The study, led by Michael J. Zelefsky, MD, of Memorial Sloan-Kettering Cancer in New York, is the first randomized, prospective, controlled trial to demonstrate that a phosphodiesterase type 5 inhibitor is useful as a rehabilitation strategy in patients undergoing radiotherapy for PCa, according to a report published online ahead of print in The Journal of Urology.
Dr. Zelefsky’s team randomized 279 PCa radiotherapy patients to receive either sildenafil citrate 50 mg or placebo daily. The drug or placebo was initiated three days prior to radiotherapy and continued daily for six months.
At 12 months, erectile function scores, as measured using the International Index of Erectile Function, were significantly better for the sildenafil citrate group than for placebo recipients, with 73% of the medication recipients reporting mild or no erectile dysfunction (ED) compared with 50% of placebo recipients.
At 24 months, erectile function scores were no longer significantly better in the sildenafil citrate arm, but 81.6% of sildenafil citrate recipients had functional erections (with or without ED medications) compared with 56.0% of placebo recipients, a significant difference between the groups. The sildenafil citrate group had higher sexual desire scores despite completing drug therapy 18 months prior, according to the investigators.