title: Effect of delayed activated charcoal on acetaminophen concentration after simulated overdose of oxycodone and acetaminophen.
abstract: OBJECTIVE
  To determine the effect of activated charcoal (AC) on acetaminophen (APAP) absorption kinetics when administered at 1, 2, or 3 h after combined oral overdose with oxycodone.
  
  
  METHODS
  IRB-approved, prospective cross-over study of nine healthy human volunteers ingesting 5 g of APAP + 0.5 mg/kg of oxycodone on each of four study days. On the control day, subjects received no AC. On the remaining study days, subjects ingested 50 g of AC at 1, 2, or 3 h after drug ingestion. We measured serum APAP concentration hourly from 0 through 8 h and compared basic non-compartmental pharmacokinetic parameters.
  
  
  RESULTS
  Compared to the control, AC reduced area under the curve by 43% when given at 1 h (p < 0.0001), 22% when given at 2 h (p = 0.02), and 15% when given at 3 h (p = 0.26). AC at 1 h resulted in a 25% reduction in peak APAP concentration from 48.6 to 36.3 mcg/mL (p = 0.012) with no significant difference when given at 2 or 3 h. There was no significant difference in elimination half-life among the four study days.
  
  
  CONCLUSIONS
  The effect of AC rapidly declines between 1 and 3 h after combined oral overdose of APAP and oxycodone. AC is unlikely to be beneficial at or beyond 2 h after an overdose of acetaminophen and oxycodone.
authors.affiliation: Washington University, St. Louis, MO, USA. mullinsm@wusm.wustl.edu
authors.forename: Michael
authors.initials: M
authors.lastname: Mullins
authors.forename: Brian R
authors.initials: BR
authors.lastname: Froelke
authors.forename: Maria Regina-Paz
authors.initials: MR
authors.lastname: Rivera
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics / Q000506:poisoning*; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics / Q000506:poisoning*; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000506:poisoning*; D019540:Area Under Curve; D002606:Charcoal / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004338:Drug Combinations; D062787:Drug Overdose / Q000628:therapy; D006207:Half-Life; D006801:Humans; D007408:Intestinal Absorption; D008954:Models, Biological; D010098:Oxycodone / Q000008:administration & dosage / Q000506:poisoning*; D011446:Prospective Studies
chemical_list: D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D004338:Drug Combinations; D002606:Charcoal; D000082:Acetaminophen; D010098:Oxycodone