Canada plans to bring in new warning labels on acetaminophen -- the key ingredient in Tylenol, Excedrin and other medications -- while government experts in the United States on Tuesday said the maximum dose should be reduced to avoid lethal overdoses.

Acetaminophen is one of the most widely used drugs in the U.S and Canada. Many patients find it easier on the stomach than other painkillers like ibuprofen and Aspirin, which can cause ulcers.

Unfortunately, acetaminophen is also the leading cause of liver failure in the U.S., sending 56,000 Americans to the emergency room annually.

The new labels for acetaminophen products in Canada will include warnings about liver toxicity, including specific information for people with serious kidney and liver disease and alcohol users, said Health Canada spokesperson Christelle Legault. The new labeling standard is scheduled to take effect in September.

Meanwhile, on Tuesday, a panel for the U.S. Food and Drug Administration endorsed lowering the maximum dose of over-the-counter acetaminophen.

FDA's experts voted 21-16 to lower the current maximum daily dose of non-prescription acetaminophen, which is four grams (4,000 milligrams), or eight pills a day of a medication such as Extra Strength Tylenol.

The group was not asked to recommend an alternative maximum daily dose.

The panel also voted 24-13 to limit the maximum single dose of the drug to 650 milligrams. The current single dose of Johnson & Johnson's Extra Strength Tylenol is 1,000 mg, or two tablets.

In a third vote, a majority of panellists said the 1,000-mg dose should only be available by prescription.

But panellists rejected a proposal to pull NyQuil, and other cold and cough medicines that combine acetaminophen with other drugs, off the market.

Although the FDA said patients often pair combination drugs, like NyQuil or Novartis' Theraflu, with pure acetaminophen treatments, like Tylenol, exposing themselves to unsafe levels of the drug, the panel said those medications play a minor role in acetaminophen overdoses, with only 10 per cent of acetaminophen-related deaths involving a cold and cough product.

The FDA is not obligated to follow the recommendations of its advisory panels, but it typically does so.

Health Canada officials are attending the ongoing FDA meetings to gain further information on acetaminophen.

"Information presented at these meeting will be taken into account in any Canadian regulatory decisions," said Legault.