Updated

The antidepressant Lexapro significantly cut the number and severity of hot flashes in healthy menopausal women, offering a new way to treat the condition without hormones, U.S. researchers said on Tuesday.

Hormone replacement therapy or HRT is the only approved treatment for hot flashes. But a large study in 2002 showed it raised the risk of breast and ovarian cancers and strokes in older women, and doctors now prescribe it sparingly.

"One of the reasons for the study was to try to find something other than hormonal therapy," said Ellen Freeman of the University of Pennsylvania School of Medicine, whose study appears in the Journal of the American Medical Association.

Her team compared Forest Laboratories' Lexapro, also known as escitalopram, to a placebo in 205 healthy women who were having nearly 10 hot flashes a day.

After eight weeks of treatment, women who took Lexapro said they had half as many hot flashes, and those they had were less bothersome than at the start of the study.

"We feel the data provide an option for treatment for hot flashes, in particular if women are risk for taking hormonal therapy because they have a history of cancer or for women who don't want to take hormone therapy," Freeman said in a telephone interview.

Other antidepressants - including GlaxoSmithKline's paroxetine or Paxil; fluoxetine, sold by Pfizer as Prozac; and Pfizer's venlafaxine or Effexor - also have been found to be effective.

Smaller studies had hinted that Lexapro might help, but it had not been studied in women who were not depressed.

"What this study does is provide an answer to that question that it's effective for hot flashes in generally healthy women," Freeman said. "The side effects in these women are overall fairly low. They tolerate it very well."

The researchers found 55 percent of the women taking Lexapro saw their hot flashes drop by 50 percent or more, compared with 36 percent of women who took a placebo pill.

Freeman said the placebo effect - the number of women who benefited from taking a sugar pill - was in line with what they had expected and was smaller than in other clinical trials of hot flashes in menopausal women.

While the difference in the effect between the Lexapro and placebo groups was modest, it was statistically significant.

Three weeks after women stopped taking Lexapro, their hot flashes came back, while there was little change among women in the placebo group.

Women in the Lexapro group also were significantly more likely to want to continue on their assigned medication, with 64 percent of women taking Lexapro saying they wanted to stay on the study drug versus 42 percent who took the placebo.

"It's giving them relief," Sherry Sherman of the National Institute on Aging, which paid for the study, said in a telephone interview. "That is what we'd like to do and with a very safe profile."
Sherman said 75 percent of menopausal women have hot flashes, and 45 percent have severe hot flashes.

She said she would like to see longer-term studies to show how the drug works over time. Even so, she said, "It's looking like it's a good option."

In the United States, doctors are free to prescribe a drug as they see fit once it has been approved, but companies cannot market the drug for treatments other than those for which they have been approved. For that, Forest Labs, which markets the drug in the United States, and Danish drugmaker Lundbeck would need to seek a new indication, something Sherman said she hopes will happen.