You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is CYP 3A4 enzymes are affected by: a) Fexofenadine b) Phenytoin c) Carbamazepine d) Azithromycin e) Penicillin and explain in detail?
CYP3A4 cary out biotransformation of large number of drugs. The inhibition of this isoenzyme by erythromycin, clarithromycin, ketoconazole, itraconazole etc. is responsible for important drug interactions with terfenadine, astemizole and cisapride. Rifampicin, barbiturates and other anticonvulsants are important inducers.