Various generics; previously available as Diamox
Carbonic anhydrase inhibitor, diuretic

C	1	Yes	Yes	No
Key

• Tabs: 125, 250 mg
• Oral suspension: 25 mg/mL
• Capsules (extended release): 500 mg
• Injection (sodium): 500 mg
• Contains 2.05 mEq Na/500 mg drug

Dosing

• Diuretic (PO, IV)
  • Child: 5 mg/kg/dose once daily or every other day
  • Adult: 250–375 mg/dose once daily or every other day
• Glaucoma
  • Child:
    • PO: 8–30 mg/kg/24 hr ÷ Q6–8 hr; max. dose: 1000 mg/24 hr
    • IM/IV: 20–40 mg/kg/24 hr ÷ Q6 hr; max. dose: 1000 mg/24 hr
  • Adult:
    • PO (Simple chronic; open angle): 1000 mg/24 hr ÷ Q6 hr
    • IV (Acute secondary; closed angle): For rapid decrease in intraocular pressure, administer 500 mg/dose IV.
• Seizures (extended release product not recommended):
  • Child and adult: 8–30 mg/kg/24 hr ÷ Q6–12 hr PO; max. dose: 1 g/24 hr
• Urine alkalization:
  • Adult: 5 mg/kg/dose PO repeated BID-TID over 24 hr
• Management of hydrocephalus (see remarks): Start with 20 mg/kg/24 hr ÷ Q8 hr PO/IV; may increase to 100 mg/kg/24 hr up to a max. dose of 2 g/24 hr.
• Pseudotumor cerebri (PO; see remarks):
  • Child: Start with 25 mg/kg/24 hr ÷ once daily-QID; increase by 25 mg/kg/24 hr until clinical response or as tolerated up to a maximum of 100 mg/kg/24 hr.
  • Adolescent: Start with 1 g/24 hr ÷ once daily-QID; increase by 250 mg/24 hr until clinical response or as tolerated up to a maximum of 4 g/24 hr.

Notes

• Contraindicated in hepatic failure, severe renal failure (GFR <10 mL/min), and hypersensitivity to sulfonamides.
• T_1/2: 2–6 hr; do not use sustained release capsules in seizures; IM injection may be painful; bicarbonate replacement therapy may be required during long-term use (see Citrate Mixturesor Sodium Bicarbonate). For use in pseudotumor cerebri, doses of 60 mg/kg/24 hr may be required.
• Possible side effects (more likely with long-term therapy) include GI irritation, paresthesias, sedation, hypokalemia, acidosis, reduced urate secretion, aplastic anemia, polyuria, and development of renal calculi.
• May increase toxicity of carbamazepine and cyclosporine. Aspirin may increase toxicity of acetazolamide. May decrease the effects of salicylates, lithium, and phenobarbital. False-positive urinary protein may occur with several assays. Adjust dose in renal failure (see Chapter 31 ).