Acetazolamide

What is Acetazolamide?

Acetazolamide is a prescription-strength tablet that treats a range of conditions, such as altitude sickness, epilepsy and glaucoma. For issues related to high altitudes, like acclimatisation to high altitudes, sleep disorder of altitude, and acute mountain sickness, acetazolamide is prescribed “off-label”, because it hasn’t been officially approved for this purpose yet, although research and clinical evidence shows it can be effective.

You start taking the pills before you climb to high altitudes, where there is less oxygen. Acetazolamide works by tricking your body into breathing deeper and faster than usual, to get the oxygen it needs. This speeds up the acclimatization process and helps you avoid mountain sickness.

Who is Acetazolamide for?

Acetazolamide is for adults aged 18 or over who want to prevent altitude sickness.

Altitude sickness can occur when you travel into high altitude areas too quickly. This is anywhere around 2,500 meters above sea level.

So if you’re planning a trip to where you’ll ascend into high altitudes, taking Acetazolamide can prevent altitude sickness symptoms from developing.

How does Acetazolamide work?

Acetazolamide belongs to a class of medications known as carbonic anhydrase inhibitors (CAI).

These work by blocking carbonic anhydrase, an enzyme involved in respiration. Altitude sickness occurs when you ascend to high altitudes too quickly. When your body doesn’t adjust to air pressure changes and a reduced oxygen supply, it can cause headaches and vomiting. In severe cases, altitude sickness can be fatal.^[1] To treat this, acetazolamide increases the acidity of your blood to counteract the effects of respiratory alkalosis, which is when high altitudes cause the acid levels in your blood to drop. Acetazolamide helps to compensate for this by stimulating your breathing center to work harder, making you breathe faster and deeper, so that your body can acclimatise to the high altitudes faster

Are there different doses of Acetazolamide?

Acetazolamide comes in 125mg, 250mg, or 500mg extended-release tablets. The lowest dose is 250mg a day (divided into two doses), but your physician will advise you on how much you need to take each day.

You usually start Acetazolamide treatment one or two days before you climb into a high altitude area, and continue to take it for as long as your doctor tells you to.

How to take acetazolamide

Take Acetazolamide exactly how you’ve been advised by your physician.

Swallow your dose with a glass of water.

You’ll usually start taking Acetazolamide 24-48 hours before you reach altitudes above 2,500 meters. Starting them early means the tablets can start working in your system so you can avoid any altitude sickness symptoms starting.