All are enzyme inhibitors EXCEPT:
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 tendency)Drugs 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
Carbamazipine
Cimetidine
Valproate
Risperidone
Pharmacokinetics