Acetyl-L-carnitine plus propionyl-L-carnitine improve efficacy of sildenafil in treatment of erectile dysfunction after bilateral nerve-sparing radical retropubic prostatectomy

Objectives. To determine whether propionyl-L-carnitine (PLC) plus acetyl-L-carnitine (ALC) improves the effectiveness of sildenafil in restoring sexual potency after bilateral nerve-sparing radical retropubic prostatectomy. Methods. We analyzed the data from 96 patients who had undergone bilateral nerve-sparing radical retropubic prostatectomy: 33 were given placebo (group 1), 32 used PLC 2 g/day plus ALC 2 g/day plus sildenafil 100 mg when needed (group 2), and 35 used sildenafil alone (group 3). The studied variables were sexual function (assessed through sexual behavior interviews and the International Index of Erectile Function), peak systolic velocity and end-diastolic velocity of cavernosal arteries (assayed by dynamic echo-color Doppler), the percentage of patients able to achieve a positive intracavernous injection test, and side effects. Results. Placebo proved ineffective and sildenafil and sildenafil plus ALC and PLC proved effective. The International Index of Erectile Function-15 scores of the group 2 patients were significantly greater than those of group 3 in the following domains: erectile function, sexual intercourse satisfaction, orgasm, and general sexual well-being. The drugs did not significantly modify the score in the sexual desire domain or in the peak systolic velocity or end-diastolic velocity of the cavernosal arteries. Sexual behavior interviews revealed that 2 of 29 in group 1, 28 of 32 in group 2, and 20 of 39 in group 3 attained satisfactory sexual intercourse (P <0.01). Only group 2 had a significantly increased percentage of patients with a positive intracavernous injection test after therapy (36.4% versus 63.6%; P <0.01). ALC plus PLC did not significantly improve the side effects of sildenafil. Conclusions. PLC and ALC proved to be safe and reliable in improving the efficacy of sildenafil in restoring sexual potency after bilateral nerve-sparing radical retropubic prostatectomy.