Evaluating the effects of an alpha-2 adrenoceptor antagonist on erectile function in the human male. 1. The erectile response to erotic stimuli in volunteers.

The effects of a new alpha-2 adrenoceptor antagonist on erectile function was assessed in 12 normal volunteers (mean age 28.7, range 20-42), using a double blind, placebo controlled design with two doses of drug and three testing sessions. The drug was administered by intravenous infusion and erectile responses to erotic fantasy and films were monitored by a Rigiscan device. Four effects of the drug were observed; (i) an increase in spontaneous erections; (ii) increased subjective ratings of sexual arousal, before presentation of erotic stimuli; (iii) increased duration of erectile response to erotic stimuli; and (iv) increases in systolic BP and HR both before and during erotic stimulation. These effects were largely restricted to the high dose of the drug. Adverse effects of the drug were minimal.