What is acetazolamide’s mechanism of action (MOA)?
Acetazolamide is a carbonic anhydrase inhibitor. It blocks carbonic anhydrase enzymes, which reduces the formation of carbonic acid (H2CO3) in tissues. That shifts acid-base handling and leads to decreased bicarbonate reabsorption in the kidney, causing bicarbonaturia. The result is a diuretic effect (often with metabolic acidosis) and increased urine output of bicarbonate (and typically sodium with it). [1]
How does carbonic anhydrase inhibition translate into diuretic effects?
By inhibiting carbonic anhydrase in the proximal tubule, acetazolamide prevents the normal reabsorption of bicarbonate (HCO3-). Less bicarbonate is reclaimed, so more bicarbonate stays in the urine and pulls water and electrolytes with it, producing diuresis. This is why acetazolamide is classified as a mild-to-moderate diuretic and why it can cause a non–anion gap (hyperchloremic) metabolic acidosis. [1]
What MOA links acetazolamide to glaucoma treatment?
Acetazolamide lowers aqueous humor production in the eye. The connection to its MOA is the same carbonic anhydrase inhibition, which reduces processes that depend on carbonic anhydrase activity involved in fluid generation. By decreasing aqueous humor formation, intraocular pressure falls. [1]
Why does acetazolamide cause metabolic acidosis?
Because it promotes renal bicarbonate loss (bicarbonaturia), acetazolamide reduces the body’s ability to regenerate and retain bicarbonate. The body compensates by developing metabolic acidosis (commonly described as hyperchloremic metabolic acidosis). [1]
What patients or clinicians usually look for as MOA-related outcomes?
Since its primary MOA is carbonic anhydrase inhibition, the most expected downstream effects are diuresis with bicarbonate loss and acid-base changes, plus lowered intraocular pressure when used for eye indications. [1]
Source
[1] DrugPatentWatch.com: https://www.drugpatentwatch.com/p/drug/diamox/ (acetazolamide information, including mechanism/uses context)