Genetic testing is superior over endogenous pharmacometabolomic markers to predict safety of haloperidol in patients with alcohol-induced psychotic disorder.

BACKGROUND: Previous studies have shown that haloperidol biotransformation is mainly metabolized by CYP2D6. The CYP2D6 gene is highly polymorphic, contributing to inter-individual differences in enzymatic activity, and may impact haloperidol biotransformation rates, resulting in variable drug efficacy and safety profiles. OBJECTIVE: The study aimed to investigate the correlation of the CYPD6 activity with haloperidol's efficacy and safety rates in patients with alcohol-induced psychotic disorders. METHOD: One hundred male patients received 5-10 mg/day haloperidol by injections for 5 days. The efficacy and safety assessments were performed using PANSS, UKU, and SAS-validated psychometric scales. RESULTS: No relationship between haloperidol efficacy or safety and the experimental endogenous pharmacometabolomic marker for CYP2D6 activity, urinary 6-НО-ТНВС/pinoline ratio was identified. In contrast, we found a statistically significant association between haloperidol adverse events and the most common CYP2D6 loss-of-function allele CYP2D6*4 (p<0.001). CONCLUSION: Evaluation of the single polymorphism rs3892097 that defines CYP2D6*4 can predict the safety profile of haloperidol in patients with AIPD, whereas metabolic evaluation using an endogenous marker was not a suitable predictor. Furthermore, our results suggest haloperidol dose reductions could be considered in AIPD patients with at least one inactive CYP2D6 allele.

Effects of CYP2D6*4 polymorphism on the steady-state concentration of paroxetine in patients diagnosed with depressive episode and comorbid alcohol use disorder.

INTRODUCTION: Selective serotonin reuptake inhibitors have a common and increasing use for the treatment of patients diagnosed with depressive disorders. Some of them do not respond adequately to therapy, and numerous previous studies have indicated an increased risk of type A adverse drug reactions. OBJECTIVE: The objective of our study was to evaluate the effect of 1846G>A polymorphism of CYP2D6 on the concentration/dose ratio of paroxetine. MATERIAL AND METHODS: The study enrolled 267 patients with depressive episode (average age, 40.3 ± 14.3 years). Therapy included paroxetine in an average daily dose of 25.1 ± 9.5 mg per day. The efficacy and safety rates of treatment were evaluated using the international psychometric scales. For genotyping, we performed the real-time polymerase chain reaction. Therapeutic drug monitoring has been performed using high-performance liquid chromatography mass spectrometry (HPLC-MS/MS). RESULTS: Our study revealed the statistically significant results in terms of treatment efficacy (Hamilton Depression Rating Scale scores): (GG) 2.0 [1.0; 3.0] and (GA) 4.0 [2.0; 5.0], p < 0.001; meanwhile, no statistically significant results were obtained for the safety profile (Udvalg for Kliniske Undersogelser (UKU) Scale scores): (GG) 3.0 [2.0; 3.0] and (GA) 3.0 [3.0; 4.0], p = 0.056. We revealed the statistically significant results for the concentration/dose ratio of paroxetine in patients with different genotypes: (GG) 2.803 [2.154; 4.098] and (GA) 5.098 [3.560; 7.241], p < 0.001. CONCLUSION: The effect of CYP2D6*4 genetic polymorphism on the efficacy profile of paroxetine was demonstrated in a group of 267 patients with depressive disorder.