Sildenafil (Viagra) Effective in Women with Antidepressant- Associated Sexual Dysfunction

ALBUQUERQUE, N.M., July 22 -- For women whose sexual dysfunction is associated with the use of antidepressants, the erectile dysfunction drug sildenafil (Viagra) brought significant improvement, researchers here reported.

Compared with placebo, women randomized to sildenafil reported significant reduction in sexual dysfunction symptoms such as delayed orgasm and inadequate lubrication, H. George Nurnberg, M.D., of the University of New Mexico, and colleagues, wrote in the July 23/30 issue of the Journal of the American Medical Association.

Sildenafil treatment was associated with an increase in headache, flushing, and dyspepsia, but "no patients withdrew because of serious side effects," the researchers said.

The eight-week, parallel-group, randomized, double-blind, placebo-controlled trial enrolled 98 premenopausal women who reported sexual dysfunction as a side-effect of treatment with selective and nonselective serotonin reuptake inhibitors (SRIs).

The mean age of the women was 36.7 and on average they had been taking antidepressants for 27.7 months.

At baseline women reported a mean of three sexual problems including decreased libido, lack of lubrication, delayed orgasm, and pain.

Prior to the start of the study the women reported a mean of six sexual attempts per month with fewer than two considered successful.

After treatment, Clinical Global Impression scores improved by an average of 1.91 in the sildenafil group versus an improvement of 1.10 in the placebo group, which was significant (P=0.001).

An intention-to-treat analysis yielded a more conservative difference -- 1.5 improvement in the sildenafil arm versus 0.9 gain in the placebo group -- which was still significant at P=0.03.

Statistical significance aside, the researchers said, clinically "73% of the women taking placebo compared with 28% of women taking sildenafil reported no improvements with treatment."

There was, however, no significant improvement in sexual desire, a finding the authors said was consistent with reports that drugs like sildenafil "do not directly enhance libido."

The women were recruited at seven U.S. centers from September 1, 2007 through January 1, 2007; half (49) were randomized to sildenafil before sexual activity (starting dose 50 mg adjustable to 100 mg).

Sexual dysfunction has been reported by 30% to 70% of patients whose depression was treated with first- or second- generation agents, the researchers said, leading to a "nonadherence that approaches 70% in the first months of treatment and leads to increased relapse, recurrence, disability, and resource utilization by affected patients."

The authors said their study was the first randomized trial to demonstrate a significant reduction in adverse sexual effects compared with placebo in women undergoing treatment with SRIs, although similar findings have emerged from open-label studies.

Secondary endpoints, which included a number of standard measures of sexual satisfaction, revealed significant improvement in ability to reach orgasm and in pleasure for women in the sildenafil group compared with controls.

Endocrine levels were in the normal range with no significant differences between the treatment groups.

The researchers said the population in the study -- women taking SRIs who reported sexual dysfunction associated with treatment and who were highly motivated to improve -- probably limits the ability to generalize the findings.

Another limiting factor was the brief treatment duration -- just eight weeks. The researchers noted that it is unknown if women would be willing to take sildenafil for longer periods or what the effect of long-term treatment would be.