Objective: To audit the effectiveness of the anticonvulsant gabapentin on hot flushes in postmenopausal women.
Design: This was an open case series involving 11 postmenopausal women who were willing to take gabapentin for the relief of their hot flushes and were willing to keep a diary recording the number and intensity of their hot flushes, both before and during treatment. Gabapentin was started at a dose of 300 mg, to be taken at night, and the women were instructed to increase the dose up to 1,200 mg, according to symptom behavior.
Results: Eleven women agreed to participate for on average 53.22 days (range, 2–79 days), but two discontinued participation—one before starting treatment and one after 2 days—so there are complete data sets for nine women. Gabapentin was found to be extremely effective in reducing hot flush activity (P < 0.001;Fig. 1). A significant reduction in symptoms was observed with a dose of 300 mg/day (P < 0.001). Scores on the Green Climacteric Scale were significantly improved from a mean of 25.72 (range, 12–42) to 19.25 (range, 13–31; P < 0.001). Palpitations (P = 0.001), panic attacks (P = 0.0001), mood (P = 0.023), muscle and joint pains (P = 0.021), and paresthesias and loss of sensation in the extremities (P = 0.001) were also shown to improve with treatment.
Conclusions: In the present case series, gabapentin was well tolerated and could be a valuable alternative for the treatment of hot flushes in women with contraindications to hormonal replacement therapy. It would be particularly beneficial for women in whom aches and pains and paresthesias are also a significant feature of the climacteric syndrome.
Hot flushes are probably the most common symptom of estrogen deficiency resulting in medical consultation at the time of menopause, and for that, estrogen replacement therapy (ERT) is the treatment of choice. Estrogen, however, cannot be universally used either, because of contraindications or because of women's unwillingness to take it. Alternatives are thus required. Many agents have been investigated for their potential in alleviating hot flushes, particularly among survivors of breast cancer. The best-described nonestrogenic treatments for hot flushes are progestogens. Low doses of megestrol acetate have been shown to result in a reduction of about 80% in hot flushes, compared with a decrease of about 20% with placebo. 1 Nonetheless, the major concern about progestogen preparations remains the uncertainty over their effect on the risk of breast cancer, particularly in women at high risk of the disease. 2 Nonhormonal alternatives to alleviate hot flushes in these women are needed. Various nonhormonal therapies—including vitamin E, clonidine, methyldopa, and Bellergal (phenobarbital, ergotamine, and levorotatory alkaloids of belladonna)—have been examined but have limited efficacy or adverse side effects. Serotonin reuptake inhibitors such as venlafaxine have been used with positive results. 3 However, many women do not wish to take antidepressants for fear of habituation.
Gabapentin [1-(aminomethyl)cyclohexaneacetic acid; Neurontin] is an anticonvulsant used as add-on therapy for the treatment of epileptic seizures. In addition, gabapentin exhibits antinociceptive and anxiolytic effects. 4 There is anecdotal evidence of an effect in reducing hot flushes when given in a dose of 600 mg/day and 1,600 mg/day. 5,6
In this case series based on a clinical audit, we provide further data on the possible effect and tolerability of gabapentin for the treatment of hot flushes in women who have a contraindication to or are unwilling to take hormone therapy.