Many classes of antidepressants, including the selective serotonin reuptake inhibitors (SSRIs), can impair sexual function. Few studies have examined this adverse effect, particularly in women. While the physiology of SSRI effects on sexual function is unknown, buspirone and amantadine have been proposed as agents that might ameliorate antidepressant-induced sexual dysfunction. Michelson and associates evaluated the effectiveness of buspirone and amantadine in the treatment of sexual dysfunction associated with fluoxetine use.

The randomized placebo-controlled study included 57 women who were 50 years or younger and had received fluoxetine for at least eight weeks. All of the women reported impaired orgasm or sexual arousal that first occurred after initiation of fluoxetine therapy. The 12-week study included a four-week period of assessment and an eight-week period of treatment with buspirone (10 mg twice daily), amantadine (50 mg daily) or placebo. Pretreatment assessment included psychologic evaluation and self-reporting of sexual function. Nineteen patients were in the buspirone group, 18 were in the amantadine group and 20 were in the placebo group.

Patients used visual analog scales to rate vaginal lubrication, orgasm, sexual pleasure and any discomfort related to sexual intercourse. They rated these features following each time of sexual activity. Patients were also evaluated in structured interviews at weeks 4 and 12.

Overall sexual function improved significantly in each group, and the magnitude of mean improvement was similar in the three groups. Improvement in energy level was greatest with amantadine. The degree of improvement in the different measures, such as mood, energy, sexual interest and desire, lubrication, orgasm, pleasure and discomfort, generally ranged from 20 to 50 percent.

The authors conclude that buspirone and amantadine were no more effective in treating sexual dysfunction related to fluoxetine therapy than placebo. The authors also state that their study is the first to assess placebo response in SSRI–associated sexual dysfunction.