Prevention of acute mountain sickness by acetazolamide in Nepali porters: a double-blind controlled trial.
OBJECTIVE
This study aimed to determine the efficacy, tolerability, and practicality of acetazolamide for the prevention of acute mountain sickness (AMS) in Nepali trekking porters early in the trekking season.


METHODS
This study was a randomized, double-blind controlled trial with 400 male Nepali porters in the Mount Everest region of Nepal, trekking from Namche Bazaar (3440 m) to Lobuche (4930 m), the study endpoint. Participants were randomized to receive 250 mg acetazolamide daily or placebo, and AMS symptom scores (Lake Louise) were compared in highlanders vs lowlanders.


RESULTS
Only 109 (27.2%) of the 400 porters completed the trial (28 highlanders, 81 lowlanders). The rest either dropped out (275/400 porters, 68.8%) or were excluded (16/400 porters, 4%). Acute mountain sickness occurred in 13 (11.9%) of 109 porters; all were lowlanders; 7 were taking acetazolamide, 6 taking placebo. Birthplace, acclimatization in the week before the trial, ascent rate, and rest days were the most important variables affecting the incidence of AMS. No highlanders, but 13 (16.1%) of 81 lowlanders had AMS (P = .016). Acclimatization in the pretrial week reduced AMS incidence (P = .013), as did a slower ascent rate (P = .0126), but rest days were the most potent prophylactic variable (P = .0001). Side effects were more frequent in porters taking acetazolamide than in the placebo group (P = .0001), but there were no serious side effects.


CONCLUSIONS
Acetazolamide was tolerable, but impractical for the routine prevention of AMS in Nepali porters. A good trekking schedule and adequate acclimatization remain the most effective preventive measures. This study identified lowland porters as a high-risk group for developing AMS.
Hillenbrand
Peter
P
Department of Medicine, Good Hope Hospital NHS Trust, Sutton Coldfield, West Midlands, UK. hillydoc@marh.wanadoo.co.uk
Pahari
Anil K
AK
Soon
Yuen
Y
Subedi
Deepak
D
Bajracharya
Rajan
R
Gurung
Puncho
P
Lal
Barun K
BK
Marahatta
Ramesh
R
Pradhan
Santosh
S
Rai
Dilip
D
Sharma
Shailendra
S
D000086:Acetazolamide / Q000627:therapeutic use*; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000532:Altitude Sickness / Q000473:pathology / Q000517:prevention & control*; D000927:Anticonvulsants / Q000627:therapeutic use*; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D008875:Middle Aged; D009051:Mountaineering; D009390:Nepal; D011446:Prospective Studies; D016896:Treatment Outcome
D000927:Anticonvulsants; D000086:Acetazolamide