Theophylline improves acute mountain sickness

A randomized two-part study was conducted in order to determine the efficac y of theophylline in the treatment of acute mountain sickness during fast a scent to altitudes >2,500 m. Fourteen healthy male subjects participated in a randomized single-blind pl acebo-controlled crossover study carried out in a decompression chamber (si mulated altitude 4,500 m). A second randomized single-blind, placebo-contro lled study was conducted at a high-altitude research laboratory (3,454 m) a nd included 21 healthy male subjects. The study medication was either 375 m g oral slow-release theophylline (250 mg if <70 kg) or a matched placebo ta blet taken twice daily. The acute mountain sickness score (AMSS) was assess ed three times a day, beginning 18 h prior to altitude exposure acid contin uing for 18 h after altitude exposure. In addition, measurements of respira tory frequency, pulse rate, oxygen saturation and arterial blood gas levels were performed. Acute mountain sickness was significantly reduced by theophylline during th e decompression chamber study (mean+/-SD, 1.2+/-0.9) with placebo versus 3. 6+/-0.8 with theophylline; p=0.03). During the high-altitude study, subject s with theophylline showed a significantly lower AMSS on arrival and after 18 h at altitude (0.6 versus 2.3, p=0.03). Oxygenation was improved in both parts of the study. In conclusion, oral slow-release theophylline improves acute mountain sickn ess.