ADELPHI, Md. (AP) — The makers of Tylenol, Excedrin and other medications on Monday tried to dissuade regulators from placing new restrictions on their popular painkillers, including possibly removing some of them from store shelves.

The Food and Drug Administration assembled more than 35 experts for a two-day meeting to discuss ways to prevent overdose with acetaminophen — the pain-relieving, fever-reducing ingredient in Tylenol and dozens of other prescription and over-the-counter medications.

Despite years of educational campaigns and other federal actions, acetaminophen is the leading cause of liver failure in the U.S., sending 56,000 people to the emergency room annually, according to the FDA.

The agency on Monday asked its experts to consider a range of options: adding a “black box” warning label to the products, lowering the drug dosage in some products, or pulling certain types of medications off the market.

The drugs that could be pulled off shelves are combination medications, such as Procter & Gamble’s NyQuil or Novartis’ Theraflu, which combine acetaminophen with other ingredients that treat cough and runny nose.

The FDA says patients often pair them with a pure acetaminophen medication, like Tylenol, exposing themselves to unsafe levels of the drug.

But the industry group that represents Johnson & Johnson, Wyeth and other companies defended the products Monday, saying they pose a relatively small risk to patients.

Only 10 percent of deaths linked to acetaminophen medications involved over-the-counter combination cold medications, according to the Consumer Healthcare Products Association.

The majority of deaths were caused by either single-ingredient drugs or prescription strength combination drugs like Endo Pharmaceuticals Holdings Corp.’s Percocet, which combines oxycodone and acetaminophen.

“We believe there is a clear health benefit of over-the-counter combination products containing acetaminophen,” said Linda Suydam, the group’s president.

The FDA is not required to follow the advice of its panels, though it usually does. The panel vote is scheduled for Tuesday afternoon.

Manufacturers could lose hundreds of millions of dollars in sales if combination drugs are pulled from the market. Total sales of all acetaminophen drugs reached $2.6 billion last year, with 80 percent of the market comprised of over-the-counter products.

Tylenol-maker Johnson & Johnson also pushed back against a proposal to lower the maximum daily dose of acetaminophen, which is currently 4 grams daily, or eight pills of a medication like Extra Strength Tylenol.

While taking more than 4 grams per day can cause liver injury, J&J; argued that taking the exact dose is proven to treat osteoarthritis pain.

J&J; also warned panelists that any new restrictions on acetaminophen would force patients to switch to nonsteroidal anti-inflammatory drugs, which carry risks of gastrointestinal bleeding and sometimes fatal kidney injury.

“When switching occurs, the risk of death increases,” said Dr. Kenneth Rothman, a consultant for J&J.; According to figures from Rothman, a 30 percent switch away from acetaminophen would result in an additional 5,000 deaths per year.

Top-sellers in the anti-inflammatory drug market include Bayer AG’s aspirin and Wyeth’s Advil.

A Wyeth executive told panelists there is no evidence that the reduced use of acetaminophen would cause more negative side effects with their drug.

“There are major flaws in their arguments that are not born out in real world experience,” said Dr. Paul Desjardins, a vice president with Wyeth.

Desjardins noted that the U.K. has put tighter safety measures in place for acetaminophen without causing increased problems with Advil and other nonsteroidal anti-inflammatory drugs.

For its part, the FDA has made clear it will not play king-maker in the market for over-the-counter medications. The agency says its only goal is to reduce liver injury, “not to decrease appropriate acetaminophen use or to drive people to use NSAIDS instead.”