Medical experts on Tuesday recommended new limits on a key ingredient in Tylenol and a host of cough medicines and painkillers that could alter how patients treat common colds, headaches and severe pain.

More than 30 doctors, pharmacists and researchers recommended a range of options to help reduce liver injury associated with acetaminophen, a pain reliever and the most commonly prescribed drug in the U.S. The options, which range from putting liver injury warnings on drug labels to pulling medicines off the market, would have sweeping effects for companies, doctors and patients if implemented.

"Whatever we do on any of these options, it will really affect the whole health care system," said Gerald Dal Pan, director of the FDA's office of drug surveillance.

The committee of experts recommended the FDA lower dosing levels of acetaminophen, saying large doses makes it easy for patients to accidentally overdose and suffer either liver injury or death. The panel also suggested that large doses of Tylenol be available by prescription only. Those changes would make it harder for some patients, particularly the elderly and others who suffer from chronic pain, to get Tylenol.

The recommendation to pull certain prescription drug products containing acetaminophen from the market would affect a host of currently approved prescription products, including Abbott Laboratories (ABT) Vicodin, Johnson & Johnson's (JNJ) Ultracet and Endo Pharmaceuticals Holdings Inc.'s (ENDP) Percocet. The recommendation could also affect more than 240 drug applications that are currently under FDA review.

Acetaminophen is an ingredient found in over-the-counter painkillers such as Excedrin and Tylenol, and a host of cough medicines like NyQuil and Theraflu. The panel voted against pulling over-the-counter products that combine acetaminophen with other ingredients, citing data showing liver damage is most frequent in prescription products that include the drug.

About 100 people die annually from accidentally overdosing on the drug, though the FDA says it is safe if taken at recommended levels. Part of the problem with dealing with liver injuries associated with acetaminophen is the drug's prevalence, the FDA and panel members said. Often patients don't realize they are taking an over-the-counter product and a prescription product at the same time that contain the ingredient.

While the panel didn't always favor one recommendation over another, two proposals were well received. Thirty six of 37 panel members said prescription drug products containing acetaminophen should include strong warnings about the drug's potential to cause liver injury.

The same split of panel members said only one concentration of over-the-counter cold medicines should be available, citing concerns about liver damage in children. Products such as Theraflu and Nyquil could be affected by such a proposal.

Over-the-counter cold medicines have been under attack in the last 10 years, usually in connection with decongestants containing chemicals that were linked to strokes in women and children.

Drug makers changed their decongestant ingredients, and in 2007, manufacturers voluntarily withdrew cough and cold medicines aimed at kids under two years old. Then last year, the FDA, under pressure from consumer advocates and pediatricians, recommended that children under six not be given over the counter cold and cough medicines. The leader of the movement to limit cold-medicine usage in children was then-Baltimore City health director Joshua Sharfstein. He is now deputy commissioner of the FDA.

-Alicia Mundy contributed to this report.

-By Jared A. Favole, Dow Jones Newswires; 202-862-9207; jared.favole@dowjones.com