Carbonic Anhydrase Inhibitor

Question 1

Where do they exert their effx?

Answer 1

Proximal tubule

Question 2

Carbonic anhydrase inhibitor prototype?

Answer 2

Acetazolamide; developed from sulfanilamide after it was noticed to cause metabolic acidosis and alkaline urine

Question 3

MOA?

Answer 3

• H+ and bicarb in the tubular fluid can form carbonic acid –> carbonic anhydrase can convert to CO2 and H2O, which can cross the membrane, where CA can break down to H+ & bicarb
• Bicarbonate ions remains in early proximal tubule
• H+ cycling is lost, inhibiting NA+/H+ exchange

Question 4

Pharmacologic effect?

Answer 4

• Sodium bicarbonate diuresis (alkaline urine)

- Hyperchloremic acidosis

Question 5

Therapeutic uses?

Answer 5

• Very limited
• urinary alkinization
• metabolic alkalosis

glaucoma –> acetazolamide, dorzalamide

• Acute mountain sickness

Question 6

Adverse effects of CAI’s?

Answer 6

• Hyperchloremic metabolic acidosis
• Nephrolithiasis
• Potassium wasting