This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'CYP 3A4 enzymes are affected by: a) Fexofenadine b) Phenytoin c) Carbamazepine d) Azithromycin e) Penicillin \nSelect and explain. \nA. ab, B. bc, C. ad, D. bd', 'role': 'user'}, {'content': 'Answer: B \nExplanation: CYP3A4 cary out biotransformation of large number\xa0of drugs. The inhibition of this isoenzyme by erythromycin, clarithromycin, ketoconazole, itraconazole etc.\xa0is responsible for important drug interactions with terfenadine, astemizole and cisapride. Rifampicin,\xa0barbiturates and other anticonvulsants are important\xa0inducers.', 'role': 'assistant'}]