Among men with major depression, treatment with Cymbalta is associated with less worsening of sexual function than is treatment with Lexapro, investigators reported this week at the American Psychiatric Association 2006 annual meeting in Toronto.

“When we take surveys of patients who take their antidepressants only intermittently or discontinue them altogether, about two-thirds of patients will say it is because of side effects, of which the most common are sexual side effects,” presenter Dr. Anita Clayton told Reuters Health. Failure to take the antidepressant as prescribed is likely to result in relapse, she added.

Clayton and her colleagues at the University of Virginia in Charlottesville randomly assigned 684 patients with depression to 60 milligrams per day of Cymbalta, or to 10 milligrams per day of Lexapro (another antidepressant), or to placebo for 8 weeks. The patients completed the “Changes in Sexual Functioning Questionnaire” at regular intervals.

Approximately 42 percent of patients on Cymbalta had an antidepressant response, versus 35 percent of those treated with Lexapro, with onset as early as 2 weeks and sustained throughout the study.

At 4 and 8 weeks, Lexapro was associated with significant worsening of sexual functioning compared with placebo. In contrast, the effect of Cymbalta was similar to that of placebo.

At 8 weeks, responses to the sexual functioning questionnaire showed that 37 percent of men treated with Cymbalta, 49 percent of those taking placebo, and 59 percent among those taking Lexapro had worsening sexual functioning. Among women, the rates of worse sexual dysfunction were similar between the two drugs (36 percent and 38 percent, versus 26 percent for placebo).

The initial 8-week phase of the trial was followed by a 6-month, flexible dosing extension phase in which patients took Cymbalta 60 to 120 mg daily or Lexapro 10 to 20 mg per day. Those who discontinued placebo pills because of lack of efficacy were randomly assigned to one of the two drugs.

By the end of the 8 months, there were no significant differences between the two drugs in terms of their effect on sexual function.

“We know that among people with sexual dysfunction associated with SSRI (antidepressants), 5 percent to 10 percent get over it. They become acclimated to it, but it takes about 4 to 6 months,” Clayton noted. The reported sexual side effects in this study were also affected by attrition and dosing flexibility, she added.

When asked if medications like sildenafil (Viagra) could help reduce the sexual side effects, she answered, “Sildenafil may be helpful in men with erectile dysfunction or arousal problems related to antidepressant medication, but it has no effect on reduced sexual desire or orgasmic dysfunction.”

This study was funded by Eli Lilly and Company.