Safety alert: Too much of a good thing?

You might believe that acetaminophen, the aspirin-free pain reliever found in Tylenol, is one of the safest painkillers on the market. And used properly, it is.

But acetaminophen is the leading cause of acute liver failure in the U.S., because taking just slightly more than the maximum recommended dose for a few days can be toxic, even deadly. Overdoses are common for two reasons:

• The drug's reputation for safety might offer false reassurance that people can disregard dose recommendations.
• Acetaminophen is included in dozens of products; it's used alone to treat back pain or headache, for example, or combined with other ingredients to ease insomnia, coughs, and cold symptoms. Many people unknowingly get larger doses when they treat multiple health problems with more than one product that contains acetaminophen.

In June, a Food and Drug Administration advisory committee proposed lowering the maximum single adult dose for over-the-counter products from 1,000 milligrams to 650 mg and the maximum daily dose to less than 4,000 mg. The advisory committee also recommended either eliminating prescription acetaminophen combination products or labeling them with black-box warnings about the risk of liver damage.

Several products under the Tylenol brand name contain acetaminophen. Some other common products with the ingredient are:

• Backaid Maximum Strength Back Relief
• Benadryl Allergy and Sinus Headache Caplets
• Contac Day or Night Cold/Flu Caplets
• DayQuil Cold & Flu
• Excedrin (all products)
• Midol Menstrual Complete and Midol Teen Formula
• Nyquil Cold & Flu Relief, Nyquil Sinus
• Pamprin Multi-Symptom and Pamprin Max
• Sudafed (assorted products)
• Theraflu Packets Severe Cold & Cough
• Triaminic Cough and Fever

Read the ingredients list of all products to see if they contain acetaminophen, stick to recommended doses, and avoid acetaminophen if you have liver disease or drink alcohol heavily. If you regularly take the drug, watch for signs of liver damage: dark urine, pale stools, right-upper abdominal pain, and a yellowish tinge in the whites of eyes.