CYP3A subfamily activity affects the equilibrium concentration of Phenazepam® in patients with anxiety disorders and comorbid alcohol use disorder.

Phenazepam® is prescribed to relieve anxiety and sleep disorders during alcohol withdrawal, although it is associated with undesirable side effects. Aim: To demonstrate changes in the safety and efficacy profiles of Phenazepam in patients with anxiety disorders and comorbid alcohol use disorder. Materials & methods: A total of 94 Russian patients with alcohol use disorder received 4.0 mg of Phenazepam per day in tablets. We used a urinary 6-beta-hydroxycortisol/cortisol ratio to evaluate CYP3A activity. Results: A statistically significant inverse correlation between Phenazepam plasma concentration and CYP3A activity was found (r = -0.340 and p = 0.017). Correlation between the concentration/dose ratio and phenotyping results was also statistically significant (r = 0.301 and p = 0.026). Conclusion: The safety and efficacy of Phenazepam depend on CYP3A genetic polymorphisms.

Influence of ABCB1 and CYP3A5 gene polymorphisms on pharmacokinetics of apixaban in patients with atrial fibrillation and acute stroke.

INTRODUCTION: Difficulties in non-vitamin K anticoagulant (NOAC) administration in acute stroke can be associated with changes in pharmacokinetic parameters of NOAC such as biotransformation, distribution, and excretion. Therefore, obtaining data on pharmacokinetics of NOAC and factors that affect it may help develop algorithms for personalized use of this drug class in patients with acute cardioembolic stroke. PATIENTS AND METHODS: Pharmacokinetics of apixaban in patients with acute stroke was studied earlier by Kryukov et al. The present study enrolled 17 patients with cardioembolic stroke, who received 5 mg of apixaban. In order to evaluate the pharmacokinetic parameters of apixaban, venous blood samples were collected before taking 5 mg of apixaban (point 0) and 1, 2, 3, 4, 10, and 12 hours after drug intake. Blood samples were centrifuged at 3000 rpm for 15 minutes. Separate plasma was aliquoted in Eppendorf tubes and frozen at -70°C until analysis. High-performance liquid chromatography mass spectrometry analysis was used to determine apixaban plasma concentration. Genotyping was performed by real-time polymerase chain reaction. CYP3A isoenzyme group activity was evaluated by determining urinary concentration of endogenous substrate of the enzyme and its metabolite (6-ß-hydroxycortisol to cortisol ratio). Statistical analysis was performed using SPSS Statistics version 20.0. The protocol of this study was reviewed and approved by the ethics committee; patients or their representatives signed an informed consent. RESULTS: ABCB1 (rs1045642 and rs4148738) gene polymorphisms do not affect the pharmacokinetics of apixaban as well as CYP3A5 (rs776746) gene polymorphisms. Apixaban pharmacokinetics in groups with different genotypes did not differ statistically significantly. Correlation analysis showed no statistically significant relationship between pharmacokinetic parameters of apixaban and the metabolic activity of CYP3A. CONCLUSION: Questions such as depending on genotyping results for apixaban dosing and implementation of express genotyping in clinical practice remain open for NOACs. Large population studies are required to clarify the clinical significance of genotyping for this drug class.

The influence of CYP3A5 polymorphisms on haloperidol treatment in patients with alcohol addiction.

BACKGROUND: Isoenzymes CYP2D6 and CYP3A4, the activity of which varies widely, are involved in metabolism of haloperidol and may influence its profile of efficacy and safety. OBJECTIVE: The primary aim of this study was to estimate the relationship between CYP3A5 gene polymorphism, activity of the CYP3A isoenzyme, and the risk of development of adverse drug reactions by haloperidol in patients with alcohol abuse. METHODS: Sixty-six male alcohol-addicted patients participated in the study. The safety of haloperidol was evaluated by Udvalg for Kliniske Undersogelser Side Effect Rating Scale (UKU) and Simpson-Angus Scale for extrapyramidal symptoms (SAS). The activity of CYP3A was evaluated by determining the concentrations of an endogenous substrate of this isoenzyme (cortisol) and its urinary metabolite (6-beta-hydroxycortisol, 6-B-HC). Genotyping of CYP3A5*3 was performed by real-time polymerase chain reaction with allele-specific hybridization. RESULTS: The frequency of A-allele occurrence in Russian population was very poor (2.27%). CYP3A5*3 polymorphism had no influence on safety profile indicators of haloperidol (UKU scale: p=0.55, SAS scale: p=0.64). In addition, there was no statistical significant difference between the values of indexes of the metabolic ratio (6-B-HC/cortisol) in groups with different genotypes of CYP3A5*3: GG 5.00 (3.36; 6.39) vs AG 5.26 (2.10; 6.78) (p=0.902). CONCLUSION: The frequency of A-allele occurrence of CYP3A5*3 in Russian population is very poor, and it has no high influence on the safety of haloperidol treatment; therefore, there are no reasons to take this polymorphism into account in patients with alcohol addiction who receive haloperidol.

Pharmacodynamic genetic polymorphisms affect adverse drug reactions of haloperidol in patients with alcohol-use disorder.

BACKGROUND: Antipsychotic action of haloperidol is due to blockade of D2 receptors in the mesolimbic dopamine pathway, while the adverse drug reactions are associated with striatal D2 receptor blockade. Contradictory data concerning the effects of genetic polymorphisms of genes encoding these receptors and associated structures (catechol-O-methyltransferase [COMT], glycine transporter and gene encoding the density of D2 receptors on the neuronal membrane) are described. OBJECTIVE: The objectives of this study were to evaluate the correlation between DRD2, SLC6A3 (DAT) and COMT genetic polymorphisms and to investigate their effect on the development of adverse drug reactions in patients with alcohol-use disorder who received haloperidol. PATIENTS AND METHODS: The study included 64 male patients (average age 41.38 ± 10.14 years, median age 40 years, lower quintile [LQ] 35 years, upper quintile [UQ] 49 years). Bio-Rad CFX Manager™ software and "SNP-Screen" sets of "Syntol" (Russia) were used to determine polymorphisms rs4680, rs1800497, rs1124493, rs2242592, rs2298826 and rs2863170. In every "SNP-Screen" set, two allele-specific hybridizations were used, which allowed to determine two alleles of studied polymorphism separately on two fluorescence channels. RESULTS: Results of this study detected a statistically significant difference in the adverse drug reaction intensity in patients receiving haloperidol with genotypes 9/10 and 10/10 of polymorphic marker SLC6A3 rs28363170. In patients receiving haloperidol in tablets, the increases in the UKU Side-Effect Rating Scale (UKU) score of 9.96 ± 2.24 (10/10) versus 13 ± 2.37 (9/10; p < 0.001) and in the Simpson-Angus Scale (SAS) score of 5.04 ± 1.59 (10/10) versus 6.41 ± 1.33 (9/10; p = 0.006) were revealed. CONCLUSION: Polymorphism of the SCL6A3 gene can affect the safety of haloperidol, and this should be taken into account during the choice of drug and its dosage regimen.