From the Guidelines
The most effective medication to prevent acute mountain sickness (AMS) when hiking Kilimanjaro is acetazolamide, not dexamethasone, due to its ability to stimulate breathing and increase oxygen intake, thereby aiding in acclimatization 1. When considering medication to prevent AMS, it's crucial to prioritize the most recent and highest quality evidence.
- The recommended dose of acetazolamide is 125 mg twice daily, starting 24 hours before ascent and continuing until descent is complete or the highest altitude is reached.
- Dexamethasone can be used as an alternative for those who cannot tolerate acetazolamide, at a dose of 4 mg twice daily, following the same schedule 1.
- Proper acclimatization remains essential, even with medication, and includes the "climb high, sleep low" approach and a gradual ascent of no more than 1,000-1,500 feet or 300-500 meters per day.
- Staying well-hydrated throughout the climb and avoiding alcohol and sleeping medications are also crucial in reducing the risk of AMS.
- Acetazolamide works by causing the kidneys to excrete bicarbonate, creating a mild metabolic acidosis that stimulates breathing and increases oxygen intake, helping the body to acclimatize to the high altitude.
- Common side effects of acetazolamide include increased urination, tingling sensations in fingers and toes, and altered taste of carbonated beverages.
- Those with sulfa allergies should avoid acetazolamide and consult a travel medicine specialist before the trip for personalized recommendations.
From the Research
Medication Regimen for Preventing Acute Mountain Sickness (AMS)
To prevent acute mountain sickness (AMS) when hiking Kilimanjaro, the recommended medication regimen includes:
- Dexamethasone: Studies have shown that dexamethasone can be effective in preventing AMS 2, 3. A systematic review and meta-analysis found that oral dexamethasone reduced the incidence of AMS with an odds ratio of 6.03 (95% CI, 2.23 to 21.00) compared to placebo 2.
- Acetazolamide: Although primarily used for treatment, acetazolamide has been used as a prophylactic measure to prevent AMS 4, 5, 6. However, its effectiveness in preventing AMS is still uncertain.
Dosage and Administration
The dosage and administration of dexamethasone and acetazolamide vary:
- Dexamethasone: The recommended dosage for preventing AMS is 8-16 mg/d, with some studies suggesting that the effect of dexamethasone is related to height and dosage 2.
- Acetazolamide: The typical dosage for preventing AMS is 2 × 250 mg 6.
Efficacy of Dexamethasone
Dexamethasone has been shown to be effective in:
- Reducing the incidence of AMS: A study found that dexamethasone decreased the probability of a subject exhibiting at least one AMS symptom at high altitudes 4.
- Treating AMS: Dexamethasone has been found to be an effective treatment for AMS, with symptoms improving significantly after administration 5, 3.
Important Considerations
When using dexamethasone or acetazolamide to prevent AMS:
- It is essential to follow the recommended dosage and administration guidelines.
- The effectiveness of these medications can vary depending on individual factors, such as altitude and physical condition.
- Dexamethasone and acetazolamide should not be used as a substitute for proper acclimatization and ascent protocols.