An 8-year-old boy is brought to the physician for a follow-up appointment. He has a history of acute lymphoblastic leukemia for which he receives 6-mercaptopurine as part of his regimen. Which of the following agents must be used carefully in this case when considering tumor lysis syndrome?
A) Allopurinol
B) Azathioprine
C) Colchicine
D) Hydroxychloroquine
E) Rasburicase
