Risk of major adverse cardiovascular events of CYP2C19 loss-of-function genotype guided prasugrel/ticagrelor vs clopidogrel therapy for acute coronary syndrome patients undergoing percutaneous coronary intervention: a meta-analysis

Role of Cyp2c19 Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention

PURPOSE OF REVIEW

Identification of a reliable discriminatory test to accurately stratify patient responses to antiplatelet therapy following coronary revascularization has become increasingly desirable to optimize therapeutic efficacy and safety.

RECENT FINDINGS

The expansion of platelet function testing to include genotype assessment has been an evolutionary journey, initially fraught with confounding results. However, more recent and rigorous data analysis suggests that genotype testing- guided, tailored antiplatelet therapy may hold promise in optimizing treatment of patients after coronary intervention. Current evidence increasingly supports the use of genotype guided CYP2C19 testing to better match the post coronary intervention patient with the most efficacious and least risky antiplatelet inhibitor. The risk stratification of poor, intermediate, and good metabolizers of these drugs with such testing promises to yield clinical dividends in terms of morbidity, mortality and cost control, in this growing patient population.

Discharge of Acute Coronary Syndrome Patients on Sub-Optimal Dual Anti-Platelet Therapy: A Single Center Experience

PURPOSE

To identify and quantify the reasons why acute coronary syndrome (ACS) patients undergoing stenting at the University of New Mexico Hospital (UNMH) were prescribed sub-optimal dual antiplatelet therapy (DAPT) at discharge, and to identify practice patterns that could potentially lead to improved DAPT treatment for these patients.

METHODS

We reviewed electronic medical records and cardiac catheterization records of 326 patients who underwent percutaneous coronary intervention (PCI) at UNMH between January 1, 2021, and June 30, 2022 and identified 229 ACS patients who survived until discharge. Demographic and clinical characteristics relevant to P2Y12 inhibitor selection were obtained from a review of medical records. Pharmacists' notes documenting their efforts to secure appropriate insurance coverage and reasons for discharging patients on clopidogrel rather than ticagrelor/prasugrel were reviewed. Patients discharged on aspirin and clopidogrel underwent review of medical records and cardiac catheterization lab records to determine if the discharge P2Y12 drug was appropriate. Reasons for inappropriate discharge on clopidogrel were categorized as cost/insurance, patient preference, concern for daily adherence to a twice-daily medication, and maintenance of pre-hospital clopidogrel therapy rather than switch to ticagrelor after PCI.

RESULTS

The 229 ACS patients included 87 (38.0%) appropriately discharged on ticagrelor/prasugrel, 63 (27.5%) appropriately discharged on clopidogrel, 75 (32.8%) discharged on sub-optimal clopidogrel, and 4 (1.7%) not discharged on a P2Y12 inhibitor. For patients inappropriately discharged on clopidogrel (n = 75), the most common reasons were cost or lack of insurance (n = 56) and clinical inertia (taking clopidogrel before PCI and maintained on it afterward) (n = 17). Sub-optimal P2Y12 therapy at discharge was significantly associated with lack of insurance (odds ratio 21.5, 95% confidence interval 5.33-156,p < 0.001) but not with ethnicity, age, sex, or diabetes.

CONCLUSION

At the University of New Mexico, a safety-net hospital, increasing financially restricted access to ticagrelor/prasugrel could help up to 24.5% of ACS patients reduce their risk of ischemic events. For patients admitted on clopidogrel DAPT, escalating to ticagrelor/prasugrel could reduce ischemic risk in 7.4%. Expanding and improving healthcare insurance coverage might reduce the frequency of discharge on sub-optimal P2Y12 therapy.

The association of CYP2C19 LoF alleles with adverse clinical outcomes in stroke patients taking clopidogrel: An updated meta-analysis

The aggregated risk of recurrent stroke in stroke/transient ischemic attack (TIA) patients carrying CYP2C19 LoF alleles who take clopidogrel has not been investigated recently, and the available research is limited. This study aimed to perform an updated meta-analysis to assess the association between CYP2C19 LoF alleles and the risk of recurrent stroke in patients taking clopidogrel. Databases were searched for the literature on eligible studies. The end points were recurrent stroke, composite vascular events, and bleeding events. Odds ratios (ORs) were calculated using RevMan software, where p < 0.05 was considered statistically significant. Patients carrying CYP2C19 LoF alleles who were treated with clopidogrel had a significantly increased risk of recurrent ischemic stroke compared with non-carriers (OR 2.18, 96% CI 1.80-2.63; p < 0.00001). The risk of recurrent stroke was only significantly different in Asian patients (OR 2.29, 96% CI 1.88-2.80; p < 0.00001) but not in patients of other ethnicities; however, there were a limited number of studies in other ethnic groups. Both observational studies (OR 2.83, 96% CI 2.20-3.65; p < 0.00001) and RCTs (OR 1.48, 96% CI 1.10-1.98; p = 0.009) found associations with a significantly increased risk of recurrent ischemic stroke. Asian stroke patients or TIA patients carrying CYP2C19 LoF alleles and taking clopidogrel were at a significantly higher risk of recurrent ischemic stroke than non-carriers. Significantly increased risk of recurrent ischemic stroke was found in both observational studies and RCTs.

Pharmacogenomics and non-genetic factors affecting drug response in autism spectrum disorder in Thai and other populations: current evidence and future implications

Autism spectrum disorder (ASD) may affect family and social life profoundly. Although there is no selective pharmacotherapy for ASD, the Food and Drug Administration (FDA) has recommended risperidone/aripiprazole to treat the associated symptoms of ASD, such as agitation/irritability. Strong associations of some pharmacokinetic/pharmacodynamic gene variants, e.g., CYP2D6 and DRD2, with risperidone-induced hyperprolactinemia have been found in children with ASD, but such strong genetic associations have not been found directly for aripiprazole in ASD. In addition to pharmacogenomic (PGx) factors, drug-drug interactions (DDIs) and possibly cumulative effects of DDIs and PGx may affect the safety or effectiveness of risperidone/aripiprazole, which should be assessed in future clinical studies in children with ASD. Reimbursement, knowledge, and education of healthcare professionals are the key obstacles preventing the successful implementation of ASD pharmacogenomics into routine clinical practice. The preparation of national and international PGx-based dosing guidelines for risperidone/aripiprazole based on robust evidence may advance precision medicine for ASD.

A novel AllGlo probe-quantitative PCR method for detecting single nucleotide polymorphism in CYP2C19 to evaluate the antiplatelet activity of clopidogrel

CYP2C19 gene has multiple single nucleotide polymorphism (SNP), which is the major determinant for clopidogrel treatment responses. Therefore, CYP2C19 SNP detection is essential for predicting clopidogrel efficacy. Currently, there is still no quick and effective method for routine detection of common CYP2C19 SNPs in clinical laboratories, which is critically needed prior to clopidogrel treatment. AllGlo™ based quantitative PCR was used to develop a novel genotyping method for CYP2C19 SNP detection, termed CyPAllGlo. The performance of CyPAllGlo was compared with that of the commonly used fluorescence in situ hybridization (FISH) method, and the data was verified by DNA sequencing. CyPallGlo was used to identify CYP2C19 polymorphisms in 363 patients with coronary heart disease. The univariate analysis was used to access the antiplatelet efficacy of clopidogrel in patients. The associations between CYP2C19 polymorphisms and clopidogrel efficacy were analyzed. Using CyPAllGlo to detect CYP2C19*2 and CYP2C19*3 alleles was highly specific and fast. The detection limit was approximately 0.07 µg/µl and 0.7 µg/µl for CYP2C19*2 and CYP2C19*3, respectively. The consistency between FISH and CyPAllGlo were 98.07% for CYP2C19*2 and 99.17% for CYP2C19*3. DNA sequencing showed that the accuracy of CyPAllGlo was 100%. The analysis time for the whole CyPAllGlo procedure was approximately 60 min. Univariate analysis showed that the anticoagulation efficacy of clopidogrel was related to patient age, CYP2C19 genotype, metabolic phenotype, and LDL level. The logistic regression analysis showed that the genotype of CYP2C19 and metabolic phenotype was the two risk factors for clopidogrel antiplatelet ineffectiveness. This novel CyPAllGlo is a rapid and accurate method for detection of CYP2C19 SNP. The specificity and consistency of CyPAllGlo are comparable with that of widely used DNA sequencing. These findings provide valuable rapid method for predicting clopidogrel efficacy, which can be quickly translated to improve personalized precision medicine for coronary heart disease treatment.

The Impact of CYP2C19 Genotype on the Platelet Reactivity Index (PRI) among Chronic Coronary Syndromes (CCS) Patients Undergoing Percutaneous Coronary Intervention (PCI): Affectability of Rapid Genetic Testing

BACKGROUND

In the Asian population, the presence of the CYP2C19 loss-of-function (LOF) allele is a known genetic variation. This allele is associated with a reduced capacity to metabolize clopidogrel into its active forms through the CYP2C19 enzyme, resulting in diminished platelet inhibition and an elevated risk of recurrent cardiovascular events. Regulatory authorities have recommended an alternative P2Y12 inhibitor, ticagrelor, for individuals carrying the LOF allele. Consequently, this study seeks to assess the impact of the CYP2C19 genotype on the Platelet reactivity index (PRI) using a rapid genetic testing approach in Asian patients with chronic coronary syndromes (CCS) who undergo percutaneous coronary intervention (PCI).

METHODS

This prospective study employed a parallel design, single-center design, and randomized approach. Genotyping for the CYP2C19*2 and *3 polymorphisms was conducted using the Nested Allele-Specific Multiplex PCR (NASM-PCR) technique. Patients meeting the inclusion criteria underwent genotyping for CYP2C19 polymorphisms. Following PCI, patients were randomly assigned to receive either ticagrelor or clopidogrel. PRI assessments were performed four hours after loading dose administration. The trial was registered with ClinicalTrials.gov under the identifier NCT05516784.

RESULTS

Among the 94 patients recruited for the study, 40 (42.55%) were identified as carriers of the LOF allele for CYP2C19*2 and *3 (*1/*2, *2/*2, *1/*3). Out of the 84 patients evaluated for PRI (44 receiving clopidogrel and 40 receiving ticagrelor), 21 (47.7%) of the clopidogrel group and 39 (97.5%) of the ticagrelor group exhibited a favorable response to antiplatelet therapy (PRI < 50). Patients treated with ticagrelor demonstrated superior antiplatelet responses compared to those receiving clopidogrel, regardless of LOF carrier status (P = 0.005 and < 0.001 for non-LOF and LOF carriers, respectively).

CONCLUSION

NASM-PCR as a rapid genetic test holds promise for personalizing antiplatelet therapy in Asian CCS patients.

Progress in the clinical effects and adverse reactions of ticagrelor

BACKGROUND

Ticagrelor is a novel receptor antagonist that selectively binds to the P2Y12 receptor, thereby inhibiting adenosine diphosphate (ADP)-mediated platelet aggregation. Compared to clopidogrel, ticagrelor has the advantages of a fast onset, potent effects, and a reversible platelet inhibition function, which make this drug clinically suitable for treating acute coronary syndrome (ACS), especially acute ST-segment elevation myocardial infarction (STEMI).

OBJECTIVE

This review was performed to determine the basic characteristics, clinical effects, and adverse reactions of ticagrelor.

METHODS

Relevant trials and reports were obtained from the MEDLINE, Embase, and Cochrane Library databases.

RESULTS

Ticagrelor is rapidly absorbed by the body after oral administration, exhibits inherent activity without requiring metabolic activation, and binds reversibly to the P2Y12 receptor. Ticagrelor has been recommended in ACS treatment guidelines worldwide due to its advantageous pharmacological properties and significant clinical benefits. Ticagrelor inhibits platelet aggregation, inhibits inflammatory response, enhances adenosine function, and has cardioprotective effects. However, ticagrelor also causes adverse reactions such as bleeding tendency, dyspnea, ventricular pause, gout, kidney damage, and thrombotic thrombocytopenic purpura in clinical treatment. Therefore, it is necessary to pay attention to risk assessments when using ticagrelor.

CONCLUSION

Ticagrelor is a promising drug for the effective treatment of ACS. When using ticagrelor, individualized treatment should be provided based on the specific conditions of the patients to avoid serious adverse events.

Pharmacogenomics of chloroquine and hydroxychloroquine: current evidence and future implications

As substrates of CYP2C8, CYP3A4/5 and CYP2D6, chloroquine's (CQ) and hydroxychloroquine's (HCQ) efficacy and safety may be affected by variants in the genes encoding these enzymes. This paper aims to assimilate the current evidence on the pharmacogenomics of CQ/HCQ and to identify risk phenotypes affecting the safety or efficacy of these drugs. It has been found that some CYP3A5, CYP2D6 and CYP2C8 genetic variants may affect the safety or effectiveness of CQ/HCQ. The phenotypes predictively representing ultra-rapid and poor metabolizers have been considered high-risk phenotypes. After considering these high-risk phenotypes in different ethnic groups, it is predicted that a considerable proportion of patients taking CQ/HCQ may be at risk of either therapeutic failure or severe toxicities.

Efficacy and Safety of Ticagrelor versus Aspirin and Clopidogrel for Stroke Prevention in Patients with Vascular Disease: A Systematic Review and Meta-Analysis

INTRODUCTION

Currently, it is still controversial to treat stroke with ticagrelor alone. The purpose of our study was to systematically review and analyze the efficacy and safety of ticagrelor on cerebrovascular outcomes in patients with vascular risk factors.

METHODS

The PubMed, Cochrane Library, and Embase databases were systematically searched using the keywords stroke, ticagrelor, clopidogrel, and aspirin to identify randomized controlled trials (RCTs). Primary outcomes included reported stroke, ischemic stroke, and complex events; the secondary outcome was hemorrhagic stroke. The safety outcomes included major bleeding events, major or minor bleeding, and intracranial bleeding. The pooled odds ratio (OR), hazard ratios (HRs), and 95% confidence interval (CI) were calculated. We used I2 statistics to assess statistical heterogeneity.

RESULTS

This meta-analysis included 15 RCTs involving 63,865 patients. Compared to the control group, ticagrelor reduced the risk of stroke (OR: 0.90; 95% CI: 0.81-0.99, p = 0.03; I2 = 3%), ischemic stroke (OR: 0.81; 95% CI: 0.74-0.90, p < 0.0001; I2 = 0%). Ticagrelor was not associated with an increased risk of all-cause mortality (OR: 0.94; 95% CI: 0.84-1.06, p = 0.31; I2 = 62%), major bleeding (OR: 1.06; 95% CI: 0.97-1.15, p = 0.20; I2 = 17%), hemorrhagic strokes (OR: 1.22, 95% CI: 0.76-1.96, p = 0.41; I2 = 0%), and intracranial hemorrhage (OR: 1.06; 95% CI: 0.78-1.43, p = 0.71; I2 = 12%). There was an increased risk of major or minor bleeding with ticagrelor compared to the control group (OR: 1.40; 95% CI: 1.19-1.66, p < 0.0001; I2 = 56%). Additional analyses demonstrated that ticagrelor reduced the risk of incident recurrent stroke (HR: 0.83; 95% CI: 0.75-0.93, p = 0.0009; I2 = 0%), recurrent ischemic stroke (HR: 0.79; 95% CI: 0.71-0.89, p < 0.0001; I2 = 0%) among patients with a history of acute ischemic stroke (AIS) or transient ischemic attack (TIA). There were no significant differences in safety outcomes.

CONCLUSION

Ticagrelor is slightly better than clopidogrel and aspirin in preventing stroke, especially ischemic stroke, with significant safety risks. For patients with a history of AIS/TIA, the use of ticagrelor was superior to the use of clopidogrel or aspirin in reducing the risk of subsequent stroke. We believe that ticagrelor is a potential alternative to aspirin or clopidogrel in some cases, especially for patients with CYP2C19 deficiency.

Association of UGT1A1*6,*28 or ABCC2 c.3972C>T genetic polymorphisms with irinotecan induced toxicity in Asian cancer patients: Meta-analysis

Effects of UGT1A1*6 and UGT1A1*28 genetic polymorphisms on irinotecan‐induced severe toxicities in Asian cancer patients are inconclusive. Also, ABCC2 c.3972C>T may affect toxicity of irinotecan. The aim was to assess the aggregated risk of neutropenia or diarrhea in Asian cancer patients taking irinotecan and inherited UGT1A1*6, UGT1A1*28, or ABCC2 c.3972C>T genetic variants. A PubMed literature search for eligible studies was conducted. Odds ratios (ORs) were measured using RevMan software where p values <0.05 were statistically significant. Patients that inherited both UGT1A1*6 and UGT1A1*28 genetic variants (heterozygous: UGT1A1*1/*6 + *1/*28 and homozygous: UGT1A1*6/*6 + *28/*28) were significantly associated with increased risk of neutropenia and diarrhea compared to patients with UGT1A1*1/*1 (neutropenia: OR 2.89; 95% CI 1.97–4.23; p < 0.00001; diarrhea: OR 2.26; 95% CI 1.71–2.99; p < 0.00001). Patients carrying homozygous variants had much stronger effects in developing toxicities (neutropenia: OR 6.23; 95% CI 3.11–12.47; p < 0.00001; diarrhea: OR 3.21; 95% CI 2.13–4.85; p < 0.00001) than those with heterozygous variants. However, patients carrying the ABCC2 c.3972C>T genetic variant were not significantly associated with neutropenia (OR 1.67; 95% CI 0.98–2.84; p = 0.06) and were significantly associated with a reduction in irinotecan‐induced diarrhea (OR 0.31; 95% CI 0.11–0.81; p = 0.02). Asian cancer patients should undergo screening for both UGT1A1*6 and UGT1A1*28 genetic variants to reduce substantially irinotecan‐induced severe toxicities.

Development and Validation of a Novel Tool for the Prediction of Clopidogrel Response in Chinese Acute Coronary Syndrome Patients: The GeneFA Score

Aim: Growing evidence indicated that CYP2C19 genotypes could only explain a fraction of the pharmacodynamic response to clopidogrel, while a number of clinical factors also have contributing roles. Our objective was to develop a new risk score to improve prognostication of ischemic events in Chinese patients treated with clopidogrel. Methods: A new risk score was developed and internally validated in 445 patients with acute coronary syndrome (ACS) undergoing coronary stenting. The final score was named the GeneFA score based on the inclusion of CYP2C19 genotype, fibrinogen, and age. External validation of the GeneFA score and comparison with the ABCD-GENE score were performed in an independent ACS cohort. Results: Based on the observed frequencies of high platelet reactivity (HRPR) in relation to the GeneFA risk score, a relatively higher clinical HRPR was observed in the upper quintile with a representative score of 3 (52.90%) and 4 (59.10%), whereas it was found less frequently in groups with scores 0 (6.70%), 1 (15.10%), and 2 (16.70%). Participants with a GeneFA score >2 had an increased risk of HRPR (54.3 vs. 14.7%, p < 0.001) and ischemic recurrence (20.7 vs. 5.4%, p < 0.001). The GeneFA score exhibited a better prediction for high HRPR patients as compared to the ABCD-GENE score (p < 0.001). In the validation population, GeneFA illustrated a similarly high prognostic value for HRPR incidence (C-statistic: 0.855 for GeneFA and 0.843 for ABCD-GENE) and ischemic recurrence (C-statistic: 0.726 for GeneFA and 0.724 for ABCD-GENE) on clopidogrel as compared to ABCD-GENE. Conclusion: The GeneFA risk score had a moderate predictive ability for HRPR on clopidogrel for CAD patients in Chinese populations. The predictive value of the GeneFA score was consistent with the ABCD-GENE score for HRPR identification.

A Japanese Dose of Prasugrel versus a Standard Dose of Clopidogrel in Patients with Acute Myocardial Infarction from the K-ACTIVE Registry

BACKGROUND

Dual antiplatelet therapy (DAPT) with aspirin plus P2Y12 inhibitor is used as a standard therapy for patients with acute myocardial infarction (AMI) treated with drug-eluting stents (DESs). In Japan, clopidogrel was the major P2Y12 inhibitor used for a decade until the new P2Y12 inhibitor, prasugrel, was introduced. Based on clinical studies considering Japanese features, the set dose for prasugrel was reduced to 20 mg as a loading dose (LD) and 3.75 mg as a maintenance dose (MD); these values are 60 and 10 mg, respectively, globally. Despite this dose discrepancy, little real-world clinical data regarding its efficacy and safety exist.

METHODS

From the K-ACTIVE registry, based on the DAPT regimen, patients were divided into a prasugrel group and a clopidogrel group. The ischemic event was a composite of cardiovascular death, non-fatal MI, and non-fatal stroke. The bleeding event was type 3 or 5 bleeding based on the Bleeding Academic Research Consortium (BARC) criteria.

RESULTS

Substantially more patients were prescribed prasugrel (n = 2786) than clopidogrel (n = 890). Clopidogrel tended to be selected over prasugrel in older patients with numerous comorbidities. Before adjustments were made, the cumulative incidence of ischemic events at 1 year was significantly greater in the clopidogrel group than in the prasugrel group (p = 0.007), while the cumulative incidence of bleeding events at 1 year was comparable between the groups (p = 0.131). After adjustments were made for the age, sex, body weight, creatine level, type of AMI, history of MI, approach site, oral anticoagulation therapy, presence of multivessel disease, Killip classification, and presence of intra-aortic balloon pumping, both ischemic and bleeding events became comparable between the groups.

CONCLUSION

A Japanese dose of prasugrel was commonly used in AMI patients in the real-world database. Both the prasugrel and clopidogrel groups showed comparable rates of 1 year ischemic and bleeding events.

Effect of CYP2C19 genetic polymorphism on the pharmacodynamics and clinical outcomes for patients treated with ticagrelor: a systematic review with qualitative and quantitative meta-analysis

Background

Studies show inconsistent results regarding the impact of CYP2C19 genotype on the pharmacodynamics (PD) and clinical outcomes of ticagrelor. With the implementation of genotype-guided individualized antiplatelet therapy, the association between CYP2C19 polymorphism and the efficacy and safety of ticagrelor for patients is still worthy of exploring and studying.

Methods

This systematic review protocol has been registered in the PROSPERO network (No. CRD 42020158920). Electronic databases of PubMed, EmBase, and the Cochrane Library were systematically searched from inception to January 6th, 2022 to select studies investigating the impact of CYP2C19 genotype on PD and clinical outcomes of ticagrelor. The results were presented as odds ratio (OR) or weight mean difference with its 95% confidence interval (CI) by using the random-effects model. Trial sequential analysis (TSA) was used to control risk of random errors and detect the robustness of outcomes.

Results

Eight studies recruited a total of 6405 patients treated with ticagrelor. Mostly trials reported no significant effect of any or no CYP2C19 loss-of-function (LOF) allele (*2 or *3) on all the endpoints. Compared with no LOF allele carriers, subgroup analysis suggested any LOF allele in Asian patients was associated with a significant decreased risk of bleeding events (OR: 0.41; 95% CI: 0.22–0.75; P = 0.004). Furthermore, any LOF allele carriers didn’t yield any impact on the risk of MACEs (OR: 1.11; 95% CI: 0.76–1.64; P = 0.586), stroke (OR: 1.71; 95% CI: 0.99–2.96; P = 0.054), definite stent thrombosis (OR: 0.88; 95% CI: 0.17–4.60; P = 0.882), bleeding (OR: 0.63; 95% CI: 0.27–1.46; P = 0.281), myocardial infarction (OR: 0.81; 95% CI: 0.30–2.20; P = 0.682), and revascularization (OR: 0.81; 95% CI: 0.33–2.00; P = 0.649) in all patients. The results of TSA were indicated that more further trials would be required.

Conclusions

This qualitative and quantitative study suggested Asian patients carrying any CYP2C19 LOF allele might have a lower risk of bleeding events comparing with no LOF allele carriers when treated with ticagrelor. However, we did not prove an important role of CYP2C19 genotype on the risk of PD and clinical endpoints in the whole cohort. In future, more large-scale prospective studies and more different ethnic populations should be included.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02547-3.

Pharmacogenetics and Precision Medicine Approaches for the Improvement of COVID-19 Therapies

Many drugs are being administered to tackle coronavirus disease 2019 (COVID-19) pandemic situations without establishing clinical effectiveness or tailoring safety. A repurposing strategy might be more effective and successful if pharmacogenetic interventions are being considered in future clinical studies/trials. Although it is very unlikely that there are almost no pharmacogenetic data for COVID-19 drugs, however, from inferring the pharmacokinetic (PK)/pharmacodynamic(PD) properties and some pharmacogenetic evidence in other diseases/clinical conditions, it is highly likely that pharmacogenetic associations are also feasible in at least some COVID-19 drugs. We strongly mandate to undertake a pharmacogenetic assessment for at least these drug–gene pairs (atazanavir–UGT1A1, ABCB1, SLCO1B1, APOA5; efavirenz–CYP2B6; nevirapine–HLA, CYP2B6, ABCB1; lopinavir–SLCO1B3, ABCC2; ribavirin–SLC28A2; tocilizumab–FCGR3A; ivermectin–ABCB1; oseltamivir–CES1, ABCB1; clopidogrel–CYP2C19, ABCB1, warfarin–CYP2C9, VKORC1; non-steroidal anti-inflammatory drugs (NSAIDs)–CYP2C9) in COVID-19 patients for advancing precision medicine. Molecular docking and computational studies are promising to achieve new therapeutics against SARS-CoV-2 infection. The current situation in the discovery of anti-SARS-CoV-2 agents at four important targets from in silico studies has been described and summarized in this review. Although natural occurring compounds from different herbs against SARS-CoV-2 infection are favorable, however, accurate experimental investigation of these compounds is warranted to provide insightful information. Moreover, clinical considerations of drug–drug interactions (DDIs) and drug–herb interactions (DHIs) of the existing repurposed drugs along with pharmacogenetic (e.g., efavirenz and CYP2B6) and herbogenetic (e.g., andrographolide and CYP2C9) interventions, collectively called multifactorial drug–gene interactions (DGIs), may further accelerate the development of precision COVID-19 therapies in the real-world clinical settings.

Effects of CYP2C19 LoF allele on major adverse cardiovascular events associated with clopidogrel in acute coronary syndrome patients undergoing percutaneous coronary intervention: meta-analysis

The aggregated risk of major adverse cardiovascular events (MACE) in acute coronary syndrome (ACS) patients inheriting CYP2C19 loss-of function (LoF) alleles who underwent percutaneous coronary intervention (PCI) and were treated with clopidogrel is controversial. In the current study, we searched the literature in different databases for eligible studies. The risk ratio (RR) was measured where p<0.05 was statistically significant. The ACS patients with either one or two CYP2C19 LoF alleles who underwent PCI, treated with clopidogrel were correlated with a significantly escalated risk of MACE compared with noncarriers (RR: 1.53, 95% CI: 1.39-1.69, p<0.00001), driven by CV death (RR: 1.88, 95% CI: 1.18-3.01, p=0.008), MI (RR: 1.67, 95% CI: 1.21-2.31, p=0.002) and ST (RR: 1.90, 95% CI: 1.27-2.84, p=0.002). Patients with two CYP2C19 LoF alleles were correlated with significantly greater risk of MACE compared with noncarriers (RR: 3.91, 95% CI: 2.78-5.50, p<0.00001). Further analysis revealed that the risk of MACE was markedly significant in Asian patients (RR: 2.02, 95% CI: 1.67-2.44, p<0.00001) and was comparatively low significance in western patients (RR: 1.35, 95% CI: 1.20-1.52, p<0.00001). There was no significantly different bleeding events in patients with CYP2C19 LoF alleles compared with noncarriers (RR: 0.99, 95% CI: 0.85-1.15, p=0.87). The ACS patients inheriting CYP2C19 LoF alleles, who underwent PCI and were treated with clopidogrel were correlated with significantly increased risk of MACE compared with noncarriers.

Race and Drug Toxicity: A Study of Three Cardiovascular Drugs with Strong Pharmacogenetic Recommendations

The Clinical Pharmacogenetics Implementation Consortium (CPIC^®) establishes evidence-based guidelines for utilizing pharmacogenetic information for certain priority drugs. Warfarin, clopidogrel and simvastatin are cardiovascular drugs that carry strong prescribing guidance by CPIC. The respective pharmacogenes for each of these drugs exhibit considerable variability amongst different ethnic/ancestral/racial populations. Race and ethnicity are commonly employed as surrogate biomarkers in clinical practice and can be found in many prescribing guidelines. This is controversial due to the large variability that exists amongst different racial/ethnic groups, lack of detailed ethnic information and the broad geographic categorization of racial groups. Using a retrospective analysis of electronic health records (EHR), we sought to determine the degree to which self-reported race/ethnicity contributed to the probability of adverse drug reactions for these drugs. All models used individuals self-reporting as White as the comparison group. The majority of apparent associations between different racial groups and drug toxicity observed in the "race only" model failed to remain significant when we corrected for covariates. We did observe self-identified Asian race as a significant predictor (p = 0.016) for warfarin hemorrhagic events in all models. In addition, patients identifying as either Black/African-American (p = 0.001) or Other/Multiple race (p = 0.019) had a lower probability of reporting an adverse reaction than White individuals while on simvastatin even after correcting for other covariates. In both instances where race/ethnicity was predictive of drug toxicity (i.e., warfarin, simvastatin), the findings are consistent with the known global variability in the pharmacogenes described in the CPIC guidelines for these medications. These results confirm that the reliability of using self-identified race/ethnic information extracted from EHRs as a predictor of adverse drug reactions is likely limited to situations where the genes influencing drug toxicity display large, distinct ethnogeographic variability.

Coronary Heart Disease (CHD) in Elderly Patients: Which Drug to Choose, Ticagrelor and Clopidogrel? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: A new generation P2Y12 receptor inhibitor (ticagrelor) is recommended in current therapeutic guidelines to treat patients with coronary heart disease (CHD). However, it is unknown if ticagrelor is more effective than clopidogrel in elderly patients. Therefore, a systematic review was done to assess the effectiveness and safety of ticagrelor and clopidogrel in older patients with CHD to determine the appropriate antiplatelet treatment plan. Methodology: We performed a systematic review of randomized controlled trials (RCTs) to compare the effectiveness and safety of ticagrelor vs. clopidogrel in elderly patients with CHD. We selected eligible RCTs based on specified study criteria following a systematic search of PubMed and Scopus databases from January 2007 to May 2021. Primary efficacy outcomes assessed were major adverse cardiovascular events (MACEs), myocardial infarction (MI), stent thrombosis (ST), and all-cause death. The secondary outcome assessed was major bleeding events. We used RevMan 5.3 software to conduct a random-effects meta-analysis and estimated the pooled incidence and risk ratios (RRs) with 95% confidence intervals (CIs) for ticagrelor and clopidogrel. Results: Data from 6 RCTs comprising 21,827 elderly patients were extracted according to the eligibility criteria. There was no significant difference in the MACE outcome (incidence: 9.23% vs. 10.57%; RR = 0.95, 95% CI = 0.70–1.28, p = 0.72), MI (incidence: 5.40% vs. 6.23%; RR = 0.94, 95% CI= 0.69–1.27, p = 0.67), ST (incidence: 2.33% vs. 3.17%; RR = 0.61, 95% CI= 0.32–1.17, p = 0.13), and all-cause death (4.29% vs. 5.33%; RR = 0.86, 95% CI = 0.65–1.12, p = 0.25) for ticagrelor vs. clopidogrel, respectively. In addition, ticagrelor was not associated with a significant increase in the rate of major bleeding (incidence: 9.98% vs. 9.33%: RR = 1.37, 95% CI = 0.97–1.94, p = 0.07) vs. clopidogrel. Conclusions: This study did not find evidence that ticagrelor is significantly more effective or safer than clopidogrel in elderly patients with CHD.

A review of the effects of ticagrelor on adenosine concentration and its clinical significance

BACKGROUND

Ticagrelor is an oral antiplatelet drug that can reversibly bind to the platelet P2Y12 receptor. Ticagrelor is metabolized mainly by CYP3A4 and produces a rapid blood concentration-dependent platelet inhibitory effect. Unlike other P2Y12 receptor antagonists, many clinical features of ticagrelor are not related to P2Y12 receptor antagonism.

PURPOSE

This review aims to gather existing literature on the clinical effects of ticagrelor after inhibiting adenosine uptake.

METHODOLOGY

The current study reviewed literature related to the effects of ticagrelor on adenosine metabolism. The review also examined the drug's biological effects and clinical characteristics to see how it could be used in a clinical setting.

RESULTS

Many studies have shown that ticagrelor can inhibit equilibrative nucleoside transporter 1 (ENT1). This inhibition leads to intracellular adenosine uptake, increased adenosine half-life and plasma concentration levels and an enhanced adenosine-mediated biological effect.

CONCLUSIONS

Based on the studies reviewed, it was found that ticagrelor essentially inhibits adenosine absorption of adenosine into cells through ENT1, which increases the concentration in the blood and subsequently increases the protection of the heart muscle by adenosine. It also prevents platelet aggregation, and extends the biological effects of coronary arteries. Moreover, it leads to a lower mortality rate in acute coronary syndrome (ACS) patients.

Global distribution of CYP2C19 risk phenotypes affecting safety and effectiveness of medications

Genetic variability of CYP2C19 may affect safety or efficacy of many clinically important medications as outlined in the clinical pharmacogenetics implementation consortium (CPIC) dosing guidelines. To determine the predictive prevalence of high-risk phenotypes due to CYP2C19 genetic variants collectively in the world population and to establish a correlation how the identified high-risk phenotypes may affect safety or effectiveness of drugs, this study was conducted. Frequency of CYP2C19*2, *3 and *17 alleles were obtained from 1000 Genomes project Phase III in line with Fort Lauderdale principles. Phenotypes were assigned using international standardized consensus terms based on the carrier of characteristics alleles. Association of predicted high-risk phenotypes with the safety or effectiveness of medications was gained from CPIC dosing guidelines. Ultrarapid and poor metabolizers were considered as being as high-risk phenotypes for at least ten clinically important medications. Meta-analysis of the prevalence of high-risk phenotypes showed that it was statistically significant (p<0.0001) in different ethnic groups with pooled prevalence of 27.4% (95% CI 18-37%). The present study suggests that African (37.2; 95% CI 34-41%) and European (35.4; 95% CI 31-40%) population are being at particularly higher risk of either sub therapeutic drug responses or toxicities due to combined effects of CYP2C19*2, *3 and *17 variants. Large scale clinical studies are warranted to assess clinical outcomes of these medications considering CYP2C19 pharmacogenomics effects.

Association of CYP2C19 Loss-of-Function Alleles with Major Adverse Cardiovascular Events of Clopidogrel in Stable Coronary Artery Disease Patients Undergoing Percutaneous Coronary Intervention: Meta-analysis

PURPOSE

It was aimed to determine the aggregated risk of MACE (major adverse cardiovascular events) in stable CAD patients carrying CYP2C19 LoF alleles taking clopidogrel.

METHODS

Literature was searched in different databases for relevant studies. Aggregated risk was estimated using a fixed/random effect model where p-value<0.05 was considered statistically significant.

RESULTS

In total, 21 studies with 16,194 stable CAD patients were assessed. It was found that patients treated with clopidogrel carrying either one or two CYP2C19 LoF alleles who underwent PCI were associated with significantly increased risk of MACE compared to non-carriers (OR: 1.71, 95% CI: 1.51-1.94, p<0.00001) that was driven from cardiovascular death (OR: 1.43, 95% CI: 1.02-1.99, p=0.04), myocardial infarction (OR: 1.75, 95% CI: 1.42-2.16, p<0.00001), stroke (OR: 2.30, 95% CI: 1.52-3.47, p<0.0001), and stent thrombosis (OR: 4.08, 95% CI: 2.52-6.61, p<0.00001). It was also found that carriers of two CYP2C19 LoF alleles were associated with a significantly marked risk of MACE than non-carriers (OR: 2.22, 95% CI: 1.60-3.09, p<0.00001). Furthermore, the increased risk of MACE remained markedly significant in Asian patients (OR: 2.03, 95% CI: 1.72-2.40, p<0.00001) and was less significant in western patients (OR: 1.35, 95% CI: 1.11-1.63, p=0.002). Bleeding events were not significantly different in carriers of CYP2C19 LoF alleles compared to non-carriers (OR: 1.11, 95% CI: 0.85-1.45, p=0.43).

CONCLUSION

Stable CAD patients treated with clopidogrel and carried CYP2C19 LoF alleles undergoing PCI were associated with significantly increased risk of MACE compared to non-carriers, even markedly significant for Asian patients.

Effects of the ABCB1 C3435T single nucleotide polymorphism on major adverse cardiovascular events in acute coronary syndrome or coronary artery disease patients undergoing percutaneous coronary intervention and treated with clopidogrel: A systematic review and meta-analysis

INTRODUCTION

The effects of the ABCB1 C3435T genetic polymorphism on clopidogrel responses are conflicting and inconclusive especially in patients undergoing percutaneous coronary intervention (PCI). This study examined the pooled risk of major adverse cardiovascular events (MACE) and bleeding events associated with the ABCB1 C3435T polymorphism in acute coronary syndrome or coronary artery disease patients undergoing PCI and treated with clopidogrel.

AREAS COVERED

Literature was searched in different resources for eligible studies. The pooled risk ratio was measured using RevMan software, with p<0.05 (two-sided) set as statistically significant.

EXPERT OPINION

The ABCB1 C3435T homozygous mutant (TT) was associated with significantly increased risk of MACE compared to either wild type genotype (CC) or the combination of wild type and heterozygous genotypes (TT vs. CC: RR 1.33; 95% CI 1.06-1.68; p=0.02; TT vs. CC+CT: RR 1.32; 95% CI 1.10-1.60; p=0.004). Safety outcomes, i.e. bleeding events were not significantly different between the genetic models investigated (TT vs. CC: RR 1.93; 95% CI 0.86-4.35; p=0.11; TT vs. CC+CT: RR 1.36; 95% CI 0.89-2.09; p=0.16; CT+TT vs. CC: RR 1.20; 95% CI 0.59-2.44; p=0.61). It is suggested that ABCB1 C3435T genotype should be tested for ACS/CAD patients undergoing PCI to ensure optimum therapy of clopidogrel.