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': 'Which is Cyt. p450 inhibitor ? \nSelect and explain. \nA. Ketoconazole, B. Rifampicin, C. Phenytoin, D. INH', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ketoconazole DRUGS THAT INHIBIT DRUG METABOLIZING ENZYMES (P450) Allopurinol Diltiazem Omeprazole Amiodarane Erythromycin Propox yphene Clarithromycin Isoniazid Chloramphenicol Cimetidine Phenylbutazone Quinidine Ketoconazole Metronidazole Itraconazole Disulfiram Ciprofloxacin Verapamil Sulfonamides MAO inhibitors DRUGS THAT INDUCE MICROSOMAL ENZYMES Phenobarbitone Phenytoin Rifampin Glucocoicoids Isoniazid (I.N.H.) Chloral hydrate Phenylbutazone Griseofulvin DDT Cyclophosphamide Carbamezepine Clofibrate Meprobamate Ritonavir Glutethemide Chronic alcohol intake Cigarette smoking', 'role': 'assistant'}]