Oral therapy for erectile dysfunction

To review the available published literature relating to the use of oral therapy in the treatment of erectile dysfunction.

A literature review was undertaken using techniques of systematic review via Medline and other comparable databases. Only data relating to peer-reviewed published articles was considered. Data available in abstract form was not considered.

Currently there are 4 orally active drugs which are licensed, orally active and widely available. Three of these drugs (namely sildenafil, tadalafil and vardenafil) are inhibitors of the enzyme phosphodiesterase type 5 (PDE5)and work peripherally within the penis to potentiate the smooth muscle relaxation that is needed for a penile erection. The fourth drug (namely apomorphine) works centrally on dopaminergic receptors, probably within the paraventricular nucleus. There is considerable evidence to support the efficacy, tolerability and safety of these agents. Comparator trials have failed to show significant differences in efficacy between the PDE5 inhibitors, but have demonstrated superiority for sildenafil over apomorphine in terms of efficacy. There are currently a number of new PDE5 inhibitors under development.

Oral therapy is the first line therapy for most men with erectile dysfunction. There are a number of commercially available drugs that demonstrate good efficacy, tolerability and safety.