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.

Purpose: Despite the utility of newer antidepressants for alleviating hot flashes, antidepressants do not work adequately enough in many patients. Gabapentin is a nonhormonal agent that also can reduce hot flashes. No data have been available to address whether the combination of both agents would more effectively alleviate hot flashes, compared with gabapentin alone, in patients with inadequate hot flash control with an antidepressant alone.
Patients and Methods: This was a randomized trial in which 118 patients with inadequate hot flash control on an antidepressant were randomly assigned to receive both an antidepressant and gabapentin versus being weaned off the antidepressant and receiving gabapentin alone. Patients were observed for 5 weeks (including a baseline week in which patients continued on their current antidepressant without gabapentin) during which time they completed validated daily hot flash diaries.
Results: Ninety-one patients provided complete data at the 5-week assessment. Regardless of whether or not the antidepressant was continued when gabapentin was started, there was an approximately 50% median reduction in hot flash frequencies (54%; 95% CI, 34% to 70% for combined treatment v 49%; 95% CI, 26% to 58% for gabapentin alone) and scores (56%; 95% CI, 26% to 71% for combined treatment v 60%; 95% CI, 33% to 73% for gabapentin alone).
Conclusion: Gabapentin seems to decrease hot flashes by approximately 50% in women with inadequate hot flash control who were using an antidepressant. This study saw no significant additional hot flash reduction from continuation of the antidepressant.