Nicholas C Kanaan1, Alicia L Peterson1, Matiram Pun2, Peter S Holck3, Jennifer Starling4, Bikash Basyal2, Thomas F Freeman5, Jessica R Gehner6, Linda Keyes7, Dana R Levin8, Catherine J O'Leary9, Katherine E Stuart10, Ghan B Thapa2, Aditya Tiwari2, Jared L Velgersdyk11, Ken Zafren12, Buddha Basnyat13. 1. Division of Emergency Medicine, University of Utah, (Drs Kanaan and Peterson). 2. Institute of Medicine, Maharajgunj, Kathmandu, Nepal (Drs Pun, Basyal, Thapa, and Tiwari). 3. the Emergency Medicine Residency, Virginia Tech Carilion (Dr Gehner). 4. Department of Public Health, University of Hawaii (Dr Holck). 5. Department of Emergency Medicine, Denver Health, (Dr Starling). 6. Department of Emergency Medicine, Augusta University, GA (Dr Freeman). 7. Department of Emergency Medicine, University of Colorado, Aurora, CO (Dr Keyes). 8. Department of Aerospace Medicine, University of Texas Medical Branch (Dr Levin). 9. Department of Emergency Medicine, Thomas Jefferson University Hospital (Dr O'Leary). 10. Department of Emergency Medicine, Queen's University, Kingston, ON, Canada (Dr Stuart). 11. Department of Internal Medicine, University of North Dakota (Dr Velgersdyk); Department of Emergency Medicine, Stanford University Medical Center, Stanford, CA. 12. Himalayan Rescue Association (Dr Zafren); Oxford University Clinical Research Unit, Kathmandu, Nepal. 13. the Himalayan Rescue Association and the Centre for Tropical Medicine and Global Health, University of Oxford, UK (Dr Basnyat). Electronic address: buddha.basnyat@ndm.ox.ac.uk.
Abstract
OBJECTIVE: Recent trials have demonstrated the usefulness of ibuprofen in the prevention of acute mountain sickness (AMS), yet the proposed anti-inflammatory mechanism remains unconfirmed. Acetaminophen and ibuprofen were tested for AMS prevention. We hypothesized that a greater clinical effect would be seen from ibuprofen due to its anti-inflammatory effects compared with acetaminophen's mechanism of possible symptom reduction by predominantly mediating nociception in the brain. METHODS: A double-blind, randomized trial was conducted testing acetaminophen vs ibuprofen for the prevention of AMS. A total of 332 non-Nepali participants were recruited at Pheriche (4371 m) and Dingboche (4410 m) on the Everest Base Camp trek. The participants were randomized to either acetaminophen 1000 mg or ibuprofen 600 mg 3 times a day until they reached Lobuche (4940 m), where they were reassessed. The primary outcome was AMS incidence measured by the Lake Louise Questionnaire score. RESULTS: Data from 225 participants who met inclusion criteria were analyzed. Twenty-five participants (22.1%) in the acetaminophen group and 18 (16.1%) in the ibuprofen group developed AMS (P = .235). The combined AMS incidence was 19.1% (43 participants), 14 percentage points lower than the expected AMS incidence of untreated trekkers in prior studies at this location, suggesting that both interventions reduced the incidence of AMS. CONCLUSIONS: We found little evidence of any difference between acetaminophen and ibuprofen groups in AMS incidence. This suggests that AMS prevention may be multifactorial, affected by anti-inflammatory inhibition of the arachidonic-acid pathway as well as other analgesic mechanisms that mediate nociception. Additional study is needed.
RCT Entities:
OBJECTIVE: Recent trials have demonstrated the usefulness of ibuprofen in the prevention of acute mountain sickness (AMS), yet the proposed anti-inflammatory mechanism remains unconfirmed. Acetaminophen and ibuprofen were tested for AMS prevention. We hypothesized that a greater clinical effect would be seen from ibuprofen due to its anti-inflammatory effects compared with acetaminophen's mechanism of possible symptom reduction by predominantly mediating nociception in the brain. METHODS: A double-blind, randomized trial was conducted testing acetaminophen vs ibuprofen for the prevention of AMS. A total of 332 non-Nepali participants were recruited at Pheriche (4371 m) and Dingboche (4410 m) on the Everest Base Camptrek. The participants were randomized to either acetaminophen 1000 mg or ibuprofen 600 mg 3 times a day until they reached Lobuche (4940 m), where they were reassessed. The primary outcome was AMS incidence measured by the Lake Louise Questionnaire score. RESULTS: Data from 225 participants who met inclusion criteria were analyzed. Twenty-five participants (22.1%) in the acetaminophen group and 18 (16.1%) in the ibuprofen group developed AMS (P = .235). The combined AMS incidence was 19.1% (43 participants), 14 percentage points lower than the expected AMS incidence of untreated trekkers in prior studies at this location, suggesting that both interventions reduced the incidence of AMS. CONCLUSIONS: We found little evidence of any difference between acetaminophen and ibuprofen groups in AMS incidence. This suggests that AMS prevention may be multifactorial, affected by anti-inflammatory inhibition of the arachidonic-acid pathway as well as other analgesic mechanisms that mediate nociception. Additional study is needed.