A new study by researchers at Mayo Clinic in Rochester, Minn. indicates that the long-term use of the antidepressant drug venlafaxine may provide women treated for breast cancer with safe and effective relief from hot flashes. It also appears that this antidepressant may be an alternative to estrogen for other women who want a nonhormonal treatment for their hot flashes.

This follow-up study of 102 postmenopausal women showed that taking venlafaxine over an eight-week period maintained a 60 percent reduction in their hot flashes. The findings mirrored the results of an earlier, four-week first phase of this study that involved more than 200 women. The findings were published in Oncology Nursing Forum.

"The clear message is that now many women with breast cancer do not have to suffer with their hot flashes and that women who want a non-estrogenic choice of treatment now have one," said Dr. Charles Loprinzi, a Mayo Clinic oncologist. "The study also further reassures physicians and other health care providers that venlafaxine is a safe and effective nonhormonal treatment they can consider for their postmenopausal patients."

"We know from our previous study that venlafaxine works in the short term to control hot flashes," added Debra Barton, Ph.D., a co-author of the study. "This follow-up study provides evidence that venlafaxine continues to be effective and well tolerated over a longer period of time."

Hot flashes are a major problem for many postmenopausal women. In women without breast cancer, hormone replacement therapy involving estrogen is the typical treatment prescribed to relieve the problem.

That is not the case for women with breast cancer. Frequently, the chemotherapy used to treat the cancer causes the woman to go into early menopause and experience severe hot flashes. Because of the concern that estrogen may lead to the growth of breast cancer cells, these women are often denied estrogen for hot flashes.

The newer antidepressants, of which venlafaxine is one, offer more hope for nonhormonal management of hot flashes. These newer antidepressants work to control various neurotransmitters in the brain. Some of those neurotransmitters are thought to trigger hot flashes.

"In a dose of 75 mg per day, extended-release venlafaxine offered an average 60 percent reduction in the frequency of hot flashes," said Loprinzi. "Women in both studies also noted that venlafaxine seemed to reduce the severity of their hot flashes."

The side effects of venlafaxine include mild appetite loss, dry mouth and, in some women, nausea. Of the women in this study experiencing nausea from venlafaxine, most rated their nausea as relatively mild and transitory. For about 10 percent of the women, nausea was a more prominent problem.

SOURCES:
Oncology Nursing Forum, February 2002; 29(1): 33-40
Mayo Clinic, Rochester, Minn. (http://www.mayo.edu)