title: Acetazolamide plus low-dose dexamethasone is better than acetazolamide alone to ameliorate symptoms of acute mountain sickness.
abstract: METHODS
  In a double-blind study, we compared the efficacy of a combination of sustained-release acetazolamide and low-dose dexamethasone and acetazolamide alone for prophylaxis against acute mountain sickness (AMS) caused by rapid ascent to high altitude. Before ascent, 13 subjects were randomly assigned to receive a combination of one sustained-release acetazolamide capsule (500 mg) in the afternoon and 4 mg dexamethasone every 12 h, or a combination of the same dose of acetazolamide once daily and a placebo every 12 h. Days 1 and 2 were spent at 3698 m (La Paz, Bolivia), while days 3 and 4 were spent at 5334 m (Mount Chaclataya, Bolivia). Ascent was by 2 h motor vehicle ride. Heart rates, peripheral oxygen saturations and a modified score derived from the Environmental Symptom Questionnaire (modified-ESQ) were measured on each day. In addition, weighted averages of the cerebral (AMS-C) and respiratory (AMS-R) symptoms were calculated for days 3 and 4.
  
  
  RESULTS
  Heart rate and modified-ESQ scores increased on days 3 and 4 compared with the other days in the acetazolamide/placebo group only (p < 0.05). Oxygen saturations decreased in both groups on days 3 and 4 (p < 0.05), but the decrease was greater in the acetazolamide/placebo group (p < 0.05). AMS-C and AMS-R scores rose above the suggested thresholds for indication of AMS on days 3 and 4 in the acetazolamide/placebo group only (p < 0.05).
  
  
  CONCLUSIONS
  We conclude that this combination of sustained-release acetazolamide once daily and low-dose dexamethasone twice daily is more effective in ameliorating the symptoms of AMS than azetazolamide alone at the ascent that was studied.
authors.affiliation: Division of Anesthesiology, Shock Trauma Center, University of Maryland Medical Systems, Baltimore, USA.
authors.forename: W N
authors.initials: WN
authors.lastname: Bernhard
authors.forename: L M
authors.initials: LM
authors.lastname: Schalick
authors.forename: P A
authors.initials: PA
authors.lastname: Delaney
authors.forename: T M
authors.initials: TM
authors.lastname: Bernhard
authors.forename: G M
authors.initials: GM
authors.lastname: Barnas
mesh_terms: D000086:Acetazolamide / Q000627:therapeutic use*; D000208:Acute Disease; D000328:Adult; D000532:Altitude Sickness / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D001784:Blood Gas Analysis; D003692:Delayed-Action Preparations; D003907:Dexamethasone / Q000627:therapeutic use*; D004232:Diuretics / Q000627:therapeutic use*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
chemical_list: D000893:Anti-Inflammatory Agents; D003692:Delayed-Action Preparations; D004232:Diuretics; D003907:Dexamethasone; D000086:Acetazolamide