Alcohol's role in Tylenol-related liver failure

From the AP:

Accidental poisonings from the nation's most popular pain reliever seem to be rising, making acetaminophen the leading cause of acute liver failure.

Use it correctly and acetaminophen, best known by the Tylenol brand, lives up to its reputation as one of the safest painkillers. It's taken by about 100 million people a year, and liver damage occurs in only a small fraction of users.

The article does not mention that the American Liver Foundation considers the use of ethanol to be an important risk factor for getting the liver failure from acetaminophen:

[R]ecent reports have emphasized the occurrence of unintentional or accidental hepatotoxicity, with liver failure and death in more than 20%, typically occurring in moderate to heavy alcohol users (1,2). In most of these reports the dosage of acetaminophen reported by the patient exceeded the 4 gm/24 hour limit recommended by the manufacturer, although some patients did report taking doses within this limit. A practical and safe dosage limit for acetaminophen, particularly for the alcohol users, has not been established, but is likely to be lower than previously thought.

The manufacturer has set the maximum dosage of acetaminophen at 4 grams per day. While acetaminophen is generally a safe and effective drug when taken at recommended doses, several medical authorities recommend that the maximum therapeutic dose be lowered for individuals who drink excessive amounts of alcohol.

Hyman J. Zimmerman, MD and Willis C. Maddrey. MD, in a review article on this subject concluded: "...it is our view that individuals that take more than 60 -grams a day of alcohol should take no more than 2 grams per day of acetaminophen"

Thanks to Mickey for this post.