Intracavernosal injection of vasodilating agents has been a mainstay in the treatment of erectile dysfunction. Recently, a transurethral delivery system (MUSE) for alprostadil (prostaglandin E1) was introduced as an alternative form of pharmacotherapy.

One hundred consecutive patients with erectile dysfunction were treated with MUSE in doses ranging from 125 to 1000 μg and their erections were observed in the clinical setting. All patients had previous intracavernosal injections of combination pharmacotherapy (papavarine, Regitine, and/or prostaglandin E1).

Of these 100 patients that used MUSE, only 7% had well-sustained, rigid erections while 30% had full erections but with partial rigidity. The remaining 63% of patients did not achieve erections that they thought were adequate for penetration. Penile and/or perineal pain occurred in 24% of patients, 3% had a syncopal episode, and 3% experienced urethral bleeding. One patient had priapism that required drainage. Using intracavernosal injections, 49% had sustained rigid erections, 40% had full erections with partial rigidity, and 11 % did not have a response satisfactory for penetration.

These data suggest that intracavernosal injections appear to be more effective than MUSE in achieving a rigid erection in men with erectile dysfunction.