This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunomodulator, Subject name: Pharmacology
[{'content': 'Allopurinol is used in treatment of: \nSelect and explain. \nA. Rheumatoid arthritis, B. Psoriatic arthritis, C. Gouty arthritis, D. Poly sero arthritis', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Gouty arthritis* Allopurinol is a hypoxanthine analogue which was synthesized as a purine anti metabolite.* Allopurinol is xanthine oxidase inhibitor.* Uses:# Allopurinol is the first choice drug for chronic gout. It can be used for both over producers as well as under excretors of uric acid.# With long term allopurinol therapy, tophi gradually disappear and nephropathy is halted and even reversed.* Allopurinol is contraindicated in acute gout because a sudden decrease in urate levels may precipitate re - crystallization in the joints.* Other uses# Allopurinol may be used in some cases of kala azar or leishmaniasis but efficacy is doubtful.", 'role': 'assistant'}]