stuart, Gretchen S.; Robinson, Jennifer; Gray, Andrew L.; Tepper, Naomi K.; Gaffield, Mary E.
Objective: To summarize published evidence on drug interactions between hormonal contraceptives and antiretrovirals. Design: Systematic review of the published literature. Methods: We searched PubMed, POPLINE, and EMBASE for peer-reviewed publications of studies (in any language) from inception to 21 September 2015. We included studies of women using hormonal contraceptives and antiretrovirals concurrently. Outcomes of interest were effectiveness of either therapy, toxicity, or pharmacokinetics. We used standard abstraction forms to summarize and assess strengths and weaknesses. Results: Fifty reports from 46 studies were included. Most antiretrovirals whether used for therapy or prevention, have limited interactions with hormonal contraceptive methods, with the exception of efavirenz. Although depot medroxyprogesterone acetate is not affected, limited data on implants and combined oral contraceptive pills suggest that efavirenz-containing combination antiretroviral therapy may compromise contraceptive effectiveness of these methods. However, implants remain very effective despite such drug interactions. Antiretroviral plasma concentrations and effectiveness are generally not affected by hormonal contraceptives. Conclusion: Women taking antiretrovirals, for treatment or prevention, should not be denied access to the full range of hormonal contraceptive options, but should be counseled on the expected rates of unplanned pregnancy associated with all contraceptive methods, in order to make their own informed choices. PMID:28060009
Sönnichsen, A C; Donner-Banzhoff, N; Baum, E
With only few exceptions, administration of medicaments should, in principle, be independent of food intake (at least half an hour before or two hours after eating). This ensures uniform and assessable bioavailability. However, it also entails the risk that the patient is more likely to forget to take medication postponed to 2 hours after a meal, than when it is directly coupled to a meal. Certain foodstuffs or food constituents, such as, for example, grapefruit, Seville orange juice, red wine, alcoholic drinks in general, or large quantities of caffeine and garlic should be avoided during drug treatment. In addition, specific interactions with certain drugs must also be taken into account (e.g. MAO inhibitors and tyramine, curamine and vitamin K).
Jovanovik, Milos; Bogojeska, Aleksandra; Trajanov, Dimitar; Kocarev, Ljupco
Food - drug interactions are well studied, however much less is known about cuisine - drug interactions. Non-native cuisines are becoming increasingly more popular as they are available in (almost) all regions in the world. Here we address the problem of how known negative food - drug interactions are spread in different cuisines. We show that different drug categories have different distribution of the negative effects in different parts of the world. The effects certain ingredients have on different drug categories and in different cuisines are also analyzed. This analysis is aimed towards stressing out the importance of cuisine - drug interactions for patients which are being administered drugs with known negative food interactions. A patient being under a treatment with one such drug should be advised not only about the possible negative food - drug interactions, but also about the cuisines that could be avoided from the patient's diet.
Monte, Andrew A.; Heard, Kennon J.; Campbell, Jenny; Hamamura, D.; Weinshilboum, Richard M.; Vasiliou, Vasilis
Objectives The hepatic cytochrome 2D6 (CYP2D6) is a saturable enzyme responsible for metabolism of approximately 25% of known pharmaceuticals. CYP interactions can alter the efficacy of prescribed medications. Hydrocodone is largely dependent on CYP2D6 metabolism for analgesia, ondansetron is inactivated by CYP2D6, and oxycodone analgesia is largely independent of CYP2D6. The objective was to determine if CYP2D6 medication co-ingestion decreases the effectiveness of hydrocodone. Methods This was a prospective observational study conducted in an academic U.S. emergency department (ED). Subjects were included if they had self-reported pain or nausea; and were excluded if they were unable to speak English, were less than 18 years of age, had liver or renal failure, or carried diagnoses of chronic pain or cyclic vomiting. Detailed drug ingestion histories for the preceding 48 hours prior to the ED visit were obtained. The patient's pain and nausea were quantified using a 100-millimeter visual analogue scale (VAS) at baseline prior to drug administration and following doses of hydrocodone, oxycodone, or ondansetron. We used a mixed model with random subject effect to determine the interaction between CYP2D6 drug ingestion and study drug effectiveness. Odds ratios (OR) were calculated to compare clinically significant VAS changes between CYP2D6 users and non-users. Results Two hundred fifty (49.8%) of the 502 subjects enrolled had taken at least one CYP2D6 substrate, inhibitor, or inducing pharmaceutical, supplement, or illicit drug in the 48 hours prior to ED presentation. CYP2D6-drug users were one third as likely to respond to hydrocodone (OR 0.33, 95% CI = 0.1 to 0.8), and more than three times as likely as non-users to respond to ondansetron (OR 3.4, 95% CI = 1.3 to 9.1). There was no significant difference in oxycodone effectiveness between CYP2D6 users and non-users (OR 0.53, 95% CI = 0.3 to 1.1). Conclusions CYP2D6 drug-drug interactions appear to change
At present the use of medicaments of plant origin is on the increase. It is therefore necessary to take into consideration that there exist known as well as potential interactions between the medicament of the medicinal plant. The problematic plants include Echinacea, Allium cepa, Gingko biloba, Panax ginseng, as well as Hypericum perforatum, Valeriana officinalis, or Glycyrrhiza glabra. Its use should be limited, or completely excluded in the cases of simultaneous therapy with, e.g., warfarin, hepatotoxically acting medicaments, MAOI inhibitors, phenelzin sulphate, or phenytoin, as they may decrease of completely eliminate the therapeutic effect of the administered drugs, or they may cause a toxic damage to the organism.
Uhart, Magdalena; Wand, Gary S.
A challenging question that continues unanswered in the field of addiction is why some individuals are more vulnerable to substance use disorders than others. Numerous risk factors for alcohol and other drugs of abuse, including exposure to various forms of stress, have been identified in clinical studies. However, the neurobiological mechanisms that underlie this relationship remain unclear. Critical neurotransmitters, hormones and neurobiological sites have been recognized, which may provide the substrates that convey individual differences in vulnerability to addiction. With the advent of more sophisticated measures of brain function in humans, such as functional imaging technology, the mechanisms and neural pathways involved in the interactions between drugs of abuse, the mesocorticolimbic dopamine system and stress systems are beginning to be characterized. This review provides a neuroadaptive perspective regarding the role of the hormonal and brain stress systems in drug addiction with a focus on the changes that occur during the transition from occasional drug use to drug dependence. We also review factors that contribute to different levels of hormonal/brain stress activation, which has implications for understanding individual vulnerability to drug dependence. Ultimately, these efforts may improve our chances of designing treatment strategies that target addiction at the core of the disorder. PMID:18855803
Shibata, Yoshihiro; Takahashi, Hiroyuki; Chiba, Masato; Ishii, Yasuyuki
A novel method for the prediction of drug-drug interaction has been established based on the in vitro metabolic stability in the "serum incubation method" using cryopreserved human hepatocytes suspended in 100% human serum. As a novel approach, the inhibitory effect of inhibitors on the metabolism of substrates during the first-pass elimination process in the liver (hepatic availability) and in the elimination process from the systemic circulation (hepatic clearance) were separately predicted with the anticipated inhibitor/substrate concentrations during absorption and in the systemic circulation, respectively. Ketoconazole strongly inhibited CYP3A4-mediated terfenadine metabolism in vitro, and the method predicted 6- to 37-fold increase of terfenadine AUC by the concomitant dosing of ketoconazole, which reasonably well agreed with the observed 13- to 59-fold increase of AUC in clinical studies. The CYP3A4-mediated metabolism of indinavir was also subject to the inhibition by ketoconazole in vitro at the lower indinavir concentration (2 microM), whereas no substantial inhibition was observed at 12 microM due to the saturation of indinavir metabolism. Predicted no interaction between ketoconazole and indinavir was consistent with the minimal increase (1.3-fold increase) of indinavir AUC by ketoconazole observed in clinical study. In addition, the method was applied to the CYP2D6-mediated desipramine-quinidine interaction: the predicted 6.4-fold increase of desipramine AUC by quinidine was consistent with the observed 6.7-fold increase of AUC in the clinical drug-drug interaction study. On the other hand, desipramine metabolism was little affected by ketoconazole in vitro, and consequently, it predicted no drug-drug interaction between desipramine and ketoconazole in humans, which agreed with the negligible interaction observed in clinical study. The accuracy of predictions for drug-drug interaction by the serum incubation method was evaluated by comparing the
Ge, Beikang; Zhang, Zhen; Zuo, Zhong
Increasing and inadvertent use of herbs makes herb-drug interactions a focus of research. Concomitant use of warfarin, a highly efficacious oral anticoagulant, and herbs causes major safety concerns due to the narrow therapeutic window of warfarin. This paper presents an update overview of clinical findings regarding herb-warfarin interaction, highlighting clinical outcomes, severity of documented interactions, and quality of clinical evidence. Among thirty-eight herbs, Cannabis, Chamomile, Cranberry, Garlic, Ginkgo, Grapefruit, Lycium, Red clover, and St. John's wort were evaluated to have major severity interaction with warfarin. Herbs were also classified on account of the likelihood of their supporting evidences for interaction. Four herbs were considered as highly probable to interact with warfarin (level I), three were estimated as probable (level II), and ten and twenty-one were possible (level III) and doubtful (level IV), respectively. The general mechanism of herb-warfarin interaction almost remains unknown, yet several pharmacokinetic and pharmacodynamic factors were estimated to influence the effectiveness of warfarin. Based on limited literature and information reported, we identified corresponding mechanisms of interactions for a small amount of “interacting herbs.” In summary, herb-warfarin interaction, especially the clinical effects of herbs on warfarin therapy should be further investigated through multicenter studies with larger sample sizes. PMID:24790635
Moore, Nicholas; Pollack, Charles; Butkerait, Paul
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen have a long history of safe and effective use as both prescription and over-the-counter (OTC) analgesics/antipyretics. The mechanism of action of all NSAIDs is through reversible inhibition of cyclooxygenase enzymes. Adverse drug reactions (ADRs) including gastrointestinal bleeding as well as cardiovascular and renal effects have been reported with NSAID use. In many cases, ADRs may occur because of drug–drug interactions (DDIs) between the NSAID and a concomitant medication. For example, DDIs have been reported when NSAIDs are coadministered with aspirin, alcohol, some antihypertensives, antidepressants, and other commonly used medications. Because of the pharmacologic nature of these interactions, there is a continuum of risk in that the potential for an ADR is dependent on total drug exposure. Therefore, consideration of dose and duration of NSAID use, as well as the type or class of comedication administered, is important when assessing potential risk for ADRs. Safety findings from clinical studies evaluating prescription-strength NSAIDs may not be directly applicable to OTC dosing. Health care providers can be instrumental in educating patients that using OTC NSAIDs at the lowest effective dose for the shortest required duration is vital to balancing efficacy and safety. This review discusses some of the most clinically relevant DDIs reported with NSAIDs based on major sites of ADRs and classes of medication, with a focus on OTC ibuprofen, for which the most data are available. PMID:26203254
Phillips, Elizabeth J; Chung, Wen-Hung; Mockenhaupt, Maja; Roujeau, Jean-Claude; Mallal, Simon A
Severe cutaneous adverse reactions include syndromes such as drug reaction with eosinophilia and systemic symptoms (DRESS) or drug-induced hypersensitivity syndrome (DIHS) and Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). An important advance has been the discovery of associations between HLA alleles and many of these syndromes, including abacavir-associated hypersensitivity reaction, allopurinol-associated DRESS/DIHS and SJS/TEN, and SJS/TEN associated with aromatic amine anticonvulsants. These HLA associations have created the promise for prevention through screening and have additionally shed further light on the immunopathogenesis of severe cutaneous adverse reactions. The rollout of HLA-B∗5701 into routine clinical practice as a genetic screening test to prevent abacavir hypersensitivity provides a translational roadmap for other drugs. Numerous hurdles exist in the widespread translation of several other drugs, such as carbamazepine, in which the positive predictive value of HLA-B∗1502 is low and the negative predictive value of HLA-B∗1502 for SJS/TEN might not be 100% in all ethnic groups. International collaborative consortia have been formed with the goal of developing phenotypic standardization and undertaking HLA and genome-wide analyses in diverse populations with these syndromes.
Phillips, Elizabeth J.; Chung, Wen-Hung; Mockenhaupt, Maja; Roujeau, Jean-Claude; Mallal, Simon A.
Severe cutaneous adverse reactions (SCARs) include syndromes such as drug reaction, eosinophilia and systemic symptoms (DRESS) or drug-induced hypersensitivity syndrome (DIHS) and Stevens-Johnson Syndrome/Toxic epidermal necrolysis (SJS/TEN). An important advance has been the discovery of associations between HLA alleles and many of these syndromes including abacavir hypersensitivity reaction, allopurinol DRESS/DIHS and SJS/TEN and SJS/TEN associated with aromatic amine anticonvulsants. These HLA associations have created the promise for prevention through screening and have additionally shed further light on the immunopathogenesis of SCARs. The roll-out of HLA-B*5701 into routine clinical practice as a genetic screening test to prevent abacavir hypersensitivity provides a translational roadmap for other drugs. Numerous hurdles exist in the widespread translation of several other drugs such as carbamazepine where the positive predictive value of HLA-B*1502 is low and the negative predictive value of HLA-B*1502 for SJS/TEN may not be 100% in all ethnic groups. International collaborative consortia have been formed with the goal of developing phenotype standardization and undertaking HLA and genome-wide analyses in diverse populations with these syndromes. PMID:21354501
Trenk, D; Nührenberg, T; Stratz, C; Valina, C M; Hochholzer, W
Dual antiplatelet therapy with low-dose acetylsalicylic acid (ASA) and an inhibitor of the P2Y12 adenosine diphosphate (ADP) receptor is the standard treatment for patients presenting with acute coronary syndrome (ACS) or undergoing elective coronary interventions according to the current guidelines published by the European Society of Cardiology (ESC). New generation P2Y12 inhibitors, such as prasugrel and ticagrelor exert stronger and more consistent inhibition of the P2Y12 receptor. In clinical studies enrolling patients with ACS these drugs decreased the incidence of ischemic events compared to the standard therapy with clopidogrel and ASA; however, this beneficial effect was associated with an increase in bleeding events. Alternative therapeutic approaches via addition of drugs with different modes of action showed an overall reduction of ischemic events but also failed to uncouple this beneficial effect from an increased bleeding risk.
Lee, Chin Chiat; Ong, Charlene Li Ching; Heng, Paul Wan Sia; Chan, Lai Wah; Wong, Tin Wui
The effectiveness of an interactive mixture as a rapid drug delivery system is compared with that of a solid dispersion. The influences of drug load, particle size, and crystallinity of these test systems are investigated. The interactive mixtures and solid dispersions were prepared from polyethylene glycol (PEG) 3350 and hydrophobic nifedipine drug by means of physical mixing and melting methods, respectively. The formed products were subjected to drug particle size and crystallinity analyses, and dissolution tests. In comparison with the interactive mixtures, the solid dispersions with low drug load were more effective as a rapid drug delivery system, as the size of a given batch of drug particles was markedly reduced by the molten PEG 3350. The rate and extent of drug dissolution were mainly promoted by decreasing effective drug particle size. However, these were lower in the solid dispersions than in the interactive mixtures when a high load of fine drug particles was used as the starting material. This was attributed to drug coarsening during the preparation of the solid dispersion. Unlike solid dispersions, the interactive mixtures could accommodate a high load of fine drug particles without compromising its capacity to enhance the rate and extent of drug dissolution. The interactive mixture is appropriate for use to deliver a fine hydrophobic drug in a formulation requiring a high drug load.
Oga, Enoche F; Sekine, Shuichi; Shitara, Yoshihisa; Horie, Toshiharu
Herbal medicines are currently in high demand, and their popularity is steadily increasing. Because of their perceived effectiveness, fewer side effects and relatively low cost, they are being used for the management of numerous medical conditions. However, they are capable of affecting the pharmacokinetics and pharmacodynamics of coadministered conventional drugs. These interactions are particularly of clinically relevance when metabolizing enzymes and xenobiotic transporters, which are responsible for the fate of many drugs, are induced or inhibited, sometimes resulting in unexpected outcomes. This article discusses the general use of herbal medicines in the management of several ailments, their concurrent use with conventional therapy, mechanisms underlying herb-drug interactions (HDIs) as well as the drawbacks of herbal remedy use. The authors also suggest means of surveillance and safety monitoring of herbal medicines. Contrary to popular belief that "herbal medicines are totally safe," we are of the view that they are capable of causing significant toxic effects and altered pharmaceutical outcomes when coadministered with conventional medicines. Due to the paucity of information as well as sometimes conflicting reports on HDIs, much more research in this field is needed. The authors further suggest the need to standardize and better regulate herbal medicines in order to ensure their safety and efficacy when used alone or in combination with conventional drugs.
Elderly patients commonly receive statin drugs for the primary or secondary prevention of cardiovascular and cerebrovascular events. Elderly patients also commonly receive antidepressant drugs, usually selective serotonin reuptake inhibitors (SSRIs), for the treatment of depression, anxiety, or other conditions. SSRIs are associated with many pharmacokinetic drug interactions related to the inhibition of the cytochrome P450 (CYP) metabolic pathways. There is concern that drugs that inhibit statin metabolism can trigger statin adverse effects, especially myopathy (which can be potentially serious, if rhabdomyolysis occurs). However, a detailed literature review of statin metabolism and of SSRI effects on CYP enzymes suggests that escitalopram, citalopram, and paroxetine are almost certain to be safe with all statins, and rosuvastatin, pitavastatin, and pravastatin are almost certain to be safe with all SSRIs. Even though other SSRI-statin combinations may theoretically be associated with risks, the magnitude of the pharmacokinetic interaction is likely to be below the threshold for clinical significance. Risk, if at all, lies in combining fluvoxamine with atorvastatin, simvastatin, or lovastatin, and even this risk can be minimized by using lower statin doses and monitoring the patient.
Langness, Jacob A; Nguyen, Matthew; Wieland, Amanda; Everson, Gregory T; Kiser, Jennifer J
AIM To quantify drug-drug-interactions (DDIs) encountered in patients prescribed hepatitis C virus (HCV) treatment, the interventions made, and the time spent in this process. METHODS As standard of care, a clinical pharmacist screened for DDIs in patients prescribed direct acting antiviral (DAA) HCV treatment between November 2013 and July 2015 at the University of Colorado Hepatology Clinic. HCV regimens prescribed included ledipasvir/sofosbuvir (LDV/SOF), paritaprevir/ritonavir/ombitasvir/dasabuvir (OBV/PTV/r + DSV), simeprevir/sofosbuvir (SIM/SOF), and sofosbuvir/ribavirin (SOF/RBV). This retrospective analysis reviewed the work completed by the clinical pharmacist in order to measure the aims identified for the study. The number and type of DDIs identified were summarized with descriptive statistics. RESULTS Six hundred and sixty four patients (83.4% Caucasian, 57% male, average 56.7 years old) were identified; 369 for LDV/SOF, 48 for OBV/PTV/r + DSV, 114 for SIM/SOF, and 133 for SOF/RBV. Fifty-one point five per cent of patients were cirrhotic. Overall, 5217 medications were reviewed (7.86 medications per patient) and 781 interactions identified (1.18 interactions per patient). The number of interactions were fewest for SOF/RBV (0.17 interactions per patient) and highest for OBV/PTV/r + DSV (2.48 interactions per patient). LDV/SOF and SIM/SOF had similar number of interactions (1.28 and 1.48 interactions per patient, respectively). Gastric acid modifiers and vitamin/herbal supplements commonly caused interactions with LDV/SOF. Hypertensive agents, analgesics, and psychiatric medications frequently caused interactions with OBV/PTV/r + DSV and SIM/SOF. To manage these interactions, the pharmacists most often recommended discontinuing the medication (28.9%), increasing monitoring for toxicities (24.1%), or separating administration times (18.2%). The pharmacist chart review for each patient usually took approximately 30 min, with additional time for more complex
Saithanyamurthi, Hemamala; Faust, Alison Jazwinski
Drug-induced liver injury (DILI) is a term used to describe a spectrum of clinical presentations and severity that ranges from mild elevation of liver enzymes on routine blood work to acute liver failure and death. Approximately 10% of all patients with DILI develop acute liver failure resulting in death or liver transplantation. DILI may be prolonged with persistence of elevated liver enzymes for longer than 6 months in approximately 5% to 20% of cases. Cirrhosis and long-term liver-related morbidity and mortality have also been described but are rare, occurring in 1% to 3% of cases.
Drug-drug interactions have become an important issue in health care. It is now realized that many drug-drug interactions can be explained by alterations in the metabolic enzymes that are present in the liver and other extra-hepatic tissues. Many of the major pharmacokinetic interactions between drugs are due to hepatic cytochrome P450 (P450 or CYP) enzymes being affected by previous administration of other drugs. After coadministration, some drugs act as potent enzyme inducers, whereas others are inhibitors. However, reports of enzyme inhibition are very much more common. Understanding these mechanisms of enzyme inhibition or induction is extremely important in order to give appropriate multiple-drug therapies. In future, it may help to identify individuals at greatest risk of drug interactions and adverse events. PMID:18928560
Kakuta, Hirotoshi; Kurosaki, Eiji; Niimi, Tatsuya; Gato, Katsuhiko; Kawasaki, Yuko; Suwa, Akira; Honbou, Kazuya; Yamaguchi, Tomohiko; Okumura, Hiroyuki; Sanagi, Masanao; Tomura, Yuichi; Orita, Masaya; Yonemoto, Takako; Masuzaki, Hiroaki
A proportion of angiotensin II type 1 receptor blockers (ARBs) improves glucose dyshomeostasis and insulin resistance in a clinical setting. Of these ARBs, telmisartan has the unique property of being a partial agonist for peroxisome proliferator-activated receptor γ (PPARγ). However, the detailed mechanism of how telmisartan acts on PPARγ and exerts its insulin-sensitizing effect is poorly understood. In this context, we investigated the agonistic activity of a variety of clinically available ARBs on PPARγ using isothermal titration calorimetry (ITC) and surface plasmon resonance (SPR) system. Based on physicochemical data, we then reevaluated the metabolically beneficial effects of telmisartan in cultured murine adipocytes. ITC and SPR assays demonstrated that telmisartan exhibited the highest affinity of the ARBs tested. Distribution coefficient and parallel artificial membrane permeability assays were used to assess lipophilicity and cell permeability, for which telmisartan exhibited the highest levels of both. We next examined the effect of each ARB on insulin-mediated glucose metabolism in 3T3-L1 preadipocytes. To investigate the impact on adipogenesis, 3T3-L1 preadipocytes were differentiated with each ARB in addition to standard inducers of differentiation for adipogenesis. Telmisartan dose-dependently facilitated adipogenesis and markedly augmented the mRNA expression of adipocyte fatty acid-binding protein (aP2), accompanied by an increase in the uptake of 2-deoxyglucose and protein expression of glucose transporter 4 (GLUT4). In contrast, other ARBs showed only marginal effects in these experiments. In accordance with its highest affinity of binding for PPARγ as well as the highest cell permeability, telmisartan superbly activates PPARγ among the ARBs tested, thereby providing a fresh avenue for treating hypertensive patients with metabolic derangement.
Anderson, Judy K; Fox, Jodie R
Medication administration at mealtimes may result in food-drug interactions. Older adults are especially at risk of food-drug interactions leading to adverse drug effects and subtherapeutic responses. Research on potential food-drug interactions is limited and dated. This study examined the frequency of potential food-drug interactions in long-term care. Forty-nine percent of drugs administered at mealtimes had potential for interaction, with cardiovascular medications given most frequently. The frequency of potential interactions makes this phenomenon critically important to review. Collaboration between nurses and pharmacists may identify optimal medication scheduling. Nurses can enhance care by identifying strategies to limit interactions through knowledge and creative, collaborative administration schedules.
Faragon, John J; Piliero, Peter J
The advent of HAART has improved survival in patients infected with HIV; however, treatment is complicated by potential drug interactions. The risk of drug interactions is compounded by the use of additional therapies for comorbid conditions, such as substance abuse, and by the use of recreational drugs. HIV health care providers should be aware of the potential interaction of recreational drugs and addiction treatments with HAART because of the potential for significant adverse effects for their HIV-infected patients. This article provides a review of the literature on drug interactions among addiction therapies, recreational drugs, and HAART.
Vilar, Santiago; Lorberbaum, Tal; Hripcsak, George; Tatonetti, Nicholas P.
Identification of Drug-Drug Interactions (DDIs) is a significant challenge during drug development and clinical practice. DDIs are responsible for many adverse drug effects (ADEs), decreasing patient quality of life and causing higher care expenses. DDIs are not systematically evaluated in pre-clinical or clinical trials and so the FDA U. S. Food and Drug Administration relies on post-marketing surveillance to monitor patient safety. However, existing pharmacovigilance algorithms show poor performance for detecting DDIs exhibiting prohibitively high false positive rates. Alternatively, methods based on chemical structure and pharmacological similarity have shown promise in adverse drug event detection. We hypothesize that the use of chemical biology data in a post hoc analysis of pharmacovigilance results will significantly improve the detection of dangerous interactions. Our model integrates a reference standard of DDIs known to cause arrhythmias with drug similarity data. To compare similarity between drugs we used chemical structure (both 2D and 3D molecular structure), adverse drug side effects, chemogenomic targets, drug indication classes, and known drug-drug interactions. We evaluated the method on external reference standards. Our results showed an enhancement of sensitivity, specificity and precision in different top positions with the use of similarity measures to rank the candidates extracted from pharmacovigilance data. For the top 100 DDI candidates, similarity-based modeling yielded close to twofold precision enhancement compared to the proportional reporting ratio (PRR). Moreover, the method helps in the DDI decision making through the identification of the DDI in the reference standard that generated the candidate. PMID:26068584
Atkyns, Robert L.; Hanneman, Gerhard J.
Drug dealers are often popularly stereotyped as "pushers" who actively engage in enticing young people into the drug habit, but there have been no scientific studies of their behavior or their attitudes on drug abuse or public health. In an attempt to gain information about behavior characteristics and communication patterns of middle…
Drug interaction studies on new drug applications (NDAs) for new molecular entities (NMEs) approved in Japan between 1997 and 2008 are examined in the Pharmaceuticals and Medical Devices Agency (PMDA). The situations of drug interaction studies in NDAs have changed over the past 12 years, especially in metabolizing enzyme and transporter-based drug interactions. Materials and approaches to study drug-metabolizing enzyme-based drug interactions have improved, and become more rational based on mechanistic theory and new technologies. On the basis of incremental evidence of transporter roles in human pharmacokinetics, transporter-based drug interactions have been increasingly studied during drug development and submitted in recent NDAs. Some recently approved NMEs include transporter-based drug interaction information in their package inserts (PIs). The regulatory document "Methods of Drug Interaction Studies," in addition to recent advances in science and technology, has also contributed to plan and evaluation of drug interaction studies in recent new drug development. This review summarizes current situations and further discussion points on drug interaction studies in NDAs in Japan.
Food-drug interactions have been reported to occur in various systems in the body. The causes of these interactions are mainly divided into pharmacodynamic and pharmacokinetic processes. Among these processes, drug metabolism plays a crucial role in drug interactions. Metabolic food-drug interactions occur when a certain food alters the activity of a drug-metabolizing enzyme, leading to a modulation of the pharmacokinetics of drugs metabolized by the enzyme. A variety of interactions have been documented so far. Foods consisting of complex chemical mixtures, such as fruits, alcoholic beverages, teas, and herbs, possess the ability to inhibit or induce the activity of drug-metabolizing enzymes. According to results obtained thus far, cytochrome P450 3A4 (CYP3A4) appears to be a key enzyme in food-drug interactions. For example, interactions of grapefruit juice with felodipine and cyclosporine, red wine with cyclosporine, and St John's wort with various medicines including cyclosporine, have been demonstrated. The results indicate the requirement of dosage adjustment to maintain drug concentrations within their therapeutic windows. The CYP3A4-related interaction by food components may be related to the high level of expression of CYP3A4 in the small intestine, as well as its broad substrate specificity, as CYP3A4 is responsible for the metabolism of more than 50% of clinical pharmaceuticals. This review article summarizes the findings obtained to date concerning food-drug interactions and their clinical implications. It seems likely that more information regarding such interactions will accumulate in the future, and awareness is necessary for achieving optimal drug therapy.
Cheng, Feixiong; Zhao, Zhongming
Objective Drug–drug interactions (DDIs) are an important consideration in both drug development and clinical application, especially for co-administered medications. While it is necessary to identify all possible DDIs during clinical trials, DDIs are frequently reported after the drugs are approved for clinical use, and they are a common cause of adverse drug reactions (ADR) and increasing healthcare costs. Computational prediction may assist in identifying potential DDIs during clinical trials. Methods Here we propose a heterogeneous network-assisted inference (HNAI) framework to assist with the prediction of DDIs. First, we constructed a comprehensive DDI network that contained 6946 unique DDI pairs connecting 721 approved drugs based on DrugBank data. Next, we calculated drug–drug pair similarities using four features: phenotypic similarity based on a comprehensive drug–ADR network, therapeutic similarity based on the drug Anatomical Therapeutic Chemical classification system, chemical structural similarity from SMILES data, and genomic similarity based on a large drug–target interaction network built using the DrugBank and Therapeutic Target Database. Finally, we applied five predictive models in the HNAI framework: naive Bayes, decision tree, k-nearest neighbor, logistic regression, and support vector machine, respectively. Results The area under the receiver operating characteristic curve of the HNAI models is 0.67 as evaluated using fivefold cross-validation. Using antipsychotic drugs as an example, several HNAI-predicted DDIs that involve weight gain and cytochrome P450 inhibition were supported by literature resources. Conclusions Through machine learning-based integration of drug phenotypic, therapeutic, structural, and genomic similarities, we demonstrated that HNAI is promising for uncovering DDIs in drug development and postmarketing surveillance. PMID:24644270
Hochman, Jerome; Tang, Cuyue; Prueksaritanont, Thomayant
Drug-drug interactions (DDIs) related to altered drug absorption and plasma protein binding have received much less attention from regulatory agencies relative to DDIs mediated via drug metabolizing enzymes and transporters. In this review, a number of theoretical bases and regulatory framework are presented for these DDI aspects. Also presented is an industry perspective on how to approach these issues in support of drug development. Overall, with the exception of highly permeable and highly soluble (BCS 1) drugs, DDIs related to drug-induced changes in gastrointestinal (GI) physiology can be substantial, thus warranting more attentions. For a better understanding of absorption-associated DDI potential in a clinical setting, mechanistic studies should be conducted based on holistic integration of the pharmaceutical profiles (e.g., pH-dependent solubility) and pharmacological properties (e.g., GI physiology and therapeutic margin) of drug candidates. Although majority of DDI events related to altered plasma protein binding are not expected to be of clinical significance, exceptions exist for a subset of compounds with certain pharmacokinetic and pharmacological properties. Knowledge of the identity of binding proteins and the binding extent in various clinical setting (including disease states) can be valuable in aiding clinical DDI data interpretations, and ensuring safe and effective use of new drugs.
Liu, Lili; Chen, Lei; Zhang, Yu-Hang; Wei, Lai; Cheng, Shiwen; Kong, Xiangyin; Zheng, Mingyue; Huang, Tao; Cai, Yu-Dong
Drug-drug interaction (DDI) defines a situation in which one drug affects the activity of another when both are administered together. DDI is a common cause of adverse drug reactions and sometimes also leads to improved therapeutic effects. Therefore, it is of great interest to discover novel DDIs according to their molecular properties and mechanisms in a robust and rigorous way. This paper attempts to predict effective DDIs using the following properties: (1) chemical interaction between drugs; (2) protein interactions between the targets of drugs; and (3) target enrichment of KEGG pathways. The data consisted of 7323 pairs of DDIs collected from the DrugBank and 36,615 pairs of drugs constructed by randomly combining two drugs. Each drug pair was represented by 465 features derived from the aforementioned three categories of properties. The random forest algorithm was adopted to train the prediction model. Some feature selection techniques, including minimum redundancy maximum relevance and incremental feature selection, were used to extract key features as the optimal input for the prediction model. The extracted key features may help to gain insights into the mechanisms of DDIs and provide some guidelines for the relevant clinical medication developments, and the prediction model can give new clues for identification of novel DDIs.
Luna, Daniel R; Rizzato Lede, Daniel A; Otero, Carlos M; Risk, Marcelo R; González Bernaldo de Quirós, Fernán
Clinical Decision Support Systems can alert health professionals about drug interactions when they prescribe medications. The Hospital Italiano de Buenos Aires in Argentina developed an electronic health record with drug-drug interaction alerts, using traditional software engineering techniques and requirements. Despite enhancing the drug-drug interaction knowledge database, the alert override rate of this system was very high. We redesigned the alert system using user-centered design (UCD) and participatory design techniques to enhance the drug-drug interaction alert interface. This paper describes the methodology of our UCD. We used crossover method with realistic, clinical vignettes to compare usability of the standard and new software versions in terms of efficiency, effectiveness, and user satisfaction. Our study showed that, compared to the traditional alert system, the UCD alert system was more efficient (alerts faster resolution), more effective (tasks completed with fewer errors), and more satisfying. These results indicate that UCD techniques that follow ISO 9241-210 can generate more usable alerts than traditional design.
Weinstein, Zohar B.; Zaman, Muhammad H.
Drug interaction analysis, which reports the extent to which the presence of one drug affects the efficacy of another, is a powerful tool to select potent combinatorial therapies and predict connectivity between cellular components. Combinatorial effects of drug pairs often vary even for drugs with similar mechanism of actions. Therefore, drug interaction fingerprinting may be harnessed to differentiate drug identities. We developed a method to analyze drug interactions for the application of identifying active pharmaceutical ingredients, an essential step to assess drug quality. We developed a novel approach towards the identification of active pharmaceutical ingredients by comparing drug interaction fingerprint similarity metrics such as correlation and Euclidean distance. To expedite this method, we used bioluminescent E. coli in a simplified checkerboard assay to generate unique drug interaction fingerprints of antimicrobial drugs. Of 30 antibiotics studied, 29 could be identified based on their drug interaction fingerprints. We present drug interaction fingerprint analysis as a cheap, sensitive and quantitative method towards substandard and counterfeit drug detection. PMID:28205640
Weinstein, Zohar B; Zaman, Muhammad H
Drug interaction analysis, which reports the extent to which the presence of one drug affects the efficacy of another, is a powerful tool to select potent combinatorial therapies and predict connectivity between cellular components. Combinatorial effects of drug pairs often vary even for drugs with similar mechanism of actions. Therefore, drug interaction fingerprinting may be harnessed to differentiate drug identities. We developed a method to analyze drug interactions for the application of identifying active pharmaceutical ingredients, an essential step to assess drug quality. We developed a novel approach towards the identification of active pharmaceutical ingredients by comparing drug interaction fingerprint similarity metrics such as correlation and Euclidean distance. To expedite this method, we used bioluminescent E. coli in a simplified checkerboard assay to generate unique drug interaction fingerprints of antimicrobial drugs. Of 30 antibiotics studied, 29 could be identified based on their drug interaction fingerprints. We present drug interaction fingerprint analysis as a cheap, sensitive and quantitative method towards substandard and counterfeit drug detection.
Li, Chun; Wallace, Sidney
Targeted drug delivery aims to increase the therapeutic index by making more drug molecules available at the diseased sites while reducing systemic drug exposure. In this update, we provide an overview of polymer-drug conjugates that have advanced into the clinical trials. These systems use synthetic water-soluble polymers as the drug carriers. The preclinical pharmacology and recent data in clinical trials with poly(L-glutamic acid)-paclitaxel (PG-TXL) are discussed first. This is followed by a summary of conjugates of a variety of polymeric conjugates with chemotherapeutic agents. Results from early clinical trials of these polymer-drug conjugates have demonstrated several advantages over the corresponding parent drugs, including fewer side effects, enhanced therapeutic efficacy, ease of drug administration, and improved patient compliance. Collectively, these data warrant further clinical development of polymer-drug conjugates as a new class of anticancer agents. PMID:18374448
Nutescu, Edith; Chuatrisorn, Ittiporn; Hellenbart, Erika
Clinicians and patients around the world have been intrigued by the concept of developing an oral anticoagulant with a broad therapeutic window and few drug and dietary interactions that can be administered at fixed doses with no or minimal monitoring. The recently approved oral direct thrombin inhibitor dabigatran, along with the emerging oral anti-factor Xa inhibitors, rivaroxaban, apixaban, and edoxaban, have been developed to address many of the shortcomings of warfarin therapy. As warfarin is associated with extensive food and drug interactions, there is also a need to consider such interactions with the new oral anticoagulants. While to date few drug and dietary interactions have been reported with the new oral anticoagulants, it is still early in their development and clinical use cycle. Pharmacokinetic and pharmacodynamic profiles will have to be closely accounted for when determining the likelihood of a potential drug interaction prior to therapy initiation. As the list of drugs and supplements that interact with warfarin is continuously expanding, and the knowledge on drug interactions with the novel oral anticoagulants is still in its infancy, clinicians need to be vigilant when initiating any of these agents or when any changes in the patient's medication profile occur and perform a close screening for potential drug and dietary interactions. The objective of this paper is to give an update on drug and dietary interactions with warfarin and the novel oral anticoagulants, dabigatran, rivaroxaban, apixaban, and edoxaban.
Atorvastatin is the most commonly used of all statins to lower cholesterol. Atorvastatin is extensively metabolized in both gut and liver to produce several active metabolites. The purpose of the present study is to develop a physiologically based pharmacokinetic (PBPK) model for atorvastatin and its two primary metabolites, 2-hydroxy-atorvastatin acid and atorvastatin lactone, using in vitro and in vivo data. The model was used to predict the pharmacokinetic profiles and drug-drug interaction (DDI) effect for atorvastatin and its metabolites in different DDI scenarios. The predictive performance of the model was assessed by comparing predicted results to observed data after coadministration of atorvastatin with different medications such as itraconazole, clarithromycin, cimetidine, rifampin and phenytoin. This population based PBPK model was able to describe the concentration-time profiles of atorvastatin and its two metabolites reasonably well in the absence or presence of those drugs at different dose regimens. The predicted maximum concentration (Cmax), area under the concentration-time curve (AUC) values and between-phase ratios were in good agreement with clinically observed data. The model has also revealed the importance of different metabolic pathways on the disposition of atorvastatin metabolites. This PBPK model can be utilized to assess the safety and efficacy of atorvastatin in the clinic. This study demonstrated the feasibility of applying PBPK approach to predict the DDI potential of drugs undergoing complex metabolism.
Oga, Enoche F; Sekine, Shuichi; Shitara, Yoshihisa; Horie, Toshiharu
Antimalarials are widely used in African and Southeast Asian countries, where they are combined with other drugs for the treatment of concurrent ailments. The potential for P-glycoprotein (P-gp)-mediated drug-drug interactions (DDIs) between antimalarials and P-gp substrates was examined using a Caco-2 cell-based model. Selected antimalarials were initially screened for their interaction with P-gp based on the inhibition of rhodamine-123 (Rho-123) transport in Caco-2 cells. Verapamil (100 μM) and quinidine (1 μM) were used as positive inhibition controls. Lumefantrine, amodiaquin, and artesunate all showed blockade of Rho-123 transport. Subsequently, the inhibitory effect of these antimalarials on the bi-directional passage of digoxin (DIG) was examined. All of the drugs decreased basal-to-apical (B-A) P-gp-mediated DIG transport at concentrations of 100 μM and 1 mM. These concentrations may reflect therapeutic doses for amodiaquin and artesunate. Therefore, clinically relevant DDIs may occur between certain antimalarials and P-gp substrates in general.
Yan, Jing-He; Meyers, Dan; Lee, Zachary; Danis, Kate; Neelakantham, Srikanth; Majumdar, Tapan; Rebello, Sam; Sunkara, Gangadhar; Chen, Jin
Pradigastat, a novel diacylglycerol acyltransferase-1 inhibitor, was evaluated for both pharmacokinetic (PK) and pharmacodynamic (PD) drug-drug interactions when co-administered with digoxin or warfarin in healthy subjects. This open-label study included two parallel subject cohorts each with three sequential treatment periods. Forty subjects were enrolled in the study with 20 subjects allocated to each cohort. PK and PD (PT/INR for warfarin only) samples were collected in each period. The statistical analysis results showed that the 90% CIs of the geometric mean ratios of digoxin, R-warfarin, and S-warfarin PK parameters (AUC and Cmax) were all within 0.80-1.25 interval. The 90% CIs of the geometric mean ratios of pradigastat PK parameters (AUC and Cmax) were within 0.80-1.25 interval when co-administered with warfarin; while co-administration with digoxin slightly reduced pradigastat exposure (∼15%). The results also showed that 90% CIs of the geometric mean ratios of warfarin PD parameters (AUC(PT), PTmax, AUC(INR), and INRmax) were within 0.80-1.25 interval. Pradigastat and digoxin or warfarin had no relevant clinical PK or PD drug-drug interactions. Administration of pradigastat and warfarin or pradigastat and digoxin as a mono or combined treatment appears to be safe and tolerated.
Lu, Yin; Shen, Dan; Pietsch, Maxwell; Nagar, Chetan; Fadli, Zayd; Huang, Hong; Tu, Yi-Cheng; Cheng, Feng
Drug-drug interaction (DDI) is becoming a serious clinical safety issue as the use of multiple medications becomes more common. Searching the MEDLINE database for journal articles related to DDI produces over 330,000 results. It is impossible to read and summarize these references manually. As the volume of biomedical reference in the MEDLINE database continues to expand at a rapid pace, automatic identification of DDIs from literature is becoming increasingly important. In this article, we present a random-sampling-based statistical algorithm to identify possible DDIs and the underlying mechanism from the substances field of MEDLINE records. The substances terms are essentially carriers of compound (including protein) information in a MEDLINE record. Four case studies on warfarin, ibuprofen, furosemide and sertraline implied that our method was able to rank possible DDIs with high accuracy (90.0% for warfarin, 83.3% for ibuprofen, 70.0% for furosemide and 100% for sertraline in the top 10% of a list of compounds ranked by p-value). A social network analysis of substance terms was also performed to construct networks between proteins and drug pairs to elucidate how the two drugs could interact.
Zhang, Aijie; Li, Quansheng; He, Xin; Si, Duanyun; Liu, Changxiao
Many herbal medicines and drugs are available in the clinic as potent hepatoprotective agents for the treatment of commonly occurring liver diseases. Recently, herbal medicines such as silymarin and curcumin have gained more attention and popularity for the treatment of various liver diseases because of their safety and efficacy profiles. Some of them are related to transporters for drug disposition processes, therapeutic efficacy and/or adverse drug reactions. Currently, herbal medicines and diet supplements made from natural products are widely used in patients who are being treated with conventional prescription medicines, which are related to an increasing risk of herbal-drug interactions (HDIs) and/or drug-drug interactions (DDIs). The purpose of present review is to summarize the contemporary knowledge of transporter-mediated HDIs or DDIs for herbal medicines/drugs focusing on hepatoprotective compounds. Several herbal medicines/drugs are discussed in detail in this review.
Safdari, Reza; Ferdousi, Reza; Aziziheris, Kamal; Niakan-Kalhori, Sharareh R.; Omidi, Yadollah
Introduction: Health care industry also patients penalized by medical errors that are inevitable but highly preventable. Vast majority of medical errors are related to adverse drug reactions, while drug-drug interactions (DDIs) are the main cause of adverse drug reactions (ADRs). DDIs and ADRs have mainly been reported by haphazard case studies. Experimental in vivo and in vitro researches also reveals DDI pairs. Laboratory and experimental researches are valuable but also expensive and in some cases researchers may suffer from limitations. Methods: In the current investigation, the latest published works were studied to analyze the trend and pattern of the DDI modelling and the impacts of machine learning methods. Applications of computerized techniques were also investigated for the prediction and interpretation of DDIs. Results: Computerized data-mining in pharmaceutical sciences and related databases provide new key transformative paradigms that can revolutionize the treatment of diseases and hence medical care. Given that various aspects of drug discovery and pharmacotherapy are closely related to the clinical and molecular/biological information, the scientifically sound databases (e.g., DDIs, ADRs) can be of importance for the success of pharmacotherapy modalities. Conclusion: A better understanding of DDIs not only provides a robust means for designing more effective medicines but also grantees patient safety. PMID:27525223
Buur, J L; Baynes, R E; Smith, G W; Riviere, J E
Combination drug therapy increases the chance for an adverse drug reactions due to drug-drug interactions. Altered disposition for sulfamethazine (SMZ) when concurrently administered with flunixin meglumine (FLU) in swine could lead to increased tissue residues. There is a need for a pharmacokinetic modeling technique that can predict the consequences of possible drug interactions. A physiologically based pharmacokinetic model was developed that links plasma protein binding interactions to drug disposition for SMZ and FLU in swine. The model predicted a sustained decrease in total drug and a temporary increase in free drug concentration. An in vivo study confirmed the presence of a drug interaction. Neither the model nor the in vivo study revealed clinically significant changes that alter tissue disposition. This novel linkage approach has use in the prediction of the clinical impact of plasma protein binding interactions. Ultimately it could be used in the design of dosing regimens and in the protection of the food supply through prediction and minimization of tissue residues.
Rice, Donald P.; Faragon, John J.; Banks, Sarah; Chirch, Lisa M.
Abstract Therapy for human immunodeficiency virus (HIV) and chronic hepatitis C has evolved over the past decade, resulting in better control of infection and clinical outcomes; however, drug-drug interactions remain a significant hazard. Joint recommendations from the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America regarding drug-drug interactions between HIV antiretroviral agents and direct-acting antiviral agents for treatment of hepatitis C virus (HCV) infection are reviewed here. This review is oriented to facilitate appropriate selection of an antiviral therapy regimen for HCV infection based on the choice of antiretroviral therapy being administered and, if necessary, switching antiretroviral regimens. PMID:27777891
Peetla, Chiranjeevi; Stine, Andrew; Labhasetwar, Vinod
The transport of drugs or drug delivery systems across the cell membrane is a complex biological process, often difficult to understand because of its dynamic nature. In this regard, model lipid membranes, which mimic many aspects of cell-membrane lipids, have been very useful in helping investigators to discern the roles of lipids in cellular interactions. One can use drug-lipid interactions to predict pharmacokinetic properties of drugs, such as their transport, biodistribution, accumulation, and hence efficacy. These interactions can also be used to study the mechanisms of transport, based on the structure and hydrophilicity/hydrophobicity of drug molecules. In recent years, model lipid membranes have also been explored to understand their mechanisms of interactions with peptides, polymers, and nanocarriers. These interaction studies can be used to design and develop efficient drug delivery systems. Changes in the lipid composition of cells and tissue in certain disease conditions may alter biophysical interactions, which could be explored to develop target-specific drugs and drug delivery systems. In this review, we discuss different model membranes, drug-lipid interactions and their significance, studies of model membrane interactions with nanocarriers, and how biophysical interaction studies with lipid model membranes could play an important role in drug discovery and drug delivery. PMID:19432455
Langman, Loralie J
One of the underlying tenets of clinical pharmacology is that only free drugs are pharmacologically active. It is thought that only free drugs can cross biological membranes to interact with a given receptor to alter its function, and that drug responses, both efficacious and toxic, are a function of unbound concentrations. The rationale for measuring drugs in oral fluid is that the free fraction of a drug in plasma reaches equilibrium with the drug in saliva. Although reports concerning the appearance of organic solutes in saliva have been in the literature for over 70 years, it has only been in the past 30 years that there has been emphasis on the appearance of drugs. Although many assumptions for drug level monitoring in saliva are made, the primary requisite for salivary monitoring to be useful is a constant or predictable relationship between the drug concentration in saliva and the drug concentration in plasma. Measurement of oral fluid drug levels for the purpose of managing patients and making dosage adjustments may be useful for select drugs or drug classes. However, it does not appear to be useful for the majority of drugs therapeutically monitored. Some work with antipsychotic medications has indicated that although the measurement of drug concentrations themselves may not be useful for dosage adjustment, the ratio of parent drug to metabolite may reflect altered metabolic status due to either pharmacogenetic variation or other clinical conditions. Furthermore, analysis of saliva may provide a cost-effective approach for the screening of large populations.
Naccarato, Mark; Hall, Elise; Wai, Alan; Ostrowski, Mario; Carvalhal, Adriana
The cytochrome P450 isoform that is primarily involved in the metabolism of the antipsychotic lurasidone is CYP3A4. Drugs that inhibit or induce this enzyme would then be expected to increase or decrease serum concentrations of lurasidone, respectively. Atazanavir, an HIV-1 protease inhibitor, has demonstrated to be an inhibitor of CYP3A4 and would be expected to increase the exposure of any drug metabolized by this enzyme. We report a case of an atazanavir-precipitated drug-drug interaction that led to elevated serum concentrations of lurasidone and associated clinical symptoms of drug toxicity.
Da Costa, J B; Dieckmann, T
This mini-review will provide an overview on the recent studies of structure and thermodynamics of RNA aptamers that target drug molecules. These aptamers are studied to provide insight into RNA drug interactions. This interaction is important due to the many roles RNA plays in cell biology.
Freeman, Camille; Spelman, Kevin
Accurate information concerning drug-herb interactions is vital for both healthcare providers and patients. Unfortunately, many of the reviews on drug-herb interactions contain overstated or inaccurate information. To provide accurate information on drug-herb interactions healthcare providers must account for product verification, dosage, medicinal plant species, and plant part used. This critical review assessed the occurrence of drug interactions with one of the top selling botanical remedies, echinacea including Echinacea angustifolia, E. pallida, and E. purpurea. Only eight papers containing primary data relating to drug interactions were identified. Herbal remedies made from E. purpurea appear to have a low potential to generate cytochrome P450 (CYP 450) drug-herb interactions including CYP 450 1A2 (CYP1A2) and CYP 450 3A4 (CYP3A4). Currently there are no verifiable reports of drug-herb interactions with any echinacea product. However, further pharmacokinetic testing is necessary before conclusive statements can be made about echinacea drug-herb interactions. Given our findings, the estimated risk of taking echinacea products (1 in 100,000), the number of echinacea doses consumed yearly (> 10 million), the number of adverse events (< 100) and that the majority of use is short term, E. purpurea products (roots and/or aerial parts) do not appear to be a risk to consumers.
Hyland, Ruth; Dickins, Maurice; Collins, Claire; Jones, Hannah; Jones, Barry
AIMS To characterize the cytochrome P450 enzyme(s) responsible for the N-dealkylation of maraviroc in vitro, and predict the extent of clinical drug–drug interactions (DDIs). METHODS Human liver and recombinant CYP microsomes were used to identify the CYP enzyme responsible for maraviroc N-dealkylation. Studies comprised enzyme kinetics and evaluation of the effects of specific CYP inhibitors. In vitro data were then used as inputs for simulation of DDIs with ketoconazole, ritonavir, saquinavir and atazanvir, using the Simcyp™ population-based absorption, distribution, metabolism and elimination (ADME) simulator. Study designs for simulations mirrored those actually used in the clinic. RESULTS Maraviroc was metabolized to its N-dealkylated product via a single CYP enzyme characterized by a Km of 21 µM and Vmax of 0.45 pmol pmol−1 min−1 in human liver microsomes and was inhibited by ketoconazole (CYP3A4 inhibitor). In a panel of recombinant CYP enzymes, CYP3A4 was identified as the major CYP responsible for maraviroc metabolism. Using recombinant CYP3A4, N-dealkylation was characterized by a Km of 13 µM and a Vmax of 3 pmol pmol−1 CYP min−1. Simulations therefore focused on the effect of CYP3A4 inhibitors on maraviroc pharmacokinetics. The simulated median AUC ratios were in good agreement with observed clinical changes (within twofold in all cases), although, in general, there was a trend for overprediction in the magnitude of the DDI. CONCLUSION Maraviroc is a substrate for CYP3A4, and exposure will therefore be modulated by CYP3A4 inhibitors. Simcyp™ has successfully simulated the extent of clinical interactions with CYP3A4 inhibitors, further validating this software as a good predictor of CYP-based DDIs. WHAT IS ALREADY KNOWN ABOUT THE SUBJECTMaraviroc is known to undergo oxidative metabolism in vivo and is a substrate for cytochrome P450 (CYP).Simcyp™ has recently become more widely used for the prediction of CYP-mediated drug–drug
Zhang, Nan; Liu, Yong; Jeong, Hyunyoung
Tyrosine kinase inhibitors (TKIs) are anticancer drugs that may be co-administered with other drugs. The aims of this study are to investigate the inhibitory effects of TKIs on UDP-glucuronosyltransferase (UGT) activities, and to quantitatively evaluate their potential to cause drug-drug interactions (DDIs). Inhibition kinetic profiles of a panel of UGT enzymes (UGT1A1, 1A3, 1A4, 1A6, 1A7, 1A8, 1A9, 1A10, 2B4, 2B7, 2B15, and 2B17) by four TKIs (axitinib, imatinib, lapatinib and vandetanib) were characterized by using hepatic microsomes and recombinant proteins. Lapatinib exhibited potent competitive inhibition against UGT1A1 activity with a Ki of 0.5 μM. Imatinib was found to exhibit broad inhibition on several UGTs, particularly potent competitive inhibition against UGT2B17 with a Ki of 0.4 μM. The TKIs also exerted intermediate inhibition against several UGTs (i.e., UGT1A7 by lapatinib; UGT1A1 by imatinib; UGT1A4, 1A7 and 1A9 by axitinib; and UGT1A9 by vandetanib). Results from modeling for the quantitative prediction of DDI risk indicated that the coadministration of lapatinib or imatinib at clinical doses could result in a significant increase in AUC of drugs primarily cleared by UGT1A1 or 2B17. Lapatinib and imatinib may cause clinically significant DDIs when co-administered UGT1A1 or 2B17 substrates. PMID:26642944
Lu, Yin; Shen, Dan; Pietsch, Maxwell; Nagar, Chetan; Fadli, Zayd; Huang, Hong; Tu, Yi-Cheng; Cheng, Feng
Drug–drug interaction (DDI) is becoming a serious clinical safety issue as the use of multiple medications becomes more common. Searching the MEDLINE database for journal articles related to DDI produces over 330,000 results. It is impossible to read and summarize these references manually. As the volume of biomedical reference in the MEDLINE database continues to expand at a rapid pace, automatic identification of DDIs from literature is becoming increasingly important. In this article, we present a random-sampling-based statistical algorithm to identify possible DDIs and the underlying mechanism from the substances field of MEDLINE records. The substances terms are essentially carriers of compound (including protein) information in a MEDLINE record. Four case studies on warfarin, ibuprofen, furosemide and sertraline implied that our method was able to rank possible DDIs with high accuracy (90.0% for warfarin, 83.3% for ibuprofen, 70.0% for furosemide and 100% for sertraline in the top 10% of a list of compounds ranked by p-value). A social network analysis of substance terms was also performed to construct networks between proteins and drug pairs to elucidate how the two drugs could interact. PMID:26612138
Eyal, Sara; Hsiao, Peng; Unadkat, Jashvant D.
There is considerable interest in the therapeutic and adverse outcomes of drug interactions at the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). These include altered efficacy of drugs used in the treatment of CNS disorders, such as AIDS dementia and malignant tumors, and enhanced neurotoxicity of drugs that normally penetrate poorly into the brain. BBB- and BCSFB-mediated interactions are possible because these interfaces are not only passive anatomical barriers, but are also dynamic in that they express a variety of influx and efflux transporters and drug metabolizing enzymes. Based on studies in rodents, it has been widely postulated that efflux transporters play an important role at the human BBB in terms of drug delivery. Furthermore, it is assumed that chemical inhibition of transporters or their genetic ablation in rodents is predictive of the magnitude of interaction to be expected at the human BBB. However, studies in humans challenge this well-established paradigm and claim that such drug interactions will be lesser in magnitude but yet may be clinically significant. This review focuses on current known mechanisms of drug interactions at the blood-brain and blood-CSF barriers and the potential impact of such interactions in humans. We also explore whether such drug interactions can be predicted from preclinical studies. Defining the mechanisms and the impact of drug-drug interactions at the BBB is important for improving efficacy of drugs used in the treatment of CNS disorders while minimizing their toxicity as well as minimizing neurotoxicity of non-CNS drugs. PMID:19393264
Zhang, Yue-Li; Zeng, Mei-Zi; He, Fa-Zhong; Luo, Zhi-Ying; Luo, Jian-Quan; Wen, Jia-Gen; Chen, Xiao-Ping; Zhou, Hong-Hao; Zhang, Wei
The worldwide using of herb products and the increasing potential herb-drug interaction issue has raised enthusiasm on discovering the underlying mechanisms. Previous review indicated that the interactions may be mediated by metabolism enzymes and transporters in pharmacokinetic pathways. On the other hand, an increasing number of studies found that genetic variations showed some influence on herb-drug interaction effects whereas these genetic factors did not draw much attention in history. We highlight that pharmacogenomics may involve the pharmacokinetic or pharmacodynamic pathways to affect herb-drug interaction. We are here to make an updated review focused on some common herb-drug interactions in association with genetic variations, with the aim to help safe use of herbal medicines in different individuals in the clinic. PMID:25821484
Herbal supplements can affect concentrations of therapeutic drugs measured in biological fluids by different mechanisms. Herbal products can either directly interfere with the methodology used in the measurement of drugs or indirectly interfere by altering the pharmacokinetics of coadministered drugs. The active components of Chan Su, Lu-Shen-Wan, Dan Shen, Asian and Siberian ginseng, oleander containing supplements, and Ashwagandha interfere with digoxin measurements by immunoassays, especially the polyclonal antibody-based immunoassays. Herbal supplements are sometimes contaminated with Western drugs causing drug toxicity. A therapeutic drug monitoring (TDM) service is very helpful for diagnosis of drug toxicity in such patients. Herbal products such as St. John's wort, a popular herbal antidepressant, increase the clearance of certain drugs either by increasing the activity of liver or intestinal cytochrome P-450 mixed-function oxidase or through modulation of the P-glycoprotein efflux pump. Significantly reduced concentrations of various therapeutic drugs such as digoxin, theophylline, cyclosporine, tacrolimus, tricyclic antidepressants, warfarin, and protease inhibitors can be observed due to interaction of these drugs with St. John's wort, causing treatment failure. On the other hand, a few drugs such as carbamazepine, mycophenolic acid, and procainamide do not show any interaction with St. John's wort. Understanding the effect of herbal products on TDM methodologies and identification of interactions between herbal products and drugs by TDM are very important clinically.
Knobloch, Jacqueline; Suhendro, Daniel K.; Zieleniecki, Julius L.; Shapter, Joseph G.; Köper, Ingo
The direct interaction of drugs with the cell membrane is often neglected when drug effects are studied. Systematic investigations are hindered by the complexity of the natural membrane and model membrane systems can offer a useful alternative. Here some examples are reviewed of how model membrane architectures including vesicles, Langmuir monolayers and solid supported membranes can be used to investigate the effects of drug molecules on the membrane structure, and how these interactions can translate into effects on embedded membrane proteins. PMID:26586998
Alarcón, Liliana P; Baena, Yolima; Manzo, Rubén H
This paper reports the in vitro characterization of the interaction between the phosphate groups of DNA and the protonated species of drugs with basic groups through the determination of the affinity constants, the reversibility of the interaction, and the effect on the secondary structure of the macromolecule. Affinity constants of the counterionic condensation DNA-drug were in the order of 10⁶. The negative electrokinetic potential of DNA decreased with the increase of the proportion of loading drugs. The drugs were slowly released from the DNA-drug complexes and had release kinetics consistent with the high degree of counterionic condensation. The circular dichroism profile of DNA was not modified by complexation with atenolol, lidocaine, or timolol, but was significantly altered by the more lipophilic drugs benzydamine and propranolol, revealing modifications in the secondary structure of the DNA. The in vitro characterization of such interactions provides a physicochemical basis that would contribute to identify the effects of this kind of drugs in cellular cultures, as well as side effects observed under their clinical use. Moreover, this methodology could also be projected to the fields of intracellular DNA transfection and the use of DNA as a carrier of active drugs.
Wen, Ming; Zhang, Zhimin; Niu, Shaoyu; Sha, Haozhi; Yang, Ruihan; Yun, Yonghuan; Lu, Hongmei
Identifying interactions between known drugs and targets is a major challenge in drug repositioning. In silico prediction of drug-target interaction (DTI) can speed up the expensive and time-consuming experimental work by providing the most potent DTIs. In silico prediction of DTI can also provide insights about the potential drug-drug interaction and promote the exploration of drug side effects. Traditionally, the performance of DTI prediction depends heavily on the descriptors used to represent the drugs and the target proteins. In this paper, to accurately predict new DTIs between approved drugs and targets without separating the targets into different classes, we developed a deep-learning-based algorithmic framework named DeepDTIs. It first abstracts representations from raw input descriptors using unsupervised pretraining and then applies known label pairs of interaction to build a classification model. Compared with other methods, it is found that DeepDTIs reaches or outperforms other state-of-the-art methods. The DeepDTIs can be further used to predict whether a new drug targets to some existing targets or whether a new target interacts with some existing drugs.
Kuang, Qifan; Xu, Xin; Li, Rong; Dong, Yongcheng; Li, Yan; Huang, Ziyan; Li, Yizhou; Li, Menglong
The prediction of drug-target interactions is a key step in the drug discovery process, which serves to identify new drugs or novel targets for existing drugs. However, experimental methods for predicting drug-target interactions are expensive and time-consuming. Therefore, the in silico prediction of drug-target interactions has recently attracted increasing attention. In this study, we propose an eigenvalue transformation technique and apply this technique to two representative algorithms, the Regularized Least Squares classifier (RLS) and the semi-supervised link prediction classifier (SLP), that have been used to predict drug-target interaction. The results of computational experiments with these techniques show that algorithms including eigenvalue transformation achieved better performance on drug-target interaction prediction than did the original algorithms. These findings show that eigenvalue transformation is an efficient technique for improving the performance of methods for predicting drug-target interactions. We further show that, in theory, eigenvalue transformation can be viewed as a feature transformation on the kernel matrix. Accordingly, although we only apply this technique to two algorithms in the current study, eigenvalue transformation also has the potential to be applied to other algorithms based on kernels.
Kaufman, Amy L.; Spitz, Jared; Jacobs, Michael; Sorrentino, Matthew; Yuen, Shennin; Danahey, Keith; Saner, Donald; Klein, Teri E.; Altman, Russ B.; Ratain, Mark J.; O’Donnell, Peter H.
Objective To comprehensively assess the pharmacogenomic evidence of routinely-used drugs for clinical utility. Methods From January 2, 2011 to May 31, 2013, we assessed 71 drugs by identifying all drug/genetic variant combinations with published clinical pharmacogenomic evidence. Literature supporting each drug/variant pair was assessed for study design and methodology, outcomes, statistical significance, and clinical relevance. Proposed clinical summaries were formally scored using a modified AGREE (Appraisal of Guidelines for Research and Evaluation) II instrument, including recommendation for or against guideline implementation. Results Positive pharmacogenomic findings were identified for 51 of 71 cardiovascular drugs (71.8%) representing 884 unique drug/variant pairs from 597 publications. After analysis for quality and clinical relevance, 92 drug/variant pairs were proposed for translation into clinical summaries, encompassing 23 drugs (32.4% of drugs reviewed). All were found recommended for clinical implementation using AGREE, with average overall quality scores of 5.18 (out of 7.0; range 3.67 to 7.0; SD 0.91). Drug guidelines had highest scores in AGREE domain 1 (Scope) (average 91.9 out of 100; SD 6.1), and moderate but still robust scores in domain 3 (Rigour) (average 73.1; SD 11.1), domain 4 (Clarity) (average 67.8; SD 12.5), and domain 5 (Applicability) (average 65.8; SD 10). The drugs clopidogrel (CYP2C19), metoprolol (CYP2D6), simvastatin (rs4149056), dabigatran (rs2244613), hydralazine (rs1799983, rs1799998), and warfarin (CYP2C9/VKORC1) were distinguished by the highest scores. Eight of the 10 most commonly-prescribed drugs warranted translation guidelines summarizing clinical pharmacogenomic information. Conclusions Considerable clinically actionable pharmacogenomic information for cardiovascular drugs exists, supporting the idea that consideration of such information when prescribing is warranted. PMID:26046407
Baneyx, Guillaume; Fukushima, Yumi; Parrott, Neil
Interactions between co-administered medicines can reduce efficacy or lead to adverse effects. Understanding and managing such interactions is essential in bringing safe and effective medicines to the market. Ideally, interaction potential should be recognized early and minimized in compounds that reach late stages of drug development. Physiologically based pharmacokinetic models combine knowledge of physiological factors with compound-specific properties to simulate how a drug behaves in the human body. These software tools are increasingly used during drug discovery and development and, when integrating relevant in vitro data, can simulate drug interaction potential. This article provides some background and presents illustrative examples. Physiologically based models are an integral tool in the discovery and development of drugs, and can significantly aid our understanding and prediction of drug interactions.
Awortwe, C.; Fasinu, P.S.; Rosenkranz, B.
The Caco-2 model is employed in pre-clinical investigations to predict the likely gastrointestinal permeability of drugs because it expresses cytochrome P450 enzymes, transporters, microvilli and enterocytes of identical characteristics to the human small intestine. The FDA recommends this model as integral component of the Biopharmaceutics Classification System (BCS). Most dedicated laboratories use the Caco-2 cell line to screen new chemical entities through prediction of its solubility, bioavailability and the possibility of drug-drug or herb-drug interactions in the gut lumen. However, challenges in the inherent characteristics of Caco-2 cell and inter-laboratory protocol variations have resulted to generation of irreproducible data. These limitations affect the extrapolation of data from pre-clinical research to clinical studies involving drug-drug and herb-drug interactions. This review addresses some of these caveats and enumerates the plausible current and future approaches to reduce the anomalies associated with Caco-2 cell line investigations focusing on its application in herb-drug interactions. PMID:24735758
Yu, Jingjing; Zhou, Zhu; Owens, Katie H; Ritchie, Tasha K; Ragueneau-Majlessi, Isabelle
As a follow up to previous reviews, the aim of the present analysis was to systematically examine all drug metabolism, transport, pharmacokinetics (PK), and drug-drug interaction (DDI) data available in the 33 new drug applications (NDAs) approved by the Food and Drug Administration (FDA) in 2015, using the University of Washington Drug Interaction Database, and to highlight the significant findings. In vitro, a majority of the new molecular entities (NMEs) were found to be substrates or inhibitors/inducers of at least one drug metabolizing enzyme or transporter. In vivo, 95 clinical DDI studies displayed positive PK interactions, with an area under the curve (AUC) ratio ≥ 1.25 for inhibition or ≤ 0.8 for induction. When NMEs were considered as victim drugs, 21 NMEs had at least one positive clinical DDI, with three NMEs shown to be sensitive substrates of CYP3A (AUC ratio ≥ 5 when coadministered with strong inhibitors): cobimetinib, isavuconazole (the active metabolite of prodrug isavuconazonium sulfate), and ivabradine. As perpetrators, nine NMEs showed positive inhibition and three NMEs showed positive induction, with some of these interactions involving both enzymes and transporters. The most significant changes for inhibition and induction were observed with rolapitant, a moderate inhibitor of CYP2D6 and lumacaftor, a strong inducer of CYP3A. Physiologically based pharmacokinetics simulations and pharmacogenetics studies were used for six and eight NMEs, respectively, to inform dosing recommendations. The effects of hepatic or renal impairment on the drugs' PK were also evaluated to support drug administration in these specific populations.
Bajpayee, Ambika G; Grodzinsky, Alan J
Current intra-articular drug delivery methods do not guarantee sufficient drug penetration into cartilage tissue to reach cell and matrix targets at the concentrations necessary to elicit the desired biological response. Here, we provide our perspective on the utilization of charge-charge (electrostatic) interactions to enhance drug penetration and transport into cartilage, and to enable sustained binding of drugs within the tissue's highly negatively charged extracellular matrix. By coupling drugs to positively charged nanocarriers that have optimal size and charge, cartilage can be converted from a drug barrier into a drug reservoir for sustained intra-tissue delivery. Alternatively, a wide variety of drugs themselves can be made cartilage-penetrating by functionalizing them with specialized positively charged protein domains. Finally, we emphasize that appropriate animal models, with cartilage thickness similar to that of humans, must be used for the study of drug transport and retention in cartilage.
Boullata, Joseph I; Hudson, Lauren M
The relevance of drug?nutrient interactions in daily practice continues to grow with the widespread use of medication. Interactions can involve a single nutrient, multiple nutrients, food in general, or nutrition status. Mechanistically, drug?nutrient interactions occur because of altered intestinal transport and metabolism, or systemic distribution, metabolism and excretion, as well as additive or antagonistic effects. Optimal patient care includes identifying, evaluating, and managing these interactions. This task can be supported by a systematic approach for categorizing interactions and rating their clinical significance. This review provides such a broad framework using recent examples, as well as some classic drug?nutrient interactions. Pertinent definitions are presented, as is a suggested approach for clinicians. This important and expanding subject will benefit tremendously from further clinician involvement.
Tan, Yuxiang; Hu, Yong; Liu, Xiaoxiao; Yin, Zhinan; Chen, Xue-Wen; Liu, Mei
Adverse drug reactions (ADRs) are a major public health concern, causing over 100,000 fatalities in the United States every year with an annual cost of $136 billion. Early detection and accurate prediction of ADRs is thus vital for drug development and patient safety. Multiple scientific disciplines, namely pharmacology, pharmacovigilance, and pharmacoinformatics, have been addressing the ADR problem from different perspectives. With the same goal of improving drug safety, this article summarizes and links the research efforts in the multiple disciplines into a single framework from comprehensive understanding of the interactions between drugs and biological system and the identification of genetic and phenotypic predispositions of patients susceptible to higher ADR risks and finally to the current state of implementation of medication-related decision support systems. We start by describing available computational resources for building drug-target interaction networks with biological annotations, which provides a fundamental knowledge for ADR prediction. Databases are classified by functions to help users in selection. Post-marketing surveillance is then introduced where data-driven approach can not only enhance the prediction accuracy of ADRs but also enables the discovery of genetic and phenotypic risk factors of ADRs. Understanding genetic risk factors for ADR requires well organized patient genetics information and analysis by pharmacogenomic approaches. Finally, current state of clinical decision support systems is presented and described how clinicians can be assisted with the integrated knowledgebase to minimize the risk of ADR. This review ends with a discussion of existing challenges in each of disciplines with potential solutions and future directions.
Khan, Abbul Bashar; Khan, Javed Masood; Ali, Mohd. Sajid; Khan, Rizwan Hasan; Kabir-ud-Din
To know the interaction of amphiphilic drugs nortriptyline hydrochloride (NOT) and promazine hydrochloride (PMZ) with serum albumins (i.e., human serum albumin (HSA) and bovine serum albumin (BSA)), techniques of UV-visible, fluorescence, and circular dichroism (CD) spectroscopies are used. The binding affinity is more in case of PMZ with both the serum albumins. The quenching rate constant (kq) values suggest a static quenching process for all the drug-serum albumin interactions. The UV-visible results show that the change in protein conformation of PMZ-serum albumin interactions are more prominent as compared to NOT-serum albumin interactions. The CD results also explain the conformational changes in the serum albumins on binding with the drugs. The increment in %α-helical structure is slightly more for drug-BSA complexes as compared to drug-HSA complexes.
Khan, Abbul Bashar; Khan, Javed Masood; Ali, Mohd Sajid; Khan, Rizwan Hasan; Kabir-Ud-Din
To know the interaction of amphiphilic drugs nortriptyline hydrochloride (NOT) and promazine hydrochloride (PMZ) with serum albumins (i.e., human serum albumin (HSA) and bovine serum albumin (BSA)), techniques of UV-visible, fluorescence, and circular dichroism (CD) spectroscopies are used. The binding affinity is more in case of PMZ with both the serum albumins. The quenching rate constant (k(q)) values suggest a static quenching process for all the drug-serum albumin interactions. The UV-visible results show that the change in protein conformation of PMZ-serum albumin interactions are more prominent as compared to NOT-serum albumin interactions. The CD results also explain the conformational changes in the serum albumins on binding with the drugs. The increment in %α-helical structure is slightly more for drug-BSA complexes as compared to drug-HSA complexes.
Novak, Philipp H; Ekins-Daukes, Suzie; Simpson, Colin R; Milne, Robert M; Helms, Peter; McLay, James S
Aims To investigate the extent of acute coprescribing in primary care to children on chronic antiepileptic therapy, which could give rise to potentially harmful drug–drug interactions. Design Acute coprescribing to children on chronic antiepileptic drug therapy in primary care was assessed in 178 324 children aged 0–17 years for the year 1 November 1999 to 31 October 2000. Computerized prescribing data were retrieved from 161 representative general practices in Scotland. Setting One hundred and sixty-one general practices throughout Scotland. Results During the study year 723 (0.41%) children chronically prescribed antiepileptic therapy were identified. Fourteen antiepileptic agents were prescribed, with carbamazepine, sodium valproate and lamotrigine accounting for 80% of the total. During the year children on chronic antiepileptic therapy were prescribed 4895 acute coprescriptions for 269 different medicines. The average number of acute coprescriptions for non-epileptic drug therapy were eight, 11, six, and six for the 0–1, 2–4, 5–11, and 12–17-year-olds, respectively. Of these acute coprescriptions 72 (1.5%) prescribed to 22 (3.0%) children were identified as a potential source of clinically serious interactions. The age-adjusted prevalence rates for potentially serious coprescribing were 86, 26, 22, and 33/1000 children chronically prescribed antiepileptic therapy in the 0–1, 2–4, 5–11, and 12–17-year-old age groups, respectively. The drugs most commonly coprescribed which could give rise to such interactions were antacids, erythromycin, ciprofloxacin, theophylline and the low-dose oral contraceptive. For 10 (45.5%0 of the 20 children identified at risk of a potentially clinically serious adverse drug interaction, the acute coprescription was prescribed off label because of age or specific contraindication/warning. Conclusions In primary care, 3.0% of children on chronic antiepileptic therapy are coprescribed therapeutic agents, which could
Wang, Yu; Fu, Xin; Xu, Jing; Wang, Qiuhong; Kuang, Haixue
Polycystic ovary syndrome (PCOS) is a common multifactorial endocrine disorder among women of childbearing age. PCOS has various and heterogeneous clinical features apart from its indefinite pathogenesis and mechanism. Clinical drugs for PCOS are multifarious because it only treats separate symptoms. Berberine is an isoquinoline plant alkaloid with numerous biological activities, and it was testified to improve some diseases related to PCOS in animal models and in humans. Systems pharmacology was utilized to predict the potential targets of berberine related to PCOS and the potential drug-drug interaction base on the disease network. In conclusion, berberine is a promising polypharmacological drug for treating PCOS, and for enhancing the efficacy of clinical drugs. PMID:27306862
Wang, Jing; Dai, Shu; Guo, Yan; Xie, Wen; Zhai, Yonggong
Hormonal homeostasis is essential for a variety of physiological and pathological processes. Elimination and detoxification of xenobiotics, such as drugs introduced into the human body, could disrupt the balance of hormones due to the induction of drug metabolizing enzymes (DMEs) and transporters. Pregnane X receptor (PXR, NR1I2) functions as a master xenobiotic receptor involved in drug metabolism and drug-drug interactions by its coordinated transcriptional regulation of phase I and phase II DMEs and transporters. Recently, increasing evidences indicate that PXR can also mediate the endocrine disruptor function and thus impact the integrity of the endocrine system. This review focuses primarily on the recent advances in our understanding of the function of PXR in glucocorticoid, mineralocorticoid, androgen and estrogen homeostasis. The elucidation of PXR-mediated drug-hormone interactions might have important therapeutic implications in dealing with hormone-dependent diseases and safety assessment of drugs. PMID:26417296
Brantley, Scott J.; Argikar, Aneesh A.; Lin, Yvonne S.; Nagar, Swati
Supported by a usage history that predates written records and the perception that “natural” ensures safety, herbal products have increasingly been incorporated into Western health care. Consumers often self-administer these products concomitantly with conventional medications without informing their health care provider(s). Such herb–drug combinations can produce untoward effects when the herbal product perturbs the activity of drug metabolizing enzymes and/or transporters. Despite increasing recognition of these types of herb–drug interactions, a standard system for interaction prediction and evaluation is nonexistent. Consequently, the mechanisms underlying herb–drug interactions remain an understudied area of pharmacotherapy. Evaluation of herbal product interaction liability is challenging due to variability in herbal product composition, uncertainty of the causative constituents, and often scant knowledge of causative constituent pharmacokinetics. These limitations are confounded further by the varying perspectives concerning herbal product regulation. Systematic evaluation of herbal product drug interaction liability, as is routine for new drugs under development, necessitates identifying individual constituents from herbal products and characterizing the interaction potential of such constituents. Integration of this information into in silico models that estimate the pharmacokinetics of individual constituents should facilitate prospective identification of herb–drug interactions. These concepts are highlighted with the exemplar herbal products milk thistle and resveratrol. Implementation of this methodology should help provide definitive information to both consumers and clinicians about the risk of adding herbal products to conventional pharmacotherapeutic regimens. PMID:24335390
Hung, Joseph C.
The regulatory framework for radioactive drugs, in particular those used in positron emission tomography (PET) scans, has been gradually established since the release of the Food and Drug Administration Modernization Act in 1997. Various guidances specially tailored to accommodate special properties of PET drugs have been issued by the Food and Drug Administration (FDA) in order to ensure this valuable technology (i.e., PET molecular imaging) will continue to be available to patients and yet the safety and efficacy of PET drugs are well regulated so that public health will be protected. This article presents several key elements of this regulatory framework for PET drugs. New regulatory avenues proposed by the FDA to facilitate the research and development process to bring more new PET drugs to clinical practice, as well as to foster the opportunity of using “orphan” PET drugs in clinical practice are also discussed in this paper. PMID:24312157
Kendler, K. S.; Ohlsson, H.; Sundquist, K.; Sundquist, J.
Background Drug abuse (DA) is a clinically heterogeneous syndrome. Can we, in a large epidemiological sample, identify clinical features of DA cases that index genetic risk? Method Using registration in medical, legal or pharmacy records, we identified four kinds of relative pairs (n =935854) starting with a proband with DA: monozygotic co-twins; full siblings; half-siblings; and cousins. Using linear hazard regression, we examined the interaction between three clinical features of DA in the proband and risk for DA in these four relative pairs, ordered by degree of genetic relationship. Results Increased risk for DA in relatives was robustly predicted by early age at first registration, total number of registrations, and ascertainment in the criminal versus the medical or pharmacy registry. In multivariate models, all three of these variables remained significant and in aggregate strongly predicted DA risk in relatives. The risk for DA in siblings of DA probands in the highest decile of genetic risk predicted by our three indices was more than twice as great as that predicted in siblings of probands in the lowest decile of risk. Conclusions In an epidemiological sample, genetic risk for DA can be substantially indexed by simple clinical and historical variables. PMID:24461082
Kato, T A; Yamauchi, Y; Horikawa, H; Monji, A; Mizoguchi, Y; Seki, Y; Hayakawa, K; Utsumi, H; Kanba, S
Psychiatric disorders have long and dominantly been regarded to be induced by disturbances of neuronal networks including synapses and neurotransmitters. Thus, the effects of psychotropic drugs such as antipsychotics and antidepressants have been understood to modulate synaptic regulation via receptors and transporters of neurotransmitters such as dopamine and serotonin. Recently, microglia, immunological/inflammatory cells in the brain, have been indicated to have positive links to psychiatric disorders. Positron emission tomography (PET) imaging and postmortem studies have revealed microglial activation in the brain of neuropsychiatric disorders such as schizophrenia, depression and autism. Animal models of neuropsychiatric disorders have revealed the underlying microglial pathologies. In addition, various psychotropic drugs have been suggested to have direct effects on microglia. Until now, the relationship between microglia, neurotransmitters and psychiatric disorders has not been well understood. Therefore, in this review, at first, we summarize recent findings of interaction between microglia and neurotransmitters such as dopamine, serotonin, norepinephrine, acetylcholine and glutamate. Next, we introduce up-to-date knowledge of the effects of psychotropic drugs such as antipsychotics, antidepressants and antiepileptics on microglial modulation. Finally, we propose the possibility that modulating microglia may be a key target in the treatment of various psychiatric disorders. Further investigations and clinical trials should be conducted to clarify this perspective, using animal in vivo studies and imaging studies with human subjects.
Tirona, Rommel G; Bailey, David G
Despite their common use, it is not widely recognized that herbal medicines can alter the efficacy of coadministered prescription drugs. Constituents in herbs interact with nuclear receptors to enhance metabolizing enzyme and/or transporter activity leading to reduced drug concentrations. Although St John’s wort was the first and most frequently reported source of induction-style herb–drug interactions, this knowledge has not yet changed its current availability. This type of interaction is likely to be relevant to other herbal products. Caregivers need to be aware of the issues and options for therapeutic management. PMID:16722828
Background Despite increased investment in pharmaceutical research and development, fewer and fewer new drugs are entering the marketplace. This has prompted studies in repurposing existing drugs for use against diseases with unmet medical needs. A popular approach is to develop a classification model based on drugs with and without a desired therapeutic effect. For this approach to be statistically sound, it requires a large number of drugs in both classes. However, given few or no approved drugs for the diseases of highest medical urgency and interest, different strategies need to be investigated. Results We developed a computational method termed “drug-protein interaction-based repurposing” (DPIR) that is potentially applicable to diseases with very few approved drugs. The method, based on genome-wide drug-protein interaction information and Bayesian statistics, first identifies drug-protein interactions associated with a desired therapeutic effect. Then, it uses key drug-protein interactions to score other drugs for their potential to have the same therapeutic effect. Conclusions Detailed cross-validation studies using United States Food and Drug Administration-approved drugs for hypertension, human immunodeficiency virus, and malaria indicated that DPIR provides robust predictions. It achieves high levels of enrichment of drugs approved for a disease even with models developed based on a single drug known to treat the disease. Analysis of our model predictions also indicated that the method is potentially useful for understanding molecular mechanisms of drug action and for identifying protein targets that may potentiate the desired therapeutic effects of other drugs (combination therapies). PMID:24950817
King, Jennifer R; Dutta, Sandeep; Cohen, Daniel; Podsadecki, Thomas J; Ding, Bifeng; Awni, Walid M; Menon, Rajeev M
The combination of ombitasvir (an NS5A inhibitor), paritaprevir (an NS3/4A inhibitor) coadministered with ritonavir (r), and dasabuvir (an NS5B nonnucleoside polymerase inhibitor), referred to as the 3D regimen, and the combination of ombitasvir-paritaprevir-r, referred to as the 2D regimen, have demonstrated high efficacy with and without ribavirin in hepatitis C virus (HCV)-infected subjects. These regimens have potential for coadministration with sofosbuvir (nucleoside NS5B inhibitor) in the treatment of HCV. This phase 1, drug-drug interaction, open-label, multiple-dose study enrolled 32 healthy subjects to receive the 3D or 2D regimen in combination with sofosbuvir. Doses of study drugs were as follows: ombitasvir-paritaprevir-r, 25/150/100 mg daily (QD); dasabuvir, 250 mg twice daily (BID); and sofosbuvir, 400 mg QD. Blood samples were collected on study days 7, 14, and 21 for evaluating drug interaction at steady state. The effect of the 3D and 2D regimens on the pharmacokinetics of sofosbuvir and its circulating metabolite GS-331007 and vice versa was assessed by a repeated-measures analysis. Exposures of the 3D and 2D regimens were similar (≤20% change) during coadministration with sofosbuvir and during administration alone. Sofosbuvir exposures were 61% to 112% higher with the 3D regimen and 64% to 93% higher with the 2D regimen than with sofosbuvir alone. GS-331007 total exposures were 27% and 32% higher with the 3D and 2D regimens, respectively, than with sofosbuvir alone. Increases in sofosbuvir and GS-331007 exposures likely resulted from breast cancer resistance protein (BCRP) and/or P glycoprotein (P-gp) transporter inhibition by paritaprevir and ritonavir. No subjects discontinued the study due to study drug-related adverse events. No dose adjustment is recommended for 3D, 2D, or sofosbuvir in clinical trials exploring the safety and efficacy of the combination. (This study has been registered at ClinicalTrials.gov under registration no. NCT
Dutta, Sandeep; Cohen, Daniel; Podsadecki, Thomas J.; Ding, Bifeng; Awni, Walid M.; Menon, Rajeev M.
The combination of ombitasvir (an NS5A inhibitor), paritaprevir (an NS3/4A inhibitor) coadministered with ritonavir (r), and dasabuvir (an NS5B nonnucleoside polymerase inhibitor), referred to as the 3D regimen, and the combination of ombitasvir-paritaprevir-r, referred to as the 2D regimen, have demonstrated high efficacy with and without ribavirin in hepatitis C virus (HCV)-infected subjects. These regimens have potential for coadministration with sofosbuvir (nucleoside NS5B inhibitor) in the treatment of HCV. This phase 1, drug-drug interaction, open-label, multiple-dose study enrolled 32 healthy subjects to receive the 3D or 2D regimen in combination with sofosbuvir. Doses of study drugs were as follows: ombitasvir-paritaprevir-r, 25/150/100 mg daily (QD); dasabuvir, 250 mg twice daily (BID); and sofosbuvir, 400 mg QD. Blood samples were collected on study days 7, 14, and 21 for evaluating drug interaction at steady state. The effect of the 3D and 2D regimens on the pharmacokinetics of sofosbuvir and its circulating metabolite GS-331007 and vice versa was assessed by a repeated-measures analysis. Exposures of the 3D and 2D regimens were similar (≤20% change) during coadministration with sofosbuvir and during administration alone. Sofosbuvir exposures were 61% to 112% higher with the 3D regimen and 64% to 93% higher with the 2D regimen than with sofosbuvir alone. GS-331007 total exposures were 27% and 32% higher with the 3D and 2D regimens, respectively, than with sofosbuvir alone. Increases in sofosbuvir and GS-331007 exposures likely resulted from breast cancer resistance protein (BCRP) and/or P glycoprotein (P-gp) transporter inhibition by paritaprevir and ritonavir. No subjects discontinued the study due to study drug-related adverse events. No dose adjustment is recommended for 3D, 2D, or sofosbuvir in clinical trials exploring the safety and efficacy of the combination. (This study has been registered at ClinicalTrials.gov under registration no. NCT
Wang, Yuhao; Zeng, Jianyang
Motivation: In silico prediction of drug-target interactions plays an important role toward identifying and developing new uses of existing or abandoned drugs. Network-based approaches have recently become a popular tool for discovering new drug-target interactions (DTIs). Unfortunately, most of these network-based approaches can only predict binary interactions between drugs and targets, and information about different types of interactions has not been well exploited for DTI prediction in previous studies. On the other hand, incorporating additional information about drug-target relationships or drug modes of action can improve prediction of DTIs. Furthermore, the predicted types of DTIs can broaden our understanding about the molecular basis of drug action. Results: We propose a first machine learning approach to integrate multiple types of DTIs and predict unknown drug-target relationships or drug modes of action. We cast the new DTI prediction problem into a two-layer graphical model, called restricted Boltzmann machine, and apply a practical learning algorithm to train our model and make predictions. Tests on two public databases show that our restricted Boltzmann machine model can effectively capture the latent features of a DTI network and achieve excellent performance on predicting different types of DTIs, with the area under precision-recall curve up to 89.6. In addition, we demonstrate that integrating multiple types of DTIs can significantly outperform other predictions either by simply mixing multiple types of interactions without distinction or using only a single interaction type. Further tests show that our approach can infer a high fraction of novel DTIs that has been validated by known experiments in the literature or other databases. These results indicate that our approach can have highly practical relevance to DTI prediction and drug repositioning, and hence advance the drug discovery process. Availability: Software and datasets are available
Zhou, Quan; Yan, Xiao-Feng; Zhang, Zhong-Miao; Pan, Wen-Sheng; Zeng, Su
AIM: To review and summarize drug metabolism and its related interactions in prescribing drugs within the similar therapeutic or structural class for gastrointestinal disease treatment so as to promote rational use of medicines in clinical practice. METHODS: Relevant literature was identified by performing MEDLINE/Pubmed searches covering the period from 1988 to 2006. RESULTS: Seven classes of drugs were chosen, including gastric proton pump inhibitors, histamine H2-receptor antagonists, benzamide-type gastroprokinetic agents, selective 5-HT3 receptor antagonists, fluoroquinolones, macrolide antibiotics and azole antifungals. They showed significant differences in metabolic profile (i.e., the fraction of drug metabolized by cytochrome P450 (CYP), CYP reaction phenotype, impact of CYP genotype on interindividual pharmacokinetics variability and CYP-mediated drug-drug interaction potential). Many events of severe adverse drug reactions and treatment failures were closely related to the ignorance of the above issues. CONCLUSION: Clinicians should acquaint themselves with what kind of drug has less interpatient variability in clearance and whether to perform CYP genotyping prior to initiation of therapy. The relevant CYP knowledge helps clinicians to enhance the management of patients with gastrointestinal disease who may require treatment with polytherapeutic regimens. PMID:17948937
Hooper, J; O'Connor, J; Cheesmar, R; Price, C P
We have developed computer-based clinical case histories incorporating multimedia elements to aid the learning of medicine in a problem-based manner. Topics have been developed in the specialty of Clinical Biochemistry but the approach used is suitable for any branch of clinical medicine. Each topic has material aimed at medical students and also postgraduate candidates for professional examinations. A browser program is also incorporated. Emphasis is made on interaction through the case and modeling of real-life decisions in diagnosis and treatment. Advantages of the program are self-paced learning, assessment of understanding, feedback, and emphasis on deep understanding of the basic physiological and biochemical processes underlying clinical problems.
Ayvaz, Serkan; Horn, John; Hassanzadeh, Oktie; Zhu, Qian; Stan, Johann; Tatonetti, Nicholas P; Vilar, Santiago; Brochhausen, Mathias; Samwald, Matthias; Rastegar-Mojarad, Majid; Dumontier, Michel; Boyce, Richard D
Although potential drug-drug interactions (PDDIs) are a significant source of preventable drug-related harm, there is currently no single complete source of PDDI information. In the current study, all publically available sources of PDDI information that could be identified using a comprehensive and broad search were combined into a single dataset. The combined dataset merged fourteen different sources including 5 clinically-oriented information sources, 4 Natural Language Processing (NLP) Corpora, and 5 Bioinformatics/Pharmacovigilance information sources. As a comprehensive PDDI source, the merged dataset might benefit the pharmacovigilance text mining community by making it possible to compare the representativeness of NLP corpora for PDDI text extraction tasks, and specifying elements that can be useful for future PDDI extraction purposes. An analysis of the overlap between and across the data sources showed that there was little overlap. Even comprehensive PDDI lists such as DrugBank, KEGG, and the NDF-RT had less than 50% overlap with each other. Moreover, all of the comprehensive lists had incomplete coverage of two data sources that focus on PDDIs of interest in most clinical settings. Based on this information, we think that systems that provide access to the comprehensive lists, such as APIs into RxNorm, should be careful to inform users that the lists may be incomplete with respect to PDDIs that drug experts suggest clinicians be aware of. In spite of the low degree of overlap, several dozen cases were identified where PDDI information provided in drug product labeling might be augmented by the merged dataset. Moreover, the combined dataset was also shown to improve the performance of an existing PDDI NLP pipeline and a recently published PDDI pharmacovigilance protocol. Future work will focus on improvement of the methods for mapping between PDDI information sources, identifying methods to improve the use of the merged dataset in PDDI NLP algorithms
Froestl, Wolfgang; Pfeifer, Andrea; Muhs, Andreas
Cognitive enhancers (nootropics) are drugs to treat cognition deficits in patients suffering from Alzheimer's disease, schizophrenia, stroke, attention deficit hyperactivity disorder, or aging. Cognition refers to a capacity for information processing, applying knowledge, and changing preferences. It involves memory, attention, executive functions, perception, language, and psychomotor functions. The term nootropics was coined in 1972 when memory enhancing properties of piracetam were observed in clinical trials. In the meantime, hundreds of drugs have been evaluated in clinical trials or in preclinical experiments. To classify the compounds, a concept is proposed assigning drugs to 19 categories according to their mechanism(s) of action, in particular drugs interacting with receptors, enzymes, ion channels, nerve growth factors, re-uptake transporters, antioxidants, metal chelators, and disease modifying drugs, meaning small molecules, vaccines, and monoclonal antibodies interacting with amyloid-β and tau. For drugs, whose mechanism of action is not known, they are either classified according to structure, e.g., peptides, or their origin, e.g., natural products. The review covers the evolution of research in this field over the last 25 years.
Moosavinasab, Soheil; Patterson, Jeremy; Strouse, Robert; Rastegar-Mojarad, Majid; Regan, Kelly; Payne, Philip R. O.; Huang, Yungui; Lin, Simon M.
The process of discovering new drugs has been extremely costly and slow in the last decades despite enormous investment in pharmaceutical research. Drug repurposing enables researchers to speed up the process of discovering other conditions that existing drugs can effectively treat, with low cost and fast FDA approval. Here, we introduce ‘RE:fine Drugs’, a freely available interactive website for integrated search and discovery of drug repurposing candidates from GWAS and PheWAS repurposing datasets constructed using previously reported methods in Nature Biotechnology. ‘RE:fine Drugs’ demonstrates the possibilities to identify and prioritize novelty of candidates for drug repurposing based on the theory of transitive Drug–Gene–Disease triads. This public website provides a starting point for research, industry, clinical and regulatory communities to accelerate the investigation and validation of new therapeutic use of old drugs. Database URL: http://drug-repurposing.nationwidechildrens.org PMID:27189611
Pasqualetti, Giuseppe; Tognini, Sara; Calsolaro, Valeria; Polini, Antonio; Monzani, Fabio
The use of multi drug regimens among the elderly population has increased tremendously over the last decade although the benefits of medications are always accompanied by potential harm, even when prescribed at recommended doses. The elderly populations are particularly at an increased risk of adverse drug reactions considering comorbidity, poly-therapy, physiological changes affecting the pharmacokinetics and pharmacodynamics of many drugs and, in some cases, poor compliance due to cognitive impairment and/or depression. In this setting, drug–drug interaction may represent a serious and even life-threatening clinical condition. Moreover, the inability to distinguish drug-induced symptoms from a definitive medical diagnosis often results in addition of yet another drug to treat the symptoms, which in turn increases drug–drug interactions. Cognitive enhancers, including acetylcholinesterase inhibitors and memantine, are the most widely prescribed agents for Alzheimer’s disease (AD) patients. Behavioral and psychological symptoms of dementia, including psychotic symptoms and behavioral disorders, represent noncognitive disturbances frequently observed in AD patients. Antipsychotic drugs are at high risk of adverse events, even at modest doses, and may interfere with the progression of cognitive impairment and interact with several drugs including anti-arrhythmics and acetylcholinesterase inhibitors. Other medications often used in AD patients are represented by anxiolytic, like benzodiazepine, or antidepressant agents. These agents also might interfere with other concomitant drugs through both pharmacokinetic and pharmacodynamic mechanisms. In this review we focus on the most frequent drug–drug interactions, potentially harmful, in AD patients with behavioral symptoms considering both physiological and pathological changes in AD patients, and potential pharmacodynamic/pharmacokinetic drug interaction mechanisms. PMID:26392756
van Heeswijk, R P G; Dannemann, B; Hoetelmans, R M W
Bedaquiline has recently been approved for the treatment of pulmonary multidrug-resistant tuberculosis (TB) as part of combination therapy in adults. It is metabolized primarily by the cytochrome P450 isoenzyme 3A4 (CYP3A4) to a less-active N-monodesmethyl metabolite. Phase I and Phase II studies in healthy subjects and patients with drug-susceptible or multidrug-resistant TB have assessed the pharmacokinetics and drug-drug interaction profile of bedaquiline. Potential interactions have been assessed between bedaquiline and first- and second-line anti-TB drugs (rifampicin, rifapentine, isoniazid, pyrazinamide, ethambutol, kanamycin, ofloxacin and cycloserine), commonly used antiretroviral agents (lopinavir/ritonavir, nevirapine and efavirenz) and a potent CYP3A inhibitor (ketoconazole). This review summarizes the pharmacokinetic profile of bedaquiline as well as the results of the drug-drug interaction studies.
Cobanoglu, Murat Can; Liu, Chang; Hu, Feizhuo; Oltvai, Zoltán N; Bahar, Ivet
Quantitative analysis of known drug-target interactions emerged in recent years as a useful approach for drug repurposing and assessing side effects. In the present study, we present a method that uses probabilistic matrix factorization (PMF) for this purpose, which is particularly useful for analyzing large interaction networks. DrugBank drugs clustered based on PMF latent variables show phenotypic similarity even in the absence of 3D shape similarity. Benchmarking computations show that the method outperforms those recently introduced provided that the input data set of known interactions is sufficiently large--which is the case for enzymes and ion channels, but not for G-protein coupled receptors (GPCRs) and nuclear receptors. Runs performed on DrugBank after hiding 70% of known interactions show that, on average, 88 of the top 100 predictions hit the hidden interactions. De novo predictions permit us to identify new potential interactions. Drug-target pairs implicated in neurobiological disorders are overrepresented among de novo predictions.
Lenz, Thomas L; Gillespie, Nicole
Transdermal drug delivery systems, such as the transdermal patch, continue to be a popular and convenient way to administer medications. There are currently several medications that use a transdermal patch drug delivery system. This article describes the potential untoward side effects of increased drug absorption through the use of a transdermal patch in individuals who exercise or participate in sporting events. Four studies have been reported that demonstrate a significant increase in the plasma concentration of nitroglycerin when individuals exercise compared with rest. Likewise, several case reports and two studies have been conducted that demonstrate nicotine toxicity and increased plasma nicotine while wearing a nicotine patch in individuals who exercise or participate in sporting events compared with rest. Healthcare providers, trainers and coaches should be aware of proper transdermal patch use, especially while exercising, in order to provide needed information to their respective patients and athletes to avoid potential untoward side effects. Particular caution should be given to individuals who participate in an extreme sporting event of long duration. Further research that includes more medications is needed in this area.
Pessayre, D; Larrey, D; Funck-Brentano, C; Benhamou, J P
Drug interactions involving macrolides have been mainly reported in subjects receiving troleandomycin and in a few receiving erythromycin derivatives. In rats and in humans, troleandomycin, erythromycin and erythromycin derivatives induce microsomal enzymes; the induced isozymes of cytochrome P-450 have a high activity for these macrolides but a poor activity with several other substrates. These isozymes actively demethylate and oxidize these macrolides into nitrosoalkanes which form stable, inactive complexes with the iron of cytochrome P-450. Eventually, the oxidative metabolism of other drugs may be decreased. These effects are marked after administration of troleandomycin, moderate after administration of erythromycin derivatives and absent (or negligible) after administration of spiramycin, josamycin or midecamycin. A second adverse effect of the administration of troleandomycin or erythromycin derivatives is the possible occurrence of hepatitis. Mild hepatic dysfunction is fairly frequent and may be toxic in type. In contrast, jaundice is common, is frequently associated with hypersensitivity, and promptly recurs when the drug is readministered. Troleandomycin and erythromycin derivatives, which form nitrosoalkanes, produce hepatitis, whereas josamycin, midecamycin and spiramycin, which do not form cytochrome P-450-nitrosoalkane complexes, rarely, if ever, produce hepatitis. Nitrosoalkanes are unstable intermediates which react with glutathione but also with cysteine and might covalently bind to the SH-groups of proteins. The following mechanism might be proposed as a hypothetical attempt to link up these various observations. The macrolide (or its reactive metabolite) may have discrete toxicity; in several subjects, this may produce minor liver lesions and a mildly raised aminotransferase activity. Necrosis of a few hepatocytes may release into the circulation plasma membrane proteins altered by the covalent binding of metabolites. Such modified liver
Jensen, Kasper; Ni, Yueqiong; Panagiotou, Gianni; Kouskoumvekaki, Irene
Recent research has demonstrated that consumption of food -especially fruits and vegetables- can alter the effects of drugs by interfering either with their pharmacokinetic or pharmacodynamic processes. Despite the recognition of such drug-food associations as an important element for successful therapeutic interventions, a systematic approach for identifying, predicting and preventing potential interactions between food and marketed or novel drugs is not yet available. The overall objective of this work was to sketch a comprehensive picture of the interference of ∼ 4,000 dietary components present in ∼1800 plant-based foods with the pharmacokinetics and pharmacodynamics processes of medicine, with the purpose of elucidating the molecular mechanisms involved. By employing a systems chemical biology approach that integrates data from the scientific literature and online databases, we gained a global view of the associations between diet and dietary molecules with drug targets, metabolic enzymes, drug transporters and carriers currently deposited in DrugBank. Moreover, we identified disease areas and drug targets that are most prone to the negative effects of drug-food interactions, showcasing a platform for making recommendations in relation to foods that should be avoided under certain medications. Lastly, by investigating the correlation of gene expression signatures of foods and drugs we were able to generate a completely novel drug-diet interactome map.
Jensen, Kasper; Ni, Yueqiong; Panagiotou, Gianni; Kouskoumvekaki, Irene
Recent research has demonstrated that consumption of food -especially fruits and vegetables- can alter the effects of drugs by interfering either with their pharmacokinetic or pharmacodynamic processes. Despite the recognition of such drug-food associations as an important element for successful therapeutic interventions, a systematic approach for identifying, predicting and preventing potential interactions between food and marketed or novel drugs is not yet available. The overall objective of this work was to sketch a comprehensive picture of the interference of ∼ 4,000 dietary components present in ∼1800 plant-based foods with the pharmacokinetics and pharmacodynamics processes of medicine, with the purpose of elucidating the molecular mechanisms involved. By employing a systems chemical biology approach that integrates data from the scientific literature and online databases, we gained a global view of the associations between diet and dietary molecules with drug targets, metabolic enzymes, drug transporters and carriers currently deposited in DrugBank. Moreover, we identified disease areas and drug targets that are most prone to the negative effects of drug-food interactions, showcasing a platform for making recommendations in relation to foods that should be avoided under certain medications. Lastly, by investigating the correlation of gene expression signatures of foods and drugs we were able to generate a completely novel drug-diet interactome map. PMID:25668218
Posadzki, Paul; Watson, Leala; Ernst, Edzard
OBJECTIVES The aim of this overview of systematic reviews (SRs) is to evaluate critically the evidence regarding interactions between herbal medicinal products (HMPs) and synthetic drugs. METHODS Four electronic databases were searched to identify relevant SRs. RESULTS Forty‐six SRs of 46 different HMPs met our inclusion criteria. The vast majority of SRs were of poor methodological quality. The majority of these HMPs were not associated with severe herb–drug interactions. Serious herb–drug interactions were noted for Hypericum perforatum and Viscum album. The most severe interactions resulted in transplant rejection, delayed emergence from anaesthesia, cardiovascular collapse, renal and liver toxicity, cardiotoxicity, bradycardia, hypovolaemic shock, inflammatory reactions with organ fibrosis and death. Moderately severe interactions were noted for Ginkgo biloba, Panax ginseng, Piper methysticum, Serenoa repens and Camellia sinensis. The most commonly interacting drugs were antiplatelet agents and anticoagulants. CONCLUSION The majority of the HMPs evaluated in SRs were not associated with drug interactions with serious consequences. However, the poor quality and the scarcity of the primary data prevent firm conclusions. PMID:22670731
Mousavian, Zaynab; Khakabimamaghani, Sahand; Kavousi, Kaveh; Masoudi-Nejad, Ali
The labor-intensive and expensive experimental process of drug-target interaction prediction has motivated many researchers to focus on in silico prediction, which leads to the helpful information in supporting the experimental interaction data. Therefore, they have proposed several computational approaches for discovering new drug-target interactions. Several learning-based methods have been increasingly developed which can be categorized into two main groups: similarity-based and feature-based. In this paper, we firstly use the bi-gram features extracted from the Position Specific Scoring Matrix (PSSM) of proteins in predicting drug-target interactions. Our results demonstrate the high-confidence prediction ability of the Bigram-PSSM model in terms of several performance indicators specifically for enzymes and ion channels. Moreover, we investigate the impact of negative selection strategy on the performance of the prediction, which is not widely taken into account in the other relevant studies. This is important, as the number of non-interacting drug-target pairs are usually extremely large in comparison with the number of interacting ones in existing drug-target interaction data. An interesting observation is that different levels of performance reduction have been attained for four datasets when we change the sampling method from the random sampling to the balanced sampling.
Ledwitch, Kaitlyn V; Barnes, Robert W; Roberts, Arthur G
Drug-drug interactions (DDIs) and associated toxicity from cardiovascular drugs represents a major problem for effective co-administration of cardiovascular therapeutics. A significant amount of drug toxicity from DDIs occurs because of drug interactions and multiple cardiovascular drug binding to the efflux transporter P-glycoprotein (Pgp), which is particularly problematic for cardiovascular drugs because of their relatively low therapeutic indexes. The calcium channel antagonist, verapamil and the cardiac glycoside, digoxin, exhibit DDIs with Pgp through non-competitive inhibition of digoxin transport, which leads to elevated digoxin plasma concentrations and digoxin toxicity. In the present study, verapamil-induced ATPase activation kinetics were biphasic implying at least two verapamil-binding sites on Pgp, whereas monophasic digoxin activation of Pgp-coupled ATPase kinetics suggested a single digoxin-binding site. Using intrinsic protein fluorescence and the saturation transfer double difference (STDD) NMR techniques to probe drug-Pgp interactions, verapamil was found to have little effect on digoxin-Pgp interactions at low concentrations of verapamil, which is consistent with simultaneous binding of the drugs and non-competitive inhibition. Higher concentrations of verapamil caused significant disruption of digoxin-Pgp interactions that suggested overlapping and competing drug-binding sites. These interactions correlated to drug-induced conformational changes deduced from acrylamide quenching of Pgp tryptophan fluorescence. Also, Pgp-coupled ATPase activity kinetics measured with a range of verapamil and digoxin concentrations fit well to a DDI model encompassing non-competitive and competitive inhibition of digoxin by verapamil. The results and previous transport studies were combined into a comprehensive model of verapamil-digoxin DDIs encompassing drug binding, ATP hydrolysis, transport and conformational changes.
Gualano, Gina; Capone, Susanna; Matteelli, Alberto; Palmieri, Fabrizio
Treatment of multidrug-resistant tuberculosis (MDR-TB) cases is challenging because it relies on second-line drugs that are less potent and more toxic than those used in the clinical management of drug-susceptible TB. Moreover, treatment outcomes for MDR-TB are generally poor compared to drug sensitive disease, highlighting the need for of new drugs. For the first time in more than 50 years, two new anti-TB drugs were approved and released. Bedaquiline is a first-in-class diarylquinoline compound that showed durable culture conversion at 24 weeks in phase IIb trials. Delamanid is the first drug of the nitroimidazole class to enter clinical practice. Similarly to bedaquiline results of phase IIb studies showed increased sputum-culture conversion at 2 months and better final treatment outcomes in patients with MDR-TB. Among repurposed drugs linezolid and carbapenems may represent a valuable drug to treat cases of MDR and extensively drug-resistant TB. The recommended regimen for MDR-TB is the combination of at least four drugs to which M. tuberculosis is likely to be susceptible for the duration of 20 months. Drugs are chosen with a stepwise selection process through five groups on the basis of efficacy, safety, and cost. Clinical phase III trials on new regimen are ongoing that could prove transformative against MDR-TB, by being shorter (six months), simpler (an all-oral regimen) and safer than current standard therapy. It is fundamental that the adoption of the new drugs is done responsibly to avoid inappropriate use. Concentration of in-patient MDR-TB treatment in specialized centers could be considered in countries with low numbers of cases in order to provide appropriate clinical case management and to prevent emergence of drug resistance. PMID:27403268
Wu, Xu; Ma, Jiang; Ye, Yang; Lin, Ge
The increasing use of Chinese herbal medicines (CHMs) as complementary therapy and dietary supplement has been greatly raising the concerns about potential herb-drug interactions (HDIs). HDIs may cause the augmented or antagonized effects of prescription drugs, resulting in unexpected clinical outcomes. Therefore, it is of significance to identify or predict potential HDIs, and to delineate the underlying mechanisms. Drug transporters play key roles in transmembrane passage of a large number of drugs, affecting their absorption, distribution and elimination. Modulation of drug transporters has been recognized as one of the main causes of HDIs. In the last decade, a growing number of Chinese medicinal herbs and their derived phytochemicals have been identified to have modulatory effect toward transporter proteins, leading to pharmacokinetic HDIs when concomitantly used with conventional drugs. Some of these transporter-mediated interactions have already shown clinical significance. This review article focuses on two major transporter superfamilies, the solute carrier (SLC) and the ATP-binding cassette (ABC) transporters, to provide the recent advanced knowledge on CHMs and their inherent phytochemicals that interact with these transporters, and their induced pharmacokinetic HDIs from both preclinical and clinical aspects. In addition, the challenges and strategy for studying HDIs are also discussed.
Krupski, Antoinette; West, Imara I.; Graves, Meredith C.; Atkins, David C.; Maynard, Charles; Bumgardner, Kristin; Donovan, Dennis; Ries, Richard; Roy-Byrne, Peter
Introduction Illicit drug use is a serious public health problem associated with significant co-occurring medical disorders, mental disorders, and social problems. Yet most individuals with drug use disorders have never been treated, though they often seek medical treatment in primary care. The purpose of the present study was to examine baseline characteristics of persons presenting in primary care across a range of problem drug use severity to identify their clinical needs. Methods We examined socio-demographic characteristics, medical and psychiatric comorbidities, drug use severity, social and legal problems, and service utilization for 868 patients with drug problems recruited from primary care clinics in a safety-net medical setting. Based on Drug Abuse Screening Test (DAST-10) results, individuals were categorized as having low, intermediate, or substantial/severe drug use severity. Results Patients with substantial/severe drug use severity had serious drug use (opiates, stimulants, sedatives, intravenous drug use), high levels of homelessness (50%), psychiatric comorbidity (69%), arrests for serious crimes (24%), and frequent use of expensive emergency department and inpatient hospitals. Patients with low drug use severity were primarily users of marijuana with little reported use of other drugs, less psychiatric co-morbidity, and more stable lifestyles. Patients with intermediate drug use severity fell in-between the substantial/severe and low drug use severity subgroups on most variables. Conclusions Patients with highest drug use severity are likely to require specialized psychiatric and substance abuse care in addition to ongoing medical care that is equipped to address the consequences of severe/substantial drug use including intravenous drug use. Because of their milder symptoms, patients with low drug use severity may benefit from a collaborative care model that integrates psychiatric and substance abuse care in the primary care setting. Patients
Wolzt, Michael; Sarich, Troy S; Eriksson, Ulf G
Vitamin K antagonists including warfarin are associated with numerous interactions with other drugs and foods. In clinical practice, this complicates the task of maintaining plasma levels of warfarin within a narrow therapeutic window and so maximizing protection against thromboembolic events while minimizing the risk of complications, particularly bleeding. In contrast, ximelagatran has a low potential for pharmacokinetic drug:drug and food interactions. There is no significant metabolism of melagatran, and the main route of elimination of melagatran is renal excretion that appears to occur via glomerular filtration. Most importantly, cytochrome P450 isoenzymes that mediate many drug:drug interactions are not involved in the biotransformation of ximelagatran to melagatran. No significant pharmacokinetic interactions have been observed when oral ximelagatran is administered with a range of agents, including diclofenac, diazepam, nifedipine, digoxin, atorvastatin, or amiodarone. The low potential for drug:drug interactions with ximelagatran is also supported by an analysis of the pharmacokinetic data from clinical studies in patients with atrial fibrillation receiving long-term treatment with oral ximelagatran. Increases of mean melagatran area under the curve and maximum plasma concentration ( Cmax) of up to approximately 80% have been observed when ximelagatran is co-administered with the macrolide antibiotics erythromycin or azithromycin, and the mechanism for this interaction is currently under investigation. The bioavailability of melagatran is not altered by co-administration with food or alcohol. The melagatran-induced prolongation of activated partial thromboplastin time (APTT), an ex vivo coagulation time assay used as a measure of thrombin inhibition, is not altered by other drugs [including digoxin, atorvastatin, acetylsalicylic acid (ASA), and amiodarone], food, or alcohol. The effect of melagatran on capillary bleeding time, which is prolonged as a
Nicoteri, Jo Ann L
Food-drug interactions occur more often than thought. This manuscript describes the most common interactions the NP may encounter in primary care practice. A thorough and detailed health history and dietary recall are essential for identifying potential problems when prescribing or evaluating medication efficacy. Prevention and education are vital.
Svensson, C K
Investigations that have revealed racial differences in drug response and disposition indicate the need for adequate representation of racial minorities in clinical drug trials. There is concern, however, that there may be a disproportionate use of racial and ethnic minorities in clinical research due to the inner city location of most university hospitals. To examine this issue, we reviewed the representation of American blacks in 50 recently published clinical trials of new drugs. This survey revealed that investigators do not seem to adequately take into account racial differences as a potential source of variability. It also was found that in the majority of studies, the proportion of black subjects is less than their proportion in the general population. This underrepresentation in clinical trials suggests that insufficient data exist to accurately assess the safety and efficacy of many new drugs in American blacks.
Rao, PSS; Earla, Ravindra; Kumar, Anil
Introduction Substance abuse is a common problem among HIV-infected individuals. Importantly, addictions as well as moderate use of alcohol, smoking, or other illicit drugs have been identified as major reasons for non-adherence to antiretroviral therapy (ART) among HIV patients. The literature also suggests a decrease in the response to ART among HIV patients who use these substances, leading to failure to achieve optimal virological response and increased disease progression. Areas covered This review discusses the challenges with adherence to ART as well as observed drug interactions and known toxicities with major drugs of abuse, such as alcohol, smoking, methamphetamine, cocaine, marijuana, and opioids. The lack of adherence and drug interactions potentially lead to decreased efficacy of ART drugs and increased ART, and drugs of abuse-mediated toxicity. As CYP is the common pathway in metabolizing both ART and drugs of abuse, we discuss the possible involvement of CYP pathways in such drug interactions. Expert opinion We acknowledge that further studies focusing on common metabolic pathways involving CYP and advance research in this area would help to potentially develop novel/alternate interventions and drug dose/regimen adjustments to improve medication outcomes in HIV patients who consume drugs of abuse. PMID:25539046
Huang, Guohua; Lu, Yin; Lu, Changhong; Cai, Yu-Dong
Discovering potential indications of novel or approved drugs is a key step in drug development. Previous computational approaches could be categorized into disease-centric and drug-centric based on the starting point of the issues or small-scaled application and large-scale application according to the diversity of the datasets. Here, a classifier has been constructed to predict the indications of a drug based on the assumption that interactive/associated drugs or drugs with similar structures are more likely to target the same diseases using a large drug indication dataset. To examine the classifier, it was conducted on a dataset with 1,573 drugs retrieved from Comprehensive Medicinal Chemistry database for five times, evaluated by 5-fold cross-validation, yielding five 1st order prediction accuracies that were all approximately 51.48%. Meanwhile, the model yielded an accuracy rate of 50.00% for the 1st order prediction by independent test on a dataset with 32 other drugs in which drug repositioning has been confirmed. Interestingly, some clinically repurposed drug indications that were not included in the datasets are successfully identified by our method. These results suggest that our method may become a useful tool to associate novel molecules with new indications or alternative indications with existing drugs. PMID:25821813
Thiel, Christoph; Cordes, Henrik; Fabbri, Lorenzo; Aschmann, Hélène Eloise; Baier, Vanessa; Atkinson, Francis; Blank, Lars Mathias; Kuepfer, Lars
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
Thiel, Christoph; Cordes, Henrik; Fabbri, Lorenzo; Aschmann, Hélène Eloise; Baier, Vanessa; Smit, Ines; Atkinson, Francis; Blank, Lars Mathias; Kuepfer, Lars
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.
Kiser, Jennifer J.; Burton, James R.; Everson, Gregory T.
The emergence of direct-acting antiviral agents (DAAs) for HCV infection represents a major advance in treatment. The NS3 protease inhibitors, boceprevir and telaprevir, were the first DAAs to receive regulatory approval. When combined with PEG-IFN and ribavirin, these agents increase rates of sustained virologic response in HCV genotype 1 to ~70%. However, this treatment regimen is associated with several toxicities. In addition, both boceprevir and telaprevir are substrates for and inhibitors of the drug transporter P-glycoprotein and the cytochrome P450 enzyme 3A4 and are, therefore, prone to clinically relevant drug interactions. Several new DAAs for HCV are in late stages of clinical development and are likely to be approved in the near future. These include the protease inhibitors, simeprevir and faldaprevir, the NS5A inhibitor, daclatasvir, and the nucleotide polymerase inhibitor, sofosbuvir. Herein, we review the clinical pharmacology and drug interactions of boceprevir, telaprevir and these investigational DAAs. Although boceprevir and telaprevir are involved in many interactions, these interactions are manageable if health-care providers proactively identify and adjust treatments. Emerging DAAs seem to have a reduced potential for drug interactions, which will facilitate their use in the treatment of HCV. PMID:23817323
... HUMAN SERVICES Food and Drug Administration Food and Drug Administration Clinical Trial Requirements, Regulations, Compliance, and Good Clinical Practices; Public Workshop AGENCY: Food and Drug Administration, HHS. ACTION: Notice of public workshop. SUMMARY: The Food and Drug Administration (FDA) Los...
Gurman, Pablo; Miranda, Oscar R; Clayton, Kevin; Rosen, Yitzhak; Elman, Noel M
Miniaturization of devices to micrometer and nanometer scales, combined with the use of biocompatible and functional materials, has created new opportunities for the implementation of drug delivery systems. Advances in biomedical microdevices for controlled drug delivery platforms promise a new generation of capabilities for the treatment of acute conditions and chronic illnesses, which require high adherence to treatment, in which temporal control over the pharmacokinetic profiles is critical. In addition, clinical conditions that require a combination of drugs with specific pharmacodynamic profiles and local delivery will benefit from drug delivery microdevices. This review provides a summary of various clinical applications for state-of-the-art controlled drug delivery microdevices, including cancer, endocrine and ocular disorders, and acute conditions such as hemorrhagic shock. Regulatory considerations for clinical translation of drug delivery microdevices are also discussed. Drug delivery microdevices promise a remarkable gain in clinical outcomes and a substantial social impact. A review of articles covering the field of microdevices for drug delivery was performed between January 1, 1990, and January 1, 2014, using PubMed as a search engine.
Zhang, Yijia; Lin, Hongfei; Yang, Zhihao; Wang, Jian; Li, Yanpeng
When one drug influences the level or activity of another drug this is known as a drug-drug interaction (DDI). Knowledge of such interactions is crucial for patient safety. However, the volume and content of published biomedical literature on drug interactions is expanding rapidly, making it increasingly difficult for DDIs database curators to detect and collate DDIs information manually. In this paper, we propose a single kernel-based approach to extract DDIs from biomedical literature. This novel kernel-based approach can effectively make full use of syntactic structural information of the dependency graph. In particular, our approach can efficiently represent both single subgraph topological information and the relation of two subgraphs in the dependency graph. Experimental evaluations showed that our single kernel-based approach can achieve state-of-the-art performance on the publicly available DDI corpus without exploiting multiple kernels or additional domain resources. PMID:23133662
Gupta, Umesh Chandra; Bhatia, Sandeep; Garg, Amit; Sharma, Amit; Choudhary, Vaibhav
Research focus of pharmaceutical industry has expanded to a larger extent in last few decades putting many more new molecules, particularly targeted agents, for the clinical development. On the other hand, researchers are facing serious challenges due to high failure rates of new molecules in clinical studies. The United States Food and Drug Administration (FDA) in combination with academia and industry experts identified many factors responsible for failures of new molecules, and with a vision of taking traditional drug development model toward an innovative paradigm shift, issued regulatory guidance on conduct of exploratory investigational new drug (exploratory IND) studies, often called as phase 0 clinical trials, requiring reduced preclinical testing, which has special relevance to life-threatening diseases such as cancer. Phase 0 trials, utilizing much lower drug doses, provide an opportunity to explore the clinical behavior of new molecules very early in the drug development pathway, helping to identify the promising candidates and eliminating non-promising molecules, thus improving the efficiency of overall drug development with significant savings of resources. Being non-therapeutic in nature, these studies, however, pose certain ethical challenges requiring careful study designing and informed consent process. This article reviews the insights and perspectives for the feasibility, utility, planning, designing and conduct of phase 0 clinical trials, in addition to ethical issues and industrial perspective focused at oncology new drug development. PMID:21584177
Gupta, Umesh Chandra; Bhatia, Sandeep; Garg, Amit; Sharma, Amit; Choudhary, Vaibhav
Research focus of pharmaceutical industry has expanded to a larger extent in last few decades putting many more new molecules, particularly targeted agents, for the clinical development. On the other hand, researchers are facing serious challenges due to high failure rates of new molecules in clinical studies. The United States Food and Drug Administration (FDA) in combination with academia and industry experts identified many factors responsible for failures of new molecules, and with a vision of taking traditional drug development model toward an innovative paradigm shift, issued regulatory guidance on conduct of exploratory investigational new drug (exploratory IND) studies, often called as phase 0 clinical trials, requiring reduced preclinical testing, which has special relevance to life-threatening diseases such as cancer. Phase 0 trials, utilizing much lower drug doses, provide an opportunity to explore the clinical behavior of new molecules very early in the drug development pathway, helping to identify the promising candidates and eliminating non-promising molecules, thus improving the efficiency of overall drug development with significant savings of resources. Being non-therapeutic in nature, these studies, however, pose certain ethical challenges requiring careful study designing and informed consent process. This article reviews the insights and perspectives for the feasibility, utility, planning, designing and conduct of phase 0 clinical trials, in addition to ethical issues and industrial perspective focused at oncology new drug development.
Kheshti, Raziyeh; Aalipour, Mohammadsadegh; Namazi, Soha
Objective: Drug–drug interactions (DDIs) can cause failure in treatment and adverse events. DDIs screening software is an important tool to aid clinicians in the detection and management of DDIs. However, clinicians should be aware of the advantages and limitations of these programs. We compared the ability of five common DDI programs to detect clinically important DDIs. Methods: Lexi-Interact, Micromedex Drug Interactions, iFacts, Medscape, and Epocrates were evaluated. The programs' sensitivity, specificity, and positive and negative predictive values were determined to assess their accuracy in detecting DDIs. The accuracy of each program was identified using 360 unknown pair interactions, taken randomly from prescriptions, and forty pairs of clinically important ones. The major reference was a clinical pharmacist alongside the Stockley's Drug Interaction and databases including PubMed, Scopus, and Google Scholar. Comprehensiveness of each program was determined by the number of components in the drug interaction monograph. The aggregate score for accuracy and comprehensiveness was calculated. Findings: Scoring 250 out of possible 400 points, Lexi-Interact and Epocrates, provided the most accurate software programs. Micromedex, Medscape, and iFacts ranked third, fourth, and fifth, scoring 236, 202, and 191, respectively. In comprehensiveness test, iFacts showed the highest score, 134 out of possible 134 points, whereas Lexi-Interact rated second, with a score of 120. Scoring 370 and 330 out of possible 534 points, Lexi-Interact and Micromedex, respectively, provided the most competent, complete, and user-friendly applications. Conclusion: Lexi-Interact and Micromedex showed the best performances. An increase in sensitivity is possible by the combination of more than one programs and expert pharmacist intervention. PMID:27843962
Won, Christina S.; Oberlies, Nicholas H.; Paine, Mary F.
Food-drug interaction studies are critical to evaluate appropriate dosing, timing, and formulation of new drug candidates. These interactions often reflect prandial-associated changes in the extent and/or rate of systemic drug exposure. Physiologic and physicochemical mechanisms underlying food effects on drug disposition are well-characterized. However, biochemical mechanisms involving drug metabolizing enzymes and transport proteins remain underexplored. Several plant-derived beverages have been shown to modulate enzymes and transporters in the intestine, leading to altered pharmacokinetic (PK) and potentially negative pharmacodynamic (PD) outcomes. Commonly consumed fruit juices, teas, and alcoholic drinks contain phytochemicals that inhibit intestinal cytochrome P450 and phase II conjugation enzymes, as well as uptake and efflux transport proteins. Whereas myriad phytochemicals have been shown to inhibit these processes in vitro, translation to the clinic has been deemed insignificant or undetermined. An overlooked prerequisite for elucidating food effects on drug PK is thorough knowledge of causative bioactive ingredients. Substantial variability in bioactive ingredient composition and activity of a given dietary substance poses a challenge in conducting robust food-drug interaction studies. This confounding factor can be addressed by identifying and characterizing specific components, which could be used as marker compounds to improve clinical trial design and quantitatively predict food effects. Interpretation and integration of data from in vitro, in vivo, and in silico studies require collaborative expertise from multiple disciplines, from botany to clinical pharmacology (i.e., plant to patient). Development of more systematic methods and guidelines is needed to address the general lack of information on examining drug-dietary substance interactions prospectively. PMID:22884524
Won, Christina S; Oberlies, Nicholas H; Paine, Mary F
Food-drug interaction studies are critical to evaluate appropriate dosing, timing, and formulation of new drug candidates. These interactions often reflect prandial-associated changes in the extent and/or rate of systemic drug exposure. Physiologic and physicochemical mechanisms underlying food effects on drug disposition are well-characterized. However, biochemical mechanisms involving drug metabolizing enzymes and transport proteins remain underexplored. Several plant-derived beverages have been shown to modulate enzymes and transporters in the intestine, leading to altered pharmacokinetic (PK) and potentially negative pharmacodynamic (PD) outcomes. Commonly consumed fruit juices, teas, and alcoholic drinks contain phytochemicals that inhibit intestinal cytochrome P450 and phase II conjugation enzymes, as well as uptake and efflux transport proteins. Whereas myriad phytochemicals have been shown to inhibit these processes in vitro, translation to the clinic has been deemed insignificant or undetermined. An overlooked prerequisite for elucidating food effects on drug PK is thorough knowledge of causative bioactive ingredients. Substantial variability in bioactive ingredient composition and activity of a given dietary substance poses a challenge in conducting robust food-drug interaction studies. This confounding factor can be addressed by identifying and characterizing specific components, which could be used as marker compounds to improve clinical trial design and quantitatively predict food effects. Interpretation and integration of data from in vitro, in vivo, and in silico studies require collaborative expertise from multiple disciplines, from botany to clinical pharmacology (i.e., plant to patient). Development of more systematic methods and guidelines is needed to address the general lack of information on examining drug-dietary substance interactions prospectively.
Butkiewicz, Mariusz; Restrepo, Nicole A.; Haines, Jonathan L.; Crawford, Dana C.
With age, the number of prescribed medications increases and subsequently raises the risk for adverse drug-drug interactions. These adverse effects lower quality of life and increase health care costs. Quantifying the potential burden of adverse effects before prescribing medications can be a valuable contribution to health care. This study evaluated medication lists extracted from a subset of the Vanderbilt de-identified electronic medical record system. Reported drugs were cross-referenced with the Kyoto Encyclopedia of Genes and Genomes DRUG database to identify known drug-drug interactions. On average, a medication regimen contained 6.58 medications and 2.68 drug-drug interactions. Here, we quantify the burden of potential adverse events from drug-drug interactions through drug-drug interaction profiles and include a number of alternative medications as provided by the Anatomical Therapeutic Chemical Classification System. PMID:27570646
Lombardo, Domenico; Calandra, Pietro; Barreca, Davide; Magazù, Salvatore; Kiselev, Mikhail A.
The development of smart nanocarriers for the delivery of therapeutic drugs has experienced considerable expansion in recent decades, with the development of new medicines devoted to cancer treatment. In this respect a wide range of strategies can be developed by employing liposome nanocarriers with desired physico-chemical properties that, by exploiting a combination of a number of suitable soft interactions, can facilitate the transit through the biological barriers from the point of administration up to the site of drug action. As a result, the materials engineer has generated through the bottom up approach a variety of supramolecular nanocarriers for the encapsulation and controlled delivery of therapeutics which have revealed beneficial developments for stabilizing drug compounds, overcoming impediments to cellular and tissue uptake, and improving biodistribution of therapeutic compounds to target sites. Herein we present recent advances in liposome drug delivery by analyzing the main structural features of liposome nanocarriers which strongly influence their interaction in solution. More specifically, we will focus on the analysis of the relevant soft interactions involved in drug delivery processes which are responsible of main behaviour of soft nanocarriers in complex physiological fluids. Investigation of the interaction between liposomes at the molecular level can be considered an important platform for the modeling of the molecular recognition processes occurring between cells. Some relevant strategies to overcome the biological barriers during the drug delivery of the nanocarriers are presented which outline the main structure-properties relationships as well as their advantages (and drawbacks) in therapeutic and biomedical applications. PMID:28335253
Clancy, Colleen E.; An, Gary; Cannon, William R.; Liu, Yaling; May, Elebeoba E.; Ortoleva, Peter; Popel, Aleksander S.; Sluka, James P.; Su, Jing; Vicini, Paolo; Zhou, Xiaobo; Eckmann, David M.
A wide range of length and time scales are relevant to pharmacology, especially in drug development, drug design and drug delivery. Therefore, multi-scale computational modeling and simulation methods and paradigms that advance the linkage of phenomena occurring at these multiple scales have become increasingly important. Multi-scale approaches present in silico opportunities to advance laboratory research to bedside clinical applications in pharmaceuticals research. This is achievable through the capability of modeling to reveal phenomena occurring across multiple spatial and temporal scales, which are not otherwise readily accessible to experimentation. The resultant models, when validated, are capable of making testable predictions to guide drug design and delivery. In this review we describe the goals, methods, and opportunities of multi-scale modeling in drug design and development. We demonstrate the impact of multiple scales of modeling in this field. We indicate the common mathematical techniques employed for multi-scale modeling approaches used in pharmacology and present several examples illustrating the current state-of-the-art regarding drug development for: Excitable Systems (Heart); Cancer (Metastasis and Differentiation); Cancer (Angiogenesis and Drug Targeting); Metabolic Disorders; and Inflammation and Sepsis. We conclude with a focus on barriers to successful clinical translation of drug development, drug design and drug delivery multi-scale models.
Nabovati, Ehsan; Vakili-Arki, Hasan; Taherzadeh, Zhila; Saberi, Mohammad Reza; Abu-Hanna, Ameen; Eslami, Saeid
Background When prescribing medications, physicians should recognize clinically relevant potential drug-drug interactions (DDIs). To improve medication safety, it is important to understand prescribers' knowledge and opinions pertaining to DDIs. Objective To determine the current DDI information sources used by medical residents, their knowledge of DDIs, their opinions about performance feedback on co-prescription of interacting drugs. Setting Academic hospitals of Mashhad University of Medical Sciences (MUMS) in Iran. Methods A questionnaire containing questions regarding demographic and practice characteristics, DDI information sources, ability to recognize DDIs, and opinions about performance feedback was distributed to medical residents of 22 specialties in eight academic hospitals in Iran. We analyzed their perception pertaining to DDIs, their performance on classifying drug pairs, and we used a linear regression model to assess the association of potential determinants on their DDI knowledge. Main Outcome Measure prescribers' knowledge and opinions pertaining to DDIs. Results The overall response rate and completion rate for 315 distributed questionnaires were 90% (n = 295) and 86% (n = 281), respectively. Among DDI information sources, books, software on mobile phone or tablet, and Internet were the most commonly-used references. Residents could correctly classify only 41% (5.7/14) of the drug pairs. The regression model showed no significant association between residents' characteristics and their DDI knowledge. An overwhelming majority of the respondents (n = 268, 95.4%) wished to receive performance feedback on co-prescription of interacting drugs in their prescriptions. They mostly selected information technology-based tools (i.e. short text message and email) as their preferred method of receiving feedback. Conclusion Our findings indicate that prescribers may have poor ability to prevent clinically relevant potential DDI occurrence, and they
Garattini, Silvio; Perico, Norberto
Unfortunately, abundant examples could be given of pitfalls in the current drug development paradigm-including in the design, conduct and evaluation of phase III clinical trials. This article discusses issues of particular relevance to clinical trials in nephrology, including the inappropriate use of placebo, publication of reports that emphasize potential treatment benefits over adverse reactions, the sometimes dubious impartiality of independent guidelines, and inadequate recruitment of elderly patients. This Perspectives article aims to highlight and summarize the flaws in the current drug development process, while suggesting a way forward that equally satisfies the requirements of academia, patients and the pharmaceutical industry. We suggest improvements to the drug development process and related legislation that intend to balance public needs with commercial aims and ensure effective drug evaluation by regulatory authorities.
Kikuchi, Kiyoshi; Uchikado, Hisaaki; Morioka, Motohiro; Murai, Yoshinaka; Tanaka, Eiichiro
Stroke is an enormous public health problem with an imperative need for more effective therapies. In therapies for ischemic stroke, tissue plasminogen activators, antiplatelet agents and anticoagulants are used mainly for their antithrombotic effects. However, free radical scavengers, minocycline and growth factors have shown neuroprotective effects in the treatment of stroke, while antihypertensive drugs, lipid-lowering drugs and hypoglycemic drugs have shown beneficial effects for the prevention of stroke. In the present review, we evaluate the treatment and prevention of stroke in light of clinical studies and discuss new anti-stroke effects other than the main effects of drugs, focusing on optimal pharmacotherapy. PMID:22837724
Bakkar, Nadine; Boehringer, Ashley; Bowser, Robert
The past decade has seen a dramatic increase in the discovery of candidate biomarkers for ALS. These biomarkers typically can either differentiate ALS from control subjects or predict disease course (slow versus fast progression). At the same time, late-stage clinical trials for ALS have failed to generate improved drug treatments for ALS patients. Incorporation of biomarkers into the ALS drug development pipeline and the use of biologic and/or imaging biomarkers in early- and late-stage ALS clinical trials have been absent and only recently pursued in early-phase clinical trials. Further clinical research studies are needed to validate biomarkers for disease progression and develop biomarkers that can help determine that a drug has reached its target within the central nervous system. In this review we summarize recent progress in biomarkers across ALS model systems and patient population, and highlight continued research directions for biomarkers that stratify the patient population to enrich for patients that may best respond to a drug candidate, monitor disease progression and track drug responses in clinical trials. It is crucial that we further develop and validate ALS biomarkers and incorporate these biomarkers into the ALS drug development process. This article is part of a Special Issue entitled ALS complex pathogenesis.
Wolohan, Philippa R. N.; Clark, Robert D.
We have developed a method that combines molecular interaction fields with soft independent modeling of class analogy (SIMCA) Wold:1977 to predict pharmacokinetic drug properties. Several additional considerations to those made in traditional QSAR are required in order to develop a successful QSPR strategy that is capable of accommodating the many complex factors that contribute to key pharmacokinetic properties such as ADME (absorption, distribution, metabolism, and excretion) and toxicology. An accurate prediction of oral bioavailability, for example, requires that absorption and first-pass hepatic elimination both be taken into consideration. To accomplish this, general properties of molecules must be related to their solubility and ability to penetrate biological membranes, and specific features must be related to their particular metabolic and toxicological profiles. Here we describe a method, which is applicable to structurally diverse data sets while utilizing as much detailed structural information as possible. We address the issue of the molecular alignment of a structurally diverse set of compounds using idiotropic field orientation (IFO), a generalization of inertial field orientation Clark:1998. We have developed a second flavor of this method, which directly incorporates electrostatics into the molecular alignment. Both variations of IFO produce a characteristic orientation for each structure and the corresponding molecular fields can then be analyzed using SIMCA. Models are presented for human intestinal absorption, blood-brain barrier penetration and bioavailability to demonstrate ways in which this tool can be used early in the drug development process to identify leads likely to exhibit poor pharmacokinetic behavior in pre-clinical studies, and we have explored the influence of conformation and molecular field type on the statistical properties of the models obtained.
Roe, Amy L; Paine, Mary F; Gurley, Bill J; Brouwer, Kenneth R; Jordan, Scott; Griffiths, James C
The use of natural products (NPs), including herbal medicines and other dietary supplements, by North Americans continues to increase across all age groups. This population has access to conventional medications, with significant polypharmacy observed in older adults. Thus, the safety of the interactions between multi-ingredient NPs and drugs is a topic of paramount importance. Considerations such as history of safe use, literature data from animal toxicity and human clinical studies, and NP constituent characterization would provide guidance on whether to assess NP-drug interactions experimentally. The literature is replete with reports of various NP extracts and constituents as potent inhibitors of drug metabolizing enzymes, and transporters. However, without standard methods for NP characterization or in vitro testing, extrapolating these reports to clinically-relevant NP-drug interactions is difficult. This lack of a clear definition of risk precludes clinicians and consumers from making informed decisions about the safety of taking NPs with conventional medications. A framework is needed that describes an integrated robust approach for assessing NP-drug interactions; and, translation of the data into formulation alterations, dose adjustment, labelling, and/or post-marketing surveillance strategies. A session was held at the 41st Annual Summer Meeting of the Toxicology Forum in Colorado Springs, CO, to highlight the challenges and critical components that should be included in a framework approach.
Parveen, Abida; Parveen, Bushra; Parveen, Rabea; Ahmad, Sayeed
World Health Organization (WHO) has defined herbal medicines as finished labeled medicinal product that contain an active ingredient, aerial, or underground parts of the plant or other plant material or combinations. According to a report of WHO, about 80% of the world population is reported to rely on traditional medicine for their primary health care needs. Even in the developed countries, complementary or alternative medicine is gaining popularity. A report of a global survey on national policy on traditional medicine and regulation of herbal medicines indicated that about 50 countries including China, Japan, and Germany already have their national policy and laws on regulations of traditional medicines. Herbal drugs possess a long history of its use and better patient tolerance. These are cheaper and easily available in countries like India due to rich agro culture conditions. However, reckless utilization of resources threatens the sustainability of several plant species. Traditional medicines are governed by the Drugs and Cosmetics Act of 1940 and the Drugs and Cosmetics Rules of 1945. In 1959, the Government of India amended the Drugs and Cosmetics Act to include drugs that are derived from traditional Indian medicine. In 1993, the guidelines for the safety and efficacy of herbal medicines developed by an expert committee directed that the procedures laid down by the office of the Drug Controller General of India for allopathic drugs should be followed for all traditional and herbal products to enter into clinical trials for any therapeutic condition. However, there are certain loop holes in the clinical trials of herbal drugs as the lack of stringent bylaws and regulations. Hence, a deep insight of important challenges and major regulatory guidelines for clinical trial of herbal drugs and botanicals is discussed in the present communication. There is lack of scientific evidence to evaluate safety and efficacy of herbal drugs. The quality of the trial drug
Zhang, Rui; Adam, Terrance J.; Simon, Gyorgy; Cairelli, Michael J.; Rindflesch, Thomas; Pakhomov, Serguei; Melton, Genevieve B.
Interactions between cancer drugs and dietary supplements are clinically important and have not been extensively investigated through mining of the biomedical literature. We report on a previously introduced method now enhanced by machine learning-based filtering. Potential interactions are extracted by using relationships in the form of semantic predications. Semantic predications stored in SemMedDB, a database of structured knowledge generated from MEDLINE, were filtered and connected by two interaction pathways to explore potential drug-supplement interactions (DSIs). The lasso regression filter was trained by using SemRep output features in an expert annotated corpus and used to rank retrieved predications by predicted precision. We found not only known interactions but also inferred several unknown potential DSIs by appropriate filtering and linking of semantic predications. PMID:26306241
Reinhart, Walter H; Lubszky, Szabina; Thöny, Sandra; Schulzki, Thomas
The normal red blood cell (RBC) shape is a biconcave discocyte. An intercalation of a drug in the outer half of the membrane lipid bilayer leads to echinocytosis, an intercalation in the inner half to stomatocytosis. We have used the shape transforming capacity of RBCs as a model to analyse the membrane interaction potential of various neurotropic drugs. Chlorpromazine, clomipramine, citalopram, clonazepam, and diazepam induced a reversible stomatocytosis, phenytoin induced echinocytosis, while the anticonvulsants levetiracetam, valproic acid and phenobarbital had no effect. This diversity of RBC shape transformations suggests that the pharmacological action is not linked to the membrane interaction. We conclude that this simple RBC shape transformation assay could be a useful tool to screen for potential drug interactions with cell membranes.
Curtis, Brian R
Drug-induced immune thrombocytopenia (DIIT) is a relatively uncommon adverse reaction caused by drug-dependent antibodies (DDAbs) that react with platelet membrane glycoproteins only when the implicated drug is present. Although more than 100 drugs have been associated with causing DIIT, recent reviews of available data show that carbamazepine, eptifibatide, ibuprofen, quinidine, quinine, oxaliplatin, rifampin, sulfamethoxazole, trimethoprim, and vancomycin are probably the most frequently implicated. Patients with DIIT typically present with petechiae, bruising, and epistaxis caused by an acute, severe drop in platelet count (often to <20,000 platelets/pL). Diagnosis of DIIT is complicated by its similarity to other non-drug-induced immune thrombocytopenias, including autoimmune thrombocytopenia, posttransfusion purpura, and platelet transfusion refractoriness, and must be differentiated by temporal association of exposure to a candidate drug with an acute, severe drop in platelet count. Treatment consists of immediate withdrawal of the implicated drug. Criteria for strong evidence of DIIT include (1) exposure to candidate drug-preceded thrombocytopenia; (2) sustained normal platelet levels after discontinuing candidate drug; (3) candidate drug was only drug used before onset of thrombocytopenia or other drugs were continued or reintroduced after resolution of thrombocytopenia, and other causes for thrombocytopenia were excluded; and (4) reexposure to the candidate drug resulted in recurrent thrombocytopenia. Flow cytometry testing for DDAbs can be useful in confirmation of a clinical diagnosis, and monoclonal antibody enzyme-linked immunosorbent assay testing can be used to determine the platelet glycoprotein target(s), usually GPIIb/IIIa or GPIb/IX/V, but testing is not widely available. Several pathogenic mechanisms for DIIT have been proposed, including hapten, autoantibody, neoepitope, drug-specific, and quinine-type drug mechanisms. A recent proposal
Vilar, Santiago; Quezada, Elías; Uriarte, Eugenio; Costanzi, Stefano; Borges, Fernanda; Viña, Dolores; Hripcsak, George
The development of computational methods to discover novel drug-target interactions on a large scale is of great interest. We propose a new method for virtual screening based on protein interaction profile similarity to discover new targets for molecules, including existing drugs. We calculated Target Interaction Profile Fingerprints (TIPFs) based on ChEMBL database to evaluate drug similarity and generated new putative compound-target candidates from the non-intersecting targets in each pair of compounds. A set of drugs was further studied in monoamine oxidase B (MAO-B) and cyclooxygenase-1 (COX-1) enzyme through molecular docking and experimental assays. The drug ethoxzolamide and the natural compound piperlongumine, present in Piper longum L, showed hMAO-B activity with IC50 values of 25 and 65 μM respectively. Five candidates, including lapatinib, SB-202190, RO-316233, GW786460X and indirubin-3′-monoxime were tested against human COX-1. Compounds SB-202190 and RO-316233 showed a IC50 in hCOX-1 of 24 and 25 μM respectively (similar range as potent inhibitors such as diclofenac and indomethacin in the same experimental conditions). Lapatinib and indirubin-3′-monoxime showed moderate hCOX-1 activity (19.5% and 28% of enzyme inhibition at 25 μM respectively). Our modeling constitutes a multi-target predictor for large scale virtual screening with potential in lead discovery, repositioning and drug safety. PMID:27845365
Keeton, Adam B; Salter, E Alan; Piazza, Gary A
About a third of all human cancers harbor mutations in one of the K-, N-, or HRAS genes that encode an abnormal RAS protein locked in a constitutively activated state to drive malignant transformation and tumor growth. Despite more than three decades of intensive research aimed at the discovery of RAS-directed therapeutics, there are no FDA-approved drugs that are broadly effective against RAS-driven cancers. Although RAS proteins are often said to be "undruggable," there is mounting evidence suggesting it may be feasible to develop direct inhibitors of RAS proteins. Here, we review this evidence with a focus on compounds capable of inhibiting the interaction of RAS proteins with their effectors that transduce the signals of RAS and that drive and sustain malignant transformation and tumor growth. These reports of direct-acting RAS inhibitors provide valuable insight for further discovery and development of clinical candidates for RAS-driven cancers involving mutations in RAS genes or otherwise activated RAS proteins. Cancer Res; 77(2); 221-6. ©2017 AACR.
Inoue, O.; Shinotoh, H.; Ito, T.; Suzuki, K.; Hashimoto, K.; Yamasaki, T.
The possibility of direct estimation of in vivo Bz receptor occupancy in brain was evaluated using C-11, or H-3-flumazepil (Ro15-1788). In animal experiments, 1 ..mu..Ci of H-3-Ro15-1788 was injected at 0.5 or 20 hr after i.v. injection of various dosage of clonazepam. Then radioactivity in cerebral cortex, cerebellum and blood at 5 min. after injection of the tracer was compared. Competitive inhibition of in vivo binding was clearly observed when clonazepam was pretreated at 0.5 hr before injection of the tracer. On the other hand, brain radioactivity was increased when clonazepam was administered at 20 hr before injection of the tracer. This increase in binding of H-3-Ro15-1788 might be caused by rebound of Bz receptor function by treatment with Bz agonist, and this rebound may have an important role in physiological function. Clinical investigation concerning drug interaction with brain Bz receptor was performed in normal volunteer and patients with neurological disorders. The distribution of C-11-Ro15-1788 in the brain of patients chronically treated with clonazepam were significantly heterogeneous. However, cerebral blood flow estimated with N-13 NH3 of these patients were normal.
Masuko, Kayo; Tohma, Shigeto; Matsui, Toshihiro
Various medications are used for the treatment of rheumatoid arthritis (RA). Food-drug interactions may occur with concomitant ingestion of particular food. For example, methotrexate (MTX), the anchor drug in the therapeutic strategy against RA, is an antifolate agent. Excessive presence or absence of dietary folic acid may regulate MTX metabolism, possibly leading to unexpected adverse reactions. In this review, we focus on MTX, isoniazide and calcineurin inhibitors, and the implications of potential food-drug reactions in rheumatology, suggesting the important role of nutritional evaluations in RA patients.
Pestian, John; Spencer, Malik; Matykiewicz, Pawel; Zhang, Kejian; Vinks, Alexander A.; Glauser, Tracy
This article describes the process of developing an advanced pharmacogenetics clinical decision support at one of the United States’ leading pediatric academic medical centers. This system, called CHRISTINE, combines clinical and genetic data to identify the optimal drug therapy when treating patients with epilepsy or Attention Deficit Hyperactivity Disorder. In the discussion a description of clinical decision support systems is provided, along with an overview of neurocognitive computing and how it is applied in this setting. PMID:19898682
Pestian, John; Spencer, Malik; Matykiewicz, Pawel; Zhang, Kejian; Vinks, Alexander A; Glauser, Tracy
This article describes the process of developing an advanced pharmacogenetics clinical decision support at one of the United States' leading pediatric academic medical centers. This system, called CHRISTINE, combines clinical and genetic data to identify the optimal drug therapy when treating patients with epilepsy or Attention Deficit Hyperactivity Disorder. In the discussion a description of clinical decision support systems is provided, along with an overview of neurocognitive computing and how it is applied in this setting.
Warner, Amelia W
Alopecia areata, alopecia totalis, and alopecia universalis likely represent a constellation of related diseases with similar, yet distinct heritability markers. There is currently no known curative therapy that works universally for all patients. Pharmacogenomic research enables the pharmaceutical industry to understand variability of patient responses to drugs during clinical drug development and during post-marketing surveillance. Understanding the genetic basis for patient response/non-response can enable the development of individualized therapies for those patients with an inherited basis for altered response to drug therapy. There are multiple examples of drugs that now contain a recommendation for genetic testing before dosing in their drug labels, directing clinicians to obtain genetic information for each individual patient in order to help direct drug therapy.
The prognosis and treatment outcome for primary brain tumors have remained unchanged despite advances in anticancer drug discovery and development. In clinical trials, the majority of promising experimental agents for brain tumors have had limited impact on survival or time to recurrence. These disappointing results are partially explained by the inadequacy of effective drug delivery to the CNS. The impediments posed by the various specialized physiological barriers and active efflux mechanisms lead to drug failure because of inability to reach the desired target at a sufficient concentration. This perspective reviews the leading strategies that aim to improve drug delivery to brain tumors and their likelihood to change clinical practice. The English literature was searched for defined search items. Strategies that use systemic delivery and those that use local delivery are critically reviewed. In addition, challenges posed for drug delivery by combined treatment with anti-angiogenic therapy are outlined. To impact clinical practice and to achieve more than just a limited local control, new drugs and delivery systems must adhere to basic clinical expectations. These include, in addition to an antitumor effect, a verified favorable adverse effects profile, easy introduction into clinical practice, feasibility of repeated or continuous administration, and compatibility of the drug or delivery system with any tumor size and brain location. PMID:23502426
Murtaza, Ghulam; Khan, Muhammad Yasir Ghani; Azhar, Saira; Khan, Shujaat Ali; Khan, Tahir M
Drug-drug interactions (DDIs) may result in the alteration of therapeutic response. Sometimes they may increase the untoward effects of many drugs. Hospitalized cardiac patients need more attention regarding drug-drug interactions due to complexity of their disease and therapeutic regimen. This research was performed to find out types, prevalence and association between various predictors of potential drug-drug interactions (pDDIs) in the Department of Cardiology and to report common interactions. This study was performed in the hospitalized cardiac patients at Ayub Teaching Hospital, Abbottabad, Pakistan. Patient charts of 2342 patients were assessed for pDDIs using Micromedex® Drug Information. Logistic regression was applied to find predictors of pDDIs. The main outcome measure in the study was the association of the potential drug-drug interactions with various factors such as age, gender, polypharmacy, and hospital stay of the patients. We identified 53 interacting-combinations that were present in total 5109 pDDIs with median number of 02 pDDIs per patient. Overall, 91.6% patients had at least one pDDI; 86.3% were having at least one major pDDI, and 84.5% patients had at least one moderate pDDI. Among 5109 identified pDDIs, most were of moderate (55%) or major severity (45%); established (24.2%), theoretical (18.8%) or probable (57%) type of scientific evidence. Top 10 common pDDIs included 3 major and 7 moderate interactions. Results obtained by multivariate logistic regression revealed a significant association of the occurrence of pDDIs in patient with age of 60 years or more (p < 0.001), hospital stay of 7 days or longer (p < 0.001) and taking 7 or more drugs (p < 0.001). We found a high prevalence for pDDIs in the Department of Cardiology, most of which were of moderate severity. Older patients, patients with longer hospital stay and with elevated number of prescribed drugs were at higher risk of pDDIs.
Johnson, Reed M.; Dahlgren, Lizette; Siegfried, Blair D.; Ellis, Marion D.
Background Chemical analysis shows that honey bees (Apis mellifera) and hive products contain many pesticides derived from various sources. The most abundant pesticides are acaricides applied by beekeepers to control Varroa destructor. Beekeepers also apply antimicrobial drugs to control bacterial and microsporidial diseases. Fungicides may enter the hive when applied to nearby flowering crops. Acaricides, antimicrobial drugs and fungicides are not highly toxic to bees alone, but in combination there is potential for heightened toxicity due to interactive effects. Methodology/Principal Findings Laboratory bioassays based on mortality rates in adult worker bees demonstrated interactive effects among acaricides, as well as between acaricides and antimicrobial drugs and between acaricides and fungicides. Toxicity of the acaricide tau-fluvalinate increased in combination with other acaricides and most other compounds tested (15 of 17) while amitraz toxicity was mostly unchanged (1 of 15). The sterol biosynthesis inhibiting (SBI) fungicide prochloraz elevated the toxicity of the acaricides tau-fluvalinate, coumaphos and fenpyroximate, likely through inhibition of detoxicative cytochrome P450 monooxygenase activity. Four other SBI fungicides increased the toxicity of tau-fluvalinate in a dose-dependent manner, although possible evidence of P450 induction was observed at the lowest fungicide doses. Non-transitive interactions between some acaricides were observed. Sublethal amitraz pre-treatment increased the toxicity of the three P450-detoxified acaricides, but amitraz toxicity was not changed by sublethal treatment with the same three acaricides. A two-fold change in the toxicity of tau-fluvalinate was observed between years, suggesting a possible change in the genetic composition of the bees tested. Conclusions/Significance Interactions with acaricides in honey bees are similar to drug interactions in other animals in that P450-mediated detoxication appears to play an
Sawant, Prashant D; Luu, Dewitt; Ye, Rose; Buchta, Richard
We demonstrate drug release properties from hydroethanolic formulations as a function of the drug's lipophilicity (logP), solvent lipophilicity and drug-polymer interactions, for the first time. A hydrophilic polymer, hydroxypropyl cellulose (HPC), provides the non-Fickian slower release of the lipophilic drug, lidocaine (logP=2.6) and the burst (Fickian) release of hydrophilic drug, lidocaine hydrochloride (logP
Parasrampuria, Dolly A.; Mendell, Jeanne; Shi, Minggao; Matsushima, Nobuko; Zahir, Hamim
Aims Edoxaban, a novel factor Xa inhibitor, is a substrate of cytochrome P450 3 A4 (CYP3A4) and the efflux transporter P‐glycoprotein (P‐gp). Three edoxaban drug–drug interaction studies examined the effects of P‐gp inhibitors with varying degrees of CYP3A4 inhibition. Methods In each study, healthy subjects received a single oral dose of 60 mg edoxaban with or without an oral dual P‐gp/CYP3A4 inhibitor as follows: ketoconazole 400 mg once daily for 7 days, edoxaban on day 4; erythromycin 500 mg four times daily for 8 days, edoxaban on day 7; or single dose of cyclosporine 500 mg with edoxaban. Serial plasma samples were obtained for pharmacokinetics and pharmacodynamics. Safety was assessed throughout the study. Results Coadministration of ketoconazole, erythromycin, or cyclosporine increased edoxaban total exposure by 87%, 85%, and 73%, respectively, and the peak concentration by 89%, 68%, and 74%, respectively, compared with edoxaban alone. The half‐life did not change appreciably. Exposure of M4, the major active edoxaban metabolite, was consistent when edoxaban was administered alone or with ketoconazole and erythromycin. With cyclosporine, M4 total exposure increased by 6.9‐fold and peak exposure by 8.7‐fold, suggesting an additional interaction. Pharmacodynamic effects were reflective of increased edoxaban exposure. No clinically significant adverse events were observed. Conclusions Administration of dual inhibitors of P‐gp and CYP3A4 increased edoxaban exposure by less than two‐fold. This effect appears to be primarily due to inhibition of P‐gp. The impact of CYP3A4 inhibition appears to be less pronounced, and its contribution to total clearance appears limited in healthy subjects. PMID:27530188
Parthasarathi, Laavanya; Casey, Fergal; Stein, Amelie; Aloy, Patrick; Shields, Denis C
Most biological functions are regulated through complex networks of transient protein interactions, and, thus, finding effective ways to modulate them would represent an important step towards defining the next generation of drugs. In this study, we set out to determine if existing approved drugs may represent a good source of compounds from which initial lead inhibitors of protein-protein interactions mediated by short peptide regions may be drawn. Peptide structures were defined in terms of pharmacophores and searched against U.S. Food and Drug Administration (FDA)-approved drugs to identify similar compounds. The top ranking matches (using a score that corrects root-mean-square deviation (rmsd) for the number of matched pharmacophores and for the number of drug rotatable bonds) included a number of nuclear receptor ligands that matched allosterically to the corepressor binding site of peroxisome proliferator-activated receptor alpha (PPARalpha). The top ranking drug matches were docked to the peptide-binding site using AUTODOCK. The majority of the top-ranking matches showed a negative estimated free energy change upon binding that is comparable to, or greater than, that of the original peptide. We conclude that the usage of certain approved drugs may represent a useful strategy in inhibiting specific protein-protein interactions. Such a strategy may benefit from the increased likelihood that developed compounds might have favorable bioactivity and safety profiles in clinical use.
Issa, Naiem T; Byers, Stephen W; Dakshanamurthy, Sivanesan
The process of discovering a pharmacological compound that elicits a desired clinical effect with minimal side effects is a challenge. Prior to the advent of high-performance computing and large-scale screening technologies, drug discovery was largely a serendipitous endeavor, as in the case of thalidomide for erythema nodosum leprosum or cancer drugs in general derived from flora located in far-reaching geographic locations. More recently, de novo drug discovery has become a more rationalized process where drug-target-effect hypotheses are formulated on the basis of already known compounds/protein targets and their structures. Although this approach is hypothesis-driven, the actual success has been very low, contributing to the soaring costs of research and development as well as the diminished pharmaceutical pipeline in the United States. In this review, we discuss the evolution in computational pharmacology as the next generation of successful drug discovery and implementation in the clinic where high-performance computing (HPC) is used to generate and validate drug-target-effect hypotheses completely in silico. The use of HPC would decrease development time and errors while increasing productivity prior to in vitro, animal and human testing. We highlight approaches in chemoinformatics, bioinformatics as well as network biopharmacology to illustrate potential avenues from which to design clinically efficacious drugs. We further discuss the implications of combining these approaches into an integrative methodology for high-accuracy computational predictions within the context of drug repositioning for the efficient streamlining of currently approved drugs back into clinical trials for possible new indications.
A golden age of antiepileptic drug development has yielded over a dozen useful new compounds, but the nature of clinical trials has made translation to practical use in the clinic difficult. Most clinical trials are designed for regulatory purposes and fail to answer critical clinical questions. These questions include: which drug is best as initial therapy, which drugs work as monotherapy, what are good drug combinations, what is the best starting dose and titration schedule, what is a reasonable target dose, what is the shape of the dose-response curve and does it vary significantly between patients, what is the true incidence of side effects, and what is the long-term efficacy of the drug? Most of these questions could be answered by changing trial designs, but many changes would entail additional time and money. There are encouraging signs that trials with procedures more directly applicable to the clinic are becoming common. These include direct comparative trials, longer trials with emphasis on seizure freedom, and trials with more flexible dosing schedules. In the past, funding of longer and more naturalistic trials has fallen to government agencies, but commercial funding has been obtained for several recent studies. Better quality control, innovative endpoints, structured searching for side effects, and standardisation of data collection are also promising topics for development.
Vrolijk, Misha F; Opperhuizen, Antoon; Jansen, Eugène H J M; Bast, Aalt; Haenen, Guido R M M
Many compounds display anticholinergic effects which might give rise to cognitive impairment and even delirium. These side effects are caused by their ability to bind to muscarinic receptors in our brain. Especially with combination of compounds, these serious effects are seen. This phenomenon, known as anticholinergic accumulation, is especially seen in the elderly. A classification of drugs for anticholinergic side effects has been made based on clinical observations, the ACB score. Here, we aimed to substantiate this classification by comparing the affinity of numerous drugs for the muscarinic receptors to the ACB score. Additionally, a number of supplements were screened. The affinity of the compounds was determined by their ability to displace the radioligand [(3)H]pirenzepine of the muscarinic receptor induced by these compounds. Our results show that the affinity of a compound for the muscarinic receptors correlated with its ACB score. Also food supplements appeared to bind to these muscarinic receptors. Moreover, several drug-drug, supplement-supplement and supplement-drug combinations had an affinity that is higher than the affinity of single compounds. This explains the phenomenon of anticholinergic accumulation. In conclusion, care should be taken to drug-drug and supplement-drug combinations with respect to anticholinergic accumulation.
Archer, Melissa; Proulx, Joshua; Shane-McWhorter, Laura; Bray, Bruce E.; Zeng-Treitler, Qing
While potential medication-to-medication interaction alerting engines exist in many clinical applications, few systems exist to automatically alert on potential medication to herbal supplement interactions. We have developed a preliminary knowledge base and rules alerting engine that detects 259 potential interactions between 9 supplements, 62 cardiac medications, and 19 drug classes. The rules engine takes into consideration 12 patient risk factors and 30 interaction warning signs to help determine which of three different alert levels to categorize each potential interaction. A formative evaluation was conducted with two clinicians to set initial thresholds for each alert level. Additional work is planned add more supplement interactions, risk factors, and warning signs as well as to continue to set and adjust the inputs and thresholds for each potential interaction. PMID:25954326
Cai, X J; Woods, A; Mesquida, P; Jones, S A
There is continued debate as to how nanomaterials enhance the passive diffusion of drugs through the skin. This study examined if drug-nanoparticle surface interactions, which occurred during topical application, had the capability to enhance percutaneous penetration. Atomic force microscopy force adhesion measurements were used to demonstrate that a model drug, tetracaine, strongly adsorbed to the surface of a negatively charged carboxyl-modified polystyrene nanoparticle (NanoPSCOOH) through both its methyl and amine functionalities (up to a 6- and 16-fold greater adhesion force respectively compared with the CH3-CH3 control). These drug-particle adhesion forces were significantly reduced (p < 0.05) to values that were lower than the CH3-CH3 control measurements when tetracaine interacted with a silica nanoparticle (NanoSiO2). This reduction in adhesion was attributed to the lower surface charge of the NanoSiO2 (ca. -23 mV) compared to the NanoPSCOOH (ca. -40 mV), which diminished the electrostatic interactions between positive amine of tetracaine and the negative particle. Mixing NanoPSCOOH with tetracaine on the skin retarded percutaneous drug penetration compared to the control (tetracaine saturated solution without nanoparticles), but the NanoSiO2, which still adsorbed the tetracaine, produced a 3.6-fold enhancement in percutaneous penetration compared to the same control. These data demonstrated the capability of moderate nanoparticle surface interactions that occurred within the application vehicle to promote drug percutaneous penetration.
Wheate, Nial J; Walker, Shonagh; Craig, Gemma E; Oun, Rabbab
Since its approval in 1979 cisplatin has become an important component in chemotherapy regimes for the treatment of ovarian, testicular, lung and bladder cancers, as well as lymphomas, myelomas and melanoma. Unfortunately its continued use is greatly limited by severe dose limiting side effects and intrinsic or acquired drug resistance. Over the last 30 years, 23 other platinum-based drugs have entered clinical trials with only two (carboplatin and oxaliplatin) of these gaining international marketing approval, and another three (nedaplatin, lobaplatin and heptaplatin) gaining approval in individual nations. During this time there have been more failures than successes with the development of 14 drugs being halted during clinical trials. Currently there are four drugs in the various phases of clinical trial (satraplatin, picoplatin, Lipoplatin and ProLindac). No new small molecule platinum drug has entered clinical trials since 1999 which is representative of a shift in focus away from drug design and towards drug delivery in the last decade. In this perspective article we update the status of platinum anticancer drugs currently approved for use, those undergoing clinical trials and those discontinued during clinical trials, and discuss the results in the context of where we believe the field will develop over the next decade.
Han, Lu; Li, Kang; Jin, Chaozhi; Wang, Jian; Li, Qingjun; Zhang, Qiling; Cheng, Qiyue; Yang, Jing; Bo, Xiaochen; Wang, Shengqi
As a predominant cause of human hand, foot, and mouth disease, enterovirus 71 (EV71) infection may lead to serious diseases and result in severe consequences that threaten public health and cause widespread panic. Although the systematic identification of physical interactions between viral proteins and host proteins provides initial information for the recognition of the cellular mechanism involved in viral infection and the development of new therapies, EV71-host protein interactions have not been explored. Here, we identified interactions between EV71 proteins and host cellular proteins and confirmed the functional relationships of EV71-interacting proteins (EIPs) with virus proliferation and infection by integrating a human protein interaction network and by functional annotation. We found that most EIPs had known interactions with other viruses. We also predicted ATP6V0C as a broad-spectrum essential host factor and validated its essentiality for EV71 infection in vitro. EIPs and their interacting proteins were more likely to be targets of anti-inflammatory and neurological drugs, indicating their potential to serve as host-oriented antiviral targets. Thus, we used a connectivity map to find drugs that inhibited EIP expression. We predicted tanespimycin as a candidate and demonstrated its antiviral efficiency in vitro. These findings provide the first systematic identification of EV71-host protein interactions, an analysis of EIP protein characteristics and a demonstration of their value in developing host-oriented antiviral therapies. PMID:28220872
Han, Lu; Li, Kang; Jin, Chaozhi; Wang, Jian; Li, Qingjun; Zhang, Qiling; Cheng, Qiyue; Yang, Jing; Bo, Xiaochen; Wang, Shengqi
As a predominant cause of human hand, foot, and mouth disease, enterovirus 71 (EV71) infection may lead to serious diseases and result in severe consequences that threaten public health and cause widespread panic. Although the systematic identification of physical interactions between viral proteins and host proteins provides initial information for the recognition of the cellular mechanism involved in viral infection and the development of new therapies, EV71-host protein interactions have not been explored. Here, we identified interactions between EV71 proteins and host cellular proteins and confirmed the functional relationships of EV71-interacting proteins (EIPs) with virus proliferation and infection by integrating a human protein interaction network and by functional annotation. We found that most EIPs had known interactions with other viruses. We also predicted ATP6V0C as a broad-spectrum essential host factor and validated its essentiality for EV71 infection in vitro. EIPs and their interacting proteins were more likely to be targets of anti-inflammatory and neurological drugs, indicating their potential to serve as host-oriented antiviral targets. Thus, we used a connectivity map to find drugs that inhibited EIP expression. We predicted tanespimycin as a candidate and demonstrated its antiviral efficiency in vitro. These findings provide the first systematic identification of EV71-host protein interactions, an analysis of EIP protein characteristics and a demonstration of their value in developing host-oriented antiviral therapies.
Weiss, Johanna; Gajek, Thomas; Köhler, Bruno Christian; Haefeli, Walter Emil
Venetoclax (ABT-199) represents a specific B-cell lymphoma 2 (Bcl-2) inhibitor that is currently under development for the treatment of lymphoid malignancies. So far, there is no published information on its interaction potential with important drug metabolizing enzymes and drug transporters, or its efficacy in multidrug resistant (MDR) cells. We therefore scrutinized its drug-drug interaction potential in vitro. Inhibition of cytochrome P450 enzymes (CYPs) was quantified by commercial kits. Inhibition of drug transporters (P-glycoprotein (P-gp, ABCB1), breast cancer resistance protein (BCRP), and organic anion transporting polypeptides (OATPs)) was evaluated by the use of fluorescent probe substrates. Induction of drug transporters and drug metabolizing enzymes was quantified by real-time RT-PCR. The efficacy of venetoclax in MDR cells lines was evaluated with proliferation assays. Venetoclax moderately inhibited P-gp, BCRP, OATP1B1, OATP1B3, CYP3A4, and CYP2C19, whereas CYP2B6 activity was increased. Venetoclax induced the mRNA expression of CYP1A1, CYP1A2, UGT1A3, and UGT1A9. In contrast, expression of ABCB1 was suppressed, which might revert tumor resistance towards antineoplastic P-gp substrates. P-gp over-expression led to reduced antiproliferative effects of venetoclax. Effective concentrations for inhibition and induction lay in the range of maximum plasma concentrations of venetoclax, indicating that it might act as a perpetrator drug in pharmacokinetic drug-drug interactions.
Yu, Hongbin; Balani, Suresh K; Chen, Weichao; Cui, Donghui; He, Ling; Humphreys, W Griffith; Mao, Jialin; Lai, W George; Lee, Anthony J; Lim, Heng-Keang; MacLauchlin, Christopher; Prakash, Chandra; Surapaneni, Sekhar; Tse, Susanna; Upthagrove, Alana; Walsky, Robert L; Wen, Bo; Zeng, Zhaopie
Recent European Medicines Agency (final) and US Food and Drug Administration (draft) drug interaction guidances proposed that human circulating metabolites should be investigated in vitro for their drug-drug interaction (DDI) potential if present at ≥ 25% of the parent area under the time-concentration curve (AUC) (US Food and Drug Administration) or ≥ 25% of the parent and ≥ 10% of the total drug-related AUC (European Medicines Agency). To examine the application of these regulatory recommendations, a group of scientists, representing 18 pharmaceutical companies of the Drug Metabolism Leadership Group of the Innovation and Quality Consortium, conducted a scholarship to assess the risk of contributions by metabolites to cytochrome P450 (P450) inhibition-based DDIs. The group assessed the risk of having a metabolite as the sole contributor to DDI based on literature data and analysis of the 137 most frequently prescribed drugs, defined structural alerts associated with P450 inhibition/inactivation by metabolites, and analyzed current approaches to trigger in vitro DDI studies for metabolites. The group concluded that the risk of P450 inhibition caused by a metabolite alone is low. Only metabolites from 5 of 137 drugs were likely the sole contributor to the in vivo P450 inhibition-based DDIs. Two recommendations were provided when assessing the need to conduct in vitro P450 inhibition studies for metabolites: 1) consider structural alerts that suggest P450 inhibition potential, and 2) use multiple approaches (e.g., a metabolite cut-off value of 100% of the parent AUC and the R(met) strategy) to predict P450 inhibition-based DDIs caused by metabolites in the clinic.
Background: Vinpocetine, a semi-synthetic derivative of vincamine, is a popular dietary supplement used for the treatment of several central nervous system related disorders. Despite its wide use, no pharmacokinetic drug interaction studies are reported in literature. Due to increasing use of dietar...
Williams, David; Feely, John
The HMG-CoA reductase inhibitors (statins) are effective in both the primary and secondary prevention of ischaemic heart disease. As a group, these drugs are well tolerated apart from two uncommon but potentially serious adverse effects: elevation of liver enzymes and skeletal muscle abnormalities, which range from benign myalgias to life-threatening rhabdomyolysis. Adverse effects with statins are frequently associated with drug interactions because of their long-term use in older patients who are likely to be exposed to polypharmacy. The recent withdrawal of cerivastatin as a result of deaths from rhabdomyolysis illustrates the clinical importance of such interactions. Drug interactions involving the statins may have either a pharmacodynamic or pharmacokinetic basis, or both. As these drugs are highly extracted by the liver, displacement interactions are of limited importance. The cytochrome P450 (CYP) enzyme system plays an important part in the metabolism of the statins, leading to clinically relevant interactions with other agents, particularly cyclosporin, erythromycin, itraconazole, ketoconazole and HIV protease inhibitors, that are also metabolised by this enzyme system. An additional complicating feature is that individual statins are metabolised to differing degrees, in some cases producing active metabolites. The CYP3A family metabolises lovastatin, simvastatin, atorvastatin and cerivastatin, whereas CYP2C9 metabolises fluvastatin. Cerivastatin is also metabolised by CYP2C8. Pravastatin is not significantly metabolised by the CYP system. In addition, the statins are substrates for P-glycoprotein, a drug transporter present in the small intestine that may influence their oral bioavailability. In clinical practice, the risk of a serious interaction causing myopathy is enhanced when statin metabolism is markedly inhibited. Thus, rhabdomyolysis has occurred following the coadministration of cyclosporin, a potent CYP3A4 and P-glycoprotein inhibitor, and
Horowitz, R S; Dart, R C; Gomez, H F
The macrolide class of antibiotics, including erythromycin and troleandomycin, is associated with clinically significant adverse drug interactions. This results from macrolide inhibition of cytochrome P-450 metabolism of numerous xenobiotics, resulting in elevated serum drug levels and clinical intoxication. Animal studies, however, suggest that clarithromycin, the newest approved macrolide antibiotic, has has less potential for adverse drug reactions. We describe a patient who, on her fifth day of clarithromycin therapy, developed clinical ergotism (i.e., hypertension, lingual ischemia, and peripheral cyanosis) several hours after administration of her usual 2-mg dose of ergotamine tartrate. To our knowledge, this is the first report of clinical ergotism precipitated by clarithromycin-ergotamine interaction and suggests that, like other macrolide antibiotics, ergot preparations should be avoided in patients who are taking clarithromycin.
Dupont, Alain G; Van Wilder, Philippe B
AIM We analysed the Belgian reimbursement decisions of orphan drugs as compared with those of innovative drugs for more common but equally severe diseases, with special emphasis on the quality of clinical evidence. METHODS Using the National Health Insurance Agency administrative database, we evaluated all submitted orphan drug files between 2002 and 2007. A quality analysis of the clinical evidence in the orphan reimbursement files was performed. The evaluation reports of the French ‘Haute Autorité de Santé’, including the five-point scale parameter ‘Service Médical Rendu (SMR), were examined to compare disease severity. Chi-squared tests (at P < 0.05 significance level) were used to compare the outcome of the reimbursement decisions between orphan and non-orphan innovative medicines. RESULTS Twenty-five files of orphan drugs and 117 files of non-orphan drugs were evaluated. Twenty-two of 25 (88%) submissions of orphan drugs were granted reimbursement as opposed to 74 of the 117 (63%) non-orphan innovative medicines (P = 0.02). Only 52% of the 25 orphan drug files included a randomized controlled trial as opposed to 84% in a random control sample of 25 non-orphan innovative submissions (P < 0.01). The duration of drug exposure was in most cases far too short in relation to the natural history of the disease. CONCLUSIONS Orphan drug designation predicts reimbursement despite poor quality of clinical evidence. The evidence gap at market authorization should be reduced by post-marketing programmes, in which the centralized regulatory and the local reimbursement authorities collaborate in an efficient way across the European Union member states. PMID:21395641
Qato, Dima M.; Manzoor, Beenish S.; Lee, Todd
Objectives The older adult population in the United States (U.S.) uses multiple medications and more than half of older adults drink alcohol regularly. In addition, older adults are more likely to experience adverse effects of medications and alcohol consumption may put them at higher risk. Our primary objective is to characterize the extent and nature of drug-alcohol interactions among older adults in the U.S. Design, Setting, Participants, Measurements We used a nationally-representative population-based sample of community-dwelling older adults in the U.S. Regular drinkers were defined as respondents that consumed alcohol at least weekly. Medication use was defined as the use of a prescription or non-prescription medication or dietary supplement at least daily or weekly. Micromedex was used to determine drug interactions with alcohol and their corresponding severity. Results Among the 2,975 older adults in the sample, more than 41% (N=1106) consume alcohol regularly and more than 20% (N=567) are at-risk for a drug-alcohol interaction because they are regular drinkers and concurrently using alcohol interacting medications. More than 90% of these interactions were of moderate or major severity. Antidepressants and analgesics were the most commonly used alcohol-interacting medications among regular drinkers. Older adult men with multiple chronic conditions had the highest prevalence of potential drug-alcohol interactions. Conclusion The potential for drug-alcohol interactions among the older adult population in the U.S. may have important clinical implications. Efforts to better understand and prevent the use of alcohol-interacting medications among regular drinkers, particularly heavy drinkers, are warranted in this population. PMID:26503899
Pinto, Navin; Dolan, M. Eileen
In the field of pharmacogenetics, we currently have a few markers to guide physicians as to the best course of therapy for patients. For the most part, these genetic variants are within a drug metabolizing enzyme that has a large effect on the degree or rate at which a drug is converted to its metabolites. For many drugs, response and toxicity are multi-genic traits and understanding relationships between a patient's genetic variation in drug metabolizing enzymes and the efficacy and/or toxicity of a medication offers the potential to optimize therapies. This review will focus on variants in drug metabolizing enzymes with predictable and relatively large impacts on drug efficacy and/or toxicity; some of these drug/gene variant pairs have impacted drug labels by the United States Food and Drug Administration. The challenges in identifying genetic markers and implementing clinical changes based on known markers will be discussed. In addition, the impact of next generation sequencing in identifying rare variants will be addressed. PMID:21453273
Bachurin, Sergey O; Bovina, Elena V; Ustyugov, Aleksey A
Alzheimer's disease (AD) is characterized by a chronic and progressive neurodegenerative process resulting from the intracellular and extracellular accumulation of fibrillary proteins: beta-amyloid and hyperphosphorylated Tau. Overaccumulation of these aggregates leads to synaptic dysfunction and subsequent neuronal loss. The precise molecular mechanisms of AD are still not fully understood but it is clear that AD is a multifactorial disorder and that advanced age is the main risk factor. Over the last decade, more than 50 drug candidates have successfully passed phase II clinical trials, but none has passed phase III. Here, we summarize data on current "anti-Alzheimer's" agents currently in clinical trials based on findings available in the Thomson Reuters «Integrity» database, on the public website www.clinicaltrials.gov, and on database of the website Alzforum.org. As a result, it was possible to outline some major trends in AD drug discovery: (i) the development of compounds acting on the main stages of the pathogenesis of the disease (the so-called "disease-modifying agents") - these drugs could potentially slow the development of structural and functional abnormalities in the central nervous system providing sustainable improvements of cognitive functions, which persist even after drug withdrawal; (ii) focused design of multitargeted drugs acting on multiple molecular targets involved in the pathogenesis of the disease; (3) finally, the repositioning of old drugs for new (anti-Alzheimer's) application offers a very attractive approach to facilitate the completion of clinical trials.
Zhang, Lei; Reynolds, Kellie S.; Zhao, Ping; Huang, Shiew-Mei
Pharmacokinetic drug interactions can lead to serious adverse events or decreased drug efficacy. The evaluation of a new molecular entity's (NME's) drug-drug interaction potential is an integral part of risk assessment during drug development and regulatory review. Alteration of activities of enzymes or transporters involved in the absorption, distribution, metabolism, or excretion of a new molecular entity by concomitant drugs may alter drug exposure, which can impact response (safety or efficacy). The recent Food and Drug Administration (FDA) draft drug interaction guidance ( (http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm072101.pdf)) highlights the methodologies and criteria that may be used to guide drug interaction evaluation by industry and regulatory agencies and to construct informative labeling for health practitioner and patients. In addition, the Food and Drug Administration established a 'Drug Development and Drug Interactions' website to provide up-to-date information regarding evaluation of drug interactions ( (http://www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResources/DrugInteractionsLabeling/ucm080499.htm)). This review summarizes key elements in the FDA drug interaction guidance and new scientific developments that can guide the evaluation of drug-drug interactions during the drug development process.
Zhang, Lei; Reynolds, Kellie S; Zhao, Ping; Huang, Shiew-Mei
Pharmacokinetic drug interactions can lead to serious adverse events or decreased drug efficacy. The evaluation of a new molecular entity's (NME's) drug-drug interaction potential is an integral part of risk assessment during drug development and regulatory review. Alteration of activities of enzymes or transporters involved in the absorption, distribution, metabolism, or excretion of a new molecular entity by concomitant drugs may alter drug exposure, which can impact response (safety or efficacy). The recent Food and Drug Administration (FDA) draft drug interaction guidance (http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm072101.pdf) highlights the methodologies and criteria that may be used to guide drug interaction evaluation by industry and regulatory agencies and to construct informative labeling for health practitioner and patients. In addition, the Food and Drug Administration established a "Drug Development and Drug Interactions" website to provide up-to-date information regarding evaluation of drug interactions (http://www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResources/DrugInteractionsLabeling/ucm080499.htm). This review summarizes key elements in the FDA drug interaction guidance and new scientific developments that can guide the evaluation of drug-drug interactions during the drug development process.
Peters, Lee; Kapusnik-Uner, Joan E.; Bodenreider, Olivier
Objectives: To develop normalization methods for managing the variation in clinical drug names. Methods: Manual examination of drug names from RxNorm and local variants collected from formularies led to the identification of three types of drug-specific normalization rules: expansion of abbreviations (e.g., tab to tablet);reformatting of specific elements (e.g., space between number and unit); and removal of salt variants (e.g., succinate from metoprolol succinate). Results: After drug-specific normalization, recall of 3397 previously non-matching names from formularies reaches 45% overall (70% of some subsets), compared to 10–20% after generic normalization. Ambiguity has not increased significantly in the RxNorm dataset. Conclusions: A limited number of drug-specific normalization operations provide significant improvement over general language normalization. PMID:21347056
Allen, Theresa M; Cullis, Pieter R
The first closed bilayer phospholipid systems, called liposomes, were described in 1965 and soon were proposed as drug delivery systems. The pioneering work of countless liposome researchers over almost 5 decades led to the development of important technical advances such as remote drug loading, extrusion for homogeneous size, long-circulating (PEGylated) liposomes, triggered release liposomes, liposomes containing nucleic acid polymers, ligand-targeted liposomes and liposomes containing combinations of drugs. These advances have led to numerous clinical trials in such diverse areas as the delivery of anti-cancer, anti-fungal and antibiotic drugs, the delivery of gene medicines, and the delivery of anesthetics and anti-inflammatory drugs. A number of liposomes (lipidic nanoparticles) are on the market, and many more are in the pipeline. Lipidic nanoparticles are the first nanomedicine delivery system to make the transition from concept to clinical application, and they are now an established technology platform with considerable clinical acceptance. We can look forward to many more clinical products in the future.
Sokolov, Victor V.; Chissov, Valery I.; Filonenko, E. V.; Yakubovskaya, Raisa I.; Sukhin, Garry M.; Galpern, Maria G.; Vorozhtsov, Georgy N.; Gulin, Alexander V.; Zhitkova, Margarita B.; Zharkova, Natalia N.; Kozlov, Dmitrij N.; Smirnov, V. V.
After experimental investigation clinical trials of photodynamic therapy (PDT) with the new photosensitizer Photosens -- (AL-sulphonated phthalocyanine) -- have been started. Four patients (with basal cell carcinoma, sarcoma Kaposi and early stage lung cancer) were treated by PDT. After an intravenous injection of drug in dose 2.0 mg/kg b.w. tumors were exposed to frequency-doubled radiation of Nd:yttrium aluminate laser (670 nm) with power densities from 80 to 200 mW/sq cm and total energies up to 2144 J. Immunological and clinical observations of patients are performed. First results indicate the high efficacy of the new drug as a tumor photosensitizer.
Xiao, Xuan; Min, Jian-Liang; Wang, Pu; Chou, Kuo-Chen
Involved with many diseases such as cancer, diabetes, neurodegenerative, inflammatory and respiratory disorders, GPCRs (G-protein-coupled receptors) are the most frequent targets for drug development: over 50% of all prescription drugs currently on the market are actually acting by targeting GPCRs directly or indirectly. Found in every living thing and nearly all cells, ion channels play crucial roles for many vital functions in life, such as heartbeat, sensory transduction, and central nervous system response. Their dysfunction may have significant impact to human health, and hence ion channels are deemed as "the next GPCRs". To develop GPCR-targeting or ion-channel-targeting drugs, the first important step is to identify the interactions between potential drug compounds with the two kinds of protein receptors in the cellular networking. In this minireview, we are to introduce two predictors. One is called iGPCR-Drug accessible at http://www.jci-bioinfo.cn/iGPCR-Drug/; the other called iCDI-PseFpt at http://www.jci-bioinfo.cn/iCDI-PseFpt. The former is for identifying the interactions of drug compounds with GPCRs; while the latter for that with ion channels. In both predictors, the drug compound was formulated by the two-dimensional molecular fingerprint, and the protein receptor by the pseudo amino acid composition generated with the grey model theory, while the operation engine was the fuzzy K-nearest neighbor algorithm. For the convenience of most experimental pharmaceutical and medical scientists, a step-bystep guide is provided on how to use each of the two web-servers to get the desired results without the need to follow the complicated mathematics involved originally for their establishment.
Andes, David; Azie, Nkechi; Yang, Hongbo; Harrington, Rachel; Kelley, Caroline; Tan, Ruo-Ding; Wu, Eric Q; Franks, Billy; Kristy, Rita; Lee, Edward; Khandelwal, Nikhil; Spalding, James
The majority of hospitalized patients receiving mold-active triazoles are at risk of drug-drug interactions (DDIs). Efforts are needed to increase awareness of DDIs that pose a serious risk of adverse events. Triazoles remain the most commonly utilized antifungals. Recent developments have included the mold-active triazoles (MATs) itraconazole, voriconazole, and posaconazole, which are first-line agents for the treatment of filamentous fungal infections but have the potential for DDIs. This objective of this study was to evaluate the prevalence of triazole DDIs. Hospitalized U.S. adults with MAT use were identified in the Cerner HealthFacts database, which contained data from over 150 hospitals (2005 to 2013). The severities of DDIs with MATs were categorized, using drug labels and the drug information from the Drugdex system (Thompson Micromedex), into four groups (contraindicated, major, moderate, and minor severity). DDIs of minor severity were not counted. A DDI event was considered to have occurred if the following two conditions were met: (i) the patient used at least one drug with a classification of at least a moderate interaction with the MAT during the hospitalization and (ii) there was a period of overlap between the administration of the MAT and that of the interacting drug of at least 1 day. A total of 6,962 hospitalizations with MAT use were identified. Among them, 88% of hospitalizations with voriconazole use, 86% of hospitalizations with itraconazole use, and 93% of hospitalizations with posaconazole use included the use of a concomitant interacting drug. A total of 68% of hospitalizations with posaconazole use, 34% of hospitalizations with itraconazole use, and 20% of hospitalizations with voriconazole use included the use of at least one drug with a DDI of contraindicated severity. A total of 83% of hospitalizations with posaconazole use, 61% of hospitalizations with itraconazole use, and 82% of hospitalizations with voriconazole use included the
Azie, Nkechi; Yang, Hongbo; Harrington, Rachel; Kelley, Caroline; Tan, Ruo-Ding; Wu, Eric Q.; Franks, Billy; Kristy, Rita; Lee, Edward; Khandelwal, Nikhil; Spalding, James
The majority of hospitalized patients receiving mold-active triazoles are at risk of drug-drug interactions (DDIs). Efforts are needed to increase awareness of DDIs that pose a serious risk of adverse events. Triazoles remain the most commonly utilized antifungals. Recent developments have included the mold-active triazoles (MATs) itraconazole, voriconazole, and posaconazole, which are first-line agents for the treatment of filamentous fungal infections but have the potential for DDIs. This objective of this study was to evaluate the prevalence of triazole DDIs. Hospitalized U.S. adults with MAT use were identified in the Cerner HealthFacts database, which contained data from over 150 hospitals (2005 to 2013). The severities of DDIs with MATs were categorized, using drug labels and the drug information from the Drugdex system (Thompson Micromedex), into four groups (contraindicated, major, moderate, and minor severity). DDIs of minor severity were not counted. A DDI event was considered to have occurred if the following two conditions were met: (i) the patient used at least one drug with a classification of at least a moderate interaction with the MAT during the hospitalization and (ii) there was a period of overlap between the administration of the MAT and that of the interacting drug of at least 1 day. A total of 6,962 hospitalizations with MAT use were identified. Among them, 88% of hospitalizations with voriconazole use, 86% of hospitalizations with itraconazole use, and 93% of hospitalizations with posaconazole use included the use of a concomitant interacting drug. A total of 68% of hospitalizations with posaconazole use, 34% of hospitalizations with itraconazole use, and 20% of hospitalizations with voriconazole use included the use of at least one drug with a DDI of contraindicated severity. A total of 83% of hospitalizations with posaconazole use, 61% of hospitalizations with itraconazole use, and 82% of hospitalizations with voriconazole use included the
Chautard, E; Thierry-Mieg, N; Ricard-Blum, S
Most genes, proteins and other components carry out their functions within a complex network of interactions and a single molecule can affect a wide range of other cell components. A global, integrative, approach has been developed for several years, including protein-protein interaction networks (interactomes). In this review, we describe the high-throughput methods used to identify new interactions and to build large interaction datasets. The minimum information required for reporting a molecular interaction experiment (MIMIx) has been defined as a standard for storing data in publicly available interaction databases. Several examples of interaction networks from molecular machines (proteasome) or organelles (phagosome, mitochondrion) to whole organisms (viruses, bacteria, yeast, fly, and worm) are given and attempts to cover the entire human interaction network are discussed. The methods used to perform the topological analysis of interaction networks and to extract biological information from them are presented. These investigations have provided clues on protein functions, signalling and metabolic pathways, and physiological processes, unraveled the molecular basis of some diseases (cancer, infectious diseases), and will be very useful to identify new therapeutic targets and for drug discovery. A major challenge is now to integrate data from different sources (interactome, transcriptome, phenome, localization) to switch from static to dynamic interaction networks. The merging of a viral interactome and the human interactome has been used to simulate viral infection, paving the way for future studies aiming at providing molecular basis of human diseases.
Background Drug-drug interactions are frequently reported in the increasing amount of biomedical literature. Information Extraction (IE) techniques have been devised as a useful instrument to manage this knowledge. Nevertheless, IE at the sentence level has a limited effect because of the frequent references to previous entities in the discourse, a phenomenon known as 'anaphora'. DrugNerAR, a drug anaphora resolution system is presented to address the problem of co-referring expressions in pharmacological literature. This development is part of a larger and innovative study about automatic drug-drug interaction extraction. Methods The system uses a set of linguistic rules drawn by Centering Theory over the analysis provided by a biomedical syntactic parser. Semantic information provided by the Unified Medical Language System (UMLS) is also integrated in order to improve the recognition and the resolution of nominal drug anaphors. Besides, a corpus has been developed in order to analyze the phenomena and evaluate the current approach. Each possible case of anaphoric expression was looked into to determine the most effective way of resolution. Results An F-score of 0.76 in anaphora resolution was achieved, outperforming significantly the baseline by almost 73%. This ad-hoc reference line was developed to check the results as there is no previous work on anaphora resolution in pharmalogical documents. The obtained results resemble those found in related-semantic domains. Conclusions The present approach shows very promising results in the challenge of accounting for anaphoric expressions in pharmacological texts. DrugNerAr obtains similar results to other approaches dealing with anaphora resolution in the biomedical domain, but, unlike these approaches, it focuses on documents reflecting drug interactions. The Centering Theory has proved being effective at the selection of antecedents in anaphora resolution. A key component in the success of this framework is the
Lin, Wen; Ji, Tao; Einolf, Heidi; Ayalasomayajula, Surya; Lin, Tsu-Han; Hanna, Imad; Heimbach, Tycho; Breen, Christopher; Jarugula, Venkateswar; He, Handan
Sacubitril/valsartan (LCZ696) has been approved for the treatment of heart failure. Sacubitril is an in vitro inhibitor of organic anion-transporting polypeptides (OATPs). In clinical studies, LCZ696 increased atorvastatin Cmax by 1.7-fold and area under the plasma concentration-time curve by 1.3-fold, but had little or no effect on simvastatin or simvastatin acid exposure. A physiologically based pharmacokinetics modeling approach was applied to explore the underlying mechanisms behind the statin-specific LCZ696 drug interaction observations. The model incorporated OATP-mediated clearance (CLint,T) for simvastatin and simvastatin acid to successfully describe the pharmacokinetic profiles of either analyte in the absence or presence of LCZ696. Moreover, the model successfully described the clinically observed drug effect with atorvastatin. The simulations clarified the critical parameters responsible for the observation of a low, yet clinically relevant, drug-drug interaction DDI between sacubitril and atorvastatin and the lack of effect with simvastatin acid. Atorvastatin is administered in its active form and rapidly achieves Cmax that coincide with the low Cmax of sacubitril. In contrast, simvastatin requires a hydrolysis step to the acid form and therefore is not present at the site of interactions at sacubitril concentrations that are inhibitory. Similar models were used to evaluate the drug-drug interaction risk for additional OATP-transported statins which predicted to maximally result in a 1.5-fold exposure increase.
Jalaie, Mehran; Arimoto, Rieko; Gifford, Eric; Schefzick, Sabine; Waller, Chris L
Preventing drug-drug interactions and reducing drug-related mortalities dictate cleaner and costlier medicines. The cost to bring a new drug to market has increased dramatically over the last 10 years, with post-discovery activities (preclinical and clinical) costs representing the majority of the spend. With the ever-increasing scrutiny that new drug candidates undergo in the post-discovery assessment phases, there is increasing pressure on discovery to deliver higher-quality drug candidates. Given that compound attrition in the early clinical stages can often be attributed to metabolic liabilities, it has been of great interest lately to implement predictive measures of metabolic stability/ liability in the drug design stage of discovery. The solution to this issue is wrapped in understanding the basic of the cytochrome P450 (CYP) enzymes functions and structures. Recently, experimental information on the structure of a variety of cytochrome P450 enzymes, major contributors to phase I metabolism, has become readily available. This, coupled with the availability of experimental information on substrate specificities, has lead to the development of numerous computational models (macromolecular, pharmacophore, and structure-activity) for the rationalization and prediction of CYP liabilities. A comprehensive review of these models is presented in this chapter.
Danish, Azeem; Namasivayam, Vigneshwaran; Schiedel, Anke C; Müller, Christa E
Levetiracetam (LEV) and its recently approved derivative brivaracetam are anti-epileptic drugs with a unique mechanism of action. The synaptic vesicle protein 2A (SV2A) was previously identified as their main target. In the current study, we tested a collection of 500 approved drugs for interaction with the human SV2A protein expressed in Chinese hamster ovary cells. Competition binding studies were performed using cell lysates with high SV2A expression and [(3) H]brivaracetam as a radioligand. A hit rate of 3% was obtained, defined as compounds that inhibited radioligand binding by more than 90% at a screening concentration of 20 μM. Subsequent concentration-inhibition curves revealed the antihistaminic prodrug loratadine (Ki = 1.16 μM) and the antimalarial drug quinine (Ki = 2.03 μM) to be the most potent SV2A protein ligands of the investigated drug library. Both compounds were similarly potent as LEV (Ki = 1.74 μM), providing structurally novel scaffolds for SV2A ligands. A pharmacophore model was established, which indicated steric and electronic conformities of brivaracetam with the new SV2A ligands, and preliminary structure-activity relationships were determined. The anti-convulsive effects of the natural product quinine may - at least in part - be explained by interaction with SV2A. Loratadine and quinine represent new lead structures for anti-epileptic drug development.
Morais, Everton C; Correa, Gabriel G; Brambilla, Rodrigo; Radtke, Claudio; Baibich, Ione Maluf; dos Santos, João Henrique Z
A series of seven drugs, namely, fluoxetine, gentamicin, lidocaine, morphine, nifedipine, paracetamol and tetracycline, were encapsulated. The encapsulated systems were characterized using a series of complementary techniques: Fourier-transform infrared spectroscopy (FT-IR), diffusive reflectance spectroscopy in the UV-vis region (DRS) and X-ray photoelectron spectroscopy (XPS). According to the DRS spectra, most of the encapsulated systems showed a band shift of the maximum absorption when compared with the corresponding bare pharmaceutical. Additionally, after encapsulation, the drugs exhibited infrared band shifts toward higher wavenumbers, which in turn provided insight into potential sites for interaction with the silica framework. The amine group showed a band shift in the spectra of almost all the drugs (except nifedipine and tetracycline). This finding indicates the possibility of a hydrogen bonding interaction between the drug and the silica via electron donation from the amine group to the silica framework. XPS confirmed this interaction between the pharmaceuticals and the silica through the amine group. A correlation was observed between the textural characteristics of the solids and the spectroscopic data, suggesting that the amine groups from the pharmaceuticals were more perturbed upon encapsulation.
Kalichman, Seth C.; Kalichman, Moira O.; Cherry, Charsey; Hoyt, Ginger; Washington, Christopher; Grebler, Tamar; Merely, Cindy; Welles, Brandi
Drug use poses significant challenges to medical management of HIV infection. While most research has focused on the influence of intoxication on unintentional adherence to HIV treatment, drug use may also lead to intentional non-adherence, particularly when individuals believe that mixing medications with drugs is harmful. This study examined whether interactive toxicity beliefs predict non-adherence to antiretroviral therapy (ART) over a prospective period of adherence monitoring. Men and women living with HIV who screened positive for drug use and were being treated with ART (N=530) completed computerized self-interviews, three prospective unannounced pill counts to measure ART adherence, provided urine specimens for drug screening, and HIV viral load results from medical records. Results showed that 189 (35%) participants indicated that they intentionally miss their ART when they are using drugs. These participants also reported common beliefs regarding the perceived hazards of mixing HIV medications with alcohol and other drugs. Multivariable models that controlled for demographic and health characteristics, as well as frequency of alcohol use, showed that intentional non-adherence predicted poorer ART adherence over the prospective month and also predicted poorer treatment outcomes as indexed by unsuppressed HIV viral load. These findings extend previous research to show that interactive toxicity beliefs and intentional non-adherence play a significant role in medication non-adherence for a substantial number of people living with HIV and should be actively addressed in HIV clinical care. PMID:26226250
Mizutani, Sayaka; Pauwels, Edouard; Stoven, Véronique; Goto, Susumu; Yamanishi, Yoshihiro
Motivation: Identifying the emergence and underlying mechanisms of drug side effects is a challenging task in the drug development process. This underscores the importance of system–wide approaches for linking different scales of drug actions; namely drug-protein interactions (molecular scale) and side effects (phenotypic scale) toward side effect prediction for uncharacterized drugs. Results: We performed a large-scale analysis to extract correlated sets of targeted proteins and side effects, based on the co-occurrence of drugs in protein-binding profiles and side effect profiles, using sparse canonical correlation analysis. The analysis of 658 drugs with the two profiles for 1368 proteins and 1339 side effects led to the extraction of 80 correlated sets. Enrichment analyses using KEGG and Gene Ontology showed that most of the correlated sets were significantly enriched with proteins that are involved in the same biological pathways, even if their molecular functions are different. This allowed for a biologically relevant interpretation regarding the relationship between drug–targeted proteins and side effects. The extracted side effects can be regarded as possible phenotypic outcomes by drugs targeting the proteins that appear in the same correlated set. The proposed method is expected to be useful for predicting potential side effects of new drug candidate compounds based on their protein-binding profiles. Supplementary information: Datasets and all results are available at http://web.kuicr.kyoto-u.ac.jp/supp/smizutan/target-effect/. Availability: Software is available at the above supplementary website. Contact: email@example.com, or firstname.lastname@example.org PMID:22962476
Mazzari, Andre L D A; Prieto, Jose M
A plethora of active compounds found in herbal medicines can serve as substrate for enzymes involved in the metabolism of xenobiotics. When a medicinal plant is co-administered with a conventional drug and little or no information is known about the pharmacokinetics of the plant metabolites, there is an increased risk of potential herb-drug interactions. Moreover, genetic polymorphisms in a population may act to predispose individuals to adverse reactions. The use of herbal medicines is rapidly increasing in many countries, particularly Brazil where the vast biodiversity is a potential source of new and more affordable treatments for numerous conditions. Accordingly, the Brazilian Unified Public Health System (SUS) produced a list of 71 plant species of interest, which could be made available to the population in the near future. Physicians at SUS prescribe a number of essential drugs and should herbal medicines be added to this system the chance of herb-drug interactions further increases. A review of the effects of these medicinal plants on Phase 1 and Phase 2 metabolic mechanisms and the transporter P-glycoprotein was conducted. The results have shown that approximately half of these medicinal plants lack any pharmacokinetic data. Moreover, most of the studies carried out are in vitro. Only a few reports on herb-drug interactions with essential drugs prescribed by SUS were found, suggesting that very little attention is being given to the safety of herbal medicines. Here we have taken this information to discuss the potential interactions between herbal medicines and essential drugs prescribed to Brazilian patients whilst taking into account the most common polymorphisms present in the Brazilian population. A number of theoretical interactions are pinpointed but more pharmacokinetic studies and pharmacovigilance data are needed to ascertain their clinical significance.
Mazzari, Andre L. D. A.; Prieto, Jose M.
A plethora of active compounds found in herbal medicines can serve as substrate for enzymes involved in the metabolism of xenobiotics. When a medicinal plant is co-administered with a conventional drug and little or no information is known about the pharmacokinetics of the plant metabolites, there is an increased risk of potential herb-drug interactions. Moreover, genetic polymorphisms in a population may act to predispose individuals to adverse reactions. The use of herbal medicines is rapidly increasing in many countries, particularly Brazil where the vast biodiversity is a potential source of new and more affordable treatments for numerous conditions. Accordingly, the Brazilian Unified Public Health System (SUS) produced a list of 71 plant species of interest, which could be made available to the population in the near future. Physicians at SUS prescribe a number of essential drugs and should herbal medicines be added to this system the chance of herb-drug interactions further increases. A review of the effects of these medicinal plants on Phase 1 and Phase 2 metabolic mechanisms and the transporter P-glycoprotein was conducted. The results have shown that approximately half of these medicinal plants lack any pharmacokinetic data. Moreover, most of the studies carried out are in vitro. Only a few reports on herb-drug interactions with essential drugs prescribed by SUS were found, suggesting that very little attention is being given to the safety of herbal medicines. Here we have taken this information to discuss the potential interactions between herbal medicines and essential drugs prescribed to Brazilian patients whilst taking into account the most common polymorphisms present in the Brazilian population. A number of theoretical interactions are pinpointed but more pharmacokinetic studies and pharmacovigilance data are needed to ascertain their clinical significance. PMID:25071580
Wang, Jie; Wang, Yow-Ming C; Ahn, Hae-Young
Psoriasis is a chronic inflammatory skin disease condition that involves altered expression of a broad spectrum of proinflammatory cytokines which are associated with activation of T cells and proliferation of keratinocytes. Currently approved biological products for psoriasis treatment fall into two main classes: cytokine modulators and biologics targeting T cells. In psoriatic patients, elevated levels of proinflammatory cytokines are observed. Elevated proinflammatory cytokines can suppress some cytochrome P450 (CYP) enzymes, and the treatment of psoriasis with biological products can reduce proinflammatory cytokine levels. Therefore, the exposure of CYP substrate drugs is anticipated to be affected by the psoriasis disease resulting in a higher exposure than in healthy state (named disease-drug interaction) as well as by the biological treatments due to disease improvements resulting in a decrease in exposure (named disease-drug-drug interaction, disease-DDI). However, the quantitative impact on CYP substrate exposure due to disease or due to treatment with biological products remains to be evaluated. The objective of the current review is to provide an overview of the therapeutic targets and cytokine-related pharmacodynamic effects of biological products in psoriasis treatment with a particular focus on their implications for disease-DDI. The clinical study design considerations for psoriasis disease-DDI evaluation are also discussed.
Shao, Xin; Ai, Ni; Xu, Donghang; Fan, Xiaohui
Human serum albumin (HSA) binding is one of important pharmacokinetic properties of drug, which is closely related to in vivo distribution and may ultimately influence its clinical efficacy. Compared to conventional drug, limited information on this transportation process is available for medicinal herbs, which significantly hampers our understanding on their pharmacological effects, particularly when herbs and drug are co-administrated as polytherapy to the ailment. Several lines of evidence suggest the existence of Salvia miltiorrhiza-Warfarin interaction. Since Warfarin is highly HSA bound in the plasma with selectivity to site I, it is critical to evaluate the possibility of HSA-related herb-drug interaction. Herein an integrated approach was employed to analyze the binding of chemicals identified in S. miltiorrhiza to HSA. Molecular docking simulations revealed filtering criteria for HSA site I compounds that include docking score and key molecular determinants for binding. For eight representative ingredients from the herb, their affinity and specificity to HSA site I was measured and confirmed fluorometrically, which helps to improve the knowledge of interaction mechanisms between this herb and HSA. Our results indicated that several compounds in S. miltiorrhiza were capable of decreasing the binding constant of Warfarin to HSA site I significantly, which may increase free drug concentration in vivo, contributing to the herb-drug interaction observed clinically. Furthermore, the significance of HSA mediated herb-drug interactions was further implied by manual mining on the published literatures on S. miltiorrhiza.
Harpaz, Rave; Haerian, Krystl; Chase, Herbert S; Friedman, Carol
Many adverse drug effects (ADEs) can be attributed to drug interactions. Spontaneous reporting systems (SRS) provide a rich opportunity to detect novel post-marketed drug interaction adverse effects (DIAEs), as they include populations not well represented in clinical trials. However, their identification in SRS is nontrivial. Most existing research have addressed the statistical issues used to test or verify DIAEs, but not their identification as part of a systematic large scale database-wide mining process as discussed in this work. This paper examines the application of a highly optimized and tailored implementation of the Apriori algorithm, as well as methods addressing data quality issues, to the identification of DIAEs in FDAs SRS.
Kannan, Bhaskar; Nagella, Amrutha Bindu; Sathia Prabhu, A; Sasidharan, Gopalakrishnan M; Ramesh, A S
Background: Drug-drug interactions (DDIs) are very common adverse events in health care delivery settings. The use of electronic pharmacopeias can potentially reduce the incidence of DDIs, but they are often thought to be cumbersome to use. This study is aimed at studying the incidence of potential DDIs in a surgical department, where a limited number of drugs are used in stereotyped combinations. We also compared two popular drug compendia in detecting potential DDIs. Methods: The prescriptions of selected patients were entered into Epocrates® and Medscape® for Android smartphones. Potential DDIs were generated and their categories were noted. The warnings generated by Epocrates® were compared with those generated by Medscape® and an agreement index was calculated. Results: Three hundred and thirty-one patients were included for analysis who had received a total of 2,878 drug orders. The incidence of potential DDIs was very high - 89% of all prescriptions. Phenytoin was the drug most commonly implicated, followed by furosemide. Of the DDIs detected, 0.14% were potentially serious and the drug combinations were contraindicated. There was a significant discrepancy between the categories of potential DDIs detected by Epocrates® and Medscape®. No clinically significant DDI was detected in any patient in this cohort. Conclusions: Despite routinely using only a limited number of drugs in stereotyped combinations, prescriptions in surgical departments may not be immune from a significant incidence of DDIs. The use of free apps could reduce the incidence of DDIs, enhance patient safety, and also aid in educating trainees. PMID:28018756
Fasinu, Pius S.; Bouic, Patrick J.; Rosenkranz, Bernd
Despite the lack of sufficient information on the safety of herbal products, their use as alternative and/or complementary medicine is globally popular. There is also an increasing interest in medicinal herbs as precursor for pharmacological actives. Of serious concern is the concurrent consumption of herbal products and conventional drugs. Herb–drug interaction (HDI) is the single most important clinical consequence of this practice. Using a structured assessment procedure, the evidence of HDI presents with varying degree of clinical significance. While the potential for HDI for a number of herbal products is inferred from non-human studies, certain HDIs are well established through human studies and documented case reports. Various mechanisms of pharmacokinetic HDI have been identified and include the alteration in the gastrointestinal functions with consequent effects on drug absorption; induction and inhibition of metabolic enzymes and transport proteins; and alteration of renal excretion of drugs and their metabolites. Due to the intrinsic pharmacologic properties of phytochemicals, pharmacodynamic HDIs are also known to occur. The effects could be synergistic, additive, and/or antagonistic. Poor reporting on the part of patients and the inability to promptly identify HDI by health providers are identified as major factors limiting the extensive compilation of clinically relevant HDIs. A general overview and the significance of pharmacokinetic and pharmacodynamic HDI are provided, detailing basic mechanism, and nature of evidence available. An increased level of awareness of HDI is necessary among health professionals and drug discovery scientists. With the increasing number of plant-sourced pharmacological actives, the potential for HDI should always be assessed in the non-clinical safety assessment phase of drug development process. More clinically relevant research is also required in this area as current information on HDI is insufficient for clinical
Zgheib, Nathalie K; Branch, Robert A
Despite the central role of the liver in drug metabolism, surprisingly there is lack of certainty in anticipating the extent of modification of the clearance of a given drug in a given patient. The intent of this review is to provide a conceptual framework in considering the impact of liver disease on drug disposition and reciprocally the impact of drug disposition on liver disease. It is proposed that improved understanding of the situation is gained by considering the issue as a special example of a drug-gene-environment interaction. This requires an integration of knowledge of the drug's properties, knowledge of the gene products involved in its metabolism, and knowledge of the pathophysiology of its disposition. This will enhance the level of predictability of drug disposition and toxicity for a drug of interest in an individual patient. It is our contention that advances in pharmacology, pharmacogenomics, and hepatology, together with concerted interests in the academic, regulatory, and pharmaceutical industry communities provide an ideal immediate environment to move from a qualitative reactive approach to quantitative proactive approach in individualizing patient therapy in liver disease.
McGinnity, Dermot F; Waters, Nigel J; Tucker, James; Riley, Robert J
Unbound IC(50) (IC(50,u)) values of 15 drugs were determined in eight recombinantly expressed human cytochromes P450 (P450s) and human hepatocytes, and the data were used to simulate clinical area under the plasma concentration-time curve changes (deltaAUC) on coadministration with prototypic CYP2D6 substrates. Significant differences in IC(50,u) values between enzyme sources were observed for quinidine (0.02 microM in recombinant CYP2D6 versus 0.5 microM in hepatocytes) and propafenone (0.02 versus 4.1 microM). The relative contribution of individual P450s toward the oxidative metabolism of clinical probes desipramine, imipramine, tolterodine, propranolol, and metoprolol was estimated via determinations of intrinsic clearance using recombinant P450s (rP450s). Simulated deltaAUC were compared with those observed in vivo via the ratios of unbound inhibitor concentration at the entrance to the liver to inhibition constants determined against rP450s ([I](in,u)/K(i)) and incorporating parallel substrate elimination pathways. For this dataset, there were 20% false negatives (observed deltaAUC >or= 2, predicted deltaAUC < 2), 77% correct predictions, and 3% false positives. Thus, the [I](in,u)/K(i) approach appears relatively successful at estimating the degree of clinical interactions and can be incorporated into drug discovery strategies. Using a Simcyp ADME (absorption, metabolism, distribution, elimination) simulator (Simcyp Ltd., Sheffield, UK), there were 3% false negatives, 94% correct simulations, and 3% false positives. False-negative predictions were rationalized as a result of mechanism-based inhibition, production of inhibitory metabolites, and/or hepatic uptake. Integrating inhibition and reaction phenotyping data from automated rP450 screens have shown applicability to predict the occurrence and degree of in vivo drug-drug interactions, and such data may identify the clinical consequences for candidate drugs as both "perpetrators" and "victims" of P450
Background The objective of this systematic review was to examine the benefits, harms and pharmacokinetic interactions arising from the co-administration of commonly used dietary supplements with cardiovascular drugs. Many patients on cardiovascular drugs take dietary supplements for presumed benefits and may be at risk for adverse supplement-drug interactions. Methods The Allied and Complementary Medicine Database, the Cochrane Library, EMBASE, International Bibliographic Information on Dietary Supplements and MEDLINE were searched from the inception of the review to October 2011. Grey literature was also reviewed. Two reviewers independently screened records to identify studies comparing a supplement plus cardiovascular drug(s) with the drug(s) alone. Reviewers extracted data using standardized forms, assessed the study risk of bias, graded the strength of evidence and reported applicability. Results Evidence was obtained from 65 randomized clinical trials, 2 controlled clinical trials and 1 observational study. With only a few small studies available per supplement, evidence was insufficient for all predefined gradable clinical efficacy and harms outcomes, such as mortality and serious adverse events. One long-term pragmatic trial showed no benefit from co-administering vitamin E with aspirin on a composite cardiovascular outcome. Evidence for most intermediate outcomes was insufficient or of low strength, suggesting no effect. Incremental benefits were noted for triglyceridemia with omega-3 fatty acid added to statins; and there was an improvement in levels of high-density lipoprotein cholesterol with garlic supplementation when people also consumed nitrates Conclusions Evidence of low-strength indicates benefits of omega-3 fatty acids (plus statin, or calcium channel blockers and antiplatelets) and garlic (plus nitrates or warfarin) on triglycerides and HDL-C, respectively. Safety concerns, however, persist. PMID:22651380
Ando, Yuki; Hirakawa, Akihiro; Uyama, Yoshiaki
Adaptive design is regarded as an efficient method for clinical trials in order to increase the success rate of a new drug in development, and recently has been actively discussed among regulatory agencies, industry and academia. Since adaptive design involves interim analyses and is more complex than traditional fixed design, some points such as possibility of introducing statistical and operational bias should be considered when planning and implementing such trials. In this article, we share our perspectives in the consideration of adaptive design clinical trials based on our experiences discussing adaptive design in clinical trial consultation meetings in Japan.
Roth, Robert A; Maiuri, Ashley R; Ganey, Patricia E
Idiosyncratic drug-induced liver injury continues to be a human health problem in part because drugs that cause these reactions are not identified in current preclinical testing and because progress in prevention is hampered by incomplete knowledge of mechanisms that underlie these adverse responses. Several hypotheses involving adaptive immune responses, inflammatory stress, inability to adapt to stress, and multiple, concurrent factors have been proposed. Yet much remains unknown about how drugs interact with the liver to effect death of hepatocytes. Evidence supporting hypotheses implicating adaptive or innate immune responses in afflicted patients has begun to emerge and is bolstered by results obtained in experimental animal models and in vitro systems. A commonality in adaptive and innate immunity is the production of cytokines, including interferon-γ (IFNγ). IFNγ initiates cell signaling pathways that culminate in cell death or inhibition of proliferative repair. Tumor necrosis factor-α, another cytokine prominent in immune responses, can also promote cell death. Furthermore, tumor necrosis factor-α interacts with IFNγ, leading to enhanced cellular responses to each cytokine. In this short review, we propose that the interaction of drugs with these cytokines contributes to idiosyncratic drug-induced liver injury, and mechanisms by which this could occur are discussed.
Ezuruike, Udoamaka; Prieto, Jose M.
It is becoming increasingly evident that patients with diabetes do not rely only on prescription drugs for their disease management. The use of herbal medicines is one of the self-management practices adopted by these patients, often without the knowledge of their healthcare practitioners. This study assessed the potential for pharmacokinetic herb-drug interactions (HDIs) amongst Nigerian adult diabetic patients. This was done through a literature analysis of the pharmacokinetic profile of their herbal medicines and prescription drugs, based on information obtained from 112 patients with type-2 diabetes attending two secondary health care facilities in Nigeria. Fifty percent of the informants used herbal medicines alongside their prescription drugs. Worryingly, 60% of the patients taking herbal medicines did not know their identity, thus increasing the risk of unidentified HDIs. By comparing the pharmacokinetic profile of eight identified herbs taken by the patients for the management of diabetes against those of the prescription drugs, several scenarios of potential HDIs were identified and their clinical relevance is discussed. The lack of clinical predictors points toward cultural factors as the influence for herb use, making it more difficult to identify these patients and in turn monitor potential HDIs. In identifying these possible interactions, we have highlighted the need for healthcare professionals to promote a proactive monitoring of patients' use of herbal medicines. PMID:27559312
Zeng, Like; An, Lingling; Wu, Xiaoyi
Numerous nanocarriers of various compositions and geometries have been developed for the delivery and release of therapeutic and imaging agents. Due to the high specific surface areas of nanocarriers, different mechanisms such as ion pairing and hydrophobic interaction need to be explored for achieving sustained release. Recently, we developed a three-parameter model that considers reversible drug-carrier interaction and first-order drug release from liposomes. A closed-form analytical solution was obtained. Here, we further explore the ability of the model to capture the release of bioactive molecules such as drugs and growth factors from various nanocarriers. A parameter study demonstrates that the model is capable of resembling major categories of drug release kinetics. We further fit the model to 60 sets of experimental data from various drug release systems, including nanoparticles, hollow particles, fibers, and hollow fibers. Additionally, bootstrapping is used to evaluate the accuracy of parameter determination and validate the model in selected cases. The simplicity and universality of the model and the clear physical meanings of each model parameter render the model useful for the design and development of new drug delivery systems. PMID:21845225
Prueksaritanont, Thomayant; Chu, Xiaoyan; Gibson, Christopher; Cui, Donghui; Yee, Ka Lai; Ballard, Jeanine; Cabalu, Tamara; Hochman, Jerome
Recently, the US Food and Drug Administration and European Medicines Agency have issued new guidance for industry on drug interaction studies, which outline comprehensive recommendations on a broad range of in vitro and in vivo studies to evaluate drug-drug interaction (DDI) potential. This paper aims to provide an overview of these new recommendations and an in-depth scientifically based perspective on issues surrounding some of the recommended approaches in emerging areas, particularly, transporters and complex DDIs. We present a number of theoretical considerations and several case examples to demonstrate complexities in applying (1) the proposed transporter decision trees and associated criteria for studying a broad spectrum of transporters to derive actionable information and (2) the recommended model-based approaches at an early stage of drug development to prospectively predict DDIs involving time-dependent inhibition and mixed inhibition/induction of drug metabolizing enzymes. We hope to convey the need for conducting DDI studies on a case-by-case basis using a holistic scientifically based interrogative approach and to communicate the need for additional research to fill in knowledge gaps in these areas where the science is rapidly evolving to better ensure the safety and efficacy of new therapeutic agents.
Smida, Michal; Nijman, Sebastian M B
Despite the dawn of the genomic information era, the challenges of cancer treatment remain formidable. Particularly for the most prevalent cancer types, including lung cancer, successful treatment of metastatic disease is rare and escalating costs for modern targeted drugs place an increasing strain on healthcare systems. Although powerful diagnostic tools to characterize individual tumor samples in great molecular detail are becoming rapidly available, the transformation of this information into therapy provides a major challenge. A fundamental difficulty is the molecular complexity of cancer cells that often causes drug resistance, but can also render tumors exquisitely sensitive to targeted agents. By using lung cancer as an example, we outline the principles that govern drug sensitivity and resistance from a genetic perspective and discuss how in vitro chemical-genetic screens can impact on patient stratification in the clinic.
Yang, Li-Xia; Liu, Cheng-Yuan; Zhang, Lun-Li; Lai, Ling-Ling; Fang, Ming; Zhang, Chong
Background: Drug is an important cause of liver injury and accounts for up to 40% of instances of fulminant hepatic failure. Drug-induced liver injury (DILI) is increasing while the diagnosis becomes more difficult. Though many drugs may cause DILI, Chinese herbal medicines have recently emerged as a major cause due to their extensive use in China. We aimed to provide drug safety information to patients and health carers by analyzing the clinical and pathological characteristics of the DILI and the associated drug types. Methods: A retrospective analysis was conducted in 287 patients diagnosed with DILI enrolled in our hospital from January 2011 to December 2015. The categories of causative drugs, clinical and pathological characteristics were reviewed. Results: Western medicines ranked as the top cause of DILI, accounting for 163 out of the 287 DILI patients (56.79%) in our study. Among the Western medicine, antituberculosis drugs were the highest cause (18.47%, 53 patients) of DILI. Antibiotics (18 patients, 6.27%) and antithyroid (18 patients, 6.27%) drugs also ranked among the major causes of DILI. Chinese herbal medicines are another major cause of DILI, accounting for 36.59% of cases (105 patients). Most of the causative Chinese herbal medicines were those used to treat osteopathy, arthropathy, dermatosis, gastropathy, leukotrichia, alopecia, and gynecologic diseases. Hepatocellular hepatitis was prevalent in DILI, regardless of Chinese herbal medicine or Western medicine-induced DILI. Conclusions: Risks and the rational use of medicines should be made clear to reduce the occurrence of DILI. For patients with liver injury of unknown origin, liver tissue pathological examination is recommended for further diagnosis. PMID:28091407
Liu, Dong; Yang, Fang; Xiong, Fei; Gu, Ning
With the unprecedented progresses of biomedical nanotechnology during the past few decades, conventional drug delivery systems (DDSs) have been involved into smart DDSs with stimuli-responsive characteristics. Benefiting from the response to specific internal or external triggers, those well-defined nanoplatforms can increase the drug targeting efficacy, in the meantime, reduce side effects/toxicities of payloads, which are key factors for improving patient compliance. In academic field, variety of smart DDSs have been abundantly demonstrated for various intriguing systems, such as stimuli-responsive polymeric nanoparticles, liposomes, metals/metal oxides, and exosomes. However, these nanoplatforms are lack of standardized manufacturing method, toxicity assessment experience, and clear relevance between the pre-clinical and clinical studies, resulting in the huge difficulties to obtain regulatory and ethics approval. Therefore, such relatively complex stimulus-sensitive nano-DDSs are not currently approved for clinical use. In this review, we highlight the recent advances of smart nanoplatforms for targeting drug delivery. Furthermore, the clinical translation obstacles faced by these smart nanoplatforms have been reviewed and discussed. We also present the future directions and perspectives of stimuli-sensitive DDS in clinical applications. PMID:27375781
Liu, Dong; Yang, Fang; Xiong, Fei; Gu, Ning
With the unprecedented progresses of biomedical nanotechnology during the past few decades, conventional drug delivery systems (DDSs) have been involved into smart DDSs with stimuli-responsive characteristics. Benefiting from the response to specific internal or external triggers, those well-defined nanoplatforms can increase the drug targeting efficacy, in the meantime, reduce side effects/toxicities of payloads, which are key factors for improving patient compliance. In academic field, variety of smart DDSs have been abundantly demonstrated for various intriguing systems, such as stimuli-responsive polymeric nanoparticles, liposomes, metals/metal oxides, and exosomes. However, these nanoplatforms are lack of standardized manufacturing method, toxicity assessment experience, and clear relevance between the pre-clinical and clinical studies, resulting in the huge difficulties to obtain regulatory and ethics approval. Therefore, such relatively complex stimulus-sensitive nano-DDSs are not currently approved for clinical use. In this review, we highlight the recent advances of smart nanoplatforms for targeting drug delivery. Furthermore, the clinical translation obstacles faced by these smart nanoplatforms have been reviewed and discussed. We also present the future directions and perspectives of stimuli-sensitive DDS in clinical applications.
Prado, Maria Aparecida Medeiros Barros do; Francisco, Priscila Maria Stolses Bergamo; Barros, Marilisa Berti de Azevedo
This study sought to outline the sociodemographic and health profile of elderly persons with reported diabetes, to assess the knowledge and practices regarding treatment options and describe the use of medications and potential risks for drug interactions (DI) in this subgroup. In 2008,a cross-sectional study was conducted of 1,517 elderly citizens in Campinas in which the prevalence of diabetes was estimated and its associations assessed using the Rao-Scott test (p < 0,05).The potential drug interactions were evaluated using the Micromedex® database. Diabetes prevalence was 21.7%, without significant difference between the sexes. A higher percentage of elderly diabetics was found aged over 70, with less schooling, per capita family income of less than 1 minimum wage and no occupational activity. The average drug intake was 3.9 in the previous 3 days. Possible interactions were identified in 413 cases and 53.1%, 7.8% and 7.2% of the subjects presented moderate, minor and serious risk of DI, respectively. The importance of adopting a healthy diet and physical activity for weight reduction, disease and complication control is stressed. The need for attention to the potential for drug interactions and the use of inappropriate medications among the elderly is highlighted.
Leung, Tiffany I; Dumontier, Michel
Clinical practice guidelines (CPGs) and structured product labels (SPLs) are both intended to promote evidence-based medical practices and guide clinicians' prescribing decisions. However, it is unclear how well CPG recommendations about pharmacologic therapies for certain diseases match SPL indications for recommended drugs. In this study, we use publicly available data and text mining methods to examine drug-disease associations in CPG recommendations and SPL treatment indications for 15 common chronic conditions. Preliminary results suggest that there is a mismatch between guideline-recommended pharmacologic therapies and SPL indications. Conflicting or inconsistent recommendations and indications may complicate clinical decision making and implementation or measurement of best practices.
Williams, J Andrew; Hyland, Ruth; Jones, Barry C; Smith, Dennis A; Hurst, Susan; Goosen, Theunis C; Peterkin, Vincent; Koup, Jeffrey R; Ball, Simon E
Glucuronidation is a listed clearance mechanism for 1 in 10 of the top 200 prescribed drugs. The objective of this article is to encourage those studying ligand interactions with UDP-glucuronosyltransferases (UGTs) to adequately consider the potential consequences of in vitro UGT inhibition in humans. Spurred on by interest in developing potent and selective inhibitors for improved confidence around UGT reaction phenotyping, and the increased availability of recombinant forms of human UGTs, several recent studies have reported in vitro inhibition of UGT enzymes. In some cases, the observed potency of UGT inhibitors in vitro has been interpreted as having potential relevance in humans via pharmacokinetic drug-drug interactions. Although there are reported examples of clinically relevant drug-drug interactions for UGT substrates, exposure increases of the aglycone are rarely greater than 100% in the presence of an inhibitor relative to its absence (i.e., AUCi/AUC < or = 2). This small magnitude in change is in contrast to drugs primarily cleared by cytochrome P450 enzymes, where exposures have been reported to increase as much as 35-fold on coadministration with an inhibitor (e.g., ketoconazole inhibition of CYP3