From the Guidelines
For altitude sickness, the recommended dosage of acetazolamide is 250 mg three times a day for 5 days, as indicated by the study published in MMWR Recommendations and Reports 1. When considering the treatment of altitude sickness, it's essential to weigh the benefits and risks of acetazolamide, taking into account its mechanism of action, potential side effects, and contraindications. Some key points to consider when prescribing acetazolamide for altitude sickness include:
- The medication should be started 24-48 hours before ascent to allow for optimal efficacy
- Patients should be aware of potential side effects, such as increased urination, tingling sensations, and altered taste
- Acetazolamide is contraindicated in individuals with sulfa allergies and should be used with caution in those with kidney or liver disease
- The medication should be used in conjunction with other prevention strategies, including gradual ascent, proper hydration, and avoiding alcohol
- If symptoms worsen despite treatment, descending to a lower altitude is the most effective course of action. It's also important to note that while acetazolamide can be effective in preventing and treating altitude sickness, it should not be relied upon as the sole means of prevention, and other measures such as gradual ascent and proper hydration should also be taken.
From the Research
Dosage for Acetazolamide in Altitude Sickness
- The recommended dosage of acetazolamide for preventing altitude sickness varies, but common dosages include 125 mg twice daily 2, 250 mg daily 3, 500 mg daily 3, and 750 mg daily 3.
- A study found that doses of 500-750 mg/day within 24 hours of altitude exposure appear to be the most effective for minimizing symptoms of AMS 3.
- Another study suggested 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, but improved oxygen availability to tissues not until the second day of exposure 4.
- It is also suggested that starting acetazolamide at least two days before arrival at high altitude may be of greater beneficial effect on AMS development 4.
Timing of Acetazolamide Administration
- Acetazolamide can be started the day or night before ascent 2, or on the morning of ascent 2.
- One study found that day of ascent acetazolamide demonstrated higher rates of AMS compared with traditional dosing by a small margin, but with similar rates of severe AMS and overall symptom severity 2.
- Another study found that starting acetazolamide 12 to 24 hours before ascent is effective in preventing AMS 5.