title: The [14C]-aminopyrine breath test. A comparison of different forms of analysis.
abstract: 1 Following ingestion of [14C]-aminopyrine, breath 14CO2 data were analysed from normal individuals, patients with hepatic disease, epileptics receiving anticonvulsant therapy and volunteers before and after treatment with glutethimide. 2 The 'standard' 2 h [14C]-aminopyrine breath test discriminated successfully between the main groups but failed to detect the change in microsomal enzyme function produced by glutethimide. 3 A 'modified' form of the 2 h breath test calculated from the area under the breath specific activity curve detected the increase in demethylation following glutethimide. 4 The breath elimination constant (Kb) derived from the breath 14CO2 disappearance curve was as sensitive as the 'modified' 2 h breath test and was simpler to compute. 5 Glutethimide 500 mg/day for 14 days resulted in a 42% increase in the metabolic clearance of antipyrine and a 26% increase in demethylation of [14C]-aminopyrine.
mesh_terms: D000632:Aminopyrine / Q000378:metabolism; D001944:Breath Tests; D002245:Carbon Dioxide / Q000378:metabolism; D004827:Epilepsy / Q000378:metabolism; D005937:Glucaric Acid / Q000652:urine; D005984:Glutethimide / Q000494:pharmacology; D006801:Humans; D008107:Liver Diseases / Q000378:metabolism; D010672:Phenytoin / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000632:Aminopyrine; D002245:Carbon Dioxide; D010672:Phenytoin; D005984:Glutethimide; D005937:Glucaric Acid