Vasomotor hot flashes are a common problem in menopausal women. Given concerns regarding estrogen and/or combined hormonal therapy, other treatment options are desired. Prior trials have confirmed that progestational agents and newer antidepressants effectively reduce hot flashes. This current trial compared a single intramuscular dose of medroxyprogesterone acetate (MPA), depot preparation, versus daily oral venlafaxine as treatment for hot flashes.

Women with bothersome hot flashes were entered onto this trial, were randomly assigned to treatment, and then had a baseline week where hot flash scores were recorded without treatment. They were then treated and observed for 6 weeks; daily diaries were used to measure hot flash frequencies and severities. There were 109 patients per each arm randomly assigned to receive MPA 400 mg intramuscularly for a single dose versus venlafaxine 37.5 mg per day for a week, then 75 mg per day.

During the sixth week after random assignment, hot flash scores were reduced by 55% in the venlafaxine arm versus 79% in the MPA arm (P < .0001). In an intention-to-treat analysis, 46% of venlafaxine patients (50 of 109) compared with 74% of the MPA patients (81 of 109) had a decrease in hot flashes by more than 50% from baseline (P < .0001). Less toxicity was reported in the MPA arm.

A single MPA dose seems to be well tolerated and more effectively reduces hot flashes than does venlafaxine.