This is a randomized, placebo-controlled, double-blind parallel trial evaluating the effect of acetazolamide (375 mg per day) vs. placebo on postural control at altitude (Tuja Ashu, 3200 m). Participants living in the Bishkek area, Kyrgyzstan (760m), will be transferred by car within 4h to the Tuja Ashu high altitude clinic (3200 m), and stay there for 2 days. Acetazolamide 375mg/day (or placebo) will be administered 24 hours before departure at 760 m and during the stay at altitude. Outcomes will be assessed during the stay at 3200 m. Randomization to acetazolamide or placebo will be carried out after baseline measurements in Bishkek (760 m).~Postural control will be assessed by a rectangular, stable balance platform (Wii Balance Board) measuring the body's center of gravity. The movement of the body's center of gravity will be recorded in a two-dimensional coordinate system and indicated as path length.
In this trial, the investigators will evaluate the effect of acetazolamide (375 mg per day) vs. placebo on postural control at acute altitude exposure in patients with COPD.