Up to half of those who ascend rapidly to altitudes of over 3,000 m ma
y experience symptoms of acute mountain sickness (AMS) and of these so
me 95% may suffer from high altitude headache. We report the first con
trolled trial specifically to assess an oral drug therapy for this com
mon symptom. Subjects were 21 members of mountaineering expeditions to
similar altitudes in the Bolivian Andes and the Himalayas in Nepal. T
he study was of a randomized, placebo-controlled, double-blind, within
-patient crossover design. Ibuprofen was significantly superior to pla
cebo both in reducing headache severity and in speed of relief (a mean
difference of 94 min in time to no/minimal headache). Only 14% of sub
jects who initially took ibuprofen felt the need for further medicatio
n compared to 83% of those who took placebo first (p = 0.02). Of the 1
1 subjects completing both phases of the crossover, 8 (73%) favored ib
uprofen while the remainder had no preference (p = 0.004). No attribut
able adverse effects occurred. The results suggest that ibuprofen is a
safe and effective treatment for high altitude headache.