This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Dose reduction should be done for which of the following anticancer drug, if Allopurinol is used \nSelect and explain. \nA. Methotrexate, B. Mitoxantrone, C. 6-Mercaptopurine, D. Mitomycin-C', 'role': 'user'}, {'content': 'Answer: C \nExplanation: 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%.', 'role': 'assistant'}]