Acetazolamide

Question 1

MoA

Answer 1

1. Inhibits carbonic anhydrase –> decrease HCO3- absorption –> increase in urine pH + decrease in blood pH
2. Induces small amount of natriuresis
   
   1. Na+ gets re-absorbed with HCO3- via Na+/HCO3- cotransporter

Question 2

Clinical Uses

Answer 2

1. urinary alkalization
   
   • decreases risk of calcium oxalate, uric acid, and cysteine stone formation (precipitate with decreased urine pH)
2. prophylactic for altitude sickness
   
   • offsets initial respiratory alkalosis with increased H+ retention in the body –> pH is better balanced out faster
3. glaucoma (closed & open-angle)
   
   • carbonic anhydrase also functions in the eye to produce HCO3- and aqueous humor
4. metabolic alkalosis
5. pseudotumor cerebri

Question 3

Adverse Effects

Answer 3

1. **SULFA-BASED –> risk of allergic reaction
2. *proximal renal tubular acidosis
3. paresthesias
4. NH3 toxicity
   
   • less H+ secretion –> more NH3 retention in the body
   • risk of hepatic encephalopathy, tissue damage, etc.
5. hypokalemia
   
   • second to reabsorption of Na+ in the renal tubule back into blood at the CCT –> exchanged for K+ and H+ secretion into renal tubule