How To Take Acetazolamide: Step-by-Step Usage & Dosage
Key Takeaways
- Start Early: Begin 24-48 hours before ascent for full protection
- Standard Dose: 125mg every 12 hours (½ of 250mg tablet)
- Administration: Swallow whole with water, avoid evening doses
- Duration: Continue for 48 hours at target altitude
- Max Dose: Never exceed 1000mg in 24 hours
Proper administration of acetazolamide (Diamox) is crucial for effective altitude sickness prevention. Our comprehensive guide demonstrates correct dosage techniques for tablet and extended-release forms, explains optimal timing relative to ascent schedules, and provides special considerations for different trekking itineraries and individual health factors.
Standard Dosing Protocol
For Altitude Sickness Prevention
- Adults: 125mg (½ tablet) every 12 hours
- Start: 24-48 hours before ascent
- Continue: For first 48 hours at target altitude
For AMS Treatment
- Adults: 250mg (1 tablet) every 12 hours
- Start: At first symptoms
- Continue: Until symptoms resolve or descent
How to Take Acetazolamide
Proper Administration
- Swallow Whole: Do not crush or chew (bitter taste)
- With Water: Take with a full glass (250ml)
- With Food: Preferably with meals to reduce stomach upset
- Timing:
- First dose: Morning
- Second dose: Early afternoon (before 4pm)
- Avoid evening doses to prevent nighttime urination
Storage Instructions
- Keep in original container with desiccant
- Store below 25°C (away from moisture)
- Keep out of reach of children
Recommended Usage Timeline
| Time Relative to Ascent | Action | Notes |
|---|---|---|
| -48 to -24 hours | Begin 125mg every 12 hours | Allows time for metabolic changes |
| Day of Ascent | Continue 125mg every 12 hours | Take morning dose 1 hour before ascent |
| At Arrival | Maintain schedule | Monitor for AMS symptoms |
| First 48h at Altitude | Continue 125mg every 12 hours | Critical period for acclimatization |
| After 48h at Altitude | Consider tapering to 125mg once daily | Only if staying >5 days |
Dosage Adjustments for Special Cases
| Situation | Recommended Adjustment | Rationale |
|---|---|---|
| Elderly (>65 years) | 62.5mg (¼ tablet) twice daily | Reduced clearance, higher sensitivity |
| Mild Renal Impairment | 125mg once daily | Slower drug elimination |
| Slow Ascent (<500m/day) | 125mg once daily | Lower AMS risk |
| Children (12-18 years)* | 2.5mg/kg twice daily | Max 125mg per dose |
*Not typically recommended for children under 12
What If I Miss a Dose?
Standard Protocol
- If <2 hours until next dose: Skip missed dose
- If >2 hours until next dose: Take half dose (62.5mg) now
- Never double dose to compensate
Examples
Scenario: Forgot 9am dose, remember at 12pm (next dose 9pm)
Action: Take 62.5mg at 12pm, then normal 125mg at 9pm
Scenario: Forgot 9pm dose, remember next morning
Action: Skip missed dose, take normal 125mg at 9am
FAQs
Can I cut Acetazolamide tablets?
Can I drink alcohol while taking it?
How should I store it during travel?
Is it safe for ski trips?
- Start medication before cable car ascent
- Be cautious of dizziness affecting skiing ability
- Stay hydrated in dry mountain air
 | Authored by Nabeel |
Medical Content Manager
Nabeel is a co-founder, and medical content manager of Chemist Doctor. He works closely with our medical team to ensure the information is accurate and up-to-date.
 | Reviewed by Dr. Feroz (GMC:7921697) |
Medical Doctor
Dr. Feroz is a GMC-registered doctor and a medical reviewer at Chemist Doctor. He oversees acute condition and urgent care guidance.
 | Approved by Usman |
Medical Director
Usman is a co-founder, and medical director of Chemist Doctor. He leads the organisation's strategic vision, bridging clinical and operational priorities.
Review Date: 02 August 2025
Next Review: 07 March 2025
Published on: 02 August 2025
Last Updated: 04 August 2025
Popular Conditions
Useful Links
We Are Regulated
