This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autacoids, Subject name: Pharmacology
Allopurinol potentiates the action of: 
Select and explain. 
A. Coicosteroids, B. Probenecid, C. 6-Mercaptopurine, D. Ampicilin
C: 6-Mercaptopurine
Answer: C: 6-Mercaptopurine 
Explanation: Allopurinol: used for chronic gout Reduces uric acid synthesis by competitively inhibiting xanthine oxidase Allopurinola Alloxanthine a noncompetitive inhibitor of xanthine oxidase ESSENTIALS OF MEDICAL PHARMACOLOGY;7TH EDITION;KD TRIPATHI;PAGE NO 216