title: Increased serum theophylline clearance with orally administered activated charcoal.
abstract: The purpose of this study was to determine whether the oral administration of activated charcoal would increase the clearance of theophylline. Seven normal subjects received aminophylline intravenously (8 mg/kg) on 2 separate days. On Day 1 at 2-h intervals starting immediately after the completion of the aminophylline infusion, subjects ingested 4 doses of a slurry of activated charcoal (30 g each). On Day 2 they received no charcoal. The order of the days the subjects received charcoal or no charcoal was randomized. Plasma theophylline levels were determined by an enzyme immunoassay (Syva) every 2 h after the completion of the intravenous infusion. The theophylline half-life was reduced with charcoal from 10.2 to 4.6 h (p less than 0.001), and clearance increased from 35.6 to 72.6 ml/kg/h (p less than 0.001). In a patient with an initial serum theophylline concentration of 31.0 micrograms/ml and signs of toxicity (arrhythmias and seizures), the administration of charcoal (4 doses of 30 g every 2 h) reduced the half-life from 34.4 to 5.7 h concomitant with rapid resolution of signs of toxicity. We conclude that orally administered activated charcoal significantly enhances the clearance of theophylline and offers a new therapeutic modality in the treatment of theophylline toxicity.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D002606:Charcoal / Q000008:administration & dosage / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D013806:Theophylline / Q000008:administration & dosage / Q000009:adverse effects / Q000378:metabolism*
chemical_list: D002606:Charcoal; D013806:Theophylline