Tylenol (acetaminophen) has been in the news lately. Did you know that acetaminophen appears not once, but twice in the top 10 list the American Association of Poison Control Centers of substances linked to the highest number of fatalities?  It has appeared at #4 as “acetaminophen in combination” and at #8 as “acetaminophen alone."

Many prescription medications such as Vicodin, Darvocet and Percocet contain acetaminophen.   Dozens of over-the-counter remedies also contain “hidden” acetaminophen.  Alcohol consumption increases the risk for toxicity to individuals taking acetaminophen.  Concern for accidental overdose has moved the FDA to direct changes in labeling of these drugs that include new warnings which will begin to appear in 2010. 
    
Daily ingestion of more than 4 grams of this drug  (equivalent of  8 “extras strength” tablets) can be toxic due to the production of the metabolite N-acetyl-p-benzoquinone imine that binds with liver proteins causing liver injury.

It is very important to include these cautions in your patient teaching whenever you are sending a patient home on a product containing acetaminophen or recommending its use for pain or fever. Teach patients to read labels and look for acetaminophen to avoid accidental overdose and to refrain from drinking alcohol while taking any acetaminophen product.

In the ED, diagnosis of an acetaminophen overdose includes identifying what the patient ingested and in what quantities, determination of the severity of the overdose and the likely extent of the toxicity.  Lab draws will be ordered to determine acetaminophen levels and a toxicology screen including alcohol levels will help complete the picture.  The physician may also order other tests such as serum electrolytes, glucose, creatinine, BUN, amylase and others.

Immediate treatment is aimed at preventing or decreasing the absorption of the acetaminophen.  If it is determined that ingestion was within a 2 hour period, activated charcoal, which binds with the drug, is administered. For patients at risk for hepatotoxicity, acetylcysteine will be ordered either orally, or intravenously.  Since the oral preparation smells like rotten eggs, creative nursing interventions are employed to enable the patient to take the medication --such as finding the right liquid to mix it with.  In some cases, a nasogastric tube may be required to be inserted for successful administration of this drug. IV administration may be indicated for some patients including pregnant woman.