From the Guidelines
For preventing altitude sickness, Diamox (acetazolamide) is recommended at a dosage of 125 mg twice daily, starting 24-48 hours before ascending to high altitude and continuing for at least 48 hours after reaching the highest altitude or until descent begins. This dosage is based on recent studies, including a 2021 European Respiratory Society guideline on non-cpap therapies for obstructive sleep apnoea 1, which highlights the benefits of acetazolamide in improving nocturnal oxygen saturation and reducing residual sleep apnoea at high altitudes.
The medication works by causing the kidneys to excrete bicarbonate, creating a mild metabolic acidosis that stimulates breathing and improves oxygen uptake, essentially pre-acclimatizing the body. Key benefits of using Diamox for altitude sickness prevention include:
- Improved nocturnal oxygen saturation
- Reduced residual sleep apnoea
- Reduced nocturnal transcutaneous carbon dioxide partial pressure
- Reduced excessive blood pressure increases
Common side effects of Diamox include:
- Increased urination
- Tingling sensations in the fingers and toes (paraesthaesia)
- Unpleasant taste
- Vertigo
It is essential to note that Diamox should be avoided by those allergic to sulfa drugs, and patients with kidney problems or severe liver disease should consult their doctor before use. While effective, Diamox should complement, not replace, proper acclimatization practices such as gradual ascent and adequate hydration. A test dose several days before travel is advisable to check for adverse reactions, as reported in studies such as the one published in the European Respiratory Review 1.
From the Research
Recommended Dosage and Usage of Diamox (Acetazolamide)
- The recommended dosage of acetazolamide for preventing altitude sickness is 125 mg every 12 hours, as stated in the study 2.
- Acetazolamide can be started the day before ascent or on the day of ascent, with similar efficacy in preventing acute mountain sickness (AMS) 3.
- However, starting acetazolamide at least two days before arrival at high altitude may be more beneficial in reducing AMS incidence and improving oxygen availability to tissues 4.
Efficacy of Acetazolamide in Preventing Altitude Sickness
- Acetazolamide has been shown to be effective in preventing AMS, with a significant reduction in symptoms such as headache, nausea, and vomiting 5.
- The use of acetazolamide can also improve arterial oxygen concentrations and reduce proteinuria and peripheral edema 5.
- However, the efficacy of acetazolamide in preventing high-altitude pulmonary edema (HAPE) is not well established, with some studies showing no significant reduction in HAPE incidence 6.
Important Considerations
- Acetazolamide should be used under medical supervision, especially in individuals with pre-existing medical conditions or taking other medications 2.
- The dosage and duration of acetazolamide treatment may vary depending on individual factors, such as the altitude of ascent and the individual's medical history 3.
- Acetazolamide is not a substitute for gradual acclimatization to high altitude, and individuals should still ascend gradually and monitor their symptoms closely 2.