Acetazolamide

Provider Level

Paramedic, Registered Nurse, Critical Care Paramedic, Critical Care Nurse, Physician Assistant, Advanced Practice Nurse, Physician

Class

Carbonic anhydrase inhibitor, Diuretic

Mechanism of Action

Inhibits the enzyme carbonic anhydrase in the proximal renal tubule, promoting renal excretion of sodium, potassium, bicarbonate, and water. This creates a mild metabolic acidosis that stimulates respiratory drive. It also decreases aqueous humor production, lowering intraocular pressure.

Indications

Acute mountain sickness (AMS) prophylaxis and treatment, high altitude cerebral edema (HACE) as an adjunct, acute angle-closure glaucoma.

Contraindications

Hypersensitivity to sulfonamides, severe hepatic or renal disease, hypokalemia, hyponatremia, hyperchloremic acidosis, adrenal failure.

Routes

PO, IV

Onset / Duration

Onset: 1-2 hours for PO, 2-10 minutes for IV. Duration: 8-12 hours for PO, 4-5 hours for IV.

Adverse Effects

Paresthesias (tingling in fingers, toes, and face), polyuria, altered taste sensation (especially with carbonated beverages), hypokalemia, metabolic acidosis, tinnitus, nausea, vomiting.

Precautions & Interactions

Use with caution in patients with chronic respiratory conditions, as it can occasionally worsen respiratory acidosis. Monitor for signs of electrolyte depletion, particularly hypokalemia.

Special Considerations

Authorized for RN/Paramedic use primarily in specialized wilderness, high-altitude, or critical care transport environments. Patients with a known sulfa allergy may experience cross-reactivity, though this is relatively uncommon. Does not replace descent or oxygen therapy in severe altitude illness.