Fluprazine hydrochloride decreases copulation in male rats.

The copulatory performance of 18 sexually experienced male rats was tested 30 min after IP injection of the phenylpiperazine, Fluprazine Hydrochloride (4 and 8 mg/kg), or saline solution. Three 20-min tests with an estrous female were conducted at weekly intervals. Each drug dose produced a significant depressive effect on copulatory behavior (latency to and frequency of intromissions and ejaculations) without affecting social investigation. The increased latencies to mounting and intromission observed at both doses suggest that the primary action of the Fluprazine Hydrochloride is to interfere with the transition from social to copulatory patterns. Although the drug's mode of action is currently unknown, the present findings suggest that it operates on some common mediator of sexual and aggressive behavior.