May 30, 2010 -- Hot flash frequency and severity declined by 50 percent in postmenopausal women treated for six weeks with the antidepressant citalopram, according to data from a placebo-controlled, randomized clinical trial.

The trial, conducted among 254 women with frequent hot flashes (at least 14 hot flashes a week for a month or longer), found that the lowest of three citalopram doses was as effective as the highest for dousing hot flashes, but the midrange dose appeared to have broader activity against symptoms. the findings were published online in the Journal of Clinical Oncology.

Citalopram's effects on hot flashes is not unique; a number of antidepressants in the selective serotonin reuptake inhibitor (SSRI) class have been shown to reduce hot flashes. However, citalopram may offer advantages over other SSRIs.

"Citalopram, unlike paroxetine, can be given with tamoxifen," Debra Barton of the Mayo Clinic in Rochester, Minn., and colleagues wrote. As little as 10 mg per day of citalopram is needed for a 46 percent reduction in daily frequency of hot flashes.

"This, coupled with the minimal adverse effect profile at this dose, makes this particularly useful for women who have difficulty taking pharmacologic agents and appears to be more tolerable than either gabapentin or pregabalin," the authors noted.

Citalopram is also only taken once per day and is available generically.

Up to 75 percent of women may experience hot flashes, a vasomotor symptom associated with menopause and breast cancer treatments (either tamoxifen or aromatase inhibitors), which can negatively impact quality of life. The physiology is not definitively understood, and hot flashes can vary considerably in frequency, severity, and persistence. In some women, hot flashes resolve within two years, but for others symptoms can persist for years, especially in long-term treatment for breast cancer.

Several drugs in the SSRI class have reduced hot flashes by 50 percent or more in placebo-controlled clinical trials, including paroxetine, fluoxetine, and venlafaxine (Effexor). However, uncertainty surrounding how hot flashes occur and how SSRIs act to ameliorate them suggest that the effects cannot be assumed to be a class effect.

Citalopram May Beat Other Antidepressants Against Hot Flashes

For example, clinical trials of the SSRI sertraline have shown more modest reductions in hot flashes. In addition, some doubt persists about serotonergic agents' effect on hot flashes, since not all clinical trials have yielded positive results, the authors noted.

Mixed results have also come from other clinical trials of citalopram to treat hot flashes. In addition, the appropriate dose of the drug for hot-flash prevention has not been determined.

For the trial, the Mayo Clinic investigators enrolled 254 postmenopausal women who were not receiving hormone therapy or cancer treatment and reported at least 14 hot flashes per week for a month or longer. The women were divided into four groups -- one which took a placebo, and three which took differing daily doses of citalopram: 10, 20, or 30 mg.

After six weeks of treatment, hot-flashes had declined by 23 percent in the placebo group and by 49 percent, 50 percent, and 55 percent in the women assigned to 10, 20, and 30-mg doses of citalopram, respectively.

The authors note that one limitation of the study was its limited time period of seven weeks; therefore, long-term control of hot flashes or the occurrence of adverse effects with citalopram could not be determined.