From the Guidelines
Acetazolamide is the most effective medication for preventing altitude sickness when traveling to high elevations, as it helps the body acclimatize faster by increasing respiratory rate and improving oxygen saturation. According to a recent study published in 2024 in the journal Sports Medicine 1, adequate acclimatization, slow ascent speed, and/or preventive medication such as acetazolamide are recommended to minimize the risks of acute mountain sickness. The typical dosage of acetazolamide is 125-250 mg twice daily, starting 24-48 hours before ascent and continuing for 48 hours after reaching the highest altitude.
Some key points to consider when taking acetazolamide include:
- Ascending gradually, no more than 1,000-1,500 feet per day above 8,000 feet
- Staying hydrated
- Avoiding alcohol
- Considering a high-carbohydrate diet
- Being aware of potential side effects, such as tingling in fingers and toes, altered taste of carbonated beverages, increased urination, and rarely, allergic reactions
It is essential to consult a doctor before taking acetazolamide, especially if you have sulfa allergies, kidney problems, or liver disease. While dexamethasone can be an alternative for those who cannot take acetazolamide, it has more significant side effects with prolonged use, making acetazolamide the preferred choice for preventing altitude sickness 1.
From the Research
Medications for Preventing Altitude Sickness
- Acetazolamide is an effective pharmacological agent to prevent acute high altitude illness (HAI) in dosages of 250 to 750 mg/day 2
- The risk of acute mountain sickness (AMS) was reduced with acetazolamide (risk ratio 0.47,95% confidence interval 0.39 to 0.56) 2
- Higher doses of acetazolamide (500-750 mg/day) appear to be the most effective for minimizing symptoms of AMS during rapid ascents to altitudes >3,500 m 3
- Acetazolamide is associated with an increased risk of paraesthesia, although there are few reports about other adverse events from the available evidence 2
Comparison of Medications
- Acetazolamide plus low-dose dexamethasone is better than acetazolamide alone to ameliorate symptoms of acute mountain sickness 4
- Dexamethasone significantly reduced the incidence of acute mountain sickness and the severity of symptoms, and can be considered for persons without contraindications who are intolerant of acetazolamide 5
- Combination therapy of acetazolamide-dexamethasone may be effective in preventing AMS, with significant reductions in ESQ, AMS-C, and AMS-R scores 6
Key Findings
- The severity of AMS is closely related to hypoxemia, and combination therapy of acetazolamide-dexamethasone may be effective in preventing AMS 6
- Acetazolamide and dexamethasone have different side effect profiles, with acetazolamide causing mild to moderate diuresis and dexamethasone causing fewer headaches 6