Question

A patient is going skiing high in the Rockies,

and is given acetazolamide to protect against altitude sickness. Unfortunately, the patient is also a Type 1 diabetic. He is admitted to the hospital in a worsening ketoacidosis. In which of the following cells has acetazolamide inhibited a reaction that has led to the severity
of the metabolic acidosis?
(A) White blood cells
(B) Red blood cells
(C) Lens of the eye
(D) Hepatocyte
(E) Muscle

Answer 1

Acetazolamide, a carbonic anhydrase inhibitor, worsens metabolic acidosis by affecting the red blood cells, impeding the body's acid excretion ability, particularly during diabetic ketoacidosis.

Step-by-step explanation:

The patient with Type 1 diabetes was given acetazolamide to prevent altitude sickness, but this medication exacerbated the severity of ketoacidosis. Acetazolamide is a carbonic anhydrase inhibitor that primarily affects the enzyme in the red blood cells (Option B). This enzyme's normal function is to convert bicarbonate into carbon dioxide, which can then be exhaled. Inhibiting this reaction with acetazolamide impairs the body's ability to excrete acid, thus worsening metabolic acidosis, especially in a patient with diabetic ketoacidosis, where the accumulation of ketone bodies like acetoacetic acid and beta-hydroxybutyric acid already lowers blood pH.

In the context of diabetic ketoacidosis, the liver produces an excess of ketone bodies due to the metabolism of fatty acids since glucose is not adequately utilized. This condition is dangerous because it leads to acidification of the blood, and acetazolamide further reduces the body's ability to compensate by excreting acid, aggravating the acidosis.