Medroxyprogesterone at high altitude. The effects on blood gases, cerebral regional oxygenation, and acute mountain sickness.

Objective: To study the effect of medroxyprogesterone on blood gases and cerebral regional oxygenation at high altitude, alone and in conjunction with acetazolamide, and to assess the effect on acute mountain sickness (AMS).

Design: Two placebo-controlled trials during rapid ascent to high altitude.

Participants: In the first trial, 20 participants, and in the second trial, 24 participants.