Purpose: We compared the efficacy of paroxetine alone and combined with sildenafil in patients complaining of premature ejaculation.

Materials and methods: Enrolled in this study were 80 consecutive potent men 19 to 47 years old (mean age 34) with premature ejaculation but without any obvious organic cause. Pretreatment evaluation included a history, self-administration of the International Index of Erectile Function (IIEF) questionnaire, physical examination and the Meares-Stamey test to exclude genital tract infection. The initial 40 patients received 10 mg. paroxetine daily for 21 days and then 20 mg. as needed, that is 3 to 4 hours before planned sexual activity, for 6 months (group 1). The other group of 40 men received 10 mg. paroxetine daily for 21 days and then 20 mg. as needed plus 50 mg. sildenafil as needed, that is 1 hour before planned sexual activity, for 6 months (group 2). Patients were followed 3 and 6 months after beginning therapy and were evaluated using several general assessment questions, IIEF and ejaculatory latency time.

Results: Mean ejaculatory latency time +/- SE in group 1 was 0.33 +/- 0.04, 3.7 +/- 0.10 (p <0.01) and 4.2 +/- 0.03 (p <0.01) minutes at baseline, 3 and 6-month followup, while in group 2 it was 0.35 +/- 0.03, 4.5 +/- 0.07 (p <0.01) and 5.3 +/- 0.02 (p <0.001) minutes, respectively. When improvement in ejaculatory latency time was compared in the 2 groups, group 2 results proved to be significantly greater (p <0.05). Baseline, and 3 and 6-month mean intercourse satisfaction domain values of the IIEF were 9, 11 and 11 (p = 0.09, not significant), and 9, 11 and 14 (p <0.05) in groups 1 and 2, respectively. Group 2 patients reported significantly greater intercourse satisfaction than those in group 1 (p <0.05). At baseline, 3 and 6 months there was a mean of 0.9 +/- 0.1, 1.7 +/- 0.3 (not significant) and 2.5 +/- 0.3 (p <0.01) coitus episodes weekly in group 1, and 1 +/- 0.2, 2.3 +/- 0.3 (p <0.01) and 3.2 +/- 0.1 (p <0.001) in group 2, respectively. Group 2 patients reported a significantly higher number of coitus episodes weekly (p <0.05). Side effects in the 40 group 1 cases included anejaculation in 1 (2.5%), gastrointestinal upset and/or nausea in 5 (12.5%), headache in 4 (10%) and decreased libido in 2 (5%). Side effects in the 40 group 2 cases included anejaculation in 1 (2.5%), headache in 8 (20%), gastrointestinal upset and/or nausea in 6 (15%) and flushing in 6 (15%). Group 2 patients reported significantly more headaches (p <0.01) and flushing episodes (p <0.001) than those in group 1. After 6 months of treatment 33 men (82.5%) in group 1 and 36 (90%) in group 2 were willing to continue therapy (not significant).

Conclusions: Paroxetine combined with sildenafil appears to provide significantly better results in terms of ejaculatory latency time and intercourse satisfaction versus paroxetine alone in potent patients with premature ejaculation. However, combined treatment is associated with a mild increase in drug related side effects.