Meds and you

Updated 07 November 2013


Acetazolamide is a carbonic anhydrase inhibitor and anti-convulsant. These are drugs that reduce pressure within the eye, and are effective in the treatment of epilepsy.


Acetazolamide is the active ingredient of Azomid tablets (Nappi code: 789771-004) & Diamox tablets (Nappi code: 719471-001).

General information

Acetazolamide is a carbonic anhydrase inhibitor and anti-convulsant. These are drugs that reduce pressure within the eye, and are effective (although rarely used) in the treatment of epilepsy.

In South Africa acetazolamide is registered for the treatment of glaucoma, a condition associated with high pressure inside the eye; altitude sickness – a condition caused by of oxygen deficiency in the blood and tissues at high altitudes, and epilepsy adjunct to other anti-convulsants.

This medication may make your skin more sensitive to sunlight. Sunscreen and protective clothing are advised.

It should be noted that because this drug may cause dizziness, light-headedness and/or sedation, driving and any hazardous tasks should be avoided until you know how this medication affects you.

How does acetazolamide work?

Acetazolamide decreases the amount of aqueous humour produced in the eye, thereby reducing the pressure inside the eye, making it effective in treating glaucoma.

In the brain it is thought to decrease abnormal neuronal firing, thereby assisting in the treatment of epilepsy.

Fast facts

Drug schedule: schedule 3

Available as: acetazolamide is available as tablets

What does it do? Acetazolamide reduces pressure inside the eye and is therefore used for treating glaucoma. It is also used to prevent mountain sickness (altitude sickness) and to treat epilepsy.

Dependence risk: low

Is acetazolamide available as a generic? yes

Is Acetazolamide available on prescription only? yes

User information

Onset of effect: within 90 minutes

Duration of action: up to 12 hours

Dietary advice: take with food to reduce stomach upset/irritation. Take 2 - 3 litres of water daily to prevent dehydration and kidney stones.

Stopping this medicine: do not stop taking this drug without consulting your doctor.

Prolonged use: regular eye examinations are advised.

Special precautions

Consult your doctor before using this drug if:

  • you have kidney disease
  • you have liver disease
  • you are allergic to sulfonamides
  • you are pregnant, or suspect that you may be pregnant
  • you have gout
  • you have a chronic lung disease
  • you have diabetes

Pregnancy: avoid. Potential risk to the foetus has been reported. Consult your doctor before use, or if you are planning to fall pregnant.

Breastfeeding: avoid. It is unknown how this medication may affect your baby. Consult your doctor before use.

Porphyria: this medication is safe to use.

Infants and children: this medication is not intended for use in children under the age of 5 years.

Driving and hazardous work: caution is advised as use of this medication may lead to dizziness, light-headedness and/or sedation. Avoid such activities until you know how this medication affects you.

Alcohol: avoid concomitant use of alcohol with this medication.

Possible side effects

Side effects Frequency
Consult your doctor

Common Rare Only if severe In all cases
electrolyte disturbances x
muscle cramps x
weakness x
lethargy x
nausea x
vomiting x
headache x
x x
skin reactions
unusual bleeding or bruising


Drug interactions

quinidine increased risk of quinidine side-effects
tricyclic antidepressants

increased risk of TCA side-effects

phenobarbital reduced effect of phenobarbital
barbiturates reduced effect of barbiturate
asprin risk of acetazolamide loss
corticosteroids increased potassium loss
amphotericin increased potassium loss
primidone reduced concentrations of primiodone

Overdose action

A small overdose is no cause for concern. In case of intentional large overdose, seek emergency medical attention.

Recommended dosage

Adults, oral: glaucoma: 250 mg to 1 g/day


This material is not intended to substitute medical advice, but is for informational purposes only.

Please consult a physician for specific treatment and recommendations.


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