Medicines & Supplements A to Z > Acetazolamide


Last updated on 18/03/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions  |   Tips  |   Where To Buy  

GENERIC NAME: Acetazolamide


BRAND NAME(S) IN HONG KONG: Apo-Acetazolamide, Diamox

DRUG CLASS: Carbonic anhydrase inhibitor

USED FOR: Glaucoma, epilepsy, edema, treatment and prevention of acute mountain sickness

OTHER DRUGS IN THE SAME CLASS: Brinzolamide, Dorzolamide


What is Acetazolamide for?

Acetazolamide belongs to a class of medications called carbonic anhydrase inhibitors. It can reduce the pressure in your eyes and hence can be used to treat glaucoma. It is also effective in treating epilepsy, edema and preventing high altitude disorders.

How to use it?

Acetazolamide can be taken orally as tablets.

If you are using it to treat glaucoma, either capsules or tablets can be used. If you are taking tablets, you should take 250-500 mg daily.

If you are using it to treat epilepsy, you should take 250-1000 mg daily in divided doses. If it is taken as an adjunctive therapy, you should take 250 mg daily.

If you are using it to treat edema, you should take 250-375 mg once daily in the morning for 1 or 2 days, alternating with a day of rest.

To prevent high altitude illness, the usual dose is 125 mg twice daily. It is usually best to start taking acetazolamide the day before climbing up, and continue for at least 2 days during your stay at a high altitude.

What are the side effects of Acetazolamide?  

Common side effects of Acetazolamide include lightheadedness, flushing, change in taste (especially carbonated beverages), frequent urination, blurred vision, abnormal burning or tingling sensation in arms and legs.

Who should not take Acetazolamide?

– People who are allergic to Acetazolamide
– People with severe liver or kidney disease
– People with reduced blood levels of sodium or potassium

Pharmacist Tips:

Allergic reactions can rarely occur with Acetazolamide. If you experience a rash, swelling or hives after taking Acetazolamide, stop using it and seek medical care.

Common dosing schedule:
It’s best to take Acetazolamide with food to minimize the chance of stomach upset.

This schedule is for reference only, adjustments may be made according to individual needs.

Some common medications that Acetazolamide may interact with:
– High-dose Aspirin

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Acetazolamide in Hong Kong?

In Hong Kong, Acetazolamide is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

Need more information?

For detailed information about the use of Acetazolamide in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.