[Detection of cytochrome P4502C19 gene polymorphism to optimize therapy of acid-dependent diseases]

Therapeutic efficacy of proton pump inhibitors (PPI) used in therapy of acid-dependent diseases largely depends on cytochrome CYP2C9 activity. The rate of washout of medications metabolized by this enzyme varies 5-20-fold in different patients and ethnic groups, in the first place due to genetic polymorphism. The natural metabolic status of CYP2C19 can be evaluated by genotyping and non-invasive 13C-pantoprazole breath test. The aim of the study was to assess the frequency of fast, intermediate, and slow types of metabolism in Crimeans suffering gastroesophageal reflux disease by the latter method.

The study included 32 patients (21 women, 11 men) aged 18-60 (mean 42.25±3.02) years. They underwent the 13C-pantoprazole breath test prior to the onset of therapy.

The patients were divided into 3 groups based on the results of the test. 12 (37.5%) of them had fast-type metabolism (mean delta over base (DOB) 4.725%+-0.3), 14 (43.75%) had intermediate metabolism (mean DOB 2.44±0.162%) and 6 (18,75%) had slow metabolism (mean DOB 0.85±0.22%). The study showed the prevalence of fast and intermediate type metabolism in the inhabitants of Crimea which suggests the necessity of correction of standard PPI doses.