N-Acetylcysteine: Difference between revisions
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===[[Acetaminophen (tylenol) toxicity]]=== | ===[[Acetaminophen (tylenol) toxicity]]=== | ||
====PO==== | ====PO==== | ||
*140mg/kg PO load | |||
*70mg/kg PO q4hr x17 doses additional; dilute to 5% soln | |||
====IV==== | ====IV==== | ||
*Loading dose: 150mg/kg in 100 mL D5W over 60min | |||
*Second (maintenance) dose: 50mg/kg in 250 mL D5W over 4hr | |||
*Third dose: 100mg/kg in 500 mL D5W over 16hr | |||
====Comments==== | ====Comments==== | ||
*Almost 100% effective if given <8 hr post-ingestion; less effective if 16-24 hr post-ingestion | |||
*May still be useful >24 hr post-ingestion, even with fulminant hepatic failure. Give NAC until LFTs improve (not until APAP level is 0) <ref>Keays R, Harrison PM, Wendon JA, et al. Intravenous acetylcysteine in paracetamol-induced fulminant hepatic failure: a prospective controlled trial. BMJ. 1991;303(6809):1026-1029. (Prospective randomized controlled trial; 50 patients)</ref> <ref>Harrison PM, Keays R, Bray GP, et al. Improved outcome of paracetamol-induced fulminant hepatic failure by late administration of N-acetylcysteine. Lancet. 1990;335(8705):1572- 1573. (Retrospective analysis; 100 patients)</ref> | |||
*Be aware NAC treatment may affect PT. May see a dose-dependent increase in PT following NAC in patients without hepatotoxicity. <ref>Wasserman GS, Garg U. Intravenous administration of Nacetylcysteine: interference with coagulopathy testing. Ann Emerg Med. 2004;44(5):546-547. (Letter)</ref> | |||
==Pediatric Dosing== | ==Pediatric Dosing== | ||
Revision as of 20:09, 28 January 2015
General
- Type:
- Dosage Forms:
- Common Trade Names: NAC;
Adult Dosing
Acetaminophen (tylenol) toxicity
PO
- 140mg/kg PO load
- 70mg/kg PO q4hr x17 doses additional; dilute to 5% soln
IV
- Loading dose: 150mg/kg in 100 mL D5W over 60min
- Second (maintenance) dose: 50mg/kg in 250 mL D5W over 4hr
- Third dose: 100mg/kg in 500 mL D5W over 16hr
Comments
- Almost 100% effective if given <8 hr post-ingestion; less effective if 16-24 hr post-ingestion
- May still be useful >24 hr post-ingestion, even with fulminant hepatic failure. Give NAC until LFTs improve (not until APAP level is 0) [1] [2]
- Be aware NAC treatment may affect PT. May see a dose-dependent increase in PT following NAC in patients without hepatotoxicity. [3]
Pediatric Dosing
Special Populations
- Pregnancy Rating:
- Both IV or oral NAC may be used in pregnant patients with Acetaminophen toxicity. [4]
- IV formulation may be preferred to increase fetal NAC concentrations
- Lactation:
- Renal Dosing
- Adult
- Pediatric
- Hepatic Dosing
- Adult
- Pediatric
Contraindications
- Allergy to class/drug
Adverse Reactions
Serious
- Anaphylactoid reaction but also associated with seizures, cerebral edema, & herniation. [5]
- Anaphylaxis responds to standard therapies and can usually restart NAC without safely without complications. [6]
Common
- sulfur-smell causes nausea and vomiting. Consider mixing with juice or soda, in a cup with a lid and straw
Pharmacology
- Half-life:
- Metabolism:
- Excretion:
- Mechanism of Action:
- Intravenous acetylcysteine is indicated for the treatment of acetaminophen overdose by preventing depletion of glutathione reserves.
See Also
Sources
- ↑ Keays R, Harrison PM, Wendon JA, et al. Intravenous acetylcysteine in paracetamol-induced fulminant hepatic failure: a prospective controlled trial. BMJ. 1991;303(6809):1026-1029. (Prospective randomized controlled trial; 50 patients)
- ↑ Harrison PM, Keays R, Bray GP, et al. Improved outcome of paracetamol-induced fulminant hepatic failure by late administration of N-acetylcysteine. Lancet. 1990;335(8705):1572- 1573. (Retrospective analysis; 100 patients)
- ↑ Wasserman GS, Garg U. Intravenous administration of Nacetylcysteine: interference with coagulopathy testing. Ann Emerg Med. 2004;44(5):546-547. (Letter)
- ↑ Heard KJ. Acetylcysteine for acetaminophen poisoning. N Eng J Med. 2008;359(3):285-292. (Review)
- ↑ http://journals.lww.com/em-news/Fulltext/2012/02000/Toxicology_Rounds__Lessons_from_the_Courtroom_.9.aspx
- ↑ Sandilands EA, Bateman DN. Adverse reactions associated with acetylcysteine. Clin Toxicol (Phila). 2009;47(2):81-88. (Systematic literature review)