Bottles of Tylenol sold in the U.S. will soon bear red warnings alerting users to the potentially fatal risks of taking too much of the popular pain reliever. The unusual step, disclosed by the company that makes Tylenol, comes amid a growing number of lawsuits and pressure from the federal government that could have widespread ramifications for a medicine taken by millions of people every day.

Johnson & Johnson says the warning will appear on the cap of each new bottle of Extra Strength Tylenol sold in the U.S. in October and on most other Tylenol bottles in coming months. The warning will make it explicitly clear that the over-the-counter drug contains acetaminophen, a pain-relieving ingredient that's the nation's leading cause of sudden liver failure. The new cap is designed to grab the attention of people who don't read warnings that already appear in the fine print on the product's label, according to company executives.

"We're always looking for ways to better communicate information to patients and consumers," says Dr. Edwin Kuffner, vice president of McNeil Consumer Healthcare, the Johnson & Johnson unit that makes Tylenol.

Overdoses from acetaminophen send 55,000 to 80,000 people to the emergency room in the U.S. each year and kill at least 500, according the Centers for Disease Control and Prevention and the Food and Drug Administration. Acetaminophen can be found in more than 600 common over-the-counter products used by nearly one in four American adults every week, including household brands like Nyquil cold formula, Excedrin pain tablets and Sudafed sinus pills.

--ASSOCIATED PRESS