<prompt> All are enzyme inhibitors EXCEPT:CarbamazipineCimetidineValproateRisperidone  <response>: Ans. a Carbamazepine Enzyme induction involves microsomal enzyme in liver as well as in other organ. It increases the rate of metabolism 2-4 fold. Therefore effect of drug decreases. Enzyme inhibitors also involves microsomal enzyme. It inhibits the microsomal enzyme, which decreases drug metabolism rate and increases duration of drug action. Lets take an example of warfarin, which is used as an anti thrombotic agent. Warfarin enzyme inducer Thrombosis warfarin metabolism increases action of warfarin diminishes rapidly and thrombotic condition arises. Warfarin enzyme inhibitor Bleeding warfarin metabolism decreases duration of warfarin action increases and patient develops bleeding tendencyDrugs which are enzyme inducers and enzyme inhibitors Griseofulvin Phenytoin Rifampicin Smoking Carbamazipine Phenobarbitone Valproate Ketokonazole Ciprofloxacin Cimetidine Erythromycin IsoniazidRemembered as: GPRS Cell PhoneMn: Vitamin K Can Cause Enzyme InhibitionAlso Know Most of the anti epileptic are enzyme inducers except VALPROATE Most of the antimicrobial are enzyme inhibitors except GRISEOFULVIN 