Relationship of the 1846G > A Polymorphism of the CYP2D6 Gene to the Equilibrium Concentration Levels of Haloperidol in Patients with Acute Alcoholic Hallucinosis

Haloperidol is currently used in addictology for the treatment of acute psychotic disorders, including acute alcoholic hallucinosis. The use of haloperidol is often accompanied by the occurrence of adverse drug reactions (ADRs). There is evidence that CYP2D6 isoenzyme is involved in the biotransformation of haloperidol. The study aimed to evaluate the relationship of 1846G > A polymorphism of the CYP2D6 gene to the equilibrium concentration levels of haloperidol in patients with acute alcoholic hallucinosis. The study was conducted on 100 male patients with acute alcoholic hallucinosis (mean age 41.4 ± 14.4 years). The efficacy profile was evaluated using the PANSS (Positive and Negative Syndrome Scale) scale. The safety of therapy was assessed using the UKU Side-Effect Rating Scale and the SAS (Simpson-Angus Scale for Extrapyramidal Symptoms) scale. Genotyping was performed using the real-time polymerase chain reaction (Real-time PCR). Equilibrium plasma concentration levels of haloperidol were investigated using the high-performance liquid chromatography with mass spectrometry (HPLC with MS/MS). No statistically significant results were obtained during the therapy efficacy assessment (dynamics of the PANSS score: genotype (-13.00 [-16.00; -16.00; -11.00]), genotype (-15.00 [-16.75; -13.00], p = 0.728). There was a statistically significant difference in safety assessment scores (dynamics of the UKU score: genotype (8.00 [7.00; 10.00]), genotype (15.00 [9.25; 18.00], p < 0.001); dynamics of the SAS score: genotype (11.00 [9.00; 14.00]), genotype (14.50 [12.00; 18.00], p < 0.001). The pharmacokinetic study results showed a statistically significant difference: (3.13 [2.32; 3.95]), (3.89 [2.92; 5.26], p = 0.010). Thus, a study conducted on a group of 100 patients with acute alcoholic hallucinosis demonstrated an association between the > polymorphism of the gene ( ) and the safety profile of haloperidol therapy. We also revealed the presence of statistically significant difference in the equilibrium concentration levels of haloperidol in patients with the and genotypes. It can be concluded that patients with the genotype have a higher risk of ADRs compared to patients carrying the genotype. It is shown that > polymorphism of the gene ( ) has a statistically significant effect on the equilibrium concentration levels of haloperidol.