Acetazolamide in Patients at High Risk for Altitude Illness

The increasing frequency of adventure travel to mountain destinations by patients considered to be at excess risk for high-altitude illness prompted investigators from Switzerland and the Kyrgyz Republic to conduct two randomized trials of acetazolamide to prevent altitude illness. One study involved 185 patients with mostly moderate chronic obstructive pulmonary disease (COPD; mean forced expiratory volume in 1 second [FEV₁], 63%), and another involved 349 healthy lowlanders (mean age, 53). In both trials, participants were assessed at 2500 feet elevation and treated with acetazolamide (125 mg in the morning and 250 mg at night) or placebo starting 24 hours before ascending to 10,100 feet for 48 hours. (This is a U.S. FDA-approved indicati…