Pathophysiology and treatment of hot flashes.

Hot flashes affect about three fourths of postmenopausal women and are one of the most common health problems in this demographic group. Dysfunction of central thermoregulatory centers caused by changes in estrogen levels at the time of menopause has long been postulated to be the cause of hot flashes. Treatment should begin with a careful patient history, with specific attention to the frequency and severity of hot flashes and their effect on the individual's function. For mild symptoms that do not interfere with sleep or daily function, behavioral changes in conjunction with vitamin E (800 IU/d) use is a reasonable initial approach. For more severe symptoms, the next step is to determine whether there is a contraindication or a personal reservation to estrogen replacement therapy. For women who are able and willing to use estrogen, it will successfully relieve symptoms by about 80% to 90%. In patients with a history of breast or uterine cancer, treatment with the progestational agent megesterol acetate appears to be a safe alternative that also decreases hot flashes by approximately 80%. For women unwilling or unable to use hormone therapy, one of the newer antidepressant agents can be prescribed. Venlafaxine decreases hot flashes by about 60%. Gabapentin is another drug that appears promising as therapy for women unable or unwilling to use estrogen, and the results of ongoing trials to determine its efficacy are eagerly awaited. The use of clonidine, methyldopa, and belladonna should be discouraged because of their modest efficacy and adverse effects.