Forest Laboratories antidepressant drug Lexapro is arranged in a Cambridge, Massachusetts. Photographer: JB Reed/Bloomberg

Forest Laboratories Inc.’s top-selling product, the antidepressant Lexapro, eased hot flashesin menopausal women in a study, proving itself a potentialalternative to hormone treatments.

The number of daily hot flashes dropped 47 percent forwomen taking Lexapro for 2 months compared with 33 percent forthose given a placebo, according to U.S.-funded researchpublished today in the Journal of the American MedicalAssociation. Lexapro also reduced the severity of the symptomsand resulted in no “serious adverse events,” scientists said.

Prempro and Premarin, from new York-based Pfizer Inc., areamong the hormone therapies that are the only approved U.S.treatments for menopausal signs such as hot flashes and nightsweats. Research has linked hormone therapies to higher risks of breast cancer and cardiovascular disease.

“The medication that we studied provides an option formenopausal hot flashes,” said Ellen Freeman, the study’s leadauthor and a research professor in the Department of Obstetrics& Gynecology at the University of Pennsylvania in Philadelphia,in a telephone interview on Jan. 14. “It’s important to beclear that it is off-label, and probably further studies wouldbe important to determine both that these results are consistentand also to compare this directly with hormone therapy.”

Lexapro, or escitalopram oxalate, is approved to treatdepression and anxiety. Sales of Lexapro for the six monthsended Sept. 30 were $1.13 billion. The drug loses patentprotection next year.

New York-based Forest won’t seek U.S. clearance of the drugas a treatment for hot flashes, the company said in a messagerelayed on Jan. 14 by Cohn & Wolfe, a public relations agencyowned by Dublin-based WPP Plc. asked for the reason, the agencyhad no immediate response.

The medicine is part of a group of drugs called selectiveserotonin reuptake inhibitors, including Forest’s Celexa, Prozacfrom Indianapolis-based Eli Lilly & Co., Zoloft from Pfizer andLondon-based GlaxoSmithKline Plc’s Paxil.

It’s unclear how the medicines, which increase the chemicalserotonin in the brain, reduce hot flashes, Freeman said.

In the 8-week study, 104 women received Lexapro and 101women were given a placebo. At the start, all the women had anaverage of 9.8 hot flashes a day. After 8 weeks, the numberdecreased to 5.3 a day for women on Lexapro, while those onplacebo experienced 6.4 hot flashes daily, the study found.

Fifty-five percent of those taking Lexapro and 36 percentof those given the placebo had a decrease of more than 50percent in hot flash frequency at week 8, the researchers said.The study found the reduction in severity and frequency of hotflashes was the same regardless of race, Freeman said.

“There’s been previous evidence of benefit from a widerange of medications including the same class of antidepressantstested in this study,” said Randall Stafford, an associateprofessor of medicine at Stanford University near Palo Alto, California. “This in my mind is the most conclusive study ofnon-estrogens and their benefits.”

Stafford, who wasn’t an author of the Lexapro paper, was aninvestigator on the Women’s Health Initiative, which in 2002linked estrogen and progesterone therapy to higher risks ofheart attack, stroke and breast cancer, and has been involved infollow-up studies. He hopes doctors will use the Lexapro studyto prescribe women antidepressants before giving hormonetreatments, particularly for those with mild menopausalsymptoms, he said.

In some women, the benefits of Lexapro were seen after oneweek of treatment in the study, Freeman said. Within two tothree weeks of stopping the drug, the number and severity of hotflashes rose, she said.

“The drug does not cure hot flashes, it controls them,”Freeman said. “So when you stop taking the drug, if you stillhave hot flashes, they’re going to come back.”

Menopause occurs mostly about age 50 and marks the end of awoman’s fertility. more than 6 million women took Prempro andrelated menopause drugs to replace hormones the body stopsmaking before the Women’s Health Initiative highlighted therisks. Wyeth’s hormone drugs — including Prempro, a combinationof estrogen and progestin — had annual sales of more than $2billion before the health initiative report. Pfizer, whichbought Wyeth in 2009, is fighting lawsuits over the drug’srisks.

The Lexapro study was sponsored by the National Institutesof Health, based in Bethesda, Maryland, as part of a $22 millionprogram to research potential treatments for menopause.

Sherry Sherman, program director of clinical aging andreproductive hormone research at the National Institute ofAging, also in Bethesda, said the Lexapro findings offerpromise.

“If women are really having problems, there’s not muchout there that’s efficacious,” Sherman said in a telephoneinterview on Jan. 14.

Sherman said scientists also will study the benefits ofexercise or yoga plus omega-3s on menopausal symptoms. Thatresearch should be available next year.

To contact the reporter on this story:Nicole Ostrow in New York at .

To contact the editor responsible for this story:Reg Gale at