AcetaZOLAMIDE

Disclaimer to the Online Edition

This Manual has been designed for use in the NICU at London Health Sciences Centre (LHSC), London, Ontario, Canada, and represents clinical practice at this institution. The information contained within the Manual may not be applicable to other centres. If users of this Manual are not familiar with a drug, it is recommended that the official monograph be consulted before it is prescribed and administered. Any user of this information is advised that the contributors, Editor and LHSC are not responsible for any errors or omissions, and / or any consequences arising from the use of the information in this Manual.

AcetaZOLAMIDE

Indications

  • AcetaZOLAMIDE is not a first line drug in this unit. It has rarely been used
  • Mild diuretic
  • An anticonvulsant in refractory neonatal seizures
  • Decreases CSF production in posthemorrhagic hydrocephalus
  • The treatment of renal tubular acidosis

Pharmacology

  • AcetaZOLAMIDE belongs to a class of drugs called carbonic anhydrase inhibitors (CAIs)
  • CAIs decrease the formation of hydrogen and bicarbonate ion from water and carbon dioxide by inhibiting the enzyme carbonic anhydrase

carbonic anhydrase
H2O + CO2 ---> H+ + HCO3-

  • In the renal tubules the above action results in reduction of H+ concentration, and increased excretion of HCO3-, and to a lesser extent, Na and K. Resorption of water is decreased, the urine becomes alkaline, and urine volume is increased
  • Results in a decrease in plasma HCO3-, a possible increase in plasma Cl, and may lead to a metabolic acidosis
  • AcetaZOLAMIDE has an anticonvulsant effect that is not related to its diuretic action. It is rarely used for this purpose

Side Effects

  • GI: vomiting, diarrhea, weight loss, dryness of mouth
  • CNS: drowsiness, fatigue, irritability
  • Bone marrow suppression
  • Renal calculi, hyperchloremic metabolic acidosis

Precautions

  • Do not administer IM because of the alkaline pH of the drug

Dose

Diuretic
  • 5 mg/kg once daily, po or IV
Anticonvulsant
  • 3 to 10 mg/kg, po or IV, q8h
Decrease CSF production

15 to 30 mg/kg, po or IV, q8h

Alkalanize urine 
  • 5 mg/kg, po or IV, q8h to q12h
  • Administer by slow IV push
  • Reconstitute 500 mg powder with 5 mL sterile water for injection to produce a final concentration of 100 mg/mL

Supplied

  • 500 mg vial (powder) 25 mg/mL oral suspension, prepared by the Pharmacy Department
References
  1. McEvoy G K (ed): AHFS Drug Information, American Society of Hospital Pharmacists, 1991.
  2. Gomella TL (Ed): Neonatology - Management, Procedures, On-Call Problems, Diseases, Drugs, 1992, Appleton and Lange, Norwalk, Connecticut.
  3. Taketomo CK, Hodding JH and Kraus DM: Pediatric Dosage Handbook, Lexi-Comp Inc., Cleveland, 1992.