No relationship between-141C Ins/Del polymorphism in the promoter region of dopamine D2 receptor and extrapyramidal adverse effects of selective dopamine D2 antagonists in schizophrenic patients: a preliminary study

Previous studies have shown that subjects without Del alleles of the -141C Ins/Del polymorphism in the promoter region of the dopamine D2 receptor. (D RD2) gene have lower DRD2 density that those with one or two Del alleles. T he present study aims to investigate the relationship between the -141C Ins /Del polymorphism and extrapyramidal adverse effects of bromperidol and nem onapride, antipsychotic drugs with a selective and potent DRD2 antagonistic property, in schizophrenic inpatients. Twenty-seven patients were treated with bromperidol at a fixed-dose of 6, 12 or 18 mg/day, and 25 patients wer e treated with nemonapride at a fixed-dose of 18 mg/day. The duration of tr eatment with these drugs was 3 weeks. The Ins and Del alleles were determin ed by PCR. Extrapyramidal adverse effects were assessed by the Udvalg for K liniske Undersogelser side effects rating scale. The subjects consisted of 38 homozygotes of the Ins allele and 14 heterozygotes of the Ins and Del al leles. There were no significant differences in the incidence or severity o f extrapyramidal adverse effects between patients with and without the Del allele. It is possible that this result was due to a lack of statistical po wer. However, the present study suggests that the - 141C Ins/Del polymorphi sm is not related to the development of extrapyramidal adverse effects duri ng acute-phase treatment with antidopaminergic agents. (C) 2001 Elsevier Sc ience Ireland Ltd. All rights reserved.