Pharmacogenetic evaluation of adverse events’ risk in patients with alcohol withdrawal syndrome taking bromdihydrochlorphenylbenzodiazepine: The role of CYP2C19 gene polymorphisms

Abstract

Introduction. Bromdihydrochlorphenylbenzodiazepine is the Russian original tranquilizer which widely using in psychiatry, narcology, neurology and general medicine. Particularly, that drug prescribing for patients with alcohol withdrawal syndrome (AWS). Isoenzyme CYP2C19 takes part in metabolism of the most of benzodiazepines, so the gene CYP2C19 might be included into pharmacogenetics study of bromdihydrochlorphenylbenzodiazepine. There was no study of CYP2C19 polymorphisms as biomarkers of bromdihydrochlorphenylbenzodiazepine’s safety.
 Methods. 102 male patients with non-comlicated AWS (F 10.3 by ICD-10) were involved into the study. During 6 days of dynamic observation each participant was prescribed bromdihydrochlorphenylbenzodiazepine (Phenazepam). 5 ml of venous blood was collected from each participant for genotyping. 38 participants were added Pagluferal (contains phenobarbitalum, natrium coffeine-benzoate, bromisoval, papaverine) and/or Carbamazepine. Blood samples were analyzed to detect the CYP2C19*2 (rs4244285), *3 (rs4986893) и *17 (rs12248560) polymorphisms. Safety of therapy was evaluated with UKU Side Effects Rating Scale. Data analysis was performed with SPSS Statistics 21.0.
 Results. Carriers of CYP2C19*2 GA+AA genotypes compared to GG homozygous significantly more often had such adverse effects as «Polyuria/polydipsia» in mean grade of penetration (33,3% vs 9%, p=0,016) and “Palpitations/Tachycardia” (16,7% vs 3,8%, p=0,018). Observed relationship between «Polyuria/polydipsia» and CYP2C19*2 GA+AA genotypes was confirmed in the subgroup “Combined pharmacotherapy” (37,5% vs 0%, p=0,006). CYP2C19*17 polymorphism in tendency to significance was associated with less frequent AE «Polyuria/polydipsia» among patients taking bromdihydrochlorphenylbenzodiazepine as monotherapy carriers of allele T had that AE in 16,9%, and CC homozygous in 24,2% (p=0,067).
 Conclusion. Significant associations between CYP2C19*2 polymorphism and several AE in patients with alcohol withdrawal syndrome taking bromdihydrochlorphenylbenzodiazepine. Substantial role of CYP2C19*17 as predictor of AE associated with bromdihydrochlorphenylbenzodiazepine was not confirmed. Gene CYP2C19 is the sufficient biomarker of bromdihydrochlorphenylbenzodiazepine’s safety profile and needs further research.