These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The value of plasma acetaminophen half-life in antidote-treated acetaminophen overdosage.
    Author: Schiødt FV, Ott P, Christensen E, Bondesen S.
    Journal: Clin Pharmacol Ther; 2002 Apr; 71(4):221-5. PubMed ID: 11956504.
    Abstract:
    BACKGROUND: A plasma acetaminophen (INN, paracetamol) half-life of more than 4 hours has been correlated with hepatotoxicity in acetaminophen overdosing not treated with an antidote. Acetaminophen half-life has not been studied in patients receiving the antidote N -acetylcysteine. METHODS: Prospectively, 112 patients with acetaminophen overdosage all treated with intravenous N -acetylcysteine were studied. A minimum of 2 plasma acetaminophen values >20 micromol/L were available for calculation of acetaminophen half-life, assuming first-order kinetics. RESULTS: Overall, the median acetaminophen half-life was 5.4 hours (range, 0.8-119.7 hours). Forty-eight patients with no or little hepatotoxicity (ALT <1000 U/L), 43 patients with hepatotoxicity without encephalopathy, and 21 patients with hepatotoxicity and encephalopathy had acetaminophen half-lives of 3.0 hours (range, 0.8-10.0 hours), 6.4 hours (range, 1.3-19.0 hours), and 18.4 hours (range, 4.6-119.7 hours), respectively (P <.001). An acetaminophen half-life >4 hours was observed in 71 patients, and 56 of those (79%) had hepatotoxicity (ALT >1000 U/L or coma). Thirty-three of 41 patients (81%) with an acetaminophen half-life <4 hours had no hepatotoxicity. A receiver operating characteristic curve analysis showed that an acetaminophen half-life of 5.5 hours provided better discrimination; hepatotoxicity was therefore present in 49 of 54 patients with an acetaminophen half-life >5.5 hours (positive predictive value, 91%) and in 15 of 58 patients with a half-life below this limit (negative predictive value, 74%) despite treatment with N -acetylcysteine. CONCLUSIONS: Acetaminophen half-life correlates well with the degree of liver damage in patients treated with the antidote N-acetylcysteine. Longer half-lives reflect a greater toxic effect on the liver.
    [Abstract] [Full Text] [Related] [New Search]