Objective: 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.
Methods: 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.
Results: 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.
Conclusions: 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.