Acetazolamide - oral

Patient Medicine Information
Why do I need this medicine?
Acetazolamide is used together with other medicines to treat glaucoma (increased pressure in the eye). It can also help reduce the pressure in the eye before undergoing a surgery.

This medicine may also be used to treat other conditions such as epilepsy (fits or seizures) and mountain sickness (condition caused by a travel to high altitudes where there are low air pressure and oxygen levels).

Acetazolamide may also be used to treat water retention caused by heart failure, menstrual disorder and some medications. Water retention may be noticed as swelling of the feet, ankles, lower leg and hands, or shortness of breath. For this reason, it is commonly known as a “water pill”.
How do I take this medicine?
Take this medicine exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.

Take it together with food or immediately after a meal. Try to take it at the same time each day.

Acetazolamide is available as a tablet, or as an extended-release or prolonged-release capsule.

If you are taking the extended-release or prolonged-release type of capsule (usually labelled as “ER” or “PR”), swallow it whole. Do not chew or crush the capsule.

The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on your condition.

Acetazolamide must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.
What should I do if I have forgotten to take this medicine?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.

If you often forget to take your medicine, let your doctor and pharmacist know.
When should I not use this medicine?
Do not take Acetazolamide if you ever had an allergic reaction (rashes, breathlessness, swollen eyes) to this medicine or certain antibiotics such as sulfonamides or sulfonamide related medicines.

Alert your doctor if you have the following conditions:
  • severe liver disease
  • severe kidney disease
  • low levels of potassium and sodium in the blood
  • adrenal gland disorder
  • hyperchloraemic acidosis (low bicarbonate and high chloride concentration in the blood)
  • long term non-congestive angle closure glaucoma (glaucoma caused by blocked drainage canals, resulting in a sudden rise in pressure inside the eyes)
as Acetazolamide may not be suitable for you.
What should I take note of while taking this medicine?
Inform your doctor if you have the following conditions:
  • diabetes
  • lung disease e.g. respiratory acidosis (lungs cannot remove enough carbon dioxide)
  • kidney problems e.g. kidney stones, blocked bladder
  • liver problems
Let your doctor know if you are pregnant or breastfeeding.

Be sure to check with your doctor or pharmacist before giving this medicine to an elderly. Elderly may be more sensitive to the side effects.

If you are going for certain laboratory tests (e.g. urine protein test, HPLC theophylline test), inform your doctor that you are taking this medicine.

Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.
  • Routine tests (e.g. complete blood count, electrolyte levels, eye examination) may be done while you are being treated with this medicine. Your doctor will advise you about how often you will need to have these tests.
  • Monitoring of signs of suicidal thoughts or attempts may also be needed.
What side effects could I experience?
Acetazolamide may cause dizziness, drowsiness or near-sightedness. If affected, do not drive or take part in any activity in which you need to be alert.

Other side effects include any of the following: headache, ringing in the ears, nausea, vomiting, diarrhoea, loss of appetite, metallic taste in the mouth, numbness or tingling sensation in the hands and feet, tiredness and irritability.

If you develop rashes, breathlessness, swollen mouth or eyes, stop taking Acetazolamide and inform your doctor quickly. These could be signs of an allergic reaction.

Some side effects may be serious, although they are not common. Alert your doctor quickly if you experience any of the following:
  • yellowing of the skin and eyes
  • fever with persistent sore throat or mouth ulcers, unusual bleeding or bruising
  • rashes with peeling of the skin or blistering of the lips, mouth or eyes accompanied by fever
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Can I take this with other medicines?
Inform your doctor and pharmacist if you are taking any of these medicines:
  • certain antibiotics e.g. methenamine
  • aspirin (blood-thinning medicine)
  • medicines for epilepsy (fits or seizures) e.g. carbamazepine, phenytoin, primidone
  • medicines for heart disease e.g. quinidine, digoxin
  • medicines for diabetes e.g. gliclazide, metformin
  • lithium (medicine for mood disorders)
  • ciclosporin (medicine used in organ transplant or certain immune disorders)
  • sodium bicarbonate (medicine to neutralise excessive acid in the body)
This list does not include all medicines that may interact with Acetazolamide.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics, such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
What special dietary instructions should I follow?
Avoid alcohol.
How should I store this medicine?
Store in a cool, dry place away from the reach of children.

Medicines must not be used past the expiry date.
This information is independently developed by MIMS based on acetazolamide - oral and is provided for your reference only. It is not a replacement for and should only be used in conjunction with full consultation with a licensed healthcare professional, the information provided by your pharmacist and/or the manufacturer of the medication. It may not contain all the available information you require and cannot substitute professional medical care, nor does it take into account all individual circumstances. Although great effort has been made to ensure content accuracy, we shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2022 MIMS. All rights reserved. Powered by
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