Dose reduction should be done for which of the following anticancer drug, if Allopurinol is used: (A) Methotrexate, (B) Mitoxantrone, (C) 6-Mercaptopurine, (D) Mitomycin-C
Answer is C. Allopurinol inhibits the metabolism of 6-mercaptopurine and result in toxicity. Therefore if Allopurinol is used, dose of 6-mercaptopurine should be decreased by 75%.