<prompt> Zero-order kinetics occur in the following drug with high dosePhenytoin and TheophyllineDigoxin and PropranolAmiloride and ProbenecidLithium and Theophylline  <response>: zero order kinetics -the rate of elimination remains constant irrespective of drug concentration, clearance decreases with increase in concentration, or a constant amount of drug is eliminated in unit time The elimination of some drugs changes from first order to zero order at higher doses eg ; Phenytoin, Tolbutamide, Theophylline, Warfarin, DIGOXIN, aspirin ref; KD Tripathi Pharmacology 7th edition page no;31 