QT time prolongation
Adverse drug events
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Explanations of the substances for patients
We have no additional warnings for the combination of abiraterone and clopidogrel. Please also consult the relevant specialist information.
|Clopidogrel||2.55 [1.29,3.25] 1||2.55|
The changes in exposure mentioned relate to changes in the plasma concentration-time curve [AUC]. Clopidogrel exposure increases to 255%, when combined with abiraterone (255%). The AUC is between 129% and 325% depending on the CYP2C19
The pharmacokinetic parameters of the average population are used as the starting point for calculating the individual changes in exposure due to the interactions.
Abiraterone has a mean oral bioavailability [ F ] of 50%, which is why the maximum plasma levels [Cmax] tend to change with an interaction. The terminal half-life [ t12 ] is 18 hours and constant plasma levels [ Css ] are reached after approximately 72 hours. The protein binding [ Pb ] is very strong at 99.8% and the volume of distribution [ Vd ] is very large at 2815 liters, The metabolism mainly takes place via CYP3A4.
Clopidogrel has a mean oral bioavailability [ F ] of 50%, which is why the maximum plasma levels [Cmax] tend to change with an interaction. The terminal half-life [ t12 ] is 7.3 hours and constant plasma levels [ Css ] are reached after approximately 29.2 hours. The protein binding [ Pb ] is 98% strong and the volume of distribution [ Vd ] is very large at 350 liters. The metabolism takes place via CYP1A2, CYP2B6 and CYP2C19, among others and the active transport takes place in particular via PGP.
|Serotonergic Effects a||0||Ø||Ø|
Rating: According to our knowledge, neither abiraterone nor clopidogrel increase serotonergic activity.
|Kiesel & Durán b||0||Ø||Ø|
Rating: According to our findings, neither abiraterone nor clopidogrel increase anticholinergic activity.
QT time prolongation
Abiraterone can potentially increase QT time, but we do not know about torsades de pointes arrhythmias. We do not know of any QT-prolonging potential for clopidogrel.
General adverse effects
|Side effects||∑ frequency||abi||clo|
|Peripheral edema||20.0 %||20.0||n.a.|
|Elevated ALT||13.0 %||13.0||n.a.|
|Elevated AST||13.0 %||13.0||n.a.|
|Urinary tract infection||10.0 %||10.0||n.a.|
|Atrial fibrillation||2.6 %||2.6||n.a.|
Gastrointestinal hemorrhage (2%): clopidogrel
Angina pectoris (1.6%): abiraterone
Aplastic anemia: clopidogrel
Prolonged bleeding time: clopidogrel
Thrombotic thrombocytopenic purpura: clopidogrel
Stevens johnson syndrome: clopidogrel
Liver failure: clopidogrel
DRESS syndrome: clopidogrel
Toxic epidermal necrolysis: clopidogrel
Intracranial hemorrhage: clopidogrel
Based on your
Abstract: OBJECTIVES: To assess the tolerability, pharmacodynamic effects and pharmacokinetic parameters after repeated doses of clopidogrel (Plavix((R))) in patients with moderate or severe renal failure. PATIENTS: Eight patients with severe renal failure (endogenous creatinine clearance 5 to 15 ml/min) and eight patients with moderate renal impairment (endogenous creatinine clearance 30 to 60 ml/min) were included. STUDY DESIGN: An open, uncontrolled, parallel-group study over 8 days' administration of 75mg once-daily clopidogrel. METHODS: Measurement of changes in ADP-induced platelet aggregation and skin bleeding time and of plasma concentrations and urinary excretion of clopidogrel and its main metabolite, SR 26334. Assessment of clinical tolerance and serial haematological and biochemical investigations. RESULTS: At the end of the dosage period, platelet aggregation was equally inhibited, by about 25%, and bleeding time equally extended, by a factor of about 2, in the two groups. There were no tolerability concerns. Maximum plasma concentration (C(max)) and time to reach C(max ) (t(max)) for clopidogrel were not significantly different between the two groups. SR 26334 excreted into the urine and renal clearance rate were significantly lower in the severely impaired group, while plasma elimination half-lives were not significantly different. C(max) and t(max) did not differ significantly between the two groups, but trough levels and area under the plasma concentration-time curve from zero to 24 hours (AUC(0-24h)) after the last dose were significantly higher in the moderately impaired group. CONCLUSIONS: Clopidogrel 75mg once daily was well tolerated in patients with either moderate or severe renal failure, and provided good inhibition of ADP-induced platelet aggregation without excessive extension of bleeding time. Dose adjustment in such patients does not appear to be required.
Abstract: Four randomized, placebo-controlled, crossover studies were conducted among 282 healthy subjects to investigate whether an interaction exists between clopidogrel (300-mg loading dose/75-mg/day maintenance dose) and the proton-pump inhibitor (PPI) omeprazole (80 mg) when they are administered simultaneously (study 1); whether the interaction, if any, can be mitigated by administering clopidogrel and omeprazole 12 h apart (study 2) or by increasing clopidogrel to 600-mg loading/150-mg/day maintenance dosing (study 3); and whether the interaction applies equally to the PPI pantoprazole (80 mg) (study 4). Relative to levels after administration of clopidogrel alone in studies 1,2,3, and 4, coadministration of PPI decreased the AUC(0-24) of the clopidogrel active metabolite H4 by 40, 47, 41, and 14% (P ≤ 0.002), respectively; increased maximal platelet aggregation (MPA) induced by 5 micromol/l adenosine diphosphate (ADP) by 8.0, 5.6, 8.1, and 4.3% (P ≤ 0.014), respectively; and increased the vasodilator-stimulated phosphoprotein phosphorylation-platelet reactivity index (VASP-PRI) by 20.7, 27.1, 19.0 (P < 0.0001), and 3.9% (P = 0.3319), respectively. The results suggest that a metabolic drug-drug interaction exists between clopidogrel and omeprazole but not between clopidogrel and pantoprazole.
Abstract: BACKGROUND: Anticholinergic drugs are often involved in explicit criteria for inappropriate prescribing in older adults. Several scales were developed for screening of anticholinergic drugs and estimation of the anticholinergic burden. However, variation exists in scale development, in the selection of anticholinergic drugs, and the evaluation of their anticholinergic load. This study aims to systematically review existing anticholinergic risk scales, and to develop a uniform list of anticholinergic drugs differentiating for anticholinergic potency. METHODS: We performed a systematic search in MEDLINE. Studies were included if provided (1) a finite list of anticholinergic drugs; (2) a grading score of anticholinergic potency and, (3) a validation in a clinical or experimental setting. We listed anticholinergic drugs for which there was agreement in the different scales. In case of discrepancies between scores we used a reputed reference source (Martindale: The Complete Drug Reference®) to take a final decision about the anticholinergic activity of the drug. RESULTS: We included seven risk scales, and evaluated 225 different drugs. Hundred drugs were listed as having clinically relevant anticholinergic properties (47 high potency and 53 low potency), to be included in screening software for anticholinergic burden. CONCLUSION: Considerable variation exists among anticholinergic risk scales, in terms of selection of specific drugs, as well as of grading of anticholinergic potency. Our selection of 100 drugs with clinically relevant anticholinergic properties needs to be supplemented with validated information on dosing and route of administration for a full estimation of the anticholinergic burden in poly-medicated older adults.
Abstract: Three open-label, single-dose studies investigated the impact of hepatic or renal impairment on abiraterone acetate pharmacokinetics and safety/tolerability in non-cancer patients. Patients (n = 8 each group) with mild/moderate hepatic impairment or end-stage renal disease (ESRD), and age-, BMI-matched healthy controls received a single oral 1,000 mg abiraterone acetate (tablet dose); while patients (n = 8 each) with severe hepatic impairment and matched healthy controls received 125- and 2,000-mg abiraterone acetate (suspension doses), respectively (systemic exposure of abiraterone acetate suspension is approximately half to that of tablet formulation). Blood was sampled at specified timepoints up to 72 or 96 hours postdose to measure plasma abiraterone concentrations. Abiraterone exposure was comparable between healthy controls and patients with mild hepatic impairment or ESRD, but increased by 4-fold in patients with moderate hepatic impairment. Despite a 16-fold reduction in dose, abiraterone exposure in patients with severe hepatic impairment was about 22% and 44% of the Cmax and AUC∞ of healthy controls, respectively. These results suggest that abiraterone pharmacokinetics were not changed markedly in patients with ESRD or mild hepatic impairment. However, the capacity to eliminate abiraterone was substantially compromised in patients with moderate or severe hepatic impairment. A single-dose administration of abiraterone acetate was well-tolerated.
Abstract: Acute coronary syndromes (ACS) remain life-threatening disorders, which are associated with high morbidity and mortality. Dual antiplatelet therapy with aspirin and clopidogrel has been shown to reduce cardiovascular events in patients with ACS. However, there is substantial inter-individual variability in the response to clopidogrel treatment, in addition to prolonged recovery of platelet reactivity as a result of irreversible binding to P2Y12 receptors. This high inter-individual variability in treatment response has primarily been associated with genetic polymorphisms in the genes encoding for cytochrome (CYP) 2C19, which affect the pharmacokinetics of clopidogrel. While the US Food and Drug Administration has issued a boxed warning for CYP2C19 poor metabolizers because of potentially reduced efficacy in these patients, results from multivariate analyses suggest that additional factors, including age, sex, obesity, concurrent diseases and drug-drug interactions, may all contribute to the overall between-subject variability in treatment response. However, the extent to which each of these factors contributes to the overall variability, and how they are interrelated, is currently unclear. The objective of this review article is to provide a comprehensive update on the different factors that influence the pharmacokinetics and pharmacodynamics of clopidogrel and how they mechanistically contribute to inter-individual differences in the response to clopidogrel treatment.
Abstract: Chronic kidney disease has been identified as an independent cardiovascular risk factor. The morbidity and mortality due to cardiovascular disease are higher among chronic kidney disease patients when compared with patients with normal kidney function. Although P2Y12 inhibitors (eg. clopidogrel) are associated with increased survival rates after a myocardial infarction, most of the clinical trials excluded End-Stage Renal Disease (ESRD) patients. Besides, non-responders to P2Y12 inhibitors have been identified as at risk of cardiovascular adverse events and non-responder prevalence is higher among ESRD than in any other population. Recent data questioned the benefits from P2Y12 inhibitors among chronic kidney disease patients. This systematic review aimed to describe pharmacokinetics (PK) and pharmacodynamics (PD) evidence data among 3 widely prescribed P2Y12 inhibitors. Clopidogrel and prasugrel are bioactivated by the cytochromes P450 (CYP) while ticagrelor is already active. PD data used different assays among which the VerifyNow® which showed intravariability before and after dialysis. The potential explanation of modulated PK/PD parameters among ESRD patients will be addressed. Absorption as well as metabolism is diminished in ESRD patients. It could potentially lead to absence of clopidogrel or prasugrel bioactivation or ticagrelor accumulation. Evidence-based recommendation regarding the best option for antiaggregation secondary to percutaneous intervention in this high risk population is still lacking.
Abstract: Two novel oral drugs that target androgen signaling have recently become available for the treatment of metastatic castration-resistant prostate cancer (mCRPC). Abiraterone acetate inhibits the synthesis of the natural ligands of the androgen receptor, whereas enzalutamide directly inhibits the androgen receptor by several mechanisms. Abiraterone acetate and enzalutamide appear to be equally effective for patients with mCRPC pre- and postchemotherapy. Rational decision making for either one of these drugs is therefore potentially driven by individual patient characteristics. In this review, an overview of the pharmacokinetic characteristics is given for both drugs and potential and proven drug-drug interactions are presented. Additionally, the effect of patient-related factors on drug disposition are summarized and the limited data on the exposure-response relationships are described. The most important pharmacological feature of enzalutamide that needs to be recognized is its capacity to induce several key enzymes in drug metabolism. The potency to cause drug-drug interactions needs to be addressed in patients who are treated with multiple drugs simultaneously. Abiraterone has a much smaller drug-drug interaction potential; however, it is poorly absorbed, which is affected by food intake, and a large interpatient variability in drug exposure is observed. Dose reductions of abiraterone or, alternatively, the selection of enzalutamide, should be considered in patients with hepatic dysfunction. Understanding the pharmacological characteristics and challenges of both drugs could facilitate decision making for either one of the drugs.
Abstract: We present a case of a 77 year-old gentleman with previous coronary artery bypass grafting, admitted to hospital with recurrent torsades de pointes (TdP) due to abiraterone-induced hypokalaemia and prolonged QTc. The patient was on abiraterone and prednisone for metastatic prostate cancer. He required multiple defibrillations for recurrent TdP. Abiraterone is a relatively novel drug used in metastatic prostate cancer and we discuss this potential adverse effect and its management in this unusual presentation.
Abstract: Transporters in proximal renal tubules contribute to the disposition of numerous drugs. Furthermore, the molecular mechanisms of tubular secretion have been progressively elucidated during the past decades. Organic anions tend to be secreted by the transport proteins OAT1, OAT3 and OATP4C1 on the basolateral side of tubular cells, and multidrug resistance protein (MRP) 2, MRP4, OATP1A2 and breast cancer resistance protein (BCRP) on the apical side. Organic cations are secreted by organic cation transporter (OCT) 2 on the basolateral side, and multidrug and toxic compound extrusion (MATE) proteins MATE1, MATE2/2-K, P-glycoprotein, organic cation and carnitine transporter (OCTN) 1 and OCTN2 on the apical side. Significant drug-drug interactions (DDIs) may affect any of these transporters, altering the clearance and, consequently, the efficacy and/or toxicity of substrate drugs. Interactions at the level of basolateral transporters typically decrease the clearance of the victim drug, causing higher systemic exposure. Interactions at the apical level can also lower drug clearance, but may be associated with higher renal toxicity, due to intracellular accumulation. Whereas the importance of glomerular filtration in drug disposition is largely appreciated among clinicians, DDIs involving renal transporters are less well recognized. This review summarizes current knowledge on the roles, quantitative importance and clinical relevance of these transporters in drug therapy. It proposes an approach based on substrate-inhibitor associations for predicting potential tubular-based DDIs and preventing their adverse consequences. We provide a comprehensive list of known drug interactions with renally-expressed transporters. While many of these interactions have limited clinical consequences, some involving high-risk drugs (e.g. methotrexate) definitely deserve the attention of prescribers.
Abstract: Dasabuvir, a nonnucleoside NS5B polymerase inhibitor, is a sensitive substrate of cytochrome P450 (CYP) 2C8 with a potential for drug-drug interaction (DDI) with clopidogrel. A physiologically based pharmacokinetic (PBPK) model was developed for dasabuvir to evaluate the DDI potential with clopidogrel, the acyl-β-D glucuronide metabolite of which has been reported as a strong mechanism-based inhibitor of CYP2C8 based on an interaction with repaglinide. In addition, the PBPK model for clopidogrel and its metabolite were updated with additional in vitro data. Sensitivity analyses using these PBPK models suggested that CYP2C8 inhibition by clopidogrel acyl-β-D glucuronide may not be as potent as previously suggested. The dasabuvir and updated clopidogrel PBPK models predict a moderate increase of 1.5-1.9-fold for Cand 1.9-2.8-fold for AUC of dasabuvir when coadministered with clopidogrel. While the PBPK results suggest there is a potential for DDI between dasabuvir and clopidogrel, the magnitude is not expected to be clinically relevant.
Abstract: BACKGROUND: Pivotal clinical trials found that ticagrelor reduced ischaemic complications to a greater extent than clopidogrel, and also that the benefit gradually increased with the reduction in creatinine clearance. However, the underlying mechanisms remains poorly explored. METHODS: This was a single-centre, prospective, randomized clinical trial involving 60 hospitalized Adenosine Diphosphate (ADP) P2Y12 receptor inhibitor-naïve patients with chronic kidney disease (CKD) (estimated glomerular filtration rate <60 ml min,1.73 m,) and non-ST-elevation acute coronary syndromes (NSTE-ACS). Eligible patients were randomly assigned in a 1:1 ratio to receive ticagrelor (180 mg loading dose, then followed by 90 mg twice daily) or clopidogrel (600 mg loading dose, then followed by 75 mg once daily). The primary endpoint was the P2Y12 reactive unit (PRU) value assessed by VerifyNow at 30 days. The plasma concentrations of ticagrelor and clopidogrel and their active metabolites were measured in the first 10 patients in each group at baseline, and at 1 h, 2 h, 4 h, 8 h, 12 h and 24 h after the loading dose. RESULTS: Baseline characteristics were well matched between the two groups. Our results indicated a markedly lower PRU in patients treated with ticagrelor vs. clopidogrel at 30 days (32.6 ± 11.29 vs. 203.7 ± 17.92; P < 0.001) as well as at 2 h, 8 h and 24 h after the loading dose (P < 0.001). Ticagrelor and its active metabolite AR-C124910XX showed a similar time to reach maximum concentration (C,) of 8 h, with the maximum concentration (C,) of 355 (242.50-522.00) ng ml,and 63.20 (50.80-85.15) ng ml,, respectively. Both clopidogrel and its active metabolite approached the C,at 2 h, with a similar C,of 8.67 (6.64-27.75) ng ml,vs. 8.53 (6.94-15.93) ng ml,. CONCLUSION: Ticagrelor showed much more potent platelet inhibition in comparison with clopidogrel in patients with CKD and NSTE-ACS.