Diazepam is one of the most commonly prescribed tranquilizers for therapy of alcohol withdrawal syndrome (AWS). Despite its popularity, there is currently no precise information on the effect of genetic polymorphisms on its efficacy and safety. The objective of our study was to investigate the effect of CYP2C19*2 and CYP2C19*17 genetic polymorphisms on the efficacy and safety of diazepam in patients with AWS.
The study was conducted on 30 Russian male patients suffering from the AWS who received diazepam in injections at a dosage of 30.0 mg/day for 5 days. The efficacy and safety assessment was performed using psychometric scales and scales for assessing the severity of adverse drug reactions.
Based on the results of the study, we revealed the differences in the efficacy of therapy in patients with different CYP2C19 681G>A (CYP2C19*2, rs4244285) genotypes: (CYP2C19*1/*1) −8.5 [−15.0; −5.0], (CYP2C19*1/*2 and CYP2C19*2/*2) −12.0 [−13.0; −9.0], p = 0.021. The UKU scale scores, which were used to evaluate the safety of therapy, were also different: (CYP2C19*1/*1) 7.0 [6.0; 12.0], (CYP2C19*1/*2 and CYP2C19*2/*2) 9.5 [8.0; 11.0], p = 0.009. Patients carrying different CYP2C19 –806C>T (CYP2C19*17, rs12248560) genotypes also demonstrated differences in therapy efficacy and safety rates.
Thus, the effects of CYP2C19*2 and CYP2C19*17 genetic polymorphisms on the efficacy of diazepam were demonstrated.
Bromodihydrochlorophenylbenzodiazepine (Phenazepam®) is used in the therapy of anxiety disorders in patients with alcohol dependence. However, Phenazepam therapy often turns out to be ineffective, and some patients develop dose-related adverse drug reactions (ADR): severe sedation, dizziness, headache, dyspepsia, falling, etc. That ensures the effectiveness of this category of patients. Despite the popularity of Phenazepam® as an anxiolytic drug, there is currently no accurate data on its biotransformation, as well as the effect of polymorphism of a gene on the efficacy and safety of bromodihydrochlorophenylbenzodiazepine in patients. The aim of our study was to study the effect of the polymorphism of the CYP2C19 gene on the efficacy and safety index of Phenazepam® for patients with anxiety disorders, using algorithms for optimizing the therapy of Phenazepam® to reduce the risk of pharmacological resistance and increase the effectiveness of therapy.
The study was conducted on 86 Russian patients suffering from alcohol dependence. Patients with trauma anxiety disorders received bromdihydrochlorphenylbenzodiazepine in tablets at a dose of 4.0 [2.0; 6.0] mg per day for 5 days. Genotyping was carried out by the method of polymer chain reaction in real time with allele-specific hybridization. Efficiency and safety assessment was carried out using psychometric scales and scales of Hospital Anxiety and Depression Scale (HADS) severity scores.
Based on the results of the study, statistically significant differences in the number of scores on the scale of HADS severity of CYP2C19 CT on the third day of therapy were the following: (CC) 10.00 [9.00; 11.00], (CT) 14.00 [13.00; 16.00], (TT) 18.00 [17.00; 19.00], p=0.00, and also on the fifth day: (CC) 6.00 [5.00; 7.00], (CT) 17.50 [16.25; 19.75], (TT) 22.50 [20.00; 24.00], p=0.00. ADRs in patients with different genotypes for this polymorphic marker did not differ.
Thus, it has been shown that the polymorphism of the CYP2C19 gene may influence the effectiveness indices of Phenazepam therapy in patients with anxiety disorders comorbid with alcohol dependence. This should be taken into account in the appointment of this drug in this way in order to increase effectiveness of therapy and improve the quality of life.
Haloperidol is used for the treatment of alcohol use disorders in patients with signs of alcohol-related psychosis. Haloperidol therapy poses a high risk of adverse drug reactions (ADR). Contradictory data, which include the effects of genetic polymorphisms in genes encoding the elements of haloperidol biotransformation system on haloperidol metabolism rate and plasma drug concentration ratio, are described in patients with different genotypes. The primary objective of this study was to investigate the effects of CYP2D6 and CYP3A5 genetic polymorphisms on haloperidol equilibrium concentration in patients with alcohol use disorder.
The study included 69 male patients with alcohol use disorder. Genotyping was performed using the allele-specific real-time PCR. CYP2D6 and CYP3A were phenotyped with HPLC-MS using the concentration of endogenous substrate of the enzyme and its urinary metabolites [6-hydroxy-1,2,3,4-tetrahydro-β-carboline(6-HO-THBC) to pinoline ratio for CYP2D6 and 6-β-hydroxycortisol to cortisol ratio for CYP3A]. The equilibrium plasma concentration was determined using LC-MS-MS.
Results indicated that both C/D indexes and equilibrium concentration levels depend on CYP2D6 genetic polymorphism, but only in patients receiving haloperidol intramuscular injections [0.26 (0.09; 0.48) vs. 0.54 (0.44; 0.74), p=0.037].
The study demonstrates that CYP2D6 genetic polymorphism (1846G>A) can affect haloperidol concentration levels in patients with alcohol use disorder.