title: Unsuspected caffeine toxicity complicating theophylline therapy.
abstract: A 58-year-old man with a history of alcoholic liver disease and chronic airflow obstruction presented with heart failure and acute bronchitis. Plasma methylxanthines were estimated as a guide to further theophylline therapy and serious caffeine accumulation was noted in the presence of a subtherapeutic concentration of theophylline. After 3 weeks on a caffeine-free diet theophylline and caffeine challenge tests were performed which demonstrated the ease with which caffeine could accumulate. The importance of caffeine accumulation during theophylline therapy is discussed.
mesh_terms: D001991:Bronchitis / Q000188:drug therapy; D002110:Caffeine / Q000097:blood / Q000506:poisoning*; D006207:Half-Life; D006801:Humans; D008108:Liver Diseases, Alcoholic / Q000150:complications; D008297:Male; D008875:Middle Aged; D013806:Theophylline / Q000097:blood / Q000627:therapeutic use*
chemical_list: D002110:Caffeine; D013806:Theophylline