Stability Refrigerated: Reconstituted solutions retain their physical
and chemical properties for 3 days under refrigeration at 2° to 8°C (36°
Stability Room Temp: Store at 20° to 25°C (68° to 77°F) excursions
permitted between 15° to 30°C (59° to 86°F)
Reconstituted solutions retain their physical and chemical properties
for 12 hours at room temperature 20° to 25°C (68° to 77°F).
Reconstituted Vial/Powder: Powder
Contains no preservative. Discard unused portion.
(package insert): Store drug product at controlled room temperature 15°-30°C (59°-86°F). Reconstituted solution should be stored in refrigerator at 2°- 8°C (36° - 46°F). Use within 12 hours of reconstitution. Contains no preservative. Discard unused portion.
Injection: Store vial for injection (prior to reconstitution) at controlled room temperature. Reconstitute with at least 5 mL sterile water to provide a solution containing not more than 100 mg/mL. Reconstituted solution may be refrigerated (2°C to 8°C) for 1 week, however, use within 12 hours is recommended. Further dilute in D5W or NS for I.V. infusion. Stability of IVPB solution is 5 days at room temperature (25°C) and 44 days at refrigeration (5°C).
Dosing adjustment in renal impairment:
Clcr 10-50 mL/minute: Administer every 12 hours
Clcr<10 mL/minute: Avoid use (ineffective)
Hemodialysis: Moderately dialyzable (20% to 50%)
Peritoneal dialysis: Supplemental dose is not necessary
DOSAGE AND ADMINISTRATION
Preparation and Storage of Parenteral Solution
Each 500 mg vial containing sterile acetazolamide sodium should be reconstituted with at least 5 mL of Sterile Water for Injection prior to use. Reconstituted solutions retain their physical and chemical properties for 3 days under refrigeration at 2° - 8° C (36° - 46° F), or 12 hours at room temperature 15° - 30° C (59° - 86° F). Contains no preservative.
The direct intravenous route of administration is preferred. Intramuscular administration is not recommended.
Acetazolamide should be used as an adjunct to the usual therapy. The dosage employed in the treatment of chronic simple (open-angle) glaucoma ranges from 250 mg to 1 g of acetazolamide per 24 hours, usually in divided doses for amounts over 250 mg. It has usually been found that a dosage in excess of 1 g per 24 hours does not produce an increased effect.
It is not clearly known whether the beneficial effects observed in epilepsy are due to direct inhibition of carbonic anhydrase in the central nervous system or whether they are due to the slight degree of acidosis produced by the divided dosage. The best results to date have been seen in petit mal in children. Good results, however, have been seen in patients, both children and adult, in other types of seizures such as grand mal, mixed seizure patterns, myoclonic jerk patterns, etc. The suggested total daily dose is 8 to 30 mg per kg in divided doses. Although some patients respond to a low dose, the optimum range appears to be from 375 to 1000 mg daily. However, some investigators feel that daily doses in excess of 1 g do not produce any better results than a 1 g dose. When acetazolamide is given in combination with other anticonvulsants, it is suggested that the starting dose should be 250 mg once daily in addition to the existing medications. This can be increased to levels as indicated above. The change from other medications to acetazolamide should be gradual and in accordance with usual practice in epilepsy therapy.
Congestive Heart Failure
For diuresis in congestive heart failure, the starting dose is usually 250 to 375 mg once daily in the morning (5 mg per kg). If, after an initial response, the patient fails to continue to lose edema fluid, do not increase the dose but allow for kidney recovery by skipping medication for a day. Acetazolamide yields best diuretic results when given on alternate days, or for two days alternating with a day of rest. Failures in therapy may be due to overdosage or too frequent dosage. The use of acetazolamide does not eliminate the need for other therapy such as digitalis, bed rest, and salt restriction.
Recommended dosage is 250 to 375 mg of acetazolamide once a day for one or two days, alternating with a day of rest.
Note: The dosage recommendations for glaucoma and epilepsy differ considerably from those for congestive heart failure, since the first two conditions are not dependent upon carbonic anhydrase inhibition in the kidney which requires intermittent dosage if it is to recover from inhibitory effect of the therapeutic agent.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.