<prompt> Drug not causing enzyme inhibition isPhenobarbitoneOmeprazoleDisulfiramDiltiazem  <response>: Ans. is a i.e., Phenobarbitone Drugs that induce microsomal enzymes Phenobarbitone Carbamezepine Phenytoin Omeprazole Rifampin Clofibrate Glucocorticoids Meprobamate Isoniazid Ritonavir Chloral hydrate Glutethimide Phenylbutazone Chronic alcohol intake Griseofulvin Cigarette smoking DDT Cyclophosphamide Drugs that inhibit drug metabolizing enzymes Allopurinol Diltiazem Omeprazole Amiodarone Erythromycin Propoxyphene Clarithromycin Isoniazid Chloramphenicol Cimetidine Phenylbutazone Quinidine Ketoconazole Metronidazole Itraconazole Disulfiram Ciprofloxacin Verapamil Sulfonamides MAO inhibitors 