Efficacy and safety of transurethral alprostadil therapy in men with erectile dysfunction. MUSE Study Group

To examine the safety and efficacy of transurethral pharmacotherapy for erectile dysfunction, involving the use of a novel therapeutic system to administer alprostadil (prostaglandin E1) to the urethral mucosa in a double-blind, randomized, parallel, placebo-controlled study conducted in five countries in Europe.

In an outpatient setting, patients with primarily organic erectile dysfunction of at least 3 months' duration were treated with transurethral alprostadil, in an open-label, dose-escalating study. Testing stopped when the dose provided an erection sufficient for intercourse, as assessed by the patient and the investigator. Patients who achieved a sufficient response were then randomized to either active medication at the selected dose or to placebo for use at home for 3 months. After each home administration, patients recorded in diaries whether or not sexual intercourse occurred and any adverse reactions to the drug.

A total of 249 patients were treated in an outpatient setting; of these patients, 159 (64%) achieved an erection sufficient for intercourse and were randomized (1:1) to either active medication or placebo for home treatment. Of the patients randomized to alprostadil for home treatment, 69% reported intercourse at least once, compared with 11% of patients randomized to placebo (P < 0.001). The most common adverse reaction, urethral pain/burning, was reported by 7% of patients in the clinic. Most patients (83%) graded transurethral alprostadil as causing minimal or no discomfort in the clinic. No patient reported priapism or developed penile fibrosis.

Alprostadil delivered transurethrally by this system was well tolerated and effective in treating erectile dysfunction.