This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharmacodynamics, Subject name: Pharmacology
[{'content': 'Which of the following reduces the efficacy of oral contraceptives - \nSelect and explain. \nA. Erythromycin, B. Griseofulvin, C. Cimetidine, D. Disulfiram', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Griseofulvin o Contraceptive failure may occur if the following drugs are given concurrently :(a)Enzyme inducer -Enhances the metabolism of estrogen & progesterone.1. Phenytoin3. Carbamazepine5. Primidone2. Phenobarbitone4. Rifampicin6. Griseofulvin(b)Suppression of intestinal microflora - | enterohepatic circulation.1. Tetracyclines 2. Ampicillin", 'role': 'assistant'}]