Alprostadil efficacy

Alprostadil is approved as monotherapy for the management of ED. It is generally prescribed after failure of VEDs and phosphodiesterase inhibitors and for patients who cannot use these therapies. Of the available routes, the intracavern os al route is preferred over the intraurethral route because of better efficacy. 

Linet OI, Ogrinc FG. Efficacy and safety of intracavemo-sal alprostadil in men with erectile dysfunction. The Alprostadil Study Group. N Engl J Med 1996 334(14) 873-7. 

Intracavernosal alprostadil is still the most effective treatment, although its use is limited by the side effects and the inconvenience of self-injection and rapid onset of action, which results in an unnatural erection. More than 90% of alprostadil intracavernosal injections result in successful sexual intercourse (126). Transurethral alprostadil is a micro-suppository that is inserted into the stem of the urethra using an applicator. Although it is a more convenient route of administration, its overall efficacy is about 50% (126,127). 

The enhanced efficacy of the intracavernosal inj ection may be related to the excellent bioavailability of the drug when injected directly into the corpora cavernosum. In contrast, intraurethral alprostadil doses generally are several hundred times larger than intracavernosal doses. Intraurethral alprostadil must be absorbed from the urethra. 

In various controlled and uncontrolled studies, the overall efficacy of intracavernosal alprostadil is 70% to 90%. In a large parallel design, double-blind, multicenter study, Linet and associates documented three relevant characteristics of intracavernosal alprostadil ... 

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