From the Guidelines
The recommended dosage of Diamox (acetazolamide) for preventing altitude sickness is 125 to 250 mg taken twice daily, starting 24 to 48 hours before ascending to high altitude and continuing for at least 48 hours after arriving at the highest altitude or longer if needed while at high altitude. This dosage is based on the most recent and highest quality study available, which emphasizes the importance of proper acclimatization and gradual ascent to prevent high altitude illness, including acute mountain sickness 1.
Key Considerations
- The medication works by causing the kidneys to excrete bicarbonate, which creates a mild metabolic acidosis that stimulates breathing and increases oxygen levels in the blood.
- Common side effects include increased urination, tingling sensations in the fingers and toes, and altered taste of carbonated beverages.
- People with sulfa allergies should avoid Diamox, and those with kidney problems or who are pregnant should consult their doctor before use.
- Staying well-hydrated while taking Diamox is important to prevent dehydration and kidney stones.
Additional Guidance
- For children, the dosage is usually 2.5 mg/kg every 12 hours, up to the adult dose.
- Individuals should be aware of potential side effects like a transient myopic shift and have proper corrective measures in place.
- High altitude illness, including acute mountain sickness, is primarily prevented by proper acclimatization, gradual ascent, staying hydrated and avoiding alcohol and smoking, in addition to prophylactic medications like acetazolamide 1.
From the Research
Diamox Altitude Sickness Prevention
The recommended dosage of Diamox (acetazolamide) for preventing altitude sickness varies, but several studies provide guidance:
- A study from 2 suggests that lower dosages of acetazolamide offer adequate protection with fewer side effects, but does not specify a particular dosage.
- A 2021 study 3 recommends doses of 500-750 mg/day within 24 hours of altitude exposure for minimizing symptoms of AMS, particularly for rapid ascents to altitudes >3,500 m.
- Another study from 4 found that pre-treatment with low-dose acetazolamide (2 × 125 mg) on the day before ascending to high altitude tended to reduce AMS incidence on the first day at high altitude.
- A 2020 study 5 suggests a dosage of 125 mg every 12 hours for prophylactic use of acetazolamide to prevent HAI on rapid arrival to altitudes over 3350 m.
Key Considerations
When considering the use of Diamox for altitude sickness prevention:
- The timing of initiation is important, with some studies suggesting starting 12 to 24 hours before ascent 2, 4.
- The dosage and regimen may vary depending on individual factors and the specific altitude and activity 3, 5.
- Acetazolamide is not recommended as an emergency therapy for acute altitude sickness 6.