Abstract
Objectives. To assess the safety, erectogenic properties, and effect on sexual desire
of Melanotan II, a synthetic melanotropic initiator of erection, in men with erectile
dysfunction and organic risk factors.
Methods. Ten subjects were enrolled in a double-blind, placebo-controlled, crossover
study. Melanotan II (0.025 mg/kg) and vehicle were each administered twice by subcutaneous
injection; real-time RigiScan monitoring and a visual analog were used to quantify
the erections during a 6-hour period. The level of sexual desire and side effects
were recorded with a questionnaire.
Results. Melanotan II initiated subjectively reported erections in 12 of 19 injections
versus only 1 of 21 doses of placebo. The mean rigidity score of the responders was
6.9 on a scale of 0 to 10. The mean duration of tip rigidity greater than 80% was
45.3 minutes with Melanotan II versus 1.9 for placebo (P = 0.047). The level of sexual desire after injection was significantly higher after
Melanotan II administration than after placebo. Nausea and stretching/yawning occurred
more frequently with Melanotan II, and 4 of 19 injections were associated with severe
nausea.
Conclusions. The erectogenic properties of Melanotan II are not limited to cases of
psychogenic erectile dysfunction; men with a variety of organic risk factors developed
penile erections. The finding of increased sexual desire warrants further investigation
of centrally acting agents on disorders of sexual desire.
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Article info
Publication history
Accepted:
April 13,
2000
Received:
August 10,
1999
Footnotes
☆This study was supported by the University of Arizona Foundation and the Office of the Vice President for Research (H.W.) and U.S. Public Health Service Grant DK 17420 (V.J.H.).
Identification
Copyright
© 2000 Elsevier Science Inc. Published by Elsevier Inc. All rights reserved.
