the proximal blocker
A Carbonic Anhydrase Inhibitor that targets the proximal tubule. While a weak diuretic on its own, it is a powerful adjunct in refractory heart failure and metabolic alkalosis.
- Mechanism: Inhibits Carbonic Anhydrase in the PCT. Blocks resorption of (Sodium Bicarbonate). Result: Alkaline diuresis, correction of metabolic alkalosis, chloride retention.
- Dosing: HF (ADVOR protocol): 500 mg IV Daily. Glaucoma/IIH: 250–1000 mg PO in divided doses.
- PK: Renally excreted.
indications
- Acute Heart Failure: Adjunct to loops for improved decongestion (ADVOR Trial).
- Metabolic Alkalosis: Especially “contraction alkalosis” from loops.
- Glaucoma: Reduces aqueous humor production.
- Altitude Sickness: Prophylaxis and treatment.
adverse effects
- Metabolic Acidosis: Expected mechanism of action. Monitor bicarbonate.
- Hypokalemia: Significant potassium wasting.
- Paresthesias: Tingling in fingers/toes (common).
- Kidney Stones: Calcium phosphate stones (alkaline urine).