Fertility drug may reduce hot flashes - study

* Pilot study shows drug cut hot flashes by 80 percent

* Bigger, better studies needed to prove drug works

By Gene Emery

BOSTON, Sept 16 (Reuters) - A drug that prevents premature ovulation during fertility treatments helped reduce the number of hot flashes by up to 80 percent in a small study of women entering menopause, researchers reported on Wednesday.

They said the drug Cetrotide, made by Merck Serono, a subsidiary of the German company Merck (MRCG.DE: Quote, Profile, Research), blocked the action of a key brain hormone involved in hot flashes.

Just three women were tested, and more studies are needed, but the findings offer a potential new way to deal with hot flashes or flushes, which can raise a woman's body temperature by as much as 7 degrees Fahrenheit in a matter of minutes.

Hot flashes, which redden the face and interrupt sleep, can occur as often as twice an hour and are debilitating in one in six older women. Hormone treatments relieve them, but carry a risk of cancer, stroke or other problems.

A team led by Dr. Hans de Boer of Rijnstate Hospital in Arnhem, the Netherlands, used injections of Cetrotide, known generically as cetrorelix, to block the receptor of the brain hormone LHRH, which stands for luteinizing hormone-releasing hormone.

His findings were published in the New England Journal of Medicine.