CYP2D6 phenotype and ABCB1 haplotypes are associated with antipsychotic safety in adolescents experiencing acute psychotic episodes

To identify possible associations of CYP2D6, CYP3A4/5, and ABCB1 gene polymorphisms with the efficacy and safety of antipsychotics in adolescents with acute psychotic episodes. We examined the associations of pharmacogenetic factors with the efficacy and safety of antipsychotics in 101 adolescents with acute psychotic episodes. The diagnosis on admission was "Brief psychotic disorder"(F23.0-23.9 by ICD-10). All patients were administered antipsychotics for 14 days. Treatment efficacy and safety were assessed using the PANSS, CGAS, CGI-S(I), UKU SERS, BARS, and SAS scales. Pharmacokinetic genotyping was performed for the CYP2D6∗4, ∗10, ABCB1 1236C>T, 2677G>T, and 3435C>T genes. CYP2D6 intermediate metabolisers had "Micturition disturbances"more often than extensive metabolisers (24.2 vs. 7.4%; p=0.026). "Wild"homozygote ABCB1 3435C>T CC was associated with more prominent akathisia. Haplotype analysis of three ABCB1 polymorphisms revealed that the "wild"alleles "C-G-C"(ABCB1 1236-2677-3435) were associated with higher risk of "Reduced salivation"(OR=2.95; 95% CI=1.35-6.45; p=0.0078). CYP2D6 intermediate metabolism was associated with the risk of urinary difficulties under treatment with antipsychotics. We found that "wild"homozygotes ABCB1 1236C>T, 2677G>T, and 3435C>T were predictors of adverse drug effects caused by treatment with antipsychotics.