Sildenafil citrate (viagra) and erectile dysfunction following external beam radiotherapy for prostate cancer: A randomized, double-blind, placebo-controlled, cross-over study

Purpose: To determine the efficacy of, sildenafil citrate (Viagra) in patie nts with erectile dysfunction after three-dimensional conformal external be am radiotherapy (3D-CRT) for prostate cancer. Methods and Materials: 406 patients with complaints of erectile dysfunction and who completed radiation at least 6 months before the study were approa ched by mail. 3D-CRT had been delivered (mean dose 68 Gy). Sixty patients w ere included and entered a double-blind, placebo-controlled, cross-over stu dy lasting 12 weeks. They received during 2 weeks 50 mg of sildenafil or pl acebo; at Week 2 the dose was increased to 100 mg in case of unsatisfactory erectile response. At Week 6, patients crossed over to the alternative tre atment. Data were collected using the International Index of Erectile Funct ion (IIEF) questionnaire, and side effects were recorded. Results: Mean age was 68 years. All patients completed the study. For most questions of the IIEF questionnaire there was a significant increase in mea n scores from baseline with sildenafil, but not with placebo. Ninety percen t of the patients needed a dose adjustment to 100 mg sildenafil. Side effec ts were mud or moderate. Conclusion: Sildenafil is well tolerated and effective in improving erectil e function of patients with ED after 3D-CRT for prostate cancer. (C) 2001 E lsevier Science Inc.