In the first head-to-head study of two treatments for hot flashes, a single dose of a hormone seems to be more effective than a daily dose of a popular antidepressant.
Both the hormone medroxyprogesterone acetate, known as Depo-Provera and an antidepressant, venlafaxine (Effexor), have been shown to reduce the nighttime sweating and rapid pulse associated with severe hot flashes. However, in the first head-to-head study of these two treatments, a single injection of the hormone was three times more effective than the daily, oral antidepressant.
While this information is promising for all women looking for relief from hot flashes, it is especially helpful for women who want to avoid estrogen replacement therapy, the most common treatment for menopause symptoms. Some studies have shown that estrogen replacement therapy may increase the risk of breast cancer, so women who are already at high risk for breast cancer, or those who have had breast cancer and are at risk for recurrence, may prefer an effective non-estrogen option.
"Most of the women who want an alternative to estrogen therapy use some of the newer antidepressants, but the hormone injection has not been used as much," said Dr. Charles Loprinzi, author of the study published in The Journal of Clinical Oncology.
However, both treatments have side effects. While antidepressants sometimes cause nausea, vomiting, dry mouth and constipation, some are concerned that studies have shown that Depo-Provera may increase the risk the breast cancer when used long-term for contraception. However, according to Loprinzi, no study has determined the risk of only one injection of Depo-Provera, and only one dose is usually needed to treat hot flashes.
Hot flashes normally occur during the onset of menopause, when the body starts to produces less estrogen and progesterone. This hormonal change confuses the hypothalamus, the thermostat for the body, which sends signals to the rest of the body to turn up the heat. Often, severe hot flashes occur in women after certain types of breast cancer treatment.
Loprinzi's study, which looked at the effectiveness of both the hormonal treatment and daily antidepressants in 100 women with severe hot flashes—one-third had ten or more hot flashes a day—showed that both treatments reduce the frequency of hot flashes.
Six weeks into the study, 80 percent of the women taking Depo-Provera had at least some reduction in the number of hot flashes, while 60 percent of the women taking Effexor reported relief. Six months later, the women who had the hormone injection were three times as likely to report a 90 percent reduction in hot flashes as those taking the daily pill. In fact, Depo-Povera, which only needs to be injected once, almost completely eliminated the hot flashes for 24 percent of the women.
"If [the hormone] works for a woman, it lasts for months, sometimes years," said Loprinzi.
Besides the convenience of a once-only injection, Loprinzi says that the hormone injection also eliminates the worry about missing a pill. "It's easier and cheaper," he says.
As for the concern about an increased breast cancer risk from Depo-Provera, Loprinzi reminds both doctors and patients that there is some degree of risk with all medicines, and all factors should be weighed when making a decision to be treated for hot flashes.