CYP–450 inducers are:: (A) Cimetidine, (B) Ketoconazole, (C) Phenobarbitone, (D) Theophylline
Answer is C. - P450 inducers

   Phenobarbitone
   Rifampicin
   Phenytoin
   Chloral hydrate
   Griseofulvin
   Phenylbutazone
   DDT
   Chronic alcohol ingestion

-          Cimetidine and Ketoconazole inhibits metabolizing enzymes.