Acetazolamide and Potassium

Q: Diuresis with Acetazolamide causes? - Select one

A) hyperkalemia

B) hypokalemia

Answer: B

Acetazolamide is a carbonic anhydrase inhibitor often used to decrease serum bicarbonate levels in ICU.

Acetazolamide inhibits proximal sodium bicarbonate reabsorption and increases urinary bicarbonate excretion. This increase in sodium bicarbonate delivery to the potassium-secretory site in the collecting tubules generates kaliuresis, leading to clinically significant hypokalemia, which may require potassium repletion.

The usual dose of Acetazolamide is 250 to 500 mg, once or twice a day.

Interestingly, it is used in a wide array of diseases both on and off-label, including:

• Glaucoma
• Idiopathic intracranial hypertension
• Congestive heart failure
• Altitude sickness
• Periodic paralysis
• Epilepsy
• Central sleep apnea
• Marfan syndrome
• Prevention of high-dose methotrexate nephrotoxicity

#nephrology

#electrolytes

#acid-base

References:

1. Prieto de Paula JM, Villamandos Nicás V, Cancelo Suárez P, del Portillo Rubí A, Guillem Ares E, Prada Mínguez A, Sanz de la Fuente H. Eficacia del tratamiento con acetazolamida en pacientes con hipercapnia y alcalosis metabólica sobreimpuesta [Efficacy of acetazolamide treatment of patients with hypercapnia and superimposed metabolic alkalosis]. Rev Clin Esp. 1997 Apr;197(4):237-40. Spanish. PMID: 9254398.

2. Miller PD, Berns AS. Acute metabolic alkalosis perpetuating hypercarbia. A role for acetazolamide in chronic obstructive pulmonary disease. JAMA. 1977 Nov 28;238(22):2400-1. doi: 10.1001/jama.238.22.2400. PMID: 578870.

3. Van Berkel MA, Elefritz JL. Evaluating off-label uses of acetazolamide. Am J Health Syst Pharm. 2018 Apr 15;75(8):524-531. doi: 10.2146/ajhp170279. PMID: 29626002.

4. Farzam K, Abdullah M. Acetazolamide. [Updated 2023 Jul 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532282/