Effectiveness of Clopidogrel vs Alternative P2Y12 Inhibitors Based on the ABCD-GENE Score.

BACKGROUND: An ABCD-GENE (age, body mass index, chronic kidney disease, diabetes, and CYP2C19 genetic variants) score ≥10 predicts reduced clopidogrel effectiveness, but its association with response to alternative therapy remains unclear. OBJECTIVES: The aim of this study was to evaluate the association between ABCD-GENE score and the effectiveness of clopidogrel vs alternative P2Y12 inhibitor (prasugrel or ticagrelor) therapy after percutaneous coronary intervention (PCI). METHODS: A total of 4,335 patients who underwent PCI, CYP2C19 genotyping, and P2Y12 inhibitor treatment were included. The primary outcome was major atherothrombotic events (MAE) within 1 year after PCI. Cox regression was performed to assess event risk in clopidogrel-treated (reference) vs alternatively treated patients, with stabilized inverse probability weights derived from exposure propensity scores after stratifying by ABCD-GENE score and further by CYP2C19 loss-of-function (LOF) genotype. RESULTS: Among patients with scores <10 (n = 3,200), MAE was not different with alternative therapy vs clopidogrel (weighted HR: 0.89; 95% CI: 0.65-1.22; P = 0.475). The risk for MAE also did not significantly differ by treatment among patients with scores ≥10 (n = 1,135; weighted HR: 0.75; 95% CI: 0.51-1.11; P = 0.155). Among CYP2C19 LOF allele carriers, MAE risk appeared lower with alternative therapy in both the group with scores <10 (weighted HR: 0.50; 95% CI: 0.25-1.01; P = 0.052) and the group with scores ≥10 (weighted HR: 0.48; 95% CI: 0.29-0.80; P = 0.004), while there was no difference in the group with scores <10 and no LOF alleles (weighted HR: 1.03; 95% CI: 0.70-1.51; P = 0.885). CONCLUSIONS: These data support the use of alternative therapy over clopidogrel in CYP2C19 LOF allele carriers after PCI, regardless of ABCD-GENE score, while clopidogrel is as effective as alternative therapy in non-LOF patients with scores <10.

Impact of Pregnancy on the Pharmacokinetics and Metabolism of Nicotinamide in Humans.

In pre-eclampsia models, nicotinamide (NAM) has protective effects in pre-eclampsia and is being evaluated as a therapeutic nutraceutical in clinical studies. NAM undergoes extensive hepatic metabolism by NAM N-methyltransferase to methylnicotinamide (MNA), which is subsequently metabolized to methyl-2-pyridone-5-carboxamide (M2PY) by aldehyde oxidase. However, the pharmacokinetics of NAM and its major metabolites has never been studied in pregnant individuals. Blood samples were collected before and 1, 2, 4, 8, and 24 hours after single 1 g oral NAM dose in healthy pregnant (gestational age 24-33 weeks) and nonpregnant female volunteers (n = 6/group). Pooled urine was collected from 0 to 8 hours. NAM, MNA, and M2PY area under the concentration-time curve (AUC) data were analyzed by noncompartmental analysis. No difference in the plasma AUC0→24 of NAM (median (25%-75%): 463 (436-576) vs. 510 (423, 725) µM*hour, P = 0.430) and its intermediate metabolite MNA (89.1 (60.4, 124.4) vs. 83.8 (62.7, 93.7) µM*hour, P = 0.515) was observed in pregnant and nonpregnant volunteers, respectively; however, the terminal metabolite M2PY AUC0 → 24 was significantly lower in pregnant individuals (218 (188, 254) vs. 597 (460, 653) µM*hour, P < 0.001). NAM renal clearance (CLR ; P = 0.184), MNA CLR (P = 0.180), and total metabolite formation clearance (P = 0.405) did not differ across groups; however, M2PY CLR was significantly higher in pregnant individuals (10.5 (9.3-11.3) vs. 7.5 (6.4-8.5) L/h, P = 0.002). These findings demonstrate that the PK of NAM and systemic exposure to its intermediate metabolite MNA are not significantly altered during pregnancy, and systemic exposure to NAM's major metabolite M2PY was reduced during pregnancy due to increased renal elimination.

Antihypertensive medication use during pregnancy in a real-world cohort of patients diagnosed with a hypertensive disorder of pregnancy.

Hypertensive disorders of pregnancy (HDP) are rising in prevalence and associated with adverse maternal and infant health outcomes. Current guidelines recommend labetalol, nifedipine, and methyldopa as acceptable first-line agents to treat HDP in outpatient settings. However, the current practice regarding antihypertensive medication usage and selection remain unclear. A retrospective, observational cohort study was conducted in 1,641 patients with a physician diagnosis of HDP who delivered at two academic medical centers in North Carolina from 2014 to 2017. Use of any antihypertensive medication, and the agent selected, at any encounter during pregnancy or on the delivery date was collected from the electronic health record. Proportions were compared across HDP diagnosis (eclampsia/severe preeclampsia, chronic hypertension with superimposed preeclampsia, preeclampsia, gestational hypertension) by Chi-square tests and multivariable logistic regression. Antihypertensive medications were used in 1,276 (77.8%) patients overall. Among treated patients, labetalol (74.9%) was the most frequently used medication followed by nifedipine (29.6%) and hydralazine (20.5%). Methyldopa was used infrequently (4.4%). HDP type was the strongest factor associated with use of an antihypertensive agent. Relative to gestational hypertension, antihypertensive use was significantly more likely [odds ratio (95% CI)] in patients with severe preeclampsia [5.94 (3.85-9.16)], chronic hypertension with superimposed preeclampsia [4.99 (3.46-7.19)], and preeclampsia [2.13 (1.61-2.82)]. In a real-world setting, antihypertensive medication use among HDP patients was common, labetalol, nifedipine, and hydralazine were the most commonly selected agents, and increasing HDP severity was associated with a higher likelihood of antihypertensive use. Future studies comparing medication effectiveness in pregnant patients with distinct HDP diagnoses are needed.

Pregnancy related hormones increase CYP3A mediated buprenorphine metabolism in human hepatocytes: a comparison to CYP3A substrates nifedipine and midazolam.

Introduction: Pregnancy increases the clearance of CYP3A4 substrate drugs and pregnancy-related hormones (PRHs) induce hepatic CYP3A4 expression and metabolism. However, it remains unclear to what extent the magnitude of PRH-evoked changes in hepatic CYP3A metabolism varies across multiple substrates. This study quantified the impact of PRHs on CYP3A protein concentrations and buprenorphine metabolism in human hepatocytes, and compared the magnitude of these effects to nifedipine and midazolam metabolism. Methods: Sandwich-cultured human hepatocytes (SCHH) from female donors were exposed to PRHs, administered in combination across a range of physiologically relevant concentrations, for 72 h. Absolute protein concentrations of CYP3A4, CYP3A5, and CYP3A7 in SCHH membrane fractions were quantified by nanoLC-MS/MS, and norbuprenorphine (nor-BUP), dehydro-nifedipine (dehydro-NIF), and 1-hydroxy-midazolam (1-OH-MDZ) formation was evaluated. Results: Compared to control, PRH exposure increased CYP3A4, CYP3A7, and total CYP3A protein concentrations, but not CYP3A5 concentrations, and increased nor-BUP, dehydro-NIF, and 1-OH-MDZ formation in a concentration-dependent manner. The formation of nor-BUP, dehydro-NIF, and 1-OH-MDZ each positively correlated with PRH-mediated changes in total CYP3A protein concentrations. The PRH-evoked increase in nor-BUP formation was evident in all donors; however, the PRH induction of dehydro-NIF and 1-OH-MDZ formation was diminished in a hepatocyte donor with high basal CYP3A5 expression. Discussion: These findings demonstrate that PRHs increase buprenorphine, nifedipine, and midazolam metabolism in SCHH via induction of CYP3A4 and total CYP3A protein concentrations, and the magnitude of these effects vary across hepatocyte donors in a substrate-specific manner. These data provide insight into the contribution of PRH induction of CYP3A4 metabolism to increased buprenorphine clearance during pregnancy.

Pharmacogenetics of P2Y12 receptor inhibitors.

Oral P2Y12 inhibitors are commonly prescribed for cardiovascular disease and include clopidogrel, prasugrel, and ticagrelor. Each of these drugs has its strengths and weaknesses. Prasugrel and ticagrelor are more potent inhibitors of platelet aggregation and were shown to be superior to clopidogrel in preventing major adverse cardiovascular events after an acute coronary syndrome and percutaneous coronary intervention (PCI) in the absence of genotyping. However, both are associated with an increased risk for non-coronary artery bypass-related bleeding. Clopidogrel is a prodrug requiring bioactivation, primarily via the CYP2C19 enzyme. Approximately 30% of individuals have a CYP2C19 no function allele and decreased or no CYP2C19 enzyme activity. Clopidogrel-treated carriers of a CYP2C19 no function allele have decreased exposure to the clopidogrel active metabolite and lesser inhibition of platelet aggregation, which likely contributed to reduced clopidogrel efficacy in clinical trials. The pharmacogenetic data for clopidogrel are most robust in the setting of PCI, but evidence is accumulating for other indications. Guidance is available from expert consensus groups and regulatory agencies to assist with integrating genetic information into P2Y12 inhibitor prescribing decisions, and CYP2C19 genotype-guided antiplatelet therapy after PCI is one of the most common examples of clinical pharmacogenetic implementation. Herein, we review the evidence for pharmacogenetic associations with clopidogrel response and outcomes with genotype-guided P2Y12 inhibitor selection and describe guidance to assist with pharmacogenetic implementation. We also describe processes for applying genotype data for P2Y12 inhibitor therapy selection and remaining gaps in the field. Ultimately, consideration of both clinical and genetic factors may guide selection of P2Y12 inhibitor therapy that optimally balances the atherothrombotic and bleeding risks.

Evaluation of Potential Racial Disparities in CYP2C19-Guided P2Y12 Inhibitor Prescribing After Percutaneous Coronary Intervention.

Black patients suffer worse outcomes after percutaneous coronary intervention (PCI) than White patients. Inequities in antiplatelet prescribing may contribute to this health disparity. We compared P2Y12 inhibitor prescribing by race following CYP2C19 genotyping to guide antiplatelet therapy selection after PCI. Patients from 9 sites that performed clinical CYP2C19 genotyping after PCI were included. Alternative therapy (e.g., prasugrel or ticagrelor) was recommended for CYP2C19 no-function allele carriers, in whom clopidogrel is predicted to be less effective. The primary outcome was choice of P2Y12 inhibitor (clopidogrel vs. alternative therapy) based on genotype. Of 3,342 patients included, 2,448 (73%) were White, and 659 (20%) were Black. More Black than White patients had a no-function allele (34.3% vs. 29.7%, P = 0.024). At hospital discharge following PCI, 44.2% of Black and 44.0% of White no-function allele carriers were prescribed alternative therapy. At the time of the last follow-up within 12 months, numerically fewer Black (51.8%) than White (56.7%) no-function allele carriers were prescribed alternative therapy (P = 0.190). However, the difference was not significant after accounting for other factors associated with P2Y12 inhibitor selection (odds ratio 0.79, 95% confidence interval 0.58-1.08). Alternative therapy use did not differ between Black (14.3%) and White (16.7%) patients without a no-function allele (P = 0.232). Among real-world patients who received CYP2C19 testing after PCI, P2Y12 inhibitor prescribing rates did not differ between Black and White patients. Our data suggest an absence of racial disparity in genotype-guided antiplatelet prescribing among patients receiving CYP2C19 testing.

Impact of pregnancy related hormones on drug metabolizing enzyme and transport protein concentrations in human hepatocytes.

Pregnancy alters the disposition and exposure to multiple drugs indicated for pregnancy-related complications. Previous in vitro studies have shown that pregnancy-related hormones (PRHs) alter the expression and function of certain cytochrome P450s (CYPs) in human hepatocytes. However, the impact of PRHs on hepatic concentrations of non-CYP drug-metabolizing enzymes (DMEs) and transport proteins remain largely unknown. In this study, sandwich-cultured human hepatocytes (SCHH) from five female donors were exposed to vehicle or PRHs (estrone, estradiol, estriol, progesterone, cortisol, and placental growth hormone), administered individually or in combination, across a range of physiologically relevant PRH concentrations for 72 h. Absolute concentrations of 33 hepatic non-CYP DMEs and transport proteins were quantified in SCHH membrane fractions using a quantitative targeted absolute proteomics (QTAP) isotope dilution nanoLC-MS/MS method. The data revealed that PRHs altered the absolute protein concentration of various DMEs and transporters in a concentration-, isoform-, and hepatocyte donor-dependent manner. Overall, eight of 33 (24%) proteins exhibited a significant PRH-evoked net change in absolute protein concentration relative to vehicle control (ANOVA p < 0.05) across hepatocyte donors: 1/11 UGTs (9%; UGT1A4), 4/6 other DMEs (67%; CES1, CES2, FMO5, POR), and 3/16 transport proteins (19%; OAT2, OCT3, P-GP). An additional 8 (24%) proteins (UGT1A1, UGT2B4, UGT2B10, FMO3, OCT1, MRP2, MRP3, ENT1) exhibited significant PRH alterations in absolute protein concentration within at least two individual hepatocyte donors. In contrast, 17 (52%) proteins exhibited no discernable impact by PRHs either within or across hepatocyte donors. Collectively, these results provide the first comprehensive quantitative proteomic evaluation of PRH effects on non-CYP DMEs and transport proteins in SCHH and offer mechanistic insight into the altered disposition of drug substrates cleared by these pathways during pregnancy.

Evaluation of race and ethnicity disparities in outcome studies of CYP2C19 genotype-guided antiplatelet therapy.

Dual antiplatelet therapy with a P2Y12 inhibitor (clopidogrel, prasugrel, or ticagrelor) and aspirin remains the standard of care for all patients undergoing percutaneous coronary intervention (PCI). It is well-established that patients carrying CYP2C19 no function alleles have impaired capacity to convert clopidogrel into its active metabolite and thus, are at higher risk of major adverse cardiovascular events (MACE). The metabolism and clinical effectiveness of prasugrel and ticagrelor are not affected by CYP2C19 genotype, and accumulating evidence from multiple randomized and observational studies demonstrates that CYP2C19 genotype-guided antiplatelet therapy following PCI improves clinical outcomes. However, most antiplatelet pharmacogenomic outcome studies to date have lacked racial and ethnic diversity. In this review, we will (1) summarize current guideline recommendations and clinical outcome evidence related to CYP2C19 genotype-guided antiplatelet therapy, (2) evaluate the presence of potential racial and ethnic disparities in the major outcome studies supporting current genotype-guided antiplatelet therapy recommendations, and (3) identify remaining knowledge gaps and future research directions necessary to advance implementation of this precision medicine strategy for dual antiplatelet therapy in diverse, real-world clinical settings.

Use of Real-World Data and Physiologically-Based Pharmacokinetic Modeling to Characterize Enoxaparin Disposition in Children With Obesity.

Dosing guidance for children with obesity is often unknown despite the fact that nearly 20% of US children are classified as obese. Enoxaparin, a commonly prescribed low-molecular-weight heparin, is dosed based on body weight irrespective of obesity status to achieve maximum concentration within a narrow therapeutic or prophylactic target range. However, whether children with and without obesity experience equivalent enoxaparin exposure remains unclear. To address this clinical question, 2,825 anti-activated factor X (anti-Xa) surrogate concentrations were collected from the electronic health records of 596 children, including those with obesity. Using linear mixed-effects regression models, we observed that 4-hour anti-Xa concentrations were statistically significantly different in children with and without obesity, even for children with the same absolute dose (P = 0.004). To further mechanistically explore obesity-associated differences in anti-Xa concentration, a pediatric physiologically-based pharmacokinetic (PBPK) model was developed in adults, and then scaled to children with and without obesity. This PBPK model incorporated binding of enoxaparin to antithrombin to form anti-Xa and elimination via heparinase-mediated metabolism and glomerular filtration. Following scaling, the PBPK model predicted real-world pediatric concentrations well, with an average fold error (standard deviation of the fold error) of 0.82 (0.23) and 0.87 (0.26) in children with and without obesity, respectively. PBPK model simulations revealed that children with obesity have at most 20% higher 4-hour anti-Xa concentrations under recommended, total body weight-based dosing compared to children without obesity owing to reduced weight-normalized clearance. Enoxaparin exposure was better matched across age groups and obesity status using fat-free mass weight-based dosing.

Impact of the ABCD-GENE Score on Clopidogrel Clinical Effectiveness after PCI: A Multi-Site, Real-World Investigation.

The Age, Body mass index, Chronic kidney disease, Diabetes mellitus, and CYP2C19 GENEtic variants (ABCD-GENE) score was developed to identify patients at risk for diminished antiplatelet effects with clopidogrel after percutaneous coronary intervention (PCI). The objective of this study was to validate the ability of the ABCD-GENE score to predict the risk for atherothrombotic events in a diverse, real-world population of clopidogrel-treated patients who underwent PCI and received clinical CYP2C19 genotyping to guide antiplatelet therapy. A total of 2,341 adult patients who underwent PCI, were genotyped for CYP2C19, and received treatment with clopidogrel across four institutions were included (mean age 64 ± 12 years, 35% women, and 20% Black). The primary outcome was major atherothrombotic events, defined as the composite of all-cause death, myocardial infarction, ischemic stroke, stent thrombosis, or revascularization for unstable angina within 12 months following PCI. Major adverse cardiovascular events (MACE), defined as the composite of cardiovascular death, myocardial infarction, ischemic stroke, or stent thrombosis, was assessed as the secondary outcome. Outcomes were compared between patients with an ABCD-GENE score ≥ 10 vs. < 10. The risk of major atherothrombotic events was higher in patients with an ABCD-GENE score ≥ 10 (n = 505) vs. < 10 (n = 1,836; 24.6 vs. 14.7 events per 100 patient-years, adjusted hazard ratio (HR) 1.66, 95% confidence interval (CI), 1.23-2.25, P < 0.001). The risk for MACE was also higher among patients with a score ≥ 10 vs. < 10 (16.7 vs. 10.1 events per 100 patient-years, adjusted HR 1.59, 95% CI 1.11-2.30, P = 0.013). Our diverse, real-world data demonstrate diminished clopidogrel effectiveness in post-PCI patients with an ABCD-GENE score ≥ 10.

CYP2C19 Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention in Diverse Clinical Settings.

Background Studies have demonstrated increased risk of major atherothrombotic events in CYP2C19 loss-of-function (LOF) variant carriers versus non-carriers treated with clopidogrel after percutaneous coronary intervention (PCI). We sought to evaluate real-world outcomes with the clinical implementation of CYP2C19-guided antiplatelet therapy after PCI. Methods and Results Data from 9 medical centers where genotyping was performed in the setting of PCI were included. Alternative therapy with prasugrel or ticagrelor was recommended for patients with a CYP2C19 LOF variant. The primary outcome was the composite of major atherothrombotic events (all-cause death, myocardial infarction, ischemic stroke, stent thrombosis, or hospitalization for unstable angina) within 12 months following PCI. Moderate or severe/life-threatening bleeding within 12 months was a secondary outcome. Among 3342 patients, 1032 (31%) were LOF carriers, of whom 571/1032 (55%) were treated with alternative therapy. In LOF carriers, the rate of major atherothrombotic events was lower in patients treated with alternative therapy versus clopidogrel (adjusted HR, 0.56; 95% CI 0.39-0.82). In those without a LOF allele, no difference was observed (adjusted HR, 1.07; 95% CI 0.71-1.60). There was no difference in bleeding with alternative therapy versus clopidogrel in either LOF carriers or those without a LOF allele. Conclusions Real-world data demonstrate lower atherothrombotic risk in CYP2C19 LOF carriers treated with alternative therapy versus clopidogrel and similar risk in those without a LOF allele treated with clopidogrel or alternative therapy. These data suggest that PCI patients treated with clopidogrel should undergo genotyping so that CYP2C19 LOF carriers can be identified and treated with alternative therapy.

Pharmacogenomic prescribing opportunities in percutaneous coronary intervention and bone marrow transplant patients.

Aim: To evaluate the potential impact of preemptive multigene pharmacogenomic (PGx) testing on medication prescribing in real-world clinical settings. Patients & methods: Prescription frequencies for 65 medications with actionable PGx recommendations were collected in 215 percutaneous coronary intervention (PCI) and 131 allogeneic hematopoietic cell transplant (allo-HCT) patients. A simulation projected the number of PGx-guided prescribing opportunities. Results: In PCI and allo-HCT patients, respectively, 66.5 and 90.1% were prescribed at least one medication with actionable PGx prescribing recommendations. Simulations projected 26.5 and 41.2 total PGx-guided prescribing opportunities per 100 PCI and allo-HCT patients, respectively, if multigene PGx results were available. Conclusion: A multigene PGx testing strategy offers potential to optimize medication prescribing beyond clopidogrel and tacrolimus in PCI and allo-HCT patients.

Clinical Pharmacogenetics Implementation Consortium Guideline for CYP2C19 Genotype and Clopidogrel Therapy: 2022 Update.

CYP2C19 catalyzes the bioactivation of the antiplatelet prodrug clopidogrel, and CYP2C19 genotype impacts clopidogrel active metabolite formation. CYP2C19 intermediate and poor metabolizers who receive clopidogrel experience reduced platelet inhibition and increased risk for major adverse cardiovascular and cerebrovascular events. This guideline is an update to the 2013 Clinical Pharmacogenetics Implementation Consortium (CPIC) guideline for the use of clopidogrel based on CYP2C19 genotype and includes expanded indications for CYP2C19 genotype-guided antiplatelet therapy, increased strength of recommendation for CYP2C19 intermediate metabolizers, updated CYP2C19 genotype to phenotype translation, and evidence from an expanded literature review (updates at www.cpicpgx.org).

The Impact of Pregnancy on Antihypertensive Drug Metabolism and Pharmacokinetics: Current Status and Future Directions.

INTRODUCTION: Hypertensive disorders of pregnancy (HDP) are rising in prevalence, and increase risk of adverse maternal and fetal outcomes. Physiologic changes occur during pregnancy that alter drug pharmacokinetics. However, antihypertensive drugs lack pregnancy-specific dosing recommendations due to critical knowledge gaps surrounding the extent of gestational changes in antihypertensive drug pharmacokinetics and underlying mechanisms. AREAS COVERED: This review (1) summarizes currently recommended medications and dosing strategies for non-emergent HDP treatment, (2) reviews and synthesizes existing literature identified via a comprehensive PubMed search evaluating gestational changes in the maternal pharmacokinetics of commonly prescribed HDP drugs (notably labetalol and nifedipine), and (3) offers insight into the metabolism and clearance mechanisms underlying altered HDP drug pharmacokinetics during pregnancy. Remaining knowledge gaps and future research directions are summarized. EXPERT OPINION: A series of small pharmacokinetic studies illustrate higher oral clearance of labetalol and nifedipine during pregnancy. Pharmacokinetic modeling and preclinical studies suggest these effects are likely due to pregnancy-associated increases in hepatic UGT1A1- and CYP3A4-mediated first-pass metabolism and lower bioavailability. Accordingly, higher and/or more frequent doses may be needed to lower blood pressure during pregnancy. Future research is needed to address various evidence gaps and inform the development of more precise antihypertensive drug dosing strategies.

How-To Guide for Overcoming Barriers of Research and Scholarship Training in Pharm.D. and Pharmacy Residency Programs.

Accrediting bodies for Doctor of Pharmacy (Pharm.D.) and postgraduate residency training programs recognize the importance of research and scholarship training. However, specific guidance on how research and scholarship fundamentals should be delivered to trainees have not been provided. As a result, competing priorities often create barriers for trainees to develop research and scholarship skills and limit the trainees' ability to conduct and participate in high-quality, meaningful research experiences. The purpose of this "how-to" guide is to assist pharmacy school faculty and pharmacy residency program directors with strategies to overcome programmatic, trainee, and project barriers to providing a high-quality training experience in research and scholarship. Programmatic topics addressed include institutional support and program oversight, expertise and number of research mentors, incentives for mentor engagement, and competing priorities that diminish time for research activities. Trainee topics include lack of trainee interest in the assigned project, trainee departure prior to project completion, lack of knowledge of the publication process, and time constraints to work on the project. Project topics addressed include time needed to initiate a project, training on methodology relevant to a project, selection of projects that lack rigor, depth, or feasibility, and resource constraints to disseminate project results. A summary of specific recommended actions is provided to effectively overcome these common barriers encountered in research and scholarship training programs.

Effects of aging on clinical outcomes in patients receiving genotype-guided P2Y12 inhibitor selection after percutaneous coronary intervention.

STUDY OBJECTIVE: To compare the clinical effectiveness of genotype-guided P2Y12 inhibitor selection following PCI in older patients (≥70 years) and younger patients (<70 years). DESIGN AND SETTING: Single-center, retrospective, cohort study. Risk of major adverse cardiovascular or cerebrovascular events (MACCE), defined as stent thrombosis, ischemic stroke, transient ischemic attack, non-fatal acute coronary syndrome, or cardiovascular death during 12 months after PCI, was compared across genotype and antiplatelet therapy groups by proportional hazards regression in patients ≥70 years and <70 years. PATIENTS: 1,469 patients who underwent PCI and had CYP2C19 genotype testing at a single academic medical center. MEASUREMENTS AND MAIN RESULTS: The study population was comprised of 402 (27.4%) ≥70 years (older group) and 1067 (72.6%) <70 years (younger group). Alternative P2Y12 inhibitors (prasugrel or ticagrelor) were used less often in the older group than the younger group in patients with a CYP2C19 no function allele (55% vs. 67%; p = 0.02) and in patients without a no function allele (10% vs. 35%, p < 0.001). For patients treated with clopidogrel, MACCE was significantly higher in no function allele carriers compared to those without a no function allele in the older group (19.2% vs. 12.7%; adjusted HR 2.32; 95% CI 1.07-5.05; p = 0.03) and the younger group (17.4% vs. 10.4%; adjusted HR 2.01; 95% CI 1.17-3.46; p = 0.01). In patients without a no function allele, MACCE risk was similar with clopidogrel compared to prasugrel or ticagrelor in the older group (adjusted HR 0.99; 95% CI 0.44-2.21; p = 0.98) and the younger group (adjusted HR 1.12; 95% CI 0.72-1.74; p = 0.61). CONCLUSION: This study suggests important clinical benefits of CYP2C19 genotype-guided antiplatelet therapy after PCI in both younger and older patients.

Implementation and Initial Evaluation of a Research and Scholarship Training Pathway in a Doctor of Pharmacy Curriculum.

Objective. To design, implement, and assess the initial impact of a pharmacy student research and scholarship training pathway.Methods. The Research and Scholarship in Pharmacy (RASP) pathway was designed to create a longitudinal, elective pathway within a Doctor of Pharmacy (PharmD) curriculum at a single institution. The pathway consisted of three elective courses built around a faculty-mentored scholarly project where students framed an answerable question, generated and interpreted relevant data, and communicated their findings in oral and written form. Following implementation, a retrospective, multi-method analysis was conducted to evaluate the impact of the program on the initial two student cohorts that completed it and assess their perceptions of the value of the pathway.Results. Fifty students (25 in each of two cohorts) completed the three-course sequence. Students were supported by 33 distinct faculty mentors. Thirty-eight (76%) students presented an abstract derived from their project at a national meeting. The first cohort exit survey (96% response rate) revealed positive student perceptions regarding the value of and satisfaction with the research pathway. Twenty-three (96%) students were satisfied with their research experience, 21 (88%) were satisfied with their faculty mentor, and 24 (100%) were satisfied with their development of project management skills. In the first cohort, 10 (40%) students published an original research manuscript within one year of graduation.Conclusion. The Research and Scholarship in Pharmacy pathway feasibly and effectively provided a mechanism for students to engage in a faculty-mentored longitudinal research experience within a PharmD curriculum that promoted skill development and opportunities for scholarship. Initial implementation demonstrated high rates of student satisfaction, low rates of student attrition, and high rates of scholarly output.

Pregnancy-Related Hormones Increase UGT1A1-Mediated Labetalol Metabolism in Human Hepatocytes.

Pregnancy-related hormones (PRH) are recognized as important regulators of hepatic cytochrome P450 enzyme expression and function. However, the impact of PRH on the hepatic expression and function of uridine diphosphate glucuronosyltransferases (UGTs) remains unclear. Using primary human hepatocytes, we evaluated the effect of PRH exposure on mRNA levels and protein concentrations of UGT1A1, UGT2B7, and other key UGT enzymes, and on the metabolism of labetalol (a UGT1A1 and UGT2B7 substrate commonly prescribed to treat hypertensive disorders of pregnancy). Sandwich-cultured human hepatocytes (SCHH) from female donors were exposed to the PRH estradiol, estriol, estetrol, progesterone, and cortisol individually or in combination. We quantified protein concentrations of UGT1A1, UGT2B7, and four additional UGT1A isoforms in SCHH membrane fractions and evaluated the metabolism of labetalol to its glucuronide metabolites in SCHH. PRH exposure increased mRNA levels and protein concentrations of UGT1A1 and UGT1A4 in SCHH. PRH exposure also significantly increased labetalol metabolism to its UGT1A1-derived glucuronide metabolite in a concentration-dependent manner, which positively correlated with PRH-induced changes in UGT1A1 protein concentrations. In contrast, PRH did not alter UGT2B7 mRNA levels or protein concentrations in SCHH, and formation of the UGT2B7-derived labetalol glucuronide metabolite was decreased following PRH exposure. Our findings demonstrate that PRH alter expression and function of UGT proteins in an isoform-specific manner and increase UGT1A1-mediated labetalol metabolism in human hepatocytes by inducing UGT1A1 protein concentrations. These results provide mechanistic insight into the increases in labetalol clearance observed in pregnant individuals.

Impact of the CYP2C19*17 Allele on Outcomes in Patients Receiving Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention.

Genotyping for CYP2C19 no function alleles to guide antiplatelet therapy after percutaneous coronary intervention (PCI) improves clinical outcomes. Although results for the increased function CYP2C19*17 allele are also reported, its clinical relevance in this setting remains unclear. A collaboration across nine sites examined antiplatelet therapy prescribing and clinical outcomes in 3,342 patients after implementation of CYP2C19-guided antiplatelet therapy. Risk of major atherothrombotic and bleeding events over 12 months after PCI were compared across cytochrome P450 2C19 isozyme (CYP2C19) metabolizer phenotype and antiplatelet therapy groups by proportional hazards regression. Clopidogrel was prescribed to a similar proportion of CYP2C19 normal (84.5%), rapid (82.9%), and ultrarapid metabolizers (80.6%) (P = 0.360). Clopidogrel-treated normal metabolizers (20.4 events/100 patient-years; adjusted hazard ratio (HR) 1.00, 95% confidence interval (CI), 0.75-1.33, P = 0.993) and clopidogrel-treated rapid or ultrarapid metabolizers (19.1 events/100 patient-years; adjusted HR 0.95, 95% CI, 0.69-1.30, P = 0.734) exhibited no difference in major atherothrombotic events compared with patients treated with prasugrel or ticagrelor (17.6 events/100 patient-years). In contrast, clopidogrel-treated intermediate and poor metabolizers exhibited significantly higher atherothrombotic event risk compared with prasugrel/ticagrelor-treated patients (adjusted HR 1.56, 95% CI, 1.12-2.16, P = 0.008). When comparing clopidogrel-treated rapid or ultrarapid metabolizers to normal metabolizers, no difference in atherothrombotic (adjusted HR 0.97, 95% CI, 0.73-1.29, P = 0.808) or bleeding events (adjusted HR 1.34, 95% CI, 0.83-2.17, P = 0.224) were observed. In a real-world setting of genotype-guided antiplatelet therapy, the CYP2C19*17 allele did not significantly impact post-PCI prescribing decisions or clinical outcomes. These results suggest the CYP2C19 *1/*17 and *17/*17 genotypes have limited clinical utility to guide antiplatelet therapy after PCI.