Clinical Question: Is high-dose gabapentin (Neurontin) as effective as usual-dose estrogen for the treatment of postmenopausal hot flashes?

Setting: Outpatient (primary care)

Study Design: Randomized controlled trial (double-blinded)

Allocation: Concealed

Synopsis: The authors recruited menopausal women 35 to 60 years of age who each had at least 50 moderate to severe hot flashes weekly for at least two months. Any treatments for hot flashes, including hormones, were discontinued for at least one month before enrollment in the study. Sixty women were randomized to gabapentin 2,400 mg daily, conjugated equine estrogen 0.625 mg daily, or placebo. The gabapentin was titrated over 12 days to a total of two 400-mg capsules three times daily.

Women recorded their hot flashes in a diary and indicated the severity of each one on a visual analog scale (1 = mild, 4 = severe). The number of hot flashes was multiplied by the severity of each over the course of a week to obtain a composite hot flash score. The composite scores at 12 weeks were compared with baseline scores. The gabapentin group had a mean reduction of 71 percent, the estrogen group had a mean reduction of 72 percent, and the placebo group’s score dropped 54 percent (P < .017 for each active treatment versus placebo). There was no statistical difference between the gabapentin and estrogen groups. Five women dropped out during the study, including one in the gabapentin group because of side effects.

Bottom Line: In this small study, high-dose gabapentin was as effective as the usual dose of conjugated equine estrogens for the treatment of menopausal vasomotor symptoms. Larger studies are needed to confirm this result. (Level of evidence: 1b)