April 27, 2000 -- Women who suffer from postmenopausal hot flashes may soon be able to get relief in the form of a nasal spray, a new study shows. Used once a day, the experimental spray, which contains a liquid version of the female hormone estrogen, virtually eliminated the uncomfortable and embarrassing flashes in most women who used it.
Doctors frequently prescribe oral estrogen replacement therapy for women experiencing daily hot flashes after menopause. But doctors often must make adjustments in the therapy to find the most effective dosage. Estrogen also can be given through a patch worn on the skin, but studies have found that some women don't absorb the hormone as well by this method as with the pills, and the patches can fall off or irritate the skin.
In the study, published in the American Journal of Obstetrics and Gynecology, researchers compared standard estrogen tablets with estrogen in nasal-spray form. The 659 postmenopausal women in the study ranged in age from 40 to 60. Some were given a nasal spray bottle containing estrogen along with dummy, or placebo, pills; others got estrogen pills and a placebo spray. The women used both the pills and the spray daily for 24 weeks. All also took progesterone pills for two weeks.
Before the study, women in both groups were having an average of six hot flashes per day. By the middle of the study period, 90% of all the women were having less than one hot flash per day, and by the end of the study, most were having none, according to researcher Lars Ake Mattsson, MD. Mattsson is with the department of obstetrics and gynecology at Sahlgrens University Hospital East in Goteborg, Sweden.
Women using the estrogen nasal spray had less uterine bleeding than those taking the estrogen pill, though few side effects occurred in either group. The most common adverse effects were nasal irritation in the group that got the estrogen nasal spray, and breast tenderness or pain in the group that got estrogen pills.
The researchers say that intranasal estrogen therapy may someday be an effective and convenient option for postmenopausal women.
But an expert who discussed the study with WebMD expressed concerns about the long-term safety of the method, as inhaling a drug gets it into your bloodstream and to your brain much faster than a tablet you swallow or a skin patch you wear.
"I have a concern that you may be delivering too much estrogen to the brain at the expense of anywhere else," Wulf H. Utian, MD, PhD, tells WebMD. He says that to be safe, estrogen doses that are inhaled should be smaller than doses a woman would take in tablet form. But a major reason for taking estrogen, aside from relieving postmenopausal symptoms, is to prevent osteoporosis and, possibly, heart disease. It is unclear whether using smaller doses would still provide women with those protective benefits.
Utian, who is professor and chairman of the department of reproductive biology at Case Western Reserve University School of Medicine in Cleveland and executive director of the North American Menopause Society, also says using a spray every day may have long-term effects on the nasal passages.
"There are other ways [of taking estrogen-replacement therapy] that have had a lot more testing and that are ahead of the game on this particular delivery system," he says. If the nasal spray were available, Utian says, he would not recommend it at this point without much further testing.