From the Guidelines
Acetazolamide is the primary medication recommended for high altitude sickness prevention, with a typical dosage of 125-250 mg twice daily, starting 24-48 hours before ascent and continuing for 48 hours after reaching the highest altitude. This recommendation is based on the most recent and highest quality study available, which emphasizes the importance of adequate acclimatization, slow ascent speed, and/or preventive medication, such as acetazolamide, to mitigate the risks of acute mountain sickness 1.
The use of acetazolamide for high altitude sickness prevention is further supported by another study, which highlights the effectiveness of prophylactic medications, such as acetazolamide, in preventing high altitude illness, including acute mountain sickness 1. However, it is essential to note that individuals should be aware of potential side effects, such as a transient myopic shift, and have proper corrective measures in place.
In addition to medication, other essential components of altitude sickness prevention include:
- Gradual ascent (no more than 1,000-1,500 feet per day above 8,000 feet)
- Proper hydration
- Avoiding alcohol
- Descending if symptoms worsen It is also crucial for individuals with sulfa allergies to avoid acetazolamide and consult their doctor for alternatives before traveling to high altitudes.
From the FDA Drug Label
PACKAGE LABEL.PRINCIPAL DISPLAY PANEL Container Label NDC 68382-076-10 AcetaZOLAMIDE for Injection USP 500 mg* per vial For Intravenous Use 1 Single-Dose Vial Zydus Pharmaceuticals Rx Only Carton Label NDC 68382-076-10 AcetaZOLAMIDE for Injection USP 500 mg* per vial For Intravenous Use 1 Single-Dose Vial Zydus Pharmaceuticals Rx Only
The medication given for high altitude sickness prevention is acetazolamide.
- Key points:
- Drug Name: acetazolamide
- Route of administration: The label provided does not explicitly state the route for high altitude sickness prevention, but it does mention an injectable form. 2
From the Research
Medication for High Altitude Sickness Prevention
- Acetazolamide is the most common medication used for the prevention of acute mountain sickness (AMS) 3, 4, 5, 6, 7
- The recommended dose of acetazolamide varies, but common doses include 125 mg twice daily 3, 4, 250 mg three times a day 5, and 62.5 mg twice daily 7
- Studies have shown that acetazolamide can reduce the incidence and severity of AMS, but the optimal dosing schedule is still debated 3, 4, 6
- Some studies suggest that starting acetazolamide at least two days before arrival at high altitude may be more effective in preventing AMS 6
- A lower dose of acetazolamide (62.5 mg twice daily) has been shown to be noninferior to the standard dose (125 mg twice daily) in preventing AMS 7
Dosing Schedules
- Day of ascent dosing of acetazolamide has been shown to be effective in preventing AMS, but may have a slightly higher incidence of AMS compared to traditional dosing 3
- Starting acetazolamide 48 hours before ascent has been shown to reduce the incidence of HAPE, but the effect was not statistically significant 5
- Pre-treatment with low-dose acetazolamide on the day before ascending to high altitude may reduce AMS incidence on the first day at high altitude, but improved oxygen availability to tissues may not occur until the second day of exposure 6
Side Effects and Efficacy
- Acetazolamide has been shown to be effective in reducing the incidence and severity of AMS, but may have side effects such as nausea, headaches, and fatigue 3, 4, 7
- The incidence of side effects was similar between the reduced-dose and standard-dose groups in one study 7
- Acetazolamide may also improve oxygen availability to tissues, but the effect may not be statistically significant until the second day of exposure 6