CYP2C9 gene polymorphisms influence on antihypertensive effectiveness and hypouricemic effect of losartan among patients with arterial hypertension: an observational study.

OBJECTIVES: CYP2C9 gene polymorphic variants can decrease the effects of losartan, reducing active metabolite (E-3174) formation. Study aims to determine the influence of *2 (+430C>T; rs799853) and *3 (+1075A>C; rs1057910) CYP2C9 gene polymorphic variants on the hypotensive and uricosuric effect of losartan on patients with arterial hypertension. METHODS: Eighty one patients with stage 1-2 arterial hypertension newly diagnosed with ABMP were enrolled in the study. Physicians started losartan treatment and then we measured urine concentration of E-3174/losartan to estimate CYP2C9 activity. After 3-month losartan treatment we compared effectiveness of the therapy with ABPM and plasma uric acid level between carriers of CYP2C9 *1/*1 and CYP2C9 gene polymorphic variants (*2 and *3). RESULTS: Carriage of CYP2C9*2 and CYP2C9*3 alleles reduced the hypotensive effect of losartan (p<0.001, OR=8.13 (95% CI, 2.75-23.97)). Analysis of the ABPM data revealed that blood pressure was significantly higher in patients with polymorphic genotypes. There was no significant difference in uric acid level in plasma and losartan and its metabolite concentration in urine between genotypes. CONCLUSIONS: Carriage of low function polymorphic variants of the CYP2C9 gene (*2 and *3) reduced the hypotensive effect of losartan according to ABPM and don't affect uric acid level in plasma and E-3174/losartan in urine.

Pharmacogenetic testing by polymorphic markers 681G>A and 636G>A CYP2C19 gene in patients with acute coronary syndrome and gastric ulcer in the Republic of Sakha (Yakutia).

BACKGROUND: The focus of the study is to determine the prevalence of CYP2C19 alleles, associated with the risk of changes in the pharmacological response to clopidogrel and proton pump inhibitors in patients with acute coronary syndrome (ACS) and gastric ulcer from Russian and Yakut ethnic groups. METHODS: The research included 411 patients with ACS (143 Russians and 268 Yakuts) and 204 patients with histologically confirmed gastric ulcer (63 Russians and 141 Yakuts). Genotyping of 681G>A and 636G>A polymorphisms was performed by using polymerase real-time chain reaction. RESULTS: In both ethnic groups, Hardy-Weinberg equilibrium was followed in a distribution of alleles and genotypes in the population (p>0.05). The 681A allele frequency in the Yakut ethnic group was higher than in the Russian group: 17.53% vs. 8.39% (p=0.001). No statistically significant difference was found in the frequency of 636A in Yakuts and Russians with ACS: 3.92% vs. 3.50% (p=0.840). While comparing the frequency distribution of alleles 681A (13.49% vs. 14.54%, p=0.878) and 636A (7.94% vs. 7.80%, p=1) in patients with a gastric ulcer from Russian and Yakut ethnic groups, no significant difference was found in carrier frequency. CONCLUSIONS: The results of the present study may be helpful for developing guidelines for CYPC19 genotype-directed antiplatelet therapy for Yakut and Russian patients.