title: Effect of rifampin on theophylline disposition.
abstract: The concentrations of theophylline from single 400-mg oral doses were evaluated both before and after 7 days of oral rifampin administration (600 mg/day) in six healthy, nonsmoking adults. The mean oral clearance of theophylline was significantly increased from 54.9 +/- 21.2 to 68.9 +/- 26.5 ml/h/kg. The elimination rate constant was significantly increased in five of the six subjects, with a mean increase of approximately 25%. Although intersubject variability was large, these data indicate the potential need to increase theophylline doses in some patients receiving rifampin.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D008657:Metabolic Clearance Rate; D012293:Rifampin / Q000494:pharmacology*; D013806:Theophylline / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*
chemical_list: D013806:Theophylline; D012293:Rifampin