Switching from long-term treatment with self-injections to oral sildenafil in diabetic patients with severe erectile dysfunction.

OBJECTIVE: To assess the efficacy of oral sildenafil in diabetic men with severe erectile dysfunction (ED), who are successfully treated with intracavernous injections of vasoactive drugs.
METHODS: 81 impotent diabetic men (29 with type 1 and 52 with type 2) were treated for 1-7 years with self-injections. 13 men were treated with 10 microg and 15 with 20 microg of prostaglandin E1 (PGE1), and 53 with a mixture of PGE1 20 microg and papaverine 7.5-40 mg (MIX). After a 1-week washout period, they changed to oral sildenafil in titrating doses up to 100mg. The change was successful if the man achieved an erection and penetration even once.
RESULTS: Sildenafil was discontinued in 23 men because of insufficiency. Eleven men (13.6%), all with type 2 diabetes, responded to sildenafil (10 previously treated with 10 microg and 1 with 20 microg of PGE1, none treated with MIX). Thus, 39.2% of the treated with PGE1 responded to oral sildenafil. The response was influenced by the age, the type of diabetes (type 2) and the kind of the previously injected drug (PGE1 10 microg); it was not influenced by the duration of diabetes, ED and treatment with self-injections.
CONCLUSIONS: Despite the well documented efficacy of sildenafil, self-injections continue to be the solely effective therapeutic modality in many diabetic men afflicted by severe ED. Only the younger men with non-insulin-dependent diabetes, treated with low doses of PGE1 are more likely to respond to oral sildenafil and change treatment. Men with insulin-dependent diabetes or treated with mixtures of vasoactive drugs are not likely to respond to oral sildenafil.