Acetazolamide

Acetazolamide - is a carbonic anhydrase inhibitor normally used to reduce intra-ocular pressure in glaucoma. Metabolic alkalosis may be partially corrected by the use of acetazolamide. The most common cause of metabolic alkalosis on the ICU is usually the result of furosemide administration.

Uses
Metabolic alkalosis (unlicensed)

Contraindications
Hypokalaemia
Hyponatraemia
Hyperchloraemic acidosis
Severe liver failure
Renal failure
Sulphonamide hypersensitivity

Administration
• IV: 250–500 mg, given over 3–5 min every 8 hours Reconstitute with 5 ml WFI
Monitor: FBC, U&E and acid/base balance

How not to use acetazolamide
IM injection – painful
Not for prolonged use

Adverse effects
Metabolic acidosis
Electrolyte disturbances (hypokalaemia and hyponatraemia)
Blood disorders
Abnormal LFT

Cautions
Avoid extravasation at injection site (risk of necrosis)
Avoid prolonged use (risk of adverse effects)
Concurrent use with phenytoin (up serum level of phenytoin)

Organ failure
Renal: avoid if possible (metabolic acidosis)

CC (ml/min)	Dose (mg)	Interval (h)
20–50	250	Up to 6
10–20	250	Up to 12
< 10	250	24

epatic: avoid (abnormal LFT)