Intraurethral and topical agents.
In early 1997, the FDA approved a transurethral delivery system for a urethral suppository containing alprostadil (PGE(1)), manufactured by Vivus and called the MUSE system. Pharmacokinetic studies showed rapid absorption from the urethra (80%) in the first 10 minutes after an intraurethral dose. 873 patients tried home use of alprostadil or blinded placebos. 64.9% of the patients on alprostadil reported intercourse compared to only 18.6% of the placebo group. Successful use of MUSE at home seemed to be equal in all categories of impotence. The consistency of response increased slightly over a period of 3 months. Penile pain occurred in 32.1% of patients receiving the active ingredient (10.8% of all applications). With the MUSE system, there was minor urethral trauma in 5.1% of the patients. A small subset of patients who used MUSE reported that previous intracavernosal injection therapy was not effective. Of these, 58% reported erections sufficient for intercourse after MUSE introduction. Recently, further efficacy studies were performed in a FDA trial of the combination of the MUSE system with the veno-occlusive band (Actis). Topical medications have been anecdotally reported and do not produce spectacular results. These include organic nitrates and nitrites, minoxidil, papaverine and PGE(1) or PGE2.
Lewis
R W
RW
Medical College of Georgia, Section of Urology, Augusta, Georgia 30913-4050, USA.