The U.S. Food and Drug Administration said on Tuesday that over-the-counter pain relievers such as Tylenol and Advil will now be required to carry bolder and more extensive label warnings about the risk of liver damage and stomach bleeding within a year.

Matthew Ray Holman, PhD, the FDA's deputy director for the Division of Nonprescription Regulation Development said the new warnings are required "to raise consumer awareness about the potential for liver damage when using acetaminophen (such as Tylenol) and the potential for stomach bleeding when using [a nonsteroidal anti-inflammatory drug]."

He added that, "The regulations affect much of the U.S. population because over-the-counter pain relievers and fever reducers are some of the most commonly used drugs."

Nonsteroidal anti-inflammatory drug or NSAIDs are painkillers which include aspirin, ibuprofen, naproxen, and ketoprofen. Products that contain acetaminophen, such as Johnson & Johnson's Tylenol will be required to carry a prominent package warning about the risk of severe liver damage in cases where people took too much of the drug. The labels must bear the medication's name "prominently" and in highlighted text on the front.

The warning section would say, "Severe liver damage may occur if you take more than the maximum number of daily dosage units in 24 hours, if you take with other drugs containing acetaminophen, and if you take three or more alcoholic drinks every day while using this product."

While Wyeth's Advil and Johnson & Johnson's Motrin, will carry bold warnings about the risk of stomach bleeding, the FDA said. In the case of NSAIDs, "Every over-the-counter product containing an NSAID will have to include a bolded stomach bleeding warning at the beginning of the warnings section in the drug facts panel," Holman said.

This warning must read: "This product contains a nonsteroidal anti-inflammatory drug (NSAID), which may cause severe stomach bleeding. The chance is higher if you are age 60 or older, have had stomach ulcers or bleeding problems, take a blood thinning or steroid drug, take other drugs containing prescription or nonprescription NSAIDs, have three or more alcoholic drinks every day using this product, take more or for a longer time than directed."

"We believe the new labeling requirements will add information concerning severe adverse effects of over-the-counter pain relievers and fever reducers that many consumers may not be aware of," said Holman.

The statement, "see new warnings information," must be included on front labels of products introduced within one year from July 28, 2009.

Holman said some companies have already revised their products' packaging to add the new warnings, adding that all companies concerned must change their packaging by next April.

Johnson & Johnson's McNeil Consumer Healthcare unit, which makes Tylenol and Motrin as well as St. Joseph Aspirin, said in a statement, it would make the labeling changes as requested.

Wyeth spokesman Doug Petkus and Bayer spokeswoman Anne Coiley also said their companies would comply with FDA's order.