title: Pharmacokinetics of extended relief vs regular release Tylenol in simulated human overdose.
abstract: BACKGROUND
  The purpose of this trial was to compare the pharmacokinetics of the two available acetaminophen dosage forms in simulated human overdose.
  
  
  METHODS
  Ten healthy volunteers received acetaminophen, 75 mg/kg orally, either as the regular release or extended relief formulation in a random, crossover fashion. Blood samples were analyzed using a TDx assay and a best fit correlation of data points was determined by PCNONLIN.
  
  
  RESULTS
  The area under the curves for extended relief acetaminophen and regular release acetaminophen were 426 mg h/L and 432 mg h/L, respectively (p = 0.768). The mean half times for extended relief acetaminophen and regular release acetaminophen were 4.02 h and 2.56 h, respectively (p < 0.001). The mean maximum serum acetaminophen concentrations were 62.6 mg/L (414.4 mmol/L:) and 94.3 mg/L (624.3 mmol/L) for extended relief acetaminophen and regular release acetaminophen, respectively (p < 0.001) and the mean time to maximum serum acetaminophen concentrations were 0.87 h and 0.75 h for extended relief acetaminophen and regular release acetaminophen, respectively (p = 0.508).
  
  
  CONCLUSIONS
  Although the formulations appear to have equal bioavailability, their half-lives and peak concentrations were significantly different. Further study is required to determine whether these differences affect the assessment and management of poisoned patients.
authors.affiliation: New York City Poison Control Center, Bellevue Hospital Center New York, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Stork
authors.forename: S
authors.initials: S
authors.lastname: Rees
authors.forename: M A
authors.initials: MA
authors.lastname: Howland
authors.forename: L
authors.initials: L
authors.lastname: Kaplan
authors.forename: L
authors.initials: L
authors.lastname: Goldfrank
authors.forename: R S
authors.initials: RS
authors.lastname: Hoffman
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000506:poisoning; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000506:poisoning; D001682:Biological Availability; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D062787:Drug Overdose; D005260:Female; D006801:Humans; D008297:Male
chemical_list: D018712:Analgesics, Non-Narcotic; D003692:Delayed-Action Preparations; D000082:Acetaminophen