Adverse interaction of fluoxetine and cyproheptadine in two patients with bulimia nervosa.

The sexual side effect of anorgasmia has been reported with a variety of antidepressants, including fluoxetine. Cyproheptadine has been used to counteract these side effects. The authors report two cases of bulimia nervosa in which the serotonin antagonist effect of cyproheptadine appeared to cancel out the therapeutic benefits of the serotonin-specific uptake inhibitor fluoxetine.