Prevention or lessening of symptoms associated with acute mountain sickness (oral only); adjunctive treatment of chronic simple (open-angle) glaucoma and secondary glaucoma; preoperative treatment of acute congestive (closed-angle) glaucoma; adjunctive treatment of centrencephalic epilepsies (eg, petit mal, generalized seizures); edema caused by CHF and drug-induced edema (tablet and IV only).
Familial periodic paralysis; malignant glaucoma; prevention of migraine.
Adults and Children 12 yr of age and older:PO 500 to 1,000 mg per day in divided doses twice daily. In circumstances of rapid ascent, 1,000 mg is recommended. It is preferable to initiate dosing 24 to 48 h before ascent. Continue for 48 h while at high altitude, or longer as necessary to control symptoms.
Chronic Simple (Open-Angle) Glaucoma
Tablets: / IV 250 mg to 1 g per day, usually in divided doses for amounts above 250 mg.Adults and Children 12 yr of age and older:PO
ER capsules: 500 mg 2 times daily. It may be necessary to adjust the dose, but it has usually been found that a dose in excess of 1 g does not produce an increased effect.Diuresis in CHF
Tablets: / IV Initially 250 to 375 mg (5 mg/kg) every morning; then give on alternate days or for 2 days alternating with 1 day of rest.Drug-Induced Edema
Tablets: / IV 250 to 375 mg daily for 1 to 2 days, alternating with a day of rest.Secondary Glaucoma/Acute Congestive Closed-Angle Glaucoma
Tablets: / IV 250 mg every 4 h or 250 mg twice daily. In some acute cases, initially administer 500 mg, then 125 to 250 mg every 4 h.Adults and Children 12 yr of age and younger:
ER capsules: 500 mg 2 times daily. It may be necessary to adjust the dose, but it has usually been found that a dose in excess of 1 g does not produce an increased effect.
Tablets: / IV 8 to 30 mg/kg per day in divided doses; optimum range is 375 to 1,000 mg/day. When drug is given in combination with other anticonvulsants, initial dosage is 250 mg daily.
Hypersensitivity to any ingredients in the formulations; depressed sodium and/or potassium serum levels; marked kidney and liver disease or dysfunction; suprarenal gland failure; hyperchloremic acidosis; cirrhosis; long-term use in chronic noncongestive angle-closure glaucoma.
By alkalinizing the urine, the urinary excretion of amphetamines is decreased, enhancing the magnitude and duration of effects. Avoid coadministration, especially in overdose situations.
Coadministration may cause severe mixed acidosis in patients with respiratory disorders. Use with caution. If acidosis occurs, discontinue one or both drugs.
Carbonic anhydrase inhibitors (eg, methazolamide)
Because of additive effects, avoid other carbonic anhydrase inhibitors.
Cyclosporine concentrations may be elevated, increasing the pharmacologic effect and adverse reactions. Monitor cyclosporine concentrations and adjust the cyclosporine dose as needed.
Folic acid antagonists
The pharmacologic effects of folic acid antagonists may be increased. Use with caution.
Phenytoin serum concentrations may be elevated, increasing the pharmacologic effects and risk of toxicity. Use with caution. Monitor phenytoin concentrations and the patient’s response. Adjust the phenytoin dose as needed.
Lithium serum concentrations may be reduced, decreasing the therapeutic response. Monitor lithium concentrations and the patient’s response. If an interaction is suspected, adjust the lithium dose as needed.
Acetazolamide may interfere with the antibacterial effect of methenamine. Avoid coadministration. Consider use of a urinary antimicrobial agent not affected by urinary alkalinization.
Plasma concentrations of primidone and its metabolites may be reduced, decreasing the anticonvulsant effect. Use with caution when starting, stopping, or changing the dose of acetazolamide. If an interaction is suspected, consider use of an alternative anticonvulsant agent.
Quinidine serum levels may be increased. Because of urinary alkalinization, urinary excretion of quinidine is decreased, increasing the pharmacologic and toxic effects. Use with caution. Monitor quinidine concentrations and cardiac function when starting or stopping acetazolamide. Adjust the quinidine dose as needed.
May cause acetazolamide accumulation and toxicity, including CNS depression, and metabolic acidosis, coma, and death. Monitor salicylate concentrations, acid-base parameters, and CNS status. Adjust the acetazolamide dose as needed.
Coadministration increases the risk of renal calculus formation. Avoid coadministration.
Concomitant use of topiramate with acetazolamide may increase the risk of kidney stone formation. Avoid coadministration.