Epilepsy drug treats breast cancer-related hot flashes

Gabapentin at a dosage of 900 mg/day, but not at 300 mg/day, provides effective relief of hot flashes in women with breast cancer.

The finding derives from a randomized, double-blind, placebo-controlled trial of 420 women with breast cancer experiencing two or more hot flashes daily. Researchers gave participants placebo or one of two amounts of gabapentin by mouth in three divided doses for 8 weeks.

While 300 mg/day of gabapentin was no better than placebo, 900 mg/day reduced hot flashes by about 46% at 8 weeks of treatment (P=0.007), and the findings indicated that an even higher dose might be more effective. The researchers noted that while it is possible that side effects contributed to the withdrawal rate of 12% at 4 weeks and 17% at8 weeks in the 900 mg/day of gabapentin group, the withdrawal rate was similar in all three study groups.

Pandya KJ, Morrow GR, Roscoe JA, et al. Gabapentin for hot flashes in 420 women with breast cancer: a randomised double-blind placebo-controlled trial. Lancet. 2005;366:818-824.