Q: I have tried many different remedies but continue to be terribly irritable before each menstrual period. Is it true that there is a new treatment for this problem?
A: A recent article in the New England Journal of Medicine reported the results of a Canadian study on the treatment of premenstrual syndrome with fluoxetine (Prozac). Surveys have shown that between 3 percent and 8 percent of North American women suffer from premenstrual syndrome. Symptoms, which may begin seven to 10 days before menstrual periods and end soon after the onset of menstrual flow, include increased tension, irritability, agitation, difficulty sleeping and fatigue.
In the Canadian study, 180 women took a placebo, a small dose (20 mg) of fluoxetine, or a large dose (60 mg) of fluoxetine daily over a period of six menstrual cycles. About half of the women receiving either dose of fluoxetine had at least a moderate improvement (defined as a 50 percent improvement) in their symptoms throughout the trial. By contrast, only 22 percent of those taking the placebo reported a moderate decrease in symptoms.
Compared with those taking the placebo, significantly more women receiving fluoxetine reported better than 75 percent improvement in their symptoms. The smaller dose was just as effective as the larger one and caused substantially fewer side effects. Even on the smaller dose, nausea, fatigue, dizziness and decreased ability to concentrate were more common than in those taking the placebo.
This Canadian trial and other studies have dispelled the concern that taking fluoxetine increases the risk of suicide.
Although it is not clear how fluoxetine improves PMS, this drug is an effective treatment for depression; and many of the features of PMS are similar to those of depression.
Dr. Margolis is professor of medicine and biological chemistry at the Johns Hopkins School of Medicine.