From the Guidelines
For a 46-year-old male hiking Kilimanjaro, acetazolamide (Diamox) is the recommended medication for preventing acute mountain sickness (AMS), taken at 125mg twice daily, starting 24 hours before ascent and continuing until descent begins or the highest altitude is reached for 2-3 days, as supported by the most recent evidence 1. The most effective preventive measures for AMS include gradual ascent, proper acclimatization, and medication.
- Gradual ascent: ascending to higher elevations during the day but returning to lower elevations to sleep, further supports acclimatization and reduces AMS risk.
- Proper acclimatization: allowing the body to adapt to the higher altitude by spending a few days at lower elevations before ascending to higher elevations.
- Medication: acetazolamide (Diamox) is the recommended medication, which works by causing the kidneys to excrete bicarbonate, creating a mild metabolic acidosis that stimulates breathing, increasing oxygen intake, and speeding acclimatization. Proper hydration (4-5 liters of water daily), avoiding alcohol, and moderate physical exertion during the climb are essential complementary measures. Dexamethasone (4mg every 6 hours) can be used as an alternative for those who cannot tolerate acetazolamide, but is generally reserved for treatment rather than prevention, as noted in previous studies 1. It is essential to be aware of potential side effects of acetazolamide, such as a transient myopic shift, and have proper corrective measures in place, as highlighted in the recent study 1. High altitude illness, including acute mountain sickness, is primarily prevented by proper acclimatization, gradual ascent, staying hydrated, and avoiding alcohol and smoking, as emphasized in the recent literature review 1.
From the Research
Recommended Medications for Preventing Acute Mountain Sickness (AMS)
To prevent AMS while hiking Kilimanjaro, several medications have been studied for their efficacy. The primary medication recommended is acetazolamide.
- Acetazolamide: This medication is a carbonic anhydrase inhibitor and is commonly used for the prevention and treatment of AMS 2, 3, 4, 5. The optimal dose of acetazolamide for prophylaxis is not established, but doses of 125 mg to 750 mg daily have been identified as efficacious in decreasing the incidence and/or severity of AMS during rapid ascents 4.
- Ibuprofen: Although primarily used as a pain reliever, ibuprofen has been compared to acetazolamide for the prevention of AMS. Studies suggest that ibuprofen is effective in preventing AMS, especially with rapid ascent to 3500m, but it may be slightly inferior to acetazolamide in preventing moderate-to-severe AMS 6.
Dosage and Administration
The dosage and timing of medication administration can vary:
- Acetazolamide: Doses range from 125 mg to 750 mg daily, with some studies suggesting that higher doses may be more effective for rapid ascents to elevations above 3500m 4. Administration can start the day before ascent or on the day of ascent, with varying efficacy rates 2.
- Ibuprofen: A dose of 600 mg thrice daily, starting one day prior to ascent and continuing for three days after arrival at high altitude, has been studied for AMS prevention 6.
Considerations
When considering preventive measures and medications for AMS, it's crucial to weigh the efficacy of different medications and dosing strategies against potential side effects and individual health considerations. Always consult a healthcare professional before starting any medication regimen, especially for high-altitude travel.