<prompt> In theophylline metabolism, drug interactions Occur with all Except:CimetidinePhenobarbitoneRifamipineTetracyclines  <response>: Phenobarbitone, rifampin enhance theophylline metabolism Cimetidine inhibits theophylline metabolism ESSENTIALS OF MEDICAL PHARMACOLOGY 7TH EDITION KD TRIPATHI Page No:226,227 