Efficacy of linsidomine chlorhydrate, a direct nitric oxide donor, in the treatment of human erectile dysfunction: results of a double-blind cross over trial.

: Recent experimental work has demonstrated that nitric oxide (NO) is the neurotransmitter responsible for cavernous smooth muscle relaxation. Different studies on the performance of the direct NO-donor SIN-1 (linsidomine chlorhydrate) in patients with erectile dysfunction have come to conflicting results. We have performed a double-blind cross over trial in 40 patients with erectile dysfunction of mixed etiology comparing SIN-1, SIN-1 plus the alpha-blocker Urapidil, and prostaglandin E1 (PGE1) in order to determine the effectiveness of SIN-1. PGE1 achieved the best response, the combination of SIN-1 and Urapidil performed slightly, statistically insignificantly poorer with significantly increased side effects. SIN-1 alone performed statistically significantly (p < 0.0068) worse. SIN-1 is not a useful alternative to PGE1. The combination of SIN-1 and Urapidil performs equally as good as PGE1 but cannot be recommended due to intolerable side effects.