Allopurinol, used to prevent hyperuricemia, can prolong the action and increase the toxicity of all of the following except which one?

Question

Quizplus · Accepted Answer

Allopurinol inhibits xanthine oxidase, which is involved in the metabolism of purine analogs like azathioprine and mercaptopurine, increasing their toxicity. Cyclophosphamide is not affected by allopurinol. 5-Fluorouracil is not metabolized by xanthine oxidase, so its action and toxicity are not prolonged by allopurinol.

Allopurinol, Used to Prevent Hyperuricemia, Can Prolong the Action and Increase