Prophylactic low-dose acetazolamide reduces the incidence and severity of acute mountain sickness.
Previous studies have shown low-dose acetazolamide to be effective in preventing AMS in persons already at high altitude and then moving higher, a relatively low risk situation. We wished to evaluate prophylactic administration of low-dose acetazolamide for reducing the incidence and severity of AMS in a high-risk setting: rapid ascent from 1600 to 4300 m. We performed a double-blind, randomized, placebo-controlled study with human subjects (n=44) exposed to 4300 m for 24 h. Subjects were treated for 3 days prior to ascent to 4300 m and during day 1 at altitude with placebo (n=22) or acetazolamide 250 mg/day (125 mg bid, n=22). AMS diagnosis required both an AMS-C score from the Environmental Symptom Questionnaire-III>or=0.7 and a Lake Louise Symptom (LLS) questionnaire score>or=3 plus headache. Acetazolamide reduced the incidence of AMS compared to placebo-treated subjects (14% vs. 45%, respectively, p=0.02), and the number needed to treat was 3. The AMS-C and LLS scores were lower in acetazolamide-treated subjects, indicating less severe AMS. Low-dose acetazolamide administered prior to ascent and on day 1 at 4300 m effectively reduced the incidence and severity of AMS in a high-risk setting.
van Patot
Martha C Tissot
MC
Department of Anesthesiology, University of Colorado Denver, Aurora, Colorado 80045, USA. Martha.TissotvanPatot@UCHSC.EDU
Leadbetter
Guy
G
Keyes
Linda E
LE
Maakestad
Kirsten M
KM
Olson
Sheryl
S
Hackett
Peter H
PH
D000086:Acetazolamide / Q000008:administration & dosage*; D000208:Acute Disease; D000328:Adult; D000532:Altitude Sickness / Q000188:drug therapy / Q000517:prevention & control*; D002257:Carbonic Anhydrase Inhibitors / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006261:Headache / Q000517:prevention & control; D006801:Humans; D008297:Male; D008875:Middle Aged; D009051:Mountaineering; D011654:Pulmonary Edema / Q000517:prevention & control; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult
D002257:Carbonic Anhydrase Inhibitors; D000086:Acetazolamide