Erectile dysfunction in kidney transplanted patients: efficacy of sildenafil

BACKGROUND: Erectile dysfunction (ED) is the inability to achieve and/or maintain an erection for satisfactory sexual performance. The effects of kidney transplantation on pre-existing ED are poorly understood, as well as the onset of new ED cases after kidney transplantation. This study aimed to evaluate the effects of kidney transplantation on pre-existing ED, to assess the onset of new ED cases after renal transplantation and to assess both the efficacy and safety of sildenafil. METHODS: Erectile function was assessed using the self-administered International Index of Erectile Function (IIEF) to kidney transplanted patients. A 50 mg dose of sildenafil was prescribed. Sildenafil efficacy was assessed by re-administering the questionnaire after 4 weeks of therapy. Blood chemistry and serum cyclosporine concentration were evaluated at the beginning of the study and, in patients treated with sildenafil, after 4 weeks of treatment. RESULTS: One hundred and thirteen patients (87.5%) completed the questionnaire. Fifty-three patients (47%) did not complain of ED, the remaining 60 patients (53%) reported ED. ED was already present during dialysis in 40 patients; it appeared ex novo in 20 patients after transplantation. Pre-existing ED disappeared in 8 patients (20%), ameliorated in 13 patients (32.5%), worsened in 2 patients (5%), and remained unchanged in 17 patients (42.5%) after transplantation. The IIEF score significantly improved in sildenafil-treated patients (n=20); there were no observed changes in blood chemistry, blood pressure (BP), renal function and cyclosporine concentration. The side-effects were minimal. CONCLUSIONS: ED was still present in a large cohort of kidney transplanted men. Renal transplantation cures few ED cases. ED can appear ex novo after transplantation. Sildenafil is an effective ED treatment in kidney transplanted men.