Fluoxetine Reduces Hot Flashes in Breast Cancer Survivors

ROCHESTER, Minn—Preliminary results from an ongoing Mayo Clinic study show that fluoxetine (Prozac) reduced the incidence of hot flashes in breast cancer survivors by more than 50%, Charles L. Loprinzi, MD, said at the San Antonio Breast Cancer Symposium.

Eligible patients had more than two hot flashes a day on average, for more than 1 month. The flashes were significant enough that the women desired intervention but had concerns about use of hormone therapy. Dr. Loprinzi reported on 33 patients.

After a 1-week baseline evaluation, patients received 20 mg/d of fluoxetine or placebo in a double-blind manner for 4 weeks. Then, while still double-blinded, patients were crossed over to the alternative treatment. Hot flashes were scored as 1 (mild), 2 (moderate), 3 (severe), or 4 (very severe). Total daily points were added to get the daily hot flash score.

Study Results

“During the initial 4 weeks of therapy, the fluoxetine group experienced about a 50% reduction in hot flashes,” Dr. Loprinzi said, “while the placebo arm had approximately a 20% reduction in hot flashes. When crossed over from fluoxetine to placebo, the hot flashes came back. When crossed over from placebo to fluoxetine, the hot flashes decreased.”

In the 4th treatment week, about 19% of the placebo patients had a major reduction of hot flashes to half or less of their baseline score. About 53% of the fluoxetine patients had a similar dramatic reduction. “This is an interesting placebo effect that we need to think about when giving other agents,” he said. He noted that the P values associated with these results “are hovering around .05.”