Treating Hot Flashes Without Hormones

May 2, 2006 -- Some nonhormonal therapies may help treat hot flashes, but probably not as much as estrogen, doctors report in The Journal of the American Medical Association.

Those findings come from a review of 43 previously published studies. The reviewers included Heidi Nelson, MD, MPH, of Oregon Health & Science University.

Menopause isn't a disease. But hot flashes are common and may be severe in menopausal women.

The studies in Nelson's review tested these therapies to treat hot flashes:

• Antidepressants. Selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) such as Paxil, Prozac, Effexor, and Celexa
• Clonidine (Catapres). A blood pressure medication made in pill or patch form
• Gabapentin (Neurontin). An antiseizure medication
• Red clover isoflavone extracts
• Soy isoflavone extracts

Each treatment was separately compared with a sham treatment (placebo). The women didn't know whether they received the real treatment or placebo. They kept diaries of their hot flashes before and during treatment, which ranged in length from a few weeks to a year.

Interest Beyond Estrogen

Estrogen has long been used to treat menopausal symptoms.

"However, recent studies reporting adverse effects of estrogen, such as cardiovascular events and breast cancer, raise important concerns about its use," write Nelson and colleagues. Those concerns have spurred interest in alternative treatments for menopausal symptoms.

Estrogen may still be used to treat menopausal symptoms. The FDA advises doctors to prescribe "the smallest effective dose for the shortest duration possible," write Nelson and colleagues.

Nelson's study uses the term "nonhormonal therapies" for treatments that weren't based on the hormones estrogen, progestin, progesterone, or androgen.

Isoflavones (natural chemicals in some plants, including soy), may have estrogen-like effects. For simplicity's sake, the reviewers considered isoflavone extracts to be nonhormonal therapies.

Review's Results

The SSRIs, SNRIs, Catapres, and Neurontin studies showed evidence of effectiveness, Nelson's team writes.

However, they were less effective than estrogen. Also, there are few published studies, and most of the studies had design weaknesses, they write.

Side effects and cost may restrict use for many women, they write. Side effects included nausea, headache, dry mouth, and decreased appetite.

"These therapies may be most useful for highly symptomatic women who cannot take estrogen but are not optimal choices for most women," write Nelson and colleagues.

The researchers found no sign that red clover isoflavone extracts reduced hot flashes. The results on soy isoflavone extract studies were mixed.

As Nelson's team noted, some studies were higher in quality than others. Also, some trials included women who had had breast cancer and were taking tamoxifen; those women may not represent other menopausal women. Hot flashes are a common side effect of tamoxifen use. Those limits may make it hard to draw definite conclusions.