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.