Pharmacologic Prophylaxis for Acute Mountain Sickness: A Systematic Shortcut Review

Abstract

Study objective Multiple studies have explored pharmacologic interventions to prevent acute mountain sickness. A systematic review of this subject published in 2000 found that both acetazolamide and dexamethasone were effective. Since 2000, a number of other agents have been reported to be beneficial. This EBEM review evaluates the most current evidence on this topic. Methods We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, SPORTDiscus, Emergency Medical Abstracts, and ClinicalTrials.gov from 2000 to July 2011. Only randomized placebo-controlled trials with an N greater than or equal to 50 and systematic reviews were reviewed. Standard criteria for assessing trial quality were independently assessed by 2 authors. Results Seven hundred eighty-six citations were retrieved, of which 105 were reviewed in their entirety. Eleven randomized controlled trials and 1 systematic review appeared to meet inclusion criteria; however, 4 randomized controlled trials were excluded for high risk of bias. The remaining 7 randomized controlled trials investigated antioxidants, magnesium, sumatriptan, gabapentin, acetazolamide, and Ginkgo biloba. No trials studying dexamethasone met our criteria. Acetazolamide was associated with a reduction in acute mountain sickness symptoms, with a number needed to treat ranging from 8 to 3 among 3 trials and at doses ranging from 250 to 750 mg daily. Sumatriptan showed benefit in 1 trial (number needed to treat=4), as did gabapentin (number needed to treat=6). Antioxidants, magnesium, and G biloba were not efficacious. Reported adverse events included somnolence with gabapentin and paresthesias with acetazolamide. The systematic review affirmed our results but did not capture trials studying antioxidants, magnesium, sumatriptan, or gabapentin. Conclusion Acetazolamide is effective for the prevention of acute mountain sickness but may be associated with paresthesias. Sumatriptan and gabapentin are beneficial but require further study.