<prompt> Which is Cytochrome P450 inhibitor?KetoconazoleRifampicinPhenytoinINH  <response>: Impoant microsomal enzyme inhibitors are: Valproate Ketoconazole Cimetidine Ciprofloxacin Erythromycin Isoniazid Ref: K.D.T 6th Ed Page 27,28. 