Induction of penile erection by intracavernosal injection: A double-blind comparison of phenoxybenzamineversus papaverine-phentolamineversus saline

Abstract

Recent data suggest that intracavernous injections of phenoxybenzamine in saline, and/or papaverine with phentolamine mesylate in saline, result in erection in otherwise impotent men. A double-blind study using normal saline and normal saline mixed with phenoxybenzamine or papaverine-phenotolamine mesylate showed that none of 11 subjects with organic erection dysfunction responded with appreciable penile swelling to saline injection, but all responded with some degree of penile swelling to the other solutions. The mechanism of penile erection in response to intracavernous injections is still unclear, but it is thought to be related to the alpha-adrenergic blocking and/or smooth muscle relaxant actions of these drugs; the volume of the injection or the normal saline content of the solution are not factors in causing penile tumescence.