Approximately 75 percent of postmenopausal women and 40 percent of perimenopausal women experience hot flushes with the associated symptoms of sleep and mood disturbance and decreased quality of life. Hormone therapy effectively relieves symptoms of hot flushes, but it is now associated with increased rates of heart and breast disease and other adverse effects. Gabapentin has been noted to relieve hot flushes in patients during tamoxifen or leuprolide therapy. Guttuso and colleagues studied the ability of gabapentin to relieve the frequency and severity of hot flushes in postmenopausal women.
They recruited 59 healthy postmenopausal women who reported at least seven hot flushes daily. Women were excluded if they had less than 12 months of amenorrhea; had taken hormones or tamoxifen within two months; had changed intake of clonidine, raloxifene, or any antidepressant medication in the past month; or were taking gabapentin or a calcium channel antagonist medication. After screening, the women were randomly assigned to receive gabapentin (300 mg three times daily) or an identical-looking placebo. Patients recorded hot flushes in a diary and had follow-up visits after two, four, and 12 weeks of treatment. Assessments included sleep quality, mood, quality of life, and global impression of change measures. Adverse events also were recorded.
In the 54 women who completed the double-blind study, those assigned to the gabapentin group recorded a 45 percent decrease in mean hot flush frequency and a 54 percent reduction in mean hot flush composite score. The corresponding scores for the placebo group were 29 and 31 percent, respectively. The change was apparent after the first week of therapy and was not significantly altered by adjustment for baseline variables. Two thirds of women treated with gabapentin reported a more than 50-percent reduction in hot flush composite score, compared with 38 percent of those treated with placebo. Although 15 women treated with gabapentin reported at least one adverse effect, only four withdrew from the study because of adverse effects. The most common adverse effects were somnolence (20 percent), dizziness (13.3 percent), and rash (6.7 percent). Sleep quality initially improved in women treated with gabapentin, but by week 12, there was no significant difference between the groups. Measures of mood, general health, vital signs, and weight change were not significantly different between the groups.
The authors conclude that low-dose gabapentin effectively relieved hot flushes in postmenopausal women, and they call for larger studies to confirm their findings.