<prompt> Isoniazide is metabolized by ?AcetylationOxidationReductionHydrolysis  <response>: 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 