title: Effect of the surface area of activated charcoal on theophylline clearance.
abstract: The effect of the surface area of activated charcoal on theophylline clearance was studied. Eight fasting, healthy men received intravenous infusions of either aminophylline (6 mg/kg, N = 3) or theophylline (5 mg/kg, N = 5) over 1 hour followed by either 5 Gm standard activated charcoal every 2 hours, 20 Gm every 2 hours, or 5 Gm PX-21 activated charcoal (with 3.6 times the surface area) every 2 hours. Theophylline t 1/2 and AUC with each regimen were respectively 6.3 +/- 0.5 (S.E.) hours and 88.9 +/- 8.4 mg/liter X hr with 5 Gm standard activated charcoal, 5.3 +/- 0.3 hours and 75.4 +/- 4.9 mg/liter X hr with 5 Gm PX-21, and 4.9 +/- 0.2 hours and 67.7 +/- 3.6 mg/liter X hr with 20 Gm standard activated charcoal. There was a relationship between the activated charcoal surface area and the reduction in theophylline t 1/2 and AUC. We conclude that the clearance of theophylline is related to the surface area of activated charcoal administered and that PX-21 may be a more potent activated charcoal product for enhancing theophylline removal.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D002606:Charcoal / Q000008:administration & dosage*; D004347:Drug Interactions; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D008657:Metabolic Clearance Rate / Q000187:drug effects; D013499:Surface Properties; D013806:Theophylline / Q000097:blood / Q000378:metabolism*
chemical_list: D002606:Charcoal; D013806:Theophylline