CYP2C19 Genetic Polymorphisms Research Articles

Effect of antituberculosis treatment on CYP2C19 enzyme activity in genetically polymorphic South Indian Tamilian population.

Patients on antituberculosis therapy (ATT) are more prone to drug interactions in the presence of coexisting illnesses which require drug therapy. Rifampicin is a pleiotropic inducer of CYP enzymes, and isoniazid is an enzyme inhibitor. Genetic variations are common in the gene coding for CYP2C19 enzyme. These variations would be important in predicting the individual variations in CYP2C19 activity. The objectives of the study were to find the net effect of 1-month ATT on CYP2C19 enzyme activity and its association with CYP2C19 genetic polymorphisms. Newly diagnosed tuberculosis patients (n = 125) were included in the study. Before commencing ATT, they were given a single dose of omeprazole 20 mg as a probe drug for CYP2C19. Blood sample was collected after 3 h to carry out phenotyping for CYP2C19 enzyme by measuring omeprazole hydroxylation index (OHI) using LC-MS/MS. The phenotyping procedure was repeated after 1 month of ATT. CYP2C19 genotyping was carried out by PCR-RFLP method. Significant reduction in OHI was observed after 1 month of ATT in all the metabolizer groups. The percentage reduction in OHI was maximum with poor metabolizers, 84.1 (IQR - 74.6, 86.6), and minimum with ultra-rapid metabolizers, 39.6 (IQR - 12.7, 54.7). CYP2C19 enzyme induction is predominant in patients after 1 month of antituberculosis treatment (ATT). Genetic variations in the enzyme could not clearly explain the interindividual differences in induction. There is a potential risk of drug failure/adverse effect in poor metabolizers regardless of their genotype after ATT.

Genetic Polymorphisms of CYP2C19 and Resistance to Clopidogrel Therapy among Iranian Patients Suffering from Ischemic Heart Disease

Genetic Polymorphisms of CYP2C19 and Resistance to Clopidogrel Therapy among Iranian Patients Suffering from Ischemic Heart Disease

Effects of CYP2C9 genetic polymorphisms on the pharmacokinetics of zafirlukast.

Zafirlukast, a cysteinyl leukotriene receptor antagonist, is indicated for the treatment of patients with mild to moderate asthma. Zafirlukast is metabolized mainly by CYP3A4 and CYP2C9. We investigated the effects of the major CYP2C9 variant alleles in Asian populations, CYP2C9*3 and CYP2C9*13, on the pharmacokinetics of zafirlukast in healthy Korean subjects. A single 20-mg oral dose of zafirlukast was given to 23 Korean male subjects divided into two genotype groups according to CYP2C9 genotypes, CYP2C9EM (n=11; CYP2C9*1/*1) and CYP2C9IM (n=12; 9 and 3 carriers of CYP2C9*1/*3 and *1/*13, respectively). Zafirlukast concentrations were determined using a validated HPLC-MS/MS analytical method in plasma samples collected after the drug intake. Compared with the CYP2C9EM group, the Cmax and AUCinf of zafirlukast in the CYP2C9IM group were 1.44- and 1.70-fold higher, respectively (p<0.01 and p<0.0001). The CL/F of zafirlukast was 42.8% lower in the CYP2C9IM group compared with the CYP2C9EM group (p<0.001). Slightly higher Cmax and AUC, and lower CL/F of zafirlukast were observed in subjects with the CYP2C9*1/*13 genotype compared with the CYP2C9*1/*3 genotype subjects. CYP2C9*3 and CYP2C9*13 alleles significantly affected the plasma concentrations of zafirlukast.

Impact of CYP2C19 Polymorphisms on Clinical Outcomes and Antiplatelet Potency of Clopidogrel in Caucasian Poststroke Survivors.

Variable response after clopidogrel is well documented and may affect major adverse clinical events after stroke. Impact of CYP2C19 genetic polymorphisms is an established marker linked to variable response after clopidogrel. However, the association of certain genetic polymorphisms with prediction of major adverse clinical events following stroke still remains controversial, especially in Caucasians. The primary aim was to evaluate the impact of CYP2C19 allele *2 in heterozygote form on major adverse clinical events in Caucasian poststroke survivors treated with clopidogrel. The secondary aim was to analyze the potential link between CYP2C19 genetic polymorphism and variable response after clopidogrel. One hundred thirty patients of Caucasian origin following documented ischemic stroke were included. Platelet reactivity was assessed by light transmittance aggregometry (LTA) and matched with various CYP2C19 loss-of-function genetic polymorphisms and major adverse clinical events (composite of vascular deaths, stroke/transient ischemic attack, and myocardial infarction). Over the mean follow-up of 14.9 months, 19 patients experienced major adverse clinical events. The risk of major adverse clinical events was nearly 3-fold in loss-of-function allele carriers (hazard ratio = 2.904; 95% confidence interval, 1.083-7.786; P = 0.013), whereas the risk of ischemic stroke or transient ischemic attack alone was also higher (hazard ratio = 3.170; 95% confidence interval, 1.281-7.849; P = 0.034). Platelet activity was strongly associated with allele *2 status (rs = 0.21, P = 0.016) but not with other genetic polymorphisms. Carriers of allele*2 exhibited lower platelet response to adenosine diphosphate-mean LTA (30.1% vs. 42.0%; P = 0.017). There were no significant differences in LTA results with other agonists. Strong association of increase in adenosine diphosphate-induced aggregation with diabetes mellitus (rs = 0.20, P = 0.023), increasing age (rs = 0.23, P = 0.008), and conversely diminishing over increased weight (rs = 0.23, P = 0.009) was also detected. The carriers of other gene allele variants lack uniformed impact on variable response after clopidogrel. Even heterozygous CYP2C19*2 allele carriers among Caucasian patients after ischemic stroke had a higher risk of major adverse clinical events. The LTA, however, did not predict major adverse clinical events. The exact clinical utility of these findings is still uncertain and requires large outcome-driven randomized trial in Caucasians for proof of concept.

Effects of CYP2C19 variants on methadone metabolism in vitro

CYP2C19 is an important member of the cytochrome P450 (CYP450) enzyme super family and is responsible for clearing approximately 10% of commonly used clinical drugs that undergo phase I metabolism. Genetic polymorphisms of CYP2C19 significantly influence the efficacy and safety of some drugs, which might cause undesirable adverse effects or cure failure at standard dosages. The aim of this study was to clarify the catalytic activities of 31 CYP2C19 alleles on the oxidative in vitro metabolism of methadone. Insect microsomes expressing the CYP2C19 alleles were incubated with 50-2000 μM methadone for 30 min at 37 °C and terminated by cooling to -80 °C immediately. Methadone and its metabolite EDDP were analyzed by an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) system. Of the 31 tested CYP2C19 allelies variants, CYP2C19*1 is the wild-type. Compared with CYP2C19*1, two CYP2C19 variants (CYP2C19*3 and *35FS) had no detectable enzyme activity, one variant L16F exhibited slightly increased intrinsic clearance values, and one variant N277K showed no significant difference. In addition, 26 variants exhibited significantly decreased values (from 1.48% to 80.40%). These findings suggest that more attention should be paid in clinical administration of methadone to individuals carrying these CYP2C19 alleles. Copyright © 2016 John Wiley & Sons, Ltd.

Systematic characterization and comparison of the CYP2C9 variability of the Orang Asli in Malaysia with 12 populations

We conducted a systematic characterization of CYP2C9 variants in 61 Orang Asli and 96 Singaporean Malays using the whole genome sequences data and compared the variants with the other 11 HapMap populations. The frequency of rs1057910 (CYP2C9*3) is the highest in the Orang Asli compared to other populations. Three alleles with clinical implication were detected in the Orang Asli while 2 were found in the Singaporean Malays. Large numbers of the Orang Asli are predicted to have reduced metabolic capacity and therefore they would require a lower dose of drugs which are metabolized by CYP2C9. They are also at increased risks of adverse effects and therapeutic failures. A large number of CYP2C9 variants in the Orang Asli were not in the Hardy Weinberg Equilibrium which could be due to small sample size or mutations that disrupt the equilibrium of allele frequencies. In conclusion, different polymorphism patterns, allele frequencies, genotype frequencies and LD blocks are observed between the Orang Asli, the Singaporean Malays and the other populations. The study provided new information on the genetic polymorphism of CYP2C9 which is important for the implementation of precision medicine for the Orang Asli.

Pharmacogenetics of CYP2C19 Genetic Polymorphism on Clopidogrel Response in Patients with Ischemic Stroke from Saudi Arabia (P5.213)

Pharmacogenetics of CYP2C19 Genetic Polymorphism on Clopidogrel Response in Patients with Ischemic Stroke from Saudi Arabia (P5.213)

A multi-factorial analysis of response to warfarin in a UK prospective cohort.

BackgroundWarfarin is the most widely used oral anticoagulant worldwide, but it has a narrow therapeutic index which necessitates constant monitoring of anticoagulation response. Previous genome-wide studies have focused on identifying factors explaining variance in stable dose, but have not explored the initial patient response to warfarin, and a wider range of clinical and biochemical factors affecting both initial and stable dosing with warfarin.MethodsA prospective cohort of 711 patients starting warfarin was followed up for 6 months with analyses focusing on both non-genetic and genetic factors. The outcome measures used were mean weekly warfarin dose (MWD), stable mean weekly dose (SMWD) and international normalised ratio (INR) > 4 during the first week. Samples were genotyped on the Illumina Human610-Quad chip. Statistical analyses were performed using Plink and R.ResultsVKORC1 and CYP2C9 were the major genetic determinants of warfarin MWD and SMWD, with CYP4F2 having a smaller effect. Age, height, weight, cigarette smoking and interacting medications accounted for less than 20 % of the variance. Our multifactorial analysis explained 57.89 % and 56.97 % of the variation for MWD and SMWD, respectively. Genotypes for VKORC1 and CYP2C9*3, age, height and weight, as well as other clinical factors such as alcohol consumption, loading dose and concomitant drugs were important for the initial INR response to warfarin. In a small subset of patients for whom data were available, levels of the coagulation factors VII and IX (highly correlated) also played a role.ConclusionOur multifactorial analysis in a prospectively recruited cohort has shown that multiple factors, genetic and clinical, are important in determining the response to warfarin. VKORC1 and CYP2C9 genetic polymorphisms are the most important determinants of warfarin dosing, and it is highly unlikely that other common variants of clinical importance influencing warfarin dosage will be found. Both VKORC1 and CYP2C9*3 are important determinants of the initial INR response to warfarin. Other novel variants, which did not reach genome-wide significance, were identified for the different outcome measures, but need replication.Electronic supplementary materialThe online version of this article (doi:10.1186/s13073-015-0255-y) contains supplementary material, which is available to authorized users.

Genotype Frequencies of CYP2C19, P2Y12 and GPIIIa Polymorphisms in Coronary Heart Disease Patients of Han Ethnicity, and Their Impact on Clopidogrel Responsiveness.

To investigate the genotype frequencies of cytochrome P450, family2, subfamily C, polypeptide19 (CYP2C19); P2Y12 receptor; and glycoprotein IIIa polymorphisms in patients with coronary heart disease and their impact on clopidogrel responsiveness and major adverse cardiac events (MACEs).A total of 146 coronary heart disease patients of Han ethnicity, on a clopidogrel regimen, were enrolled. Polymerase chain reaction and DNA sequencing were used to detect the genotype and allelic frequencies of CYP2C19 ((*)2,(*)3,(*)17), P2Y12 (C34T, G52T, T744C) and GPIIIa (T1565C) polymorphisms. Clinical and laboratory data were compared between the high on-treatment platelet reactivity (HTPR) versus normal groups.HTPR was identified in 35 (24%) patients. CYP2C19(*)2 (G681A) polymorphism was found to be significantly associated with HTPR (P < 0.05). A allele frequencies were significantly higher in the HTPR group versus the normal group (P < 0.05). On logistic regression analysis, CYP2C19(*)2 (G681A) polymorphism was found to be an independent risk factor associated with HTPR. No link could be established between genetic polymorphisms and recurrence of MACEs, or between HTPR and recurrence of MACEs.The genetic polymorphisms in CYP2C19(*)2 were closely associated with HTPR. The frequency of the A allele of CYP2C19(*)2 was significantly associated with HTPR, with A allele carriers being more likely to develop HTPR.

The effect of CYP2C9 and VKORC1 genetic polymorphisms on warfarin dose requirements in a pediatric population

The effect of CYP2C9 and VKORC1 genetic polymorphisms on warfarin dose requirements in a pediatric population

Evaluation of CYP2C19, P2Y12, and ABCB1 polymorphisms and phenotypic response to clopidogrel in healthy Indian adults.

Introduction:CYP2C19 and P2Y12 polymorphisms have been claimed to alter the pharmacodynamic response to clopidogrel. ABCB1 polymorphism has been associated with the efflux of clopidogrel resulting in decreased bioavailability. Due to paucity of data from Indian population, the present study was undertaken to evaluate the association of genetic polymorphisms of CYP2C19, P2Y12, and ABCB1 with inhibition of platelet aggregation (IPA) by clopidogrel.Methods:Healthy adults (n = 90) of either gender were administered single dose of 300 mg clopidogrel. Baseline, 4 h postdose, and day 7 assessment of platelet aggregation and genotype of CYP2C19, P2Y12, and ABCB1 were carried out using standardized laboratory methods. The difference in the maximum platelet aggregation (MPA) between baseline and 4 h postdose was considered as delta-MPA (DMPA), and percentage change of MPA at 4 h from baseline was considered as IPA. Those with an IPA of <30% were considered as poor responders. Inferential statistics was applied to find out significant difference of these parameters between various groups of genetic polymorphisms.Results:Mean (standard deviation [SD]) of MPA (%) at baseline, 4 h postdose, and day 7 were 78 (5), 56 (16), and 71 (8), respectively. Similarly, mean (SD) of DMPA (%) and IPA (%) were 23 (17) and 29 (21), respectively. A total of 54/90 (60%) cases were found to be poor responders to clopidogrel. A wild genotype (*1/*1) of CYP2C19 was observed in 35 (40.2%), 42 (48.3%) had *1/*2, 2 (2.3%) individuals had *1/*3, and 8 (9.2%) had *2/*2 mutant genotypes. Although statistically not significant (P = 0.09), a trend was observed in having decreased inhibition values (both MPA and IPA) as we proceed from wild genotype (*1/*1) to mutant genotypes in the order of *1/*2, *1/*3, and *2/*2. Similarly, in P2Y12, a wild haplotype (H1/H1) was present in 77 (89.5%) and 9 (10.5%) individuals had H1/H2 type. A statistically significant difference in DMPA and IPA was observed with more IPA by clopidogrel in individuals with H2 haplotype. No association was observed between the carriers and noncarriers of mutant (T) allele of ABCB1.Conclusion:A trend of decrease in the IPA with CYP2C19 genotypes and an increase in the same with the H2 haplotype of P2Y12 following clopidogrel in Indian healthy adults were observed. Assessment of genetic polymorphisms of the same may aid in personalizing the therapy with clopidogrel.

Multicenter Study of Antibiotic Resistance Profile of H. pylori and Distribution of CYP2C19 Gene Polymorphism in Rural Population of Chongqing, China.

This study was to investigate the antibiotic resistance profile of H. pylori and the distribution of CYP2C19 gene polymorphism in rural population of Chongqing, China. 214 and 111 strains of H. pylori were isolated from rural and urban patients, respectively. 99.53%, 20.09%, and 23.36% of the isolates in rural patients were found to be resistant to metronidazole, clarithromycin, and levofloxacin, while the resistant rate in urban patients was 82.88%, 19.82%, and 24.32%. The multiple antibiotic resistance percentage significantly increased from 28.26% (below 45 years) to 41.80% (above 45 years) in rural patients. Up to 44.39%, 45.79%, and 9.81% of rural patients from whom H. pylori was isolated were found to be extensive metabolizers, intermediate metabolizers, and poor metabolizers. No correlation was observed between antibiotic resistance profile of H. pylori and genetic polymorphism of CYP2C19 among rural population. There was a high prevalence of H. pylori strains resistant to metronidazole, clarithromycin, and levofloxacin in rural patients in Chongqing, China. The choice of therapy in this area should be based on local susceptibility patterns. Amoxicillin, gentamicin, and furazolidone are recommended as the first-line empiric regimen.

Association between high on-treatment platelet reactivity and occurrence of cerebral ischemic events in patients undergoing percutaneous coronary intervention

IntroductionPercutaneous coronary angioplasty (PCI) has become a routine treatment in symptomatic patients with coronary artery disease. The use of new generation drug eluting stents (DES) and dual antiplatelet therapy has significantly improved treatment outcomes and increased patients' safety by reducing the risk of stent thrombosis. AimsThe goal of this study was to assess whether high on treatment platelet reactivity (HTPR), despite clopidogrel treatment, measured with Multiplate Electrode Aggregometer (MEA) is associated with the risk of adverse ischemic cerebral events. MethodsSymptomatic patients with coronary artery disease admitted for coronary angiography and angioplasty (PCI) were consecutively enrolled in this study. 249 consecutive patients underwent coronary artery stenting for stable angina (n=215) or non-ST-elevation acute coronary syndrome (n=34). Inhibition of platelet aggregation was assessed by MEA. Genetic polymorphism of CYP2C19 was tested by HRM Real-Time PCR method in 150 patients. ResultsPatients with HTPR were more frequently diagnosed with ischemic stroke (p=0.0351, OR=16.818, 95% CI [1.464–193.23]) and other ischemic cerebral events (stroke or TIA, p=0.0339, OR=6.5, 95% CI [1.36–31.07]). Cumulative assessment of all ischemic and hemorrhagic events showed no statistical significance. Cerebral ischemic event was the only adverse event that correlated with CYP2C19 (*2/*2) allele (p=0.0489, OR=10; 95% CI [1.39–71.80]). ConclusionsHTPR assessed by MEA, in patients treated with clopidogrel after coronary artery stenting was found to be an important risk factor of ischemic cerebral events. In concordance, the carriers of CYP2C19*2/*2 allele showed an increased rate of ischemic cerebral events.

Impact of CYP2C19 genetic polymorphisms on voriconazole dosing and exposure in adult patients with invasive fungal infections

Voriconazole (VCZ) use is limited by its narrow therapeutic range and significant interpatient variability in exposure. This study aimed to assess (i) the impact of CYP2C19 genotype on VCZ exposure and (ii) the doses required to achieve the therapeutic range in adult patients with invasive fungal infections (IFIs). Therapeutic drug monitoring (TDM) of VCZ, based on trough concentration measurement, and CYP2C19 genotyping were used to guide VCZ dosing in Caucasian patients with IFIs. The two common polymorphisms in Caucasians (CYP2C19*2 and *17), associated with decreased or increased CYP2C19 activity, respectively, were correlated with the daily VCZ dose, pharmacokinetic parameters and concentration-to-dose ratio. In total, 111 trough concentration measurements from 35 genotyped patients were analysed using linear mixed-effect models. The mean VCZ doses required to achieve target concentrations were significantly higher in CYP2C19*17 carriers compared with CYP2C19*1/*1 individuals (P<0.001): 2.57±0.25mg/kg twice daily in CYP2C19*1/*1 patients versus 3.94±0.39mg/kg and 6.75±0.54mg/kg in *1/*17 and *17/*17 patients, respectively. In addition, exposure to VCZ correlated with the CYP2C19*17 variant. Indices of exposure for CYP2C19*2 carriers were in line with the functional effect of this polymorphism compared with CYP2C19*1/*1 individuals, however comparisons of doses required to achieve target concentrations were not statistically different. The CYP2C19*17 allele predicted both VCZ exposure and dose required to achieve effective and non-toxic concentrations. CYP2C19 genotyping appears useful to guide VCZ initial dosing when coupled with TDM and to explain subtherapeutic concentrations frequently observed in clinical practice.

Association of CYP2C19 gene polymorphisms with long-term recurrent risk of ischemic stroke among ethnic Han Chinese from Fujian

To assess the association of genetic polymorphisms of CYP2C19*2,*3,*17 with the recurrence risk of ischemic stroke during clopidogrel prevention in ethnic Han Chinese from Fujian Province. Clinical data of 985 patients with acute ischemic stroke was collected. After 1 year postdischarge follow-up evaluations, only 114 patients with persistence of clopidogrel were enrolled. CYP2C19 genetic polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)and direct sequencing ,then we analysis the correlation between polymorphisms and the recurrence of stroke. Among the 114 patients, 23 had a second onset whilst receiving clopidogrel treatment. During the antiplatelet therapy with clopidogrel, carriers of CYP2C19 poor metabolizer (CYP2C19*2/*2 or *2/*3) had a higher rate of recurrent stroke compared with extensive metabolizers (CYP2C19*1/*1) (OR=4.71, 95%CI: 1.18-18.80, P<0.05). Carriers of CYP2C19 *2 mutant allele had increased recurrence compared with those carrying none loss-of-function allele (OR=2.31, 95%CI: 1.20-4.46, P<0.05). The rate of recurrent stroke in those carrying homozygous mutant *2 allele (CYP2C19*2/*2) was 6.14 times greater than the rate of wild-type homozygotes (CYP2C19*1/*1) (95%CI: 1.54-24.54, P<0.05). Patients with previous stroke history had increased risk of recurrence (OR= 4.146, 95%CI: 1.259-13.655, P<0.05). However, CYP2C19*17 was not detected in the group. For ethnic Han Chinese patients receiving clopidogrel treatment, carriers of poor metabolizer or homozygous mutant *2 allele (CYP2C19*2/*2) have a higher risk of recurrent stroke. The CYP2C19 *2 allele is an independent risk factor for recurrent stroke. Those with previous history of stroke are more prone to the recurrence.

CYP2C19 and CES1 polymorphisms and efficacy of clopidogrel and aspirin dual antiplatelet therapy in patients with symptomatic intracranial atherosclerotic disease.

OBJECT Symptomatic intracranial atherosclerotic disease (ICAD) has a high risk of recurrent stroke. Genetic polymorphisms in CYP2C19 and CES1 are associated with adverse outcomes in cardiovascular patients, but have not been studied in ICAD. The authors studied CYP2C19 and CES1 single-nucleotide polymorphisms (SNPs) in symptomatic ICAD patients. METHODS Genotype testing for CYP2C19*2, (*)3, (*)8, (*)17 and CES1 G143E was performed on 188 adult symptomatic ICAD patients from 3 medical centers who were medically managed with clopidogrel and aspirin. Testing was performed prospectively at 1 center, and retrospectively from a DNA sample biorepository at 2 centers. Multiple logistic regression and Cox regression analysis were performed to assess the association of these SNPs with the primary endpoint, which was a composite of transient ischemic attack (TIA), stroke, myocardial infarction, or death within 12 months. RESULTS The primary endpoint occurred in 14.9% of the 188 cases. In multiple logistic regression analysis, the presence of the CYP2C19 loss of function (LOF) alleles *2, *3, and *8 in the medically managed patients was associated with lower odds of primary endpoint compared with wild-type homozygotes (odds ratio [OR] 0.13, 95% CI 0.03-0.62, p = 0.0101). Cox regression analysis demonstrated the CYP2C19 LOF carriers had a lower risk for the primary endpoint, with hazard ratio (HR) of 0.27 (95% CI 0.08-0.95), p = 0.041. A sensitivity analysis of a secondary composite endpoint of TIA, stroke, or death demonstrated a significant trend in multiple logistic regression analysis of CYP2C19 variants, with lower odds of secondary endpoint in patients carrying at least 1 LOF allele (*2, *3, *8) than in wild-type homozygotes (OR 0.27, 95% CI 0.06-1.16, p = 0.078). Cox regression analysis demonstrated that the carriers of CYP2C19 LOF alleles had a lower risk forthe secondary composite endpoint (HR 0.22, 95% CI 0.05-1.04, p = 0.056). CONCLUSIONS This is the first study examining genetic variants and their effects in symptomatic ICAD. Variant alleles of CYP2C19 (*2, *3, *8) were associated with lower odds of the primary and secondary composite endpoints. However, the direction of the association was opposite of what is expected based on this SNP. This may reflect an incomplete understanding of this genetic variation and its effect in symptomatic ICAD and warrants further investigations.

Correlates of pre-hospital morphine use in ST-elevation myocardial infarction patients and its association with in-hospital outcomes and long-term mortality: the FAST-MI (French Registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction) programme.

The use of opioids is recommended for pain relief in patients with myocardial infarction (MI) but may delay antiplatelet agent absorption, potentially leading to decreased treatment efficacy. In-hospital complications (death, non-fatal re-MI, stroke, stent thrombosis, and bleeding) and 1-year survival according to pre-hospital morphine use were assessed in 2438 ST-elevation MI (STEMI) patients from the French Registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction (FAST-MI) 2010. The analyses were replicated in the 1726 STEMI patients of the FAST-MI 2005 cohort, in which polymorphisms of CYP2C19 and ABCB1 had been assessed. Specific subgroup analyses taking into account these genetic polymorphisms were performed in patients pre-treated with thienopyridines. The 453 patients (19%) receiving morphine pre-hospital were younger, more often male, with a lower GRACE score and higher chest pain levels. After adjustment for baseline differences, in-hospital complications and 1-year survival (hazard ratio = 0.69; 95% confidence interval: 0.35-1.37) were not increased according to pre-hospital morphine use. After propensity score matching, 1-year survival according to pre-hospital morphine was also similar. Consistent results were found in the replication cohort, including in those receiving pre-hospital thienopyridines and whatever the genetic polymorphisms of CYP2C19 and ABCB1. In two independent everyday-life cohorts, pre-hospital morphine use in STEMI patients was not associated with worse in-hospital complications and 1-year mortality. Clinicaltrials.gov identifier: NCT00673036 (FAST-MI 2005); NCT01237418 (FAST-MI 2010).

Analysis of CYP2C19 gene polymorphism among different sex, age, and BMI in the southeast of Henan province

Objective To study the frequency of CYP2C19 genotype and allele mutation of cytochrome P450 in the southeast part of Henan province, and to understand the effect of sex, age, body mass index (BMI) on the genetic polymorphism of CYP2C19. Methods Genetic polymorphism analysis of CYP2C19 gene in 161 healthy people in Henan province, using gene chip method, 87 male, 74 female, aged 26-82 years old, and BMI 17-31. Results The experiment, a total of CYP2C19 six different gene mutation type, CYP2C19 1 of (40.4%), CYP2C19*1/*2 (39.1%), CYP2C19*2/*2 (14.9%), CYP2C19*1/*3 (3.1%), CYP2C19*2/*3 (2.5%), CYP2C19*3/*3 (0%); allelomorph CYP2C19 * 2 (35.7%), follow (2.8%).87 male wild type homozygous for CYP2C19 1 of (39.1%), allelomorph CYP2C19 * 2 (39.1%), follow (3.1%), 74 female wild type homozygous for CYP2C19 1 of (41.9%), and other allelomorph CYP2C19 * 2 (32.3%), follow (2.5%).103 cases were more than or equal to 58 years old wild type homozygous for CYP2C19 1 of (47.6%), allelomorph CYP2C19 * 2 (39.8%), follow (3.7%), 58 25 groups of wild-type homozygous for CYP2C19 1 of (37.7%), allelomorph CYP2C19 * 2 (32.9%), follow (1.2%), BMI<25 groups of wild-type homozygous for CYP2C19 1 of (42.4%), and other allelomorph CYP2C19 * 2 (38.5%), follow (4.3%). Conclusion There was no significant difference in the genotype of CYP2C19*2 between the BMI and *3 in the southeast part of Henan province. Key words: CYP2C19 genotype; Allelomorph; Gene frequency; Nobu Juriko; Slow inactivator

The influence of VKORC1 gene polymorphism on warfarin maintenance dosage in pediatric patients: A systematic review and meta-analysis

IntroductionWarfarin is the most commonly used oral anticoagulant, however, there are large interindividual variations in dose responses. Genetic polymorphisms in CYP2C9, VKORC1 and CYP4F2 have been shown to play an important role in variations in the warfarin maintenance dose in adults, but their effects in children remain unclear. We aimed to investigate the effect of VKORC1 polymorphism on warfarin dosage in pediatric patients by meta-analysis. Materials and methodsUsing strict inclusion and exclusion criteria, we searched PubMed, EMBASE, Cochrane library, Chinese Biomedical Literature Database, CNKI and ChainInfo from 2004 to Mach 17th, 2015. The relationship between warfarin dose and two single nucleotide polymorphisms of the VKORC1 gene (at positions −1639 and 1173) were analyzed using Revman version 5.2.3 software. Results and conclusionsEight studies were included in the meta-analysis, involving 610 pediatric patients. Patients that were VKORC1 −1639 GA, AA or A carriers required significantly lower warfarin dosage than GG carriers (the weighted mean difference in warfarin dose ranged from −26% to −50%). Additionally, the age of the patient and indication of warfarin (i.e. Fontan procedure) significantly affected warfarin dosage, but changes in the target international normalized ratio range had no effect. On the other hand, VKORC1 1173 polymorphisms showed no significant effect on warfarin dosage, which differs from adult patients. In conclusion, we found that VKORC1 −1639 gene polymorphisms have a moderate effect on warfarin dosage in pediatric patients, but clinical characteristics such as age and indication of warfarin also play an important role.

The First-in-Class Potassium-Competitive Acid Blocker, Vonoprazan Fumarate: Pharmacokinetic and Pharmacodynamic Considerations.

Vonoprazan fumarate (Takecab) is a first-in-class potassium-competitive acid blocker that has been available in the market in Japan since February 2015. Vonoprazan is administered orally at 20 mg once daily for the treatment of gastroduodenal ulcer, at 20 and 10 mg once daily for the treatment and secondary prevention of reflux esophagitis, respectively, at 10 mg once daily for the secondary prevention of low-dose aspirin- or non-steroidal anti-inflammatory drug-induced peptic ulcer, and at 20 mg twice daily in combination with clarithromycin and amoxicillin for the eradication of Helicobacter pylori. It inhibits H(+),K(+)-ATPase activities in a reversible and potassium-competitive manner with a potency of inhibition approximately 350 times higher than the proton pump inhibitor, lansoprazole. Vonoprazan is absorbed rapidly and reaches maximum plasma concentration at 1.5-2.0 h after oral administration. Food has minimal effect on its intestinal absorption. Oral bioavailability in humans remains unknown. The plasma protein binding of vonoprazan is 80% in healthy subjects. It distributes extensively into tissues with a mean apparent volume of distribution of 1050 L. Being a base with pKa of 9.6 and with acid-resistant properties, vonoprazan is highly concentrated in the acidic canaliculi of the gastric parietal cells and elicited an acid suppression effect for longer than 24 h after the administration of 20 mg. The mean apparent terminal half-life of the drug is approximately 7.7 h in healthy adults. Vonoprazan is metabolized to inactive metabolites mainly by cytochrome P450 (CYP)3A4 and to some extent by CYP2B6, CYP2C19, CYP2D6, and SULT2A1. A mass balance study showed that 59 and 8% of the orally administered radioactivity was recovered in urine as metabolites and in an unchanged form, respectively, indicating extensive metabolism. Genetic polymorphism of CYP2C19 may influence drug exposure but only to a clinically insignificant extent (15-29%), according to the population pharmacokinetic study performed in Japanese patients. When vonoprazan was co-administered with clarithromycin, the mean AUC from time 0 to time of the next dose (dosing interval) of vonoprazan and clarithromycin were increased by 1.8 and 1.5 times, respectively, compared with the corresponding control values, indicating mutual metabolic inhibition. The mean area under the curve from time zero to infinity obtained from patients with severe liver and renal dysfunction were elevated by 2.6 and 2.4 times, respectively, compared with healthy subjects, with no significant changes in plasma protein binding. Vonoprazan increases intragastric pH above 4.0 as early as 4 h after an oral dose of 20 mg, and the extensive anti-secretory effect is maintained up to 24 h post-dose. During repeated dosing of 20 mg once daily, the 24-h intragastric pH >4 holding time ratios were 63 and 83 % on days 1 and 7, respectively. Because vonoprazan elicited a more extensive gastric acid suppression than the proton pump inhibitor, lansoprazole, it also gave rise to two to three times greater serum gastrin concentrations as compared with lansoprazole. In pre-approval clinical studies for the treatment of acid-related disorders, mild to moderate adverse drug reactions (mostly constipation or diarrhea) occurred at frequencies of 8-17%. Neither severe liver toxicity nor neuroendocrine tumor has been reported in patients receiving vonoprazan.