The dose-dependent effect of chronic administration of haloperidol, risperidone, and quetiapine on sexual behavior in the male rat.

INTRODUCTION: Antipsychotic drug-induced sexual dysfunction is a common and problematic side effect, which may diminish quality of life and lead to treatment noncompliance. Up to date, there is still a scarcity of basic research regarding the chronic effects of most antipsychotic agents on sexual behavior. AIM: The present study investigated the effect of a range of doses of three antipsychotic drugs (haloperidol, risperidone, and quetiapine) on male rat sexual competence following chronic administration.
METHODS: Twelve groups of Sprague-Dawley rats (n = 7 each) received by gavage haloperidol (0.25, 0.5, or 1 mg/kg), risperidone (0.125, 0.25, or 0.5 mg/kg), quetiapine (10, 20, and 40 mg/kg) or vehicle (distilled water) in the corresponding control groups, respectively, once daily for 21 days. Sexual function was evaluated by the copulatory behavior test 10 hours after the last dose. MAIN OUTCOME MEASURE: The male rat behavioral parameters of copulatory test.
RESULTS: Sexual function was widely and significantly suppressed by high dose haloperidol (1 mg/kg) after 21 days administration compared with the control group, which included both frequency and latency of intromission and ejaculation. Only ejaculation latency was significantly impaired after administration with 0.5 mg/kg haloperidol. Compared with the control group, high dose risperidone (0.5 mg/kg) significantly decreased the frequency of mounting. There were no significant changes in sexual behavior with the lower doses of either haloperidol or risperidone. Sexual behavior was not influenced by any dose of quetiapine.
CONCLUSIONS: Haloperidol and risperidone, but not quetiapine, could impair sexual competence in a dose-related manner in male rats.