Background: Prostaglandin E₁ ethyl ester (PGE₁-EE) is a prodrug of prostaglandin E₁ but with much improved transdermal penetration.
Patients and methods: We performed a randomized, double-blind, controlled study in 34 patients to assess the safety and efficacy of transdermally applied PGE₁-EE for the treatment of erectile dysfunction. In a first single-blinded titration period the most appropriate PGE₁-EE dose (maximum 1000 μg) was determined. PGE₁-EE was applied to the shaft of the penis using an adhesive foil patch which contained the drug. For home use, the patients were provided with 4 patches with the appropriate dose and 2 patches with placebo containing a small dose of 5 μg PGE₁-EE to use randomly prior to sexual intercourse, waiting three days between each use.
Results: The median rigidity score as the primary outcome variable was significantly higher after verum versus placebo applications. Also, concerning the secondary outcome variable satisfactory sexual activity, superiority was shown for verum versus placebo. Although penetrating intercourse could not be performed significantly more frequently, 50 % of patients considered the treatment successful. It was well-tolerated and local side effects were generally mild.
Conclusions: PGE₁-EE could be a promising drug formulation in local penile therapy of ED. In further studies higher doses should be investigated in order to potentially achieve a higher level of efficacy.