The effect of Sildenafil citrate (ViagraTM) on the frequency, duration, and degree of nocturnal penile tumescence in diabetic neuropathic men

The present study deals with the effects of sildenafil citrate (Viagra) on the nocturnal sleep related erectile dysfunctions in diabetic neuropathic men. In this investigation 50 type 1 and 50 type 2 diabetic patients with and without an objective evidence of neuropathy, aged between 15 to 60 years with a duration of diabetes distributed over 1-20 years were included along with their age matched non diabetic controls. Subjects were evaluated for nocturnal penile tumescence (NPT) and rigidity testing and the effect of oral administration of 100 mg. of sildenafil citrate (Viagra) was noted on the above-mentioned parameters. Both types of diabetic neuropathic patients exhibited a highly significant decrease in all nocturnal tumescence parameters including frequency, duration, and degree. However, both type 1 and type 2 patients without neuropathy showed a non-significant difference in the above-mentioned parameters than their respective control subjects, thus suggesting that impotence and altered nocturnal erectile responses are likely to be associated with an increased frequency to autonomic neuropathy in these patients irrespective of their type of diabetes. Treatment with oral administration of 100 mg. of sildenafil in both type 1 and type 2 diabetic neuropathic patients indicated significant increase (P<0.0001) in all the parameters of NTP and rigidity testing, however this difference was not significant in both types of diabetic patients without neuropathy before and after oral administration of sildenafil and when compared with their respective control subjects thus suggesting that oral administration of sildenafil citrate improves the quality of nocturnal erection in both type 1 and type 2 neuropathic group of patients. We thus conclude that sildenafil citrate is an effective first-line therapy for erectile dysfunction in diabetic men with impotence of neuropathic etiology. These results will improve our insight into the management of sexual disorders as part of diabetic care, and suggest guidelines for the prescription of Viagra in diabetic neuropathic patients.