Acetazolamide

It is a Carbonic Anhydrase inhibitor. Its effect is inhibition of HCO-3 reabsorption which results in prompt mild alkaline diuresis. Other extra renal actions are lowering of intraocular tension due to decresed formation of aqueous humour (it is rich in HCO-3). Raised level of carbon dioxide in brain & acidosis helps raising seizure threshold, sedation.

Indications

Epilepsy, adjunct in treatment of oedema due to CHF. Open angle, secondary & acute angle closure glaucoma.

Dosage

Epilepsy : 8-30 mg/kg body not daily in div. doses. Glaucoma : 250mg-1gm daily.

Contra-Indications

Liver disease (may precipitate hepatic coma). Pregnancy. Adrenal insufficiency. Sodium or potassium depletion. Renal hyper-chloraemic acidosis, prolong therapy in chronic non-congestive angle closure glaucoma.

Special Precautions

Gout, diabetes, potassium supplements may be required. Paediatrics: Not usually prescribed, reduce dose necessary. Pregnancy: May cause abnormalities in the developing infants. Lactation: The drug passes into breast milk. Elderly: Increased likelihood of adverse effects.

Side Effects

Acidosis, hypokalemia, drowsiness, paresthesias.Hypersensitivity reactions, fever, rashes.

Drug Interactions

Potentiate effect of Folic acid antagonists, oral hypoglycaemic agents & oral anticoagulants. Potentiates effect of mercurial diuretics. Inhibit renal excretion of basic drugs (eg. quinidine, amphetamines), and promote excretion of acidic drugs. Hypokalaemia with corticosteroids, potassium-wasting diuretics. Diminish effect of lithium, primidone. Cause osteomalacia with phenytoin.