title: The human metabolism of caffeine to theophylline.
abstract: Theophylline peak plasma concentration of over 170 ng/ml average was observed when 300 mg of caffeine, equivalent to 2-3 cups of coffee, was administered to humans. This peak level was not observed until at least 7 hr post administration. Accumulation of caffeine, with its subsequent metabolism to theophylline, in patients, who consume average quantities of caffeine-containing beverages relative to those patients who avoid such drinks could interfere with bioavailability studies in normal volunteers. However, it may account for only a small portion of the variable clinical effects associated with aminophylline administration.
mesh_terms: D000493:Allopurinol / Q000494:pharmacology; D000628:Aminophylline / Q000378:metabolism; D001682:Biological Availability; D002110:Caffeine / Q000378:metabolism*; D006801:Humans; D008297:Male; D013806:Theophylline / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000628:Aminophylline; D002110:Caffeine; D000493:Allopurinol; D013806:Theophylline