Mayo Clinic study confirms venlafaxine is safe, effective for women with and without breast cancer

ROCHESTER, MINN. -- A Mayo Clinic study indicates long-term use of the antidepressant drug venlafaxine provides women treated for breast cancer with safe and effective relief from hot flashes. It also appears that this antidepressant can be an alternative to estrogen for women who want a nonhormonal treatment for their hot flashes.

This follow-up study showed that women receiving venlafaxine over eight weeks maintained approximately a 60 percent reduction in their hot flashes. A total of 102 postmenopausal women participated in this investigation. The findings of the eight-week evaluation mirrored the results of the first phase of this study -- a four-week double-blinded, randomized study that involved more than 200 women.

The results of the study are published in the current edition of 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," says Charles Loprinzi, M.D., 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."

Dr. Loprinzi co-authored this study with Debra L. Barton, Ph.D., a Mayo Clinic oncology nurse researcher.

"We know from our previous study that venlafaxine works in the short term to control hot flashes," says Dr. Barton. "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," says Dr. 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 minority of women in this study experiencing nausea from venlafaxine, most rated their nausea as relatively mild and transitory. In about 10 percent of the women, nausea was a more prominent problem.

---Mayo Clinic

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