Correlation between plasma homovanillic acid levels and the response to atypical antipsychotics in male patients with schizophrenia

OBJECTIVE: The authors investigated the effects of atypical antipsychotic drugs-olanzapine, perospirone, and quetiapine-on plasma homovanillic acid (pHVA) in male patients with chronic schizophrenia. METHODS: In this prospective, open-label study, the subjects were 30 inpatients who were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria for schizophrenia. The authors switched patients from typical antipsychotic drugs to olanzapine, perospirone, or quetiapine. Each patient gave informed consent for the research. pHVA was assessed before and after switching medications. RESULTS: After the switch, the authors found a significant improvement in psychotic symptoms, nonsignificant improvement in extrapyramidal symptoms, and a nonsignificant reduction in pHVA. In addition, the baseline pHVA correlated positively with the score changes from baseline in the Brief Psychiatric Rating Scale (BPRS) total, positive, and negative symptoms in the group with a whole sample and in the olanzapine-treated group, and with the score changes in the BPRS total and positive symptoms in the quetiapine-treated group. CONCLUSION: Our findings indicated that the preswitching pHVA levels could be used to predict changes in the psychotic symptoms of male patients with chronic schizophrenia when switching to atypical antipsychotic drugs.