There are 4 clinical trials
Percutaneous coronary intervention (PCI) with stent implantation is the preferred reperfusion strategy for treatment of acute myocardial infarction (AMI). Despite advances in both devices and pharmacological support for AMI patients undergoing PCI, the risk of recurrent ischemic events has been higher than that of elective PCI. Among therapeutic options for surmounting clopidogrel hyporesponsiveness, higher loading doses and maintenance doses of clopidogrel achieved significant enhancements in the speed of onset and intensity of inhibition and these approaches have been widely adapted in clinical practice. Interestingly, recent studies found that carriers of the loss-of-function hepatic cytochrome (CYP) 2C19 allele had significantly lower levels of the active metabolite of clopidogrel, diminished platelet inhibition, and a higher rate of major adverse cardiovascular events than did non-carriers, in the setting of PCI and acute coronary syndrome (ACS). These findings raise the need of solutions to overcome enhanced post-clopidogrel platelet reactivity by the influence of the loss-of-function CYP2C19 allele. Increasing the dose of clopidogrel, new potent P2Y12 antagonists (such as prasugrel), or other antiplatelet drugs such as cilostazol may be alternative antiplatelet regimens in patients with the loss-of-function CYP variant. A recent study demonstrated that adjunctive cilostazol to dual antiplatelet therapy (triple antiplatelet therapy) intensified platelet inhibition as compared with a high maintenance-dose (MD) of 150 mg/day. Therefore, triple antiplatelet therapy could also be an alternative antiplatelet therapy to improve platelet inhibition and clinical outcomes in carriers of CYP2C19 mutant allele. The purpose of this study was to determine the impact of adjunctive cilostazol on platelet inhibition in carriers and non-carriers of the loss-of-function CYP2C19 allele. The investigators compared the enhanced inhibition of platelet aggregation by adjunctive cilostazol 100 mg twice daily versus high-MD clopidogrel 150 mg/day in AMI patients treated with emergent coronary stenting, according to the CYP2C19 polymorphism.
2. Two CYP2C19 polymorphisms, CYP2C19*2 (rs4244285, c. 681G>A, p.P227P), and CYP2C19*3 (rs4986893, c. 636G>A, p. W212X), are investigated using the ABI SNaPshot reaction and the ABI 3100 automated genetic analyzer (Applied Biosystems, Foster City, CA, USA).
The aim of the present study is to evaluate candidate variables,including Cytochrome P450 2C19(CYP2C19) genotypes, clinical and demographic variables,to establish a simple risk score that can be easily adopted by clinicians to identify patients who are at risk for HPR and composite cardiovascular outcomes in Chinese Han patients treated with dual antiplatelet therapy.
The loss of function alleles, CYP2C19*2 (rs4244285) and CYP2C19*3 (rs4986893), will be genotyped by the polymerase chain reaction(PCR)-ligase detection reactions(LDR)sequencing method.
Description: A threshold of 50% maximal post-procedural aggregation was chosen to define HPR.Measure: high on-treatment platelet reactivity (HPR) Time: After 30 days maintenance dose of clopidogrel administration
Description: The composite of death from cardiovascular causes, non-fatal myocardial infarction, non-fatal stroke , urgent coronal revascularization,and stent thrombosis.Measure: Composite ischemia cardiovascular outcomes Time: 1 year
Description: The primary clinical safety end point of the study is the 1-year incidence of combined major and minor bleeding events defined according to the Thrombolysis in Myocardial Infarction (TIMI) criteria . TIMI major bleedings include hemoglobin reduction >5 g/dL(with or without obvious bleeding spots) , intracranial hemorrhages, and cardiac tamponade.TIMI minor bleedings include hemoglobin reduction >3 g/dL but ≤5 g/dL ,macroscopic hematuria,hemoptysis,hematemesis,ecchymoma,mucous membrane and other minor bleedings.Measure: Hemorrhagic complications Time: 1 year
This is a randomized, prospective, open label study to determine the cost-effectiveness of genotype-guided antiplatelet therapy. Patients undergoing percutaneous intervention (PCI) with stent implantation, will be randomized either to genotype guided dosing of antiplatelet therapy or usual care. The study utilizes a novel genotyping device, SpartanRx, to determine CYP2C19 genotypes from a buccal swab sample with 1 hour turnaround time.
The most common loss of function (LOF) allele is *2 (c.681G>A; rs4244285), with frequencies of ~15% in Caucasians and Africans and 29-35% in Asians.
Description: The number (percentage) of participants receiving prasugrel/ticagrelor in each randomized armMeasure: The Number (Percentage) of Participants Receiving Prasugrel/Ticagrelor Time: for up to 7 days after PCI
Description: Agreement to suggested treatment recommendations based on genotype. The agreement rate was defined as the number of participants in genotyped group with loss of function variants that received prasugrel or ticagrelor + the number of participants without these variants that received clopidogrel divided by the total number in this group.Measure: Number of Participants With Drug Orders in Agreement With the Genotype-guided Recommendations Time: for up to 7 days after PCI
Description: major cardiac events defined as occurrence of first myocardial infarction, ischemic stroke, cardiovascular death, stent thrombosis, or need for urgent revascularizationMeasure: Number of Participants With Major Cardiac Events Time: 1 year
Description: major bleeding events defined by the Bleeding Academic Research Consortium (BARC) type 3 or 5. Type 3= Overt bleeding requiring: blood transfusion, surgical intervention or intravenous vasoactive agents; cardiac tamponade; intracranial hemorrhage; intraocular bleeding. Type 5= fatal bleedingMeasure: Number of Participants With Bleeding Events Time: 1 year
Clozapine (Clz), an atypical antipsychotic, is the reference medication for patients with treatment-resistant schizophrenia. Due to the high inter-individual variability of its pharmacokinetics and its narrow therapeutic index, a close therapeutic drug monitoring (TDM) of Clz is highly recommended. Several factors can cause a variation in the pharmacokinetics as age, smoking habits, coffee consumption and drug interaction. Genetic factors related to hepatic expression levels of the cytochrome P450 (CYP), regulate the hepatic clearance of Clz, thereby determine its bioavailability. The CYP1A2 and CYP2C19 isoenzymes are mainly responsible for the metabolism of several drugs including Clz. It has been demonstrated that there is an interethnic variation in the expression and function of these two isoenzymes. This variation is caused by single nucleotide polymorphisms (SNPs) of genes encoding these proteins. While the Influence of the different polymorphisms related to CYP1A2 and CYP2C19 have been established especially in Asian and Caucasian populations, no study has examined the impact of these SNPs in the southern Mediterranean populations. Moreover, the impact of these SNPs is very controversial. The present study aims to investigate in Tunisian schizophrenic patients, the influence of genetic (CYP1A2 and CYP2C19 polymorphisms) and non-genetic factors on Clz pharmacokinetics.
Determination of the correlation between the presence of CYP1A2*1F (rs762551;-163C> A), CYP1A2*1C (rs2069514;-3860 G> A) and CYP 2C19*2 (rs4244285; 681G>A) and the variability of C0/Daily dose.. - Technique: PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism).
Description: Technique : HPLC/UV (high-performance liquid chromatography associated with a UV detector)Measure: Determination of trough plasma concentration of clozapine (C0) Time: One and a half months
Description: - Technique: PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism)Measure: Determination of the correlation between the presence of CYP1A2*1F (rs762551;-163C> A), CYP1A2*1C (rs2069514;-3860 G> A) and CYP 2C19*2 (rs4244285; 681G>A) and the variability of C0/Daily dose. Time: One and a half months