What is the mechanism of action of Diamox (acetazolamide) in AMS management?

What is the mechanism of action of Diamox (acetazolamide) in AMS management?

• A. Carbonic anhydrase inhibitor causing bicarbonate diuresis and pH drop
• B. Increases oxygen carrying capacity
• C. Reduces cerebral blood flow
• D. Stimulants respiration by activating chemoreceptors

Answer: (A)

Diamox works by inhibiting the enzyme carbonic anhydrase. In the kidney this prevents reabsorption of bicarbonate, causing bicarbonate-rich urine and a mild metabolic acidosis (pH drop). That acid-base shift stimulates the respiratory center to increase ventilation, which improves arterial oxygenation at altitude and helps relieve AMS symptoms. There’s also a contribution from reduced CSF production due to carbonic anhydrase inhibition, which can help lessen cerebral edema. The other options don’t reflect this mechanism: the drug doesn’t increase oxygen-carrying capacity, directly reduce cerebral blood flow as the primary effect, or stimulate respiration by directly activating chemoreceptors—the trigger is the metabolic acidosis-driven rise in breathing.

Diamox works by inhibiting the enzyme carbonic anhydrase. In the kidney this prevents reabsorption of bicarbonate, causing bicarbonate-rich urine and a mild metabolic acidosis (pH drop). That acid-base shift stimulates the respiratory center to increase ventilation, which improves arterial oxygenation at altitude and helps relieve AMS symptoms. There’s also a contribution from reduced CSF production due to carbonic anhydrase inhibition, which can help lessen cerebral edema. The other options don’t reflect this mechanism: the drug doesn’t increase oxygen-carrying capacity, directly reduce cerebral blood flow as the primary effect, or stimulate respiration by directly activating chemoreceptors—the trigger is the metabolic acidosis-driven rise in breathing.