Newer antidepressants and gabapentin for hot flashes: a discussion of trial duration

Information regarding the ideal length of hot flash trials is scarce. In the literature, hot flash trial durations have commonly varied from 4 to 12 weeks. This article is devoted to providing scientific data to better ascertain how long it is necessary to conduct hot flash trials with newer centrally acting agents.

Individual participant data were collected from all known published, through December 2007, randomized, placebo-controlled, double-blinded clinical trials regarding the use of newer antidepressants and gabapentin for hot flash relief. Trials that studied periods longer than 4 weeks were included for this project. Profile analysis was applied to the hot flash activity longitudinal data for each study individually, allowing a comparison of data collected for 6 to 12 treatment weeks versus data collected for only 4 treatment weeks.

Ten studies were identified, five of them fulfilled the eligibility criteria for this investigation, three evaluating gabapentin, and two newer antidepressants. Flatness tests from a profile analysis did not provide any evidence that hot flash activity increased or decreased between week 4 and time periods up to 12 weeks.

Changes in hot flash scores from newer antidepressants and gabapentin are apparent within 4 weeks of therapy. Available data indicate that hot flash treatment efficacy, compared with that of placebo, remains stable for up to 12 weeks of follow-up.