Allopurinol should be avoided, or reduced doses should be used if given with which of the chemotherapeutic agent ? (LQ)
a. Mercaptopurine and other thiopurine are purine antimetabolites that are metabolically inactivated by xanthine oxidase. This purine degradation pathway of metabolism not only leads to formation of uric acid, but also is important to reducing host cell toxicity to the thiopurines.
b. Thus, concomitant use of allopurinol increases the risk of host cell toxicity.
c. Azathioprine (an inhibitor of B and T lymphocyte proliferation, and typically used as an immunosuppressant) is metabolized to mercaptopurine.
d. As a result, it interacts with allopurinol.
e. The metabolism of the other drugs listed is not xanthine oxidase dependent.