The antidepressant citalopram may help lessen the severity of menopausal hot flashes, at least in the short term, a new clinical trial suggests.

The findings, from a seven-week study of 254 women, add to evidence that certain antidepressants can offer relief from severe hot flashes.

Studies have found that some antidepressants in the class known as selective serotonin reuptake inhibitors (SSRIs) may help treat hot flashes; those drugs include paroxetine (Paxil), fluoxetine (Prozac) and venlafaxine (Effexor).

But citalopram (Celexa), another SSRI, has an advantage over some of those medications - namely, paroxetine and fluoxetine - in that it can be used by women on tamoxifen. Tamoxifen is a drug prescribed to treat and lower the risk of breast cancer, and hot flashes are a common side effect.

Because paroxetine and fluoxetine inhibit an enzyme needed to metabolize tamoxifen, women on the drug cannot use those antidepressants for hot flashes.

For the new study, published in the Journal of Clinical Oncology, researchers recruited 254 postmenopausal women who said they had at least 14 “bothersome” hot flashes per week.

For the first week of the study, the women recorded their hot-flash frequency and severity. The researchers then randomly assigned them to take one of three doses of citalopram - 10, 20 or 30 milligrams (mg) per day - or a placebo for six weeks.

In general, the study found, women on the antidepressant showed greater reductions in their hot-flash “score” - a measure of the severity and frequency of hot flashes - than those on the placebo: a reduction of 49 percent to 55 percent, depending on the dose, versus 23 percent with the placebo.

The difference among the three citalopram doses was not significant, suggesting that even a low 10-mg dose can ease hot flashes, the researchers say.

However, as a group, women on the 20-mg dose reported additional benefits, including better sleep and improved mood, noted lead researcher Dr. Debra L. Barton, an associate professor of oncology at the Mayo Clinic in Rochester, Minnesota.

The doses used in this study were lower than what is typically used for treating depression, Barton told Reuters Health in an email, and there was no evidence of an increased risk of side effects with the 10- or 20-mg doses, versus placebo.

With the 30-mg dose, there was some evidence of more sexual side effects; the difference, however, was not significant in statistical terms, so it is unclear if the finding was due to chance.

Sexual side effects, such as decreased libido and difficulty reaching orgasm, are among the potential adverse effects of citalopram and other antidepressants - as are sleep problems, drowsiness and weight changes.

Barton said that more research is needed to study both the effectiveness and risk of side effects when citalopram is taken over a longer period to treat hot flashes.

For now, the current findings suggest the antidepressant stands as an option for women with lasting, bothersome hot flashes, according to the researcher.

“In my opinion, this was a large, placebo-controlled trial that provides a good evidence base to support the use of this medication for hot flash management,” Barton said.

For many women, menopausal hot flashes are manageable and gradually subside within a couple years. For others, they are longer lasting and more severe. Right now, the most effectiveness therapy for severe hot flashes is hormone replacement therapy (HRT).

But given the potential risks of HRT - including heightened odds of heart attack, stroke or breast cancer - experts recommend that if women use hormones for menopausal symptoms, they take them at the lowest dose and for the shortest time possible. And many women would prefer an alternative to HRT.

Some studies have suggested that soy, black cohosh and other sources of phytoestrogens (plant-based estrogen-like chemicals) may help cool hot flashes; other studies, however, have found no such benefit, and the jury is still out on whether these alternative therapies are effective.

And as with hormone replacement, phytoestrogens would not be recommended for women with a history of breast cancer or an increased risk of the disease, which includes women on tamoxifen.

An advantage of citalopram, Barton and her colleagues point out, is that it’s available as a generic. On average, a month’s supply of generic 10-mg citalopram costs about $35.

The study was government funded and the researchers report no potential conflicts of interest.

SOURCE:  Journal of Clinical Oncology, online May 24, 2010.