From the Guidelines
The most effective way to prevent altitude sickness is through gradual acclimatization, and for those who cannot acclimatize, acetazolamide (Diamox) is the recommended medication, typically taken at a dose of 125mg twice daily, starting 24 hours before ascent and continuing for 48 hours after reaching the target altitude, as supported by recent studies 1.
How Diamox Helps in Altitude Prevention
Diamox, or acetazolamide, helps in preventing altitude sickness by increasing respiratory rate and urinary bicarbonate excretion, which combats the respiratory alkalosis that occurs at high altitudes 1. This mechanism of action is crucial for individuals who ascend quickly or have a history of altitude sickness.
Key Points for Altitude Sickness Prevention
- Gradual acclimatization is the primary method for preventing altitude sickness
- Acetazolamide (Diamox) is the most effective medication for those who cannot acclimatize, with a recommended dose of 125mg twice daily
- Staying well-hydrated, avoiding alcohol and sedatives, and consuming a high-carbohydrate diet can also help prevent altitude sickness
- Dexamethasone can be used as an alternative to acetazolamide for those who cannot tolerate it, at a dose of 4mg every 6 hours 1
Considerations for Specific Populations
Recent studies suggest that sex-dependent physiological reactions to hypoxia may contribute to an increased vulnerability to acute mountain sickness in some women, highlighting the importance of adequate acclimatization, slow ascent speed, and/or preventive medication like acetazolamide for this population 1.
Conclusion is not needed as per the guidelines, so the answer will be ended here.
From the FDA Drug Label
Acetazolamide is used for the prevention or less commonly, treatment of altitude sickness
The recommended treatment for preventing altitude sickness is acetazolamide (Diamox). It is used to prevent altitude sickness by increasing the amount of urine production and helping the body acclimate to high altitudes.
- Dosage: The dosage for preventing altitude sickness is typically 125-250 mg every 6-12 hours, starting 24 hours before ascent and continuing for 2-3 days after reaching the highest altitude.
- Mechanism of action: Acetazolamide works by increasing renal excretion of bicarbonate, leading to a mild metabolic acidosis, which stimulates ventilation and helps the body adapt to high altitudes.
- Important note: Patients should be advised to drink plenty of fluids and to report any signs of altitude sickness, such as headache, nausea, or fatigue, to their healthcare provider. 2
From the Research
Altitude Sickness Prevention
Diamox, also known as acetazolamide, is a medication used to prevent altitude sickness. The recommended treatment for preventing altitude sickness involves taking acetazolamide before ascending to high altitudes.
- The dosage of acetazolamide for preventing altitude sickness is typically 125 mg every 12 hours 3.
- Studies have shown that acetazolamide is effective in reducing the risk of altitude sickness, with a risk reduction of up to 50% 4.
- The medication works by increasing urine production, which helps to reduce the amount of fluid in the body and prevent the buildup of fluid in the lungs and brain, a common cause of altitude sickness.
Timing of Acetazolamide Treatment
The timing of acetazolamide treatment is important for preventing altitude sickness.
- One study found that pre-treatment with acetazolamide the day before arrival at high altitude tended to reduce the incidence of altitude sickness on the first day at high altitude, but improved oxygen availability to tissues not until the second day of exposure 5.
- Another study suggested that starting acetazolamide at least two days before arrival at high altitude may be more effective in preventing altitude sickness 5.
Effectiveness of Acetazolamide in Different Populations
Acetazolamide has been shown to be effective in preventing altitude sickness in different populations, including:
- Healthy adults 3, 4, 6
- Patients with chronic obstructive pulmonary disease (COPD) 6
- Military and emergency medical personnel who need to ascend rapidly to high altitudes 4
Additional Benefits of Acetazolamide
In addition to preventing altitude sickness, acetazolamide has been shown to: