Researchers have reported in the December 2005 issues of Hepatology, that acetaminophen, the most widely used analgesic in the US, an active ingredient in Tylenol and other popular prescription and over-the-counter (OTC) medicines, is the most common cause of acute liver failure (ALF), which can be fatal.

"We were surprised that the incidence of acetaminophen ALF has risen in the US over the years," says lead researcher Dr Anne Larson (University of Washington Medical Center, Seattle). "This was rather alarming, particularly since half the cases were accidental (unintentional)," she states.

Key findings in the report…

~ ALF cases due to acetaminophen have nearly doubled in the past six years compared to the 1980s where there was no mention of acetaminophen as a cause of ALF.

~ Acetaminophen intoxication that lead to ALF, comprised 28% of all ALF cases in 1998, but by 2003, had climbed to an alarming 51%

~ People with liver disease are at risk of ALF even if they take only prescribed amounts of acetaminophen.

~Half of the cases were determined to be “accidental overdoses.” This rate was much higher in the U.S. than abroad where acetaminophen is more closely regulated.

~Nearly as many cases were the result of suicide, and the remaining 8% were of unknown intent.

~Patients with chronic pain were particularly susceptible to accidental overdose, especially those suffering from fibromyalgia, rheumatologic pain, or orthopedic pain.

~ALF occurred with as little as seven days after excessive ingestion with no signs of chronic injury or discomfort. The “excessive ingestion” could be as little as .75 mg/day to produce these devastating results.

~Half of the cases used OTC products like Tylenol and other popular analgesics.

What is Acetaminophen? Acetaminophen is one of the most common analgesic medications found in households. It is used for the treatment of pain and to lower fever.

Over many years, it has been used countless times by many people and has long been considered to be a safe and effective medication.

However, if taken in excess amounts (overdose, whether on purpose or by accident), acetaminophen can cause life-threatening illness.

Acetaminophen in Tylenol and Many Other Popular Analgesics Acetaminophen is the active ingredient in Tylenol. It is also found in many other over-the-counter medications you can buy at the drug store and in prescription drugs your doctor prescribes: Common names include Actifed, Alka-Seltzer Plus, Benadryl, Butalbital, Co-Gesic, Contac, Darvocet, Excedrin, Fioricet, Lortab, Midrin, Norco, Percocet, Robitussin, Sedapap, Sinutab, Sudafed, TheraFlu, Unisom With Pain, Vick's Nyquil and DayQuil, Vicodin, Wygesic, and Zydone.

Potentially Irreparable Liver Damage… Acetaminophen in overdose can seriously damage the liver. If the damage is severe, a liver transplant may be necessary in order to save a life.

Antidote… The antidote to acetaminophen overdose is N-acetylcysteine (NAC). It is most effective when given within 8 hours of ingesting acetaminophen. Indeed, NAC can prevent liver failure if given early enough. For this reason, it is absolutely necessary that acetaminophen poisoning be recognized, diagnosed, and treated as early as possible.

Symptoms… ~ Nausea ~ Vomiting ~ Not feeling well ~ Not able to eat or poor appetite ~ Abdominal pain

Preventive Measures.

Always securely close acetaminophen containers and use child-proof bottles. Keep all medication out of the reach of children and securely locked up.

Know the correct dose of acetaminophen and the amount of acetaminophen in the preparation you are using. If taken in recommended doses, there is no risk of poisoning from acetaminophen.

Never mix different medications if both medications contain acetaminophen, except if instructed to do so by your doctor. For example, acetaminophen with codeine and cold medicine containing acetaminophen should not be taken together. Read product labels. They clearly indicate the contents.

If you or a family member is depressed or suicidal, remove all medications and dangerous substances from the house and seek medical attention immediately.

If you are unsure about how and when to take pain medications, ask your doctor for a plan. Write this plan down and follow it.

When you are given a new medication, always make sure the doctor knows all of the medication and supplements that you are taking, both prescribed and non-prescribed. The easiest way to do this is to keep a written list of medications and supplements and go over it with your doctor.

Do not take acetaminophen if you consume more than 3 alcoholic beverages per day. Indeed, if you consume more than 3 alcoholic beverages per day, you should consult a physician before taking any pain medications and to discuss ways to reduce your alcohol consumption.

References:

Larson A, Polson J, Fontana RJ, et al. Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study. Hepatology 2005; 42:1364-1372.

O'Grady JG. Broadening the view of acetaminophen hepatotoxicity. Hepatology 2005; 42:1252-1254.

Hawton K, Simkin S, Deeks J, et al. UK legislation on analgesic packs: before and after study of long-term effect on poisonings. BMJ 2004; 329:1076.