Common drugs offer some hot flash relief.

A variety of drugs can slightly reduce the number of hot flashes that a woman experiences during menopause, an overview of studies finds.

Studies have shown that estrogen therapy can substantially reduce hot flashes. However, studies of nonhormonal treatments have been less definitive. So, researchers reviewed 43 studies in which a drug or nutritional supplement was compared with a placebo in menopausal women experiencing hot flashes.

The women entered most of the studies averaging six or seven hot flashes per day, says Heidi D. Nelson, an internist and epidemiologist at the Oregon Health and Science University and Providence Health System in Portland.

Receiving a placebo lessened the number of hot flashes by one or two per day, the overview showed. Antidepressants called selective serotonin reuptake inhibitors (SSRIs) and the blood pressure--lowering drug clonidine lowered that tally by one additional hot flash per day, Nelson says. The antiseizure drug gabapenfin reduced flashes by two per day beyond the placebo's effect.

Extracts from soy and red clover failed to lessen hot flashes beyond the placebo effect, the scientists report in the May 3 Journal of the American Medical Association.

Research suggests that the estrogen loss that precipitates menopause also disrupts the brain area called the hypothalamus, which regulates body temperature. Some doctors already treat women's hot flashes with SSRIs, which may modulate the concentration of the signaling chemical serotonin in the hypothalamus, note Jeffrey A. Tice and Deborah Grady of the University of California, San Francisco in an editorial in the same journal issue.

--N.S