Dr. Susan Love Research Foundation | Breast Cancer

The drug gabapentin (brand name Neurontin) appears to reduce the incidence of hot flashes in women with breast cancer, according to a new study.

Many women receiving systemic treatment—chemotherapy or hormone therapy—for breast cancer experience hot flashes. Chemotherapy frequently puts premenopausal women into menopause (sometimes referred to as chemopause), which can trigger hot flashes. And hot flashes are a common side effect of the hormone therapies (tamoxifen and the aromatase inhibitors) used to treat women with hormone-sensitive tumors.

In women who have not had breast cancer, hormone replacement therapy (HRT) may be offered to help with hot flashes. But women who have had breast cancer should not take HRT, as research indicates that HRT appears to increase the risk of a breast cancer recurrence or of a second breast cancer. For this reason, women with breast cancer need to have alternative ways to treat their hot flashes.

For this study, Kishan Pandya, MD, of the University of Rochester Cancer Center, and colleagues randomized 420 women with breast cancer who were having two or more hot flashes per day to one of three treatment groups: placebo, 300mg/day of gabapentin, or 900mg/day of gabapentin. All of the women kept a diary of the hot flashes they experienced before the study began and during the eight weeks they were being treated.

The researchers found that the placebo reduced hot flashes by 15 percent, 300mg/day of gabapentin reduced hot flashes by 31 percent, and 900mg/day of gabapentin reduced hot flashes by 46 percent. The differences between the groups were statistically significant. Based on their findings the researchers conclude, "Gabapentin is effective in the control of hot flashes at a dose of 900 mg/day" and that it "should be considered for treatment of hot flashes in women with breast cancer." The study, "Gabapentin for Hot Flashes in 420 Women with Breast Cancer: A Randomized Double-Blind Placebo-Controlled Trial," appears in the September 3, 2005, issue of The Lancet.

Susan says:
Finding alternatives to HRT for women with breast cancer hasn't been easy. Antidepressants have been one option. Now gabapentin appears to be another.

Gabapentin has been approved for use in the United States since December 1993. It is used to treat seizures, shingles pain, and migraines. A study published in the February 1, 2003, issue of Obstetrics and Gynecology found that gabapentin reduced hot flashes in postmenopausal women by about 54 percent. The above study was conducted to see if the drug was also effective in reducing hot flashes in women with breast cancer.

If your hot flashes are making your life uncomfortable, you should talk to your oncologist about your options. Gabapentin probably won't make your hot flashes go away. The drug reduced hot flashes by 46 percent, or about half. This means that if you have four hot flashes a day, you might now only have two. But if you have a lot of hot flashes, cutting them in half (or even one-third) could be the difference between a horrible day and a pleasant one.