Improvement in antipsychotic-induced hyperprolactinemia with the addition of aripiprazole in schizophrenic patients

Abstract

Purpose: Hyperprolactinemia, a common adverse effect of antipsychotics, frequently impacts patients' quality of life. Aripiprazole is a potent dopamine D2 receptor partial agonist and rarely increases the serum prolactin concentration. The authors investigated the effect of aripiprazole coadministration on antipsychotic-induced hyperprolactinemia and associated symptoms in patients with schizophrenia.Method: The subjects were 9 patients (8 females, 1 male) with hyperprolactinemia induced by risperidone, olanzapine, haloperidol, zotepine, bromperidol, levomepromazine, and quetiapine; 6 of the females had oligomenorrhea and 2 amenorrhea, and the male had erectile dysfunction. All of the patients received concomitant aripiprazole for more than 8 weeks at a mean dose (range) of 7.7 (3-18) mg/day. The doses of all other medications, including the hyperprolactinemia-inducing antipsychotics, remained fixed throughout the study period.Results: The mean serum concentration (range) of prolactin during aripiprazole coadministration (29.9 (9.8-53) ng/ml) was significantly (p=0.008) lower than that before aripiprazole coadministration (81.1(27-153) ng/ml). The associated symptoms were improved in 4 females (regularized or regained menstruation) and the male (normalized erectile function), while no changes were observed in the other clinical symptoms of schizophrenia.Discussion: The results of the present study suggest that even small doses of coadministered aripiprazole effectively limit excessive prolactin response to antipsychotics without interfering with the benefits of existing prescriptions.