Intranasal Drug Holds Promise for ED
By acting on the brain pathway that controls sexual function, novel medication initiates erection.
A synthetic peptide, bremelanotide works directly on the pathway of the brain that controls sexual function, not systematically on the vascular system like phosphodiesterase-5 (PDE-5) inhibitors such as sildenafil, tadalafil, and vardenafil. Because of its novel mechanism, bremelanotide initiates rather than facilitates an erection.
Bremelanotide binds primarily to a melanocortin receptor in the hypothalamus, triggering descending neural signals to the penis. In the study, men who used intranasal bremelanotide reported improvement in sexual relationships, sexual satisfaction, confidence, and self-esteem. The medication also may lead to significant improvements in erectile function during 12 weeks of on-demand therapy.
The researchers tested the agent in 726 non-diabetic men with ED (mean age 55 years; range 21-70 years). The men had ED for a mean of six years and most already had experience with PDE-5 inhibitors. All were in stable heterosexual relationships. The men were randomized to receive 5, 7.5, 10, 12.5, or 15 mg of bremelanotide intranasally or placebo. The medication was taken at home for 12 weeks; subjects were advised to inhale the drug 45 minutes prior to sexual activity.
Investigators administered the Self-Esteem and Relationship (SEAR) tool, a validated psychological instrument with two major domains—sexual relationship and confidence—and found statistically and clinically significant improvements in self-esteem and relationships resulting from the drug. Moreover, the 7.5, 10, 12.5, and 15 mg dose of the medication was associated with improvements in scores on the International Index of Erectile Dysfunction.
“These results indicate that bremelanotide improves sexual confidence and has the potential to be an important treatment option for patients with ED,” said Stanley Althof, PhD, professor of psychology in the department of urology at Case Western Reserve School of Medicine in
Findings were presented here at the American Urological Association annual meeting.
Bremelanotide is the first in a new class of drugs called melanocortin receptor agonists. It is being developed jointly by Palatin Technologies and King Pharmaceuticals for the treatment of ED in men and for women experiencing female sexual dysfunction.
“Not everybody can take Viagra and there are some contraindications for taking it. It is always good for people to have more than one tool in their toolbox,” Dr. Althof told Renal & Urology News.
The primary adverse effects observed with bremelanotide were nausea, emesis, flushing, BP increases, headache, spontaneous erection, skin darkening, and nasal symptoms. Except for flushing and nasal symptoms, the incidence of adverse events was dose related. The most important effects leading to patient discontinuation from the study were nausea, emesis, and BP increases. Emesis and BP increases were mandated reasons for patient discontinuation.