Acetaminophen Toxicity Medication
- Author: Susan E Farrell, MD; Chief Editor: Asim Tarabar, MD more...
Medication Summary
Agents used in the treatment of acetaminophen (APAP) poisoning include oral activated charcoal (AC), oral or intravenous N -acetylcysteine (NAC), and antiemetics.
GI Decontaminants
Class Summary
Gastrointestinal (GI) decontamination with oral AC is selectively used in the emergency treatment of poisoning caused by some drugs and chemicals. The network of pores present in AC adsorbs 100-1000 mg of drug per gram of charcoal. AC does not dissolve in water.
Activated charcoal (Actidose, Char-Caps, EZ-Char, Kerr Insta-Char)
Activated charcoal is the drug of choice when gastric decontamination is being considered.
Antidote
Class Summary
An antidote provides substrate for conjugation with the toxic metabolite of APAP. Administer all doses of the antidote, as directed under the guidance of a regional poison control center. Shortened courses of NAC administration have been studied to be effective and preventative of liver toxicity in select patients with APAP overdose.[16]
N-acetylcysteine (Acetadote)
N-acetylcysteine (NAC) is the drug of choice for the prevention and treatment of APAP-induced hepatotoxicity. This agent is approved by the US Food and Drug Administration (FDA) for both oral and intravenous administration. For the maximum hepatoprotective effects, administer NAC within 8 hours of an acute APAP ingestion. When NAC is given orally, dilute this agent in chilled juice or cola to a 5% solution. NAC may be administered via nasogastric tube (NGT) if severe nausea threatens administration. Repeat the dose if vomiting occurs within 1 hour of oral administration. When administered intravenously, dilute NAC in 5% dextrose solution and infuse per the recommended intravenous protocol.
Antiemetics
Class Summary
Emesis is frequently associated with APAP toxicity and is a common adverse effect of both AC and oral NAC administration. For these reasons, antiemetic therapy is often necessary to facilitate the successful administration of oral NAC. NOTE: If persistent nausea or vomiting precludes oral NAC administration, NAC should be administered intravenously.Antiemetics that do not decrease gastric motility or significantly alter mental status are the drugs of choice; anticholinergic drugs such as prochlorperazine are not considered beneficial, in part because of their propensity to cause both of these adverse effects. Phenothiazines may also contribute to the potential toxicity associated with other anticholinergic drugs, if they are ingested in combination with APAP-containing formulations.
Metoclopramide (Reglan, Metozolv)
Metoclopramide functions as an antiemetic by blocking dopamine receptors in the chemoreceptor trigger zone of the central nervous system. This agent is of low cost and is generally considered an initial drug of choice for the treatment of nausea.
Ondansetron (Zofran, Zuplenz)
This agent is a more effective antiemetic, with less frequent adverse effects than metoclopramide.
US Food and Drug Administration. June 29-30, 2009: Joint meeting of the Drug Safety and Risk Management Advisory Committee with the Anesthetic and Life Support Drugs Advisory Committee and the Nonprescription Drugs Advisory Committee: meeting announcement. Available at http://www.fda.gov/AdvisoryCommittees/Calendar/ucm143083.htm. Accessed August 5, 2009.
US Food and Drug Administration. Organ-specific warnings: internal analgesic, antipyretic, and antirheumatic drug products for over-the-counter human use. Federal Register. 2009 Apr 29;74(81). Available at http://edocket.access.gpo.gov/2009/pdf/E9-9684.pdf. Accessed August 5, 2009.
US Food and Drug Administration. Acetaminophen information. Available at http://www.fda.gov/Drugs/DrugSafety/InformationbyDrugClass/ucm165107.htm. Accessed August 18, 2011.
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