Background Anyone traveling to a high altitude is at risk of developing acute mountain sickness (AMS). The rate of AMS among tourist population to moderate altitudes in USA was 25%, at first 12h.

Objective To understand if ibuprofen can be used to prevent AMS in athletes.

Design Healthy adult athletes from Brazilian Team received ibuprofen 600 mg, once, 6h before ascent to moderate altitude. Questionnaires were recorded 12h and 24h after ascent. Outcome measures were incidence and severity of acute mountain sickness as calculated on the Lake Louise Questionnaire (LLQ) score. Presence of AMS sickness was defined by a LLQ score of greater than 3 in the presence of a headache.

Setting Healthy adult athletes from the Brazilian Team who participated in South American Games, 2018.

Patients (or Participants) 104 adult athletes from different modalities.

Interventions (or Assessment of Risk Factors) Participants received ibuprofen 600 mg, once, 6 hours before ascent to Cochabamba, before South American Games, 2018.

Main Outcome Measurements Because of possibility of gravity of symptoms, non-steroidal anti-inflammatory drugs, acetazolamide, dexamethasone and other drugs have been studied for the prevention of AMS. However, athletes cannot use some drugs because of the effect of doping, as diuretics and corticosteroids. So, it is important to understand if NSAIDs can prevent AMS.

Results 12 hours after ascent, 17,3% of athletes had a diagnosis of AMS (94% was a mild and 6%, severe), and after 24h, 35,6% (83% was a mild and 17%, severe). Main symptom at 12h after ascent was headache and second was fatigue and/or weakness. After 24h, main symptom was fatigue and/or weakness and second was sleep disorders.

Conclusions Based on our research ibuprofen seems efficacious for the prevention of AMS in elite athletes, occurring during first 12 hours after ascent compared with health general tourist population and may therefore represent an alternative for preventing AMS.