Which of the following about phenytoin is true ?
It follows zero order kinetics
Not an hepatic enzyme inducer
It is excreted unchanged in urine
It is not teratogenic
Ans. is 'a' i.e., It follows zero order kinetics Phenytoin is metabolized in liver by hydroxylation and glucuranide conjugation (option 'c' is incorrect) o This drug follows saturation kinetics (kinetics changes from first order to zero order within therapeutic concentrations) Phenytoin is an enzyme inducer and induces the metabolism of many drugs. Phenytoin is a known teratogenic and produces fetal hydantoin syndrome.