Prolactin responses to haloperidol in normal young women.

The prolactin (PRL) responses to intramuscular haloperidol (HPD) (0.5, 1.0, and 1.5 mg) were evaluated in six normal premenopausal women during the follicular and luteal phases of their menstrual cycles. These were compared to the PRL responses to these doses of HPD in normal young men. PRL responses to HPD did not differ between the follicular and luteal phases. The mean log-transformed PRL response to the lowest HPD dose (0.5 mg) in women was less than that in the men, but the women had greater PRL responses than the men to the higher haloperidol doses (1.0 mg and 1.5 mg).