Effect of Genotype-Guided Oral P2Y12 Inhibitor Selection vs Conventional Clopidogrel Therapy on Ischemic Outcomes After Percutaneous Coronary Intervention: The TAILOR-PCI Randomized Clinical Trial.

Importance: After percutaneous coronary intervention (PCI), patients with CYP2C19*2 or *3 loss-of-function (LOF) variants treated with clopidogrel have increased risk of ischemic events. Whether genotype-guided selection of oral P2Y12 inhibitor therapy improves ischemic outcomes is unknown. Objective: To determine the effect of a genotype-guided oral P2Y12 inhibitor strategy on ischemic outcomes in CYP2C19 LOF carriers after PCI. Design, Setting, and Participants: Open-label randomized clinical trial of 5302 patients undergoing PCI for acute coronary syndromes (ACS) or stable coronary artery disease (CAD). Patients were enrolled at 40 centers in the US, Canada, South Korea, and Mexico from May 2013 through October 2018; final date of follow-up was October 2019. Interventions: Patients randomized to the genotype-guided group (n = 2652) underwent point-of-care genotyping. CYP2C19 LOF carriers were prescribed ticagrelor and noncarriers clopidogrel. Patients randomized to the conventional group (n = 2650) were prescribed clopidogrel and underwent genotyping after 12 months. Main Outcomes and Measures: The primary end point was a composite of cardiovascular death, myocardial infarction, stroke, stent thrombosis, and severe recurrent ischemia at 12 months. A secondary end point was major or minor bleeding at 12 months. The primary analysis was in patients with CYP2C19 LOF variants, and secondary analysis included all randomized patients. The trial had 85% power to detect a minimum hazard ratio of 0.50. Results: Among 5302 patients randomized (median age, 62 years; 25% women), 82% had ACS and 18% had stable CAD; 94% completed the trial. Of 1849 with CYP2C19 LOF variants, 764 of 903 (85%) assigned to genotype-guided therapy received ticagrelor, and 932 of 946 (99%) assigned to conventional therapy received clopidogrel. The primary end point occurred in 35 of 903 CYP2C19 LOF carriers (4.0%) in the genotype-guided therapy group and 54 of 946 (5.9%) in the conventional therapy group at 12 months (hazard ratio [HR], 0.66 [95% CI, 0.43-1.02]; P = .06). None of the 11 prespecified secondary end points showed significant differences, including major or minor bleeding in CYP2C19 LOF carriers in the genotype-guided group (1.9%) vs the conventional therapy group (1.6%) at 12 months (HR, 1.22 [95% CI, 0.60-2.51]; P = .58). Among all randomized patients, the primary end point occurred in 113 of 2641 (4.4%) in the genotype-guided group and 135 of 2635 (5.3%) in the conventional group (HR, 0.84 [95% CI, 0.65-1.07]; P = .16). Conclusions and Relevance: Among CYP2C19 LOF carriers with ACS and stable CAD undergoing PCI, genotype-guided selection of an oral P2Y12 inhibitor, compared with conventional clopidogrel therapy without point-of-care genotyping, resulted in no statistically significant difference in a composite end point of cardiovascular death, myocardial infarction, stroke, stent thrombosis, and severe recurrent ischemia based on the prespecified analysis plan and the treatment effect that the study was powered to detect at 12 months. Trial Registration: ClinicalTrials.gov Identifier: NCT01742117.

Translational High-Dimensional Drug Interaction Discovery and Validation Using Health Record Databases and Pharmacokinetics Models.

Polypharmacy increases the risk of drug-drug interactions (DDIs). Combining epidemiological studies with pharmacokinetic modeling, we detected and evaluated high-dimensional DDIs among 30 frequent drugs. Multidrug combinations that increased the risk of myopathy were identified in the US Food and Drug Administration Adverse Event Reporting System (FAERS) and electronic medical record (EMR) databases by a mixture drug-count response model. CYP450 inhibition was estimated among the 30 drugs in the presence of 1 to 4 inhibitors using in vitro / in vivo extrapolation. Twenty-eight three-way and 43 four-way DDIs had significant myopathy risk in both databases and predicted increases in the area under the concentration-time curve ratio (AUCR) >2-fold. The high-dimensional DDI of omeprazole, fluconazole, and clonidine was associated with a 6.41-fold (FAERS) and 18.46-fold (EMR) increased risk of myopathy local false discovery rate (<0.005); the AUCR of omeprazole in this combination was 9.35. The combination of health record informatics and pharmacokinetic modeling is a powerful translational approach to detect high-dimensional DDIs.

Impact of an Interaction Between Clopidogrel and Selective Serotonin Reuptake Inhibitors.

Clopidogrel is a pro-drug that requires activation by the cytochrome P450 (CYP) enzyme system. Patients receiving clopidogrel are often treated with selective serotonin reuptake inhibitors (SSRIs) for co-existing depression. SSRIs that inhibit the CYP2C19 enzyme have the potential to reduce the effectiveness of clopidogrel. Using 5 US databases (1998 to 2013), we conducted a cohort study of adults who initiated clopidogrel while being treated with either an SSRI that inhibits CYP2C19 (fluoxetine and fluvoxamine) or a noninhibiting SSRI. Patients were matched by propensity score and followed for as long as they were exposed to both clopidogrel and the index SSRI group (primary analysis) or for 180 days after clopidogrel initiation (sensitivity analysis). Outcomes included a composite ischemic event (myocardial infarction, ischemic stroke, or a revascularization procedure) and a composite major bleeding event (gastrointestinal bleed or hemorrhagic stroke). The final propensity score-matched cohort comprised 9,281 clopidogrel initiators on CYP2C19-inhibiting SSRIs and 44,278 clopidogrel initiators on a noninhibiting SSRIs. Compared with those treated with a noninhibiting SSRI, patients on a CYP2C19-inhibiting SSRI had an increased risk of ischemic events (hazard ratio [HR] 1.12; 95% confidence interval [CI] 1.01 to 1.24), which was more pronounced in patients ≥65 years (HR 1.22; 95% CI 1.00 to 1.48). The HR for major bleeding was 0.76 (95% CI 0.50 to 1.17). In conclusion, the findings from this large, population-based study suggest that being treated with a CYP2C19-inhibiting SSRI when initiating clopidogrel may be associated with slight decrease in effectiveness of clopidogrel.

Voriconazole-Induced Hepatitis via Simvastatin- and Lansoprazole-Mediated Drug Interactions: A Case Report and Review of the Literature.

Therapeutic voriconazole concentrations have a narrow window of effectiveness before causing cholestatic hepatitis. After undergoing 1 year of voriconazole therapy for pulmonary aspergillosis, a 44-year-old man began treatment with 30 mg lansoprazole for gastroesophageal reflux symptoms. Within 5 days of starting treatment with lansoprazole, the patient presented with fatigue, jaundice, and cholestatic hepatitis. The hepatitis promptly resolved after stopping lansoprazole treatment. Sixteen months later, the patient was given simvastatin therapy, as recommended by the American Diabetes Association to prevent cardiovascular disease for patients with diabetes who are aged >40 years and have one additional risk factor. Within 2 weeks of taking simvastatin, a 3-hydroxy-3-methylglutaryl CoA reductase (statin) therapy, the patient redeveloped fatigue, jaundice, and cholestatic hepatitis. He described both episodes of fatigue and jaundice similarly in terms of onset and intensity. Voriconazole is metabolized by both CYP2C19 and CYP3A4 isoenzymes. Lansoprazole is an inhibitor of the CYP2C19 isoenzyme. Competition between voriconazole and lansoprazole likely led to increased voriconazole serum concentration and acute cholestatic hepatitis in this patient. Simvastatin inhibits the CYP3A4 isoenzyme. After the patient took 10 mg simvastatin daily for 2 weeks, cholestatic hepatitis occurred. The voriconazole concentration remained elevated (4.1 µg/ml) when measured 15 days after stopping simvastatin. The patient's Naranjo Adverse Drug Reaction Probability Scale score of 7 revealed that the cholestatic hepatitis was probably precipitated by lansoprazole. Likewise, the patient's Naranjo score of 9 also revealed that cholestatic hepatitis was attributable to a definite adverse drug reaction precipitated by the addition of simvastatin to the stable baseline regimen of voriconazole. In a single patient, two different inhibitors of the cytochrome P450 pathway stimulated voriconazole-induced cholestatic hepatitis. Although the major cytochrome P450 pathways for the metabolism and clearance of lansoprazole and simvastatin are different, they both likely contributed to the reduced hepatic clearance of voriconazole in this patient.

Clinical Weighting of Drug-Drug Interactions in Hospitalized Elderly.

Adverse drug reactions impact on patient health, effectiveness of pharmacological therapy and increased health care costs. This investigation intended to detect the most critical drug-drug interactions in hospitalized elderly patients, weighting clinical risk. We conducted a cross-sectional study between January and April 2014; all patients 70 years or older, hospitalized for >24 hr and prescribed at least one medication were included in the study. Drug-drug interactions were estimated by combining Stockley's, Hansten and Tatro drug interactions. Drug-drug interactions were weighted using a risk-analysis method based on failure modes, effects and criticality analysis. We calculated a criticality index for each drug involved in the drug-drug interactions based on the severity of the interaction mechanism, the frequency the drug was involved in drug-drug interactions and the risk of drug-drug interactions in patients with impaired renal function. The average number of drugs consumed in the hospital was 6 ± 2.69, involving 160 active ingredients. The most frequent were as follows: Furosemide, followed by Enalapril. Of drug-drug interactions, 2% were classified as contraindicated, 14% advised against and 83% advised caution during the hospital stay. Thirty-four drug-drug interactions were assessed, of which 23 were pharmacodynamic drug-drug interactions and 12 were pharmacokinetic drug-drug interactions (1 was both). The clinical risk calculated for each drug-drug interaction included heparins + non-steroidal anti-inflammatory drugs (NSAIDs) or Digoxin + Calcium Gluconate, cases which are pharmacodynamic drug-drug interactions with agonist effect and clinical risk of bleeding, one of the most common clinical risks in the hospital. An index of clinical risk for drug-drug interactions can be calculated based on severity by the interaction mechanism, the frequency that the drug is involved in drug-drug interactions and the risk of drug-drug interactions in an elderly patient with impaired renal function.

Use of three-compartment physiologically based pharmacokinetic modeling to predict hepatic blood levels of fluvoxamine relevant for drug-drug interactions.

Using a three-compartment physiologically based pharmacokinetic (PBPK) model and a tube model for hepatic extraction kinetics, equations for calculating blood drug levels (Cb s) and hepatic blood drug levels (Chb s, proportional to actual hepatic drug levels), were derived mathematically. Assuming the actual values for total body clearance (CLtot ), oral bioavailability (F), and steady-state distribution volume (Vdss ), Cb s, and Chb s after intravenous and oral administration of fluvoxamine (strong perpetrator in drug-drug interactions, DDIs), propranolol, imipramine, and tacrine were simulated. Values for Cb s corresponded to the actual values for all tested drugs, and mean Chb and maximal Chb -to-maximal Cb ratio predicted for oral fluvoxamine administration (50 mg twice-a-day administration) were nearly 100 nM and 2.3, respectively, which would be useful for the predictions of the DDIs caused by fluvoxamine. Fluvoxamine and tacrine are known to exhibit relatively large F values despite having CLtot similar to or larger than hepatic blood flow, which may be because of the high liver uptake (almost 0.6) upon intravenous administration. The present method is thus considered to be more predictive of the Chb for perpetrators of DDIs than other methods.

No influence of the CYP2C19-selective inhibitor omeprazole on the pharmacokinetics of the dopamine receptor agonist rotigotine.

Rotigotine, a non-ergolinic dopamine receptor agonist administered transdermally via a patch, is metabolized by several cytochrome P-450 (CYP450) isoenzymes, including CYP2C19. This open-label, multiple-dose study evaluated the effect of omeprazole, a competitive inhibitor of CYP2C19, on the pharmacokinetics of rotigotine and its metabolites under steady-state conditions in healthy male subjects (of the extensive metabolizer phenotype, CYP2C19). Subjects received rotigotine 2 mg/24 hours on days 1-3, 4 mg/24 hours on days 4-12, and omeprazole 40 mg once daily on days 7-12 immediately after patch application. Blood and urine samples were collected on days 6 and 12 to evaluate rotigotine pharmacokinetic parameters alone and in the presence of omeprazole. Data from 37 subjects were available for pharmacokinetic analysis. Point estimates (90% confidence intervals, CI) for the ratios of AUC(0-24)SS and Cmax,SS of unconjugated rotigotine for the comparison rotigotine + omeprazole:rotigotine alone were close to 1 (0.9853 [0.9024, 1.0757] for AUC(0-24)SS and 1.0613 [0.9723, 1.1585] for Cmax,SS ) with 90% CIs within the acceptance range for bioequivalence (0.80, 1.25). Selective inhibition of CYP2C19 by omeprazole did not alter the steady-state pharmacokinetic profile of rotigotine or its metabolites. Thus, rotigotine dose adjustment is not required in patients receiving omeprazole, or other CYP2C19 inhibitors.