Repeated USMLE Questions Step 1- 301

A 52-year-old man who is recently diagnosed with gout is presented to his physician to discuss his treatment plan. One of the treatments that will be taken is allopurinol.

Which of these enzymes is targeted by this medication?

A-Hypoxanthine guanine phosphoribosyltransferase

B-Phosphoribosylpyrophosphate synthase


D-Xanthine oxidase


Allopurinol is used to treat chronic gout due to its ability to decrease the production of uric acid in the body. Allopurinol is known to be an inhibitor of xanthine oxidase. Xanthine oxidase catalyzes the oxidation of hypoxanthine to xanthine and the oxidation of xanthine to uric acid.

The correct answer is D

1 thought on “Repeated USMLE Questions Step 1- 301”

Leave a Comment