Acetazolamide oral
- Drugs List
- Therapeutic Indications
- Dosage
- Contraindications
- Precautions and Warnings
- Pregnancy and Lactation
- Side Effects
- Monograph
Presentation
Oral formulations of acetazolamide.
Drugs List
Therapeutic Indications
Uses
Glaucoma
Oedema
Treatment of all forms of epilepsy
Unlicensed Uses
Altitude sickness: prophylaxis
Dosage
Adults
Glaucoma
250mg to 1000mg a day, given in divided doses.
Epilepsy
250mg to 1000mg a day, given in divided doses.
Pre-menstrual fluid retention
125mg to 375mg a day.
Associated oedema
Initial dose: 250mg to 375mg, given as a single dose in the morning.
If there is no response after the initial dose, 250mg to 375mg may be administered on alternate days or for 2 days, then have a day's break and repeat.
Children
Epilepsy
8mg/kg to 30mg/kg a day, given in divided doses.
Maximum dose: 750mg a day.
The following alternate dosing schedule may be suitable:
Children aged 12 to 18 years
250mg to be given 2 to 4 times daily
Children aged 1 month to 12 years
Initial dose: 2.5mg/kg to be given 2 to 3 times daily.
Maintenance dose: 5mg/kg to 7mg/kg to be given 2 to 3 times daily.
Maximum dose: 750mg day.
Glaucoma (unlicensed)
Children aged 12 to 18 years
250mg to be given 2 to 4 times daily.
Children 1 month to 12 years
5mg/kg to be given 2 to 4 times daily, adjusted according to individual patient response.
Maximum dose: 750mg a day.
Raised Intracranial pressure
Children aged 1 month to 12 years
Initial dose: 8mg/kg to be given three times daily (maximum daily dose 100mg/kg).
Neonates
Epilepsy
Children under 1 month
Initial dose: 2.5mg/kg to be given 2 to 3 times daily.
Maintenance dose: 5mg/kg to 7mg/kg to be given 2 to 3 times daily.
Patients with Renal Impairment
The Renal Drug Handbook suggest the following schedule:
GFR 20 to 50ml/minute: 250mg up to twice daily.
GFR 10 to 20ml/minute: 250mg up to twice daily.
GFR of less than 10ml/minute: Not recommended.
Contraindications
Adrenal insufficiency
Hepatic cirrhosis
Hyperchloraemic acidosis
Hypokalaemia
Hyponatraemia
Long term use in chronic non-congestive narrow angle glaucoma
Pregnancy
Severe hepatic impairment
Severe renal impairment
Precautions and Warnings
Elderly
Impaired glucose tolerance
Breastfeeding
Diabetes mellitus
Disorder of acid-base balance
Electrolyte imbalance
Hepatic impairment
History of nephrolithiasis
Obstructive pulmonary disease
Pulmonary emphysema
Renal impairment
Urinary obstruction
Reduce dose in patients with moderate renal impairment
Advise ability to drive/operate machinery may be affected by side effects
Diuresis is not dose-related
Blood counts should be performed before and periodically during treatment
Monitor serum electrolytes before and during treatment
Consider AGEP if feverish generalised erythema occurs
Advise patients to report any unusual rash to the prescriber
Advise patients/carers to seek medical advice if suicidal intent develops
Discontinue if hypersensitivity reactions occur
Discontinue immediately if any severe fall in blood counts occur
Discontinue permanently if AGEP is diagnosed
Pregnancy and Lactation
Pregnancy
Acetazolamide is contraindicated during pregnancy.
The manufacturer does not recommend using acetazolamide during pregnancy. Animal studies have shown teratogenic effects at doses in excess of ten times those recommended in humans. Human data is limited and as such a potential risk cannot be ruled out.
Lactation
Use acetazolamide with caution during breastfeeding.
The manufacturer advises caution if acetazolamide is used when breastfeeding. Whilst available data indicates acetazolamide is present in human breast milk, the quantity is not considered to be sufficient to cause adverse effects in the breastfed infants. Effects in exposed infants are unknown.
Side Effects
Abnormal liver function
Acute generalised exanthematous pustulosis
Agranulocytosis
Anaphylaxis
Aplastic anaemia
Ataxia
Bone marrow depression
Cholestatic jaundice
Confusion
Convulsions
Crystalluria
Depression
Diarrhoea
Dizziness
Drowsiness
Electrolyte disturbances
Erythema multiforme
Fatigue
Fever
Flaccid paralysis
Flushing
Fulminant hepatic necrosis
Glycosuria
Haematuria
Headache
Hearing disturbances
Hepatitis
Irritability
Leukopenia
Melaena
Metabolic acidosis
Myopia
Nausea
Nephrolithiasis
Pancytopenia
Paraesthesia
Photosensitivity
Polyuria
Rash
Reduced libido
Renal colic
Renal failure
Renal lesions
Stevens-Johnson syndrome
Taste disturbances
Thirst
Thrombocytopenia
Thrombocytopenic purpura
Tingling in extremities
Tinnitus
Toxic epidermal necrolysis
Ureteral colic
Urticaria
Vomiting
Overdosage
It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.
The following number will direct the caller to the relevant local centre (0844) 892 0111
Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).
Further Information
Last Full Review Date: October 2021
Reference Sources
Summary of Product Characteristics: Acetazolamide 250mg tablets. Advanz Pharma. Revised August 2019.
The Renal Drug Handbook. Fifth edition (2019) ed. Ashley, C. and Dunleavy, A. Radcliffe Publishing Ltd, London.
Martindale: The Complete Drug Reference. 39th Edition. London: Brayfield A (ed). Pharmaceutical Press; 2017.
NICE Evidence Services Available at: www.nice.org.uk Last accessed: 19 October 2021
Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content
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