Trazodone intracavernosal

Examples of other agents include trazodone (50 to 200 mg/day), yohimbine (5.4 mg three times daily), papaverine (7.5 to 60 mg [single agent therapy] or 0.5 to 20 mg [combination therapy] intracavernosal injection), and phentolamine (1 mg [combination therapy] intracavernosal injection). 

The mechanism by which trazodone produces an erection is not clear. It likely acts peripherally to antagonize a-adrenergic receptors. As a result, a predominant cholinergic effect results, which causes peripheral arteriolar vasodilation and relaxation of cavernosal tissues, which enhances blood filling of the corpora. Intracavernosal injection of trazodone in experimental studies supports this likely mechanism. ... 

Azadzoi KM, Payton T, Krane RJ, et al. Effects of intracavernosal trazodone hydrochloride Animal and human studies. J Urol 1990 144 1277-1282. 

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