Gabapentin monotherapy as effective as gabapentin plus antidepressant in treatment of hot flashes

Key Points

A phase 3 study evaluating the use of gabapentin alone and in combination with an antidepressant in women with hot flashes who had an inadequate response with antidepressant monotherapy demonstrated that gabapentin reduced hot flashes by approximately 50%, whereas the combination of an anti-depressant with gabapentin appeared to offer no additional benefit. These study results were published in the Journal of Clinical Oncology.

Hormonal therapies have recently fallen out of favor for the treatment of hot flashes. Therefore, nonhormonal treatments, including antidepressants such as venlafaxine and paroxetine, are being used for this condition. The authors noted that women may seek additional treatment, as these agents alone often are not enough to treat this problem. Therefore, the authors set out to evaluate the effect of gabapentin plus an antidepressant versus gabapentin alone in alleviating hot flashes in patients who have experienced inadequate hot flash control with antidepressant monotherapy.

This randomized trial included women already receiving a stable dose of an antidepressant, either a selective serotonin reuptake inhibitor or a serotonin norepinephrine reuptake inhibitor. A patient-reported incidence of ≥14 hot flashes/wk warranting symptom-relieving treatment was required. Additionally, women had to have a history of breast cancer or a concern about taking hormones due to a fear of breast cancer. Patients could not have had prior gabapentin use and could not be receiving hormonal therapy or chemotherapy within the 4 weeks before the study or have these treatments planned within 5 weeks after the study.

Of 118 women randomized, 113 completed the study, and 91 provided complete data. There were no significant differences between the 2 treatment arms in changes from baseline at Week 4 on hot flash score (P=.37) or hot flash frequency (P=.61). There was an approximate 50% median reduction in hot flash frequency (combination treatment, 54%; 95% CI, 34%–70%; gabapentin monotherapy, 49%; 95% CI, 26%–58%) and hot flash score (combination treatment, 56%; 95% CI, 26%–71%; gabapentin monotherapy, 60%; 95% CI, 33%–73%). There were no statistically significant between-group differences in changes from baseline for toxicities or for any of the QOL evaluations. There was a trend towards increased dizziness in gabapentin-treated patients, observed only during the time when patients were tapering off the antidepressant. There was also a trend towards increased nervousness and mood changes in the gabapentin monotherapy group.

Gabapentin seemed to decrease hot flashes by approximately 50% in women who had inadequate hot flash control with antidepressant monotherapy. This study failed to demonstrate that the combination of an antidepressant and gabapentin was more effective than gabapentin alone in alleviating the symptoms of hot flashes.

SOURCE Loprinzi CL, Kugler JW, Barton DL, et al. Phase III trial of gabapentin alone or in conjunction with an antidepressant in the management of hot flashes in women who have inadequate control with an antidepressant alone: NCCTG N03C5. J Clin Oncol. 2007;25:308–312.