CYP 3A4 enzyme are affected by

CYP3A4 cary out biotransformation of large numberof drugs. The inhibition of this isoenayme by erythromycin, clarithromycin, ketoconazole, itraconazole etc is responsible for impoant drug interactions with terfenadine, astemizole and cisapride. Rifamps barbiturates and other anticonvulsants are impoant inducers. Ref-KDT 7/e p24