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
Isoniazide is metabolized by ? 
Select and explain. 
A. Acetylation, B. Oxidation, C. Reduction, D. Hydrolysis
A: Acetylation
Answer: A: Acetylation 
Explanation: Ans. is 'a' i.e., Acetylation Isoniazid is extensively metabolized in liver most impoant pathway being N - acetylation by NAT The acetylated metabolite is excreted in urine. Drugs metabolized by acetylation Sulfonamides (including dapson) Procainamide PAS INH Hydralazine