FDA Warns of Acetaminophen in Prescription Pain Drugs
Percocet, Vicodin, Other Combination Pills to Get Dose Limit, "Black Box' Warning
By Daniel J. DeNoon
WebMD Health News
Reviewed by Laura J. Martin, MD
man pouring prescription pills into hand

Jan. 13, 2011 - The FDA is warning about the dangers of acetaminophen in popular prescription pain drugs, but did it go far enough?

Acetaminophen, the active ingredient in Tylenol, is found in a wide range of over-the-counter and prescription drugs. At normal doses, when not taken with alcohol, acetaminophen is a very safe drug. But it's easy to take too much -- a big mistake that can lead to serious liver damage.

Damage can occur when a person with normal liver function takes 4,000 milligrams or more of acetaminophen in a single day. That's easy to do if a person is taking several medications and is not aware that each contains a powerful dose of acetaminophen.

The result: some 56,000 emergency-room visits, 26,000 hospitalizations, and 458 deaths a year. Acetaminophen is the leading cause of acute liver failure in the U.S., causing some 1,600 cases a year.

Now the FDA is taking two steps. Both affect only prescription drugs. The FDA action does not affect any medication sold over the counter. The FDA say that in three years:

    * Prescription pain drugs can contain no more than 325 milligrams of acetaminophen per pill or spoonful. Currently, some of these drugs contain as much as 750 milligrams of acetaminophen.
    * Prescription pain drugs will carry the FDA's strongest "black box" warning label. That label will warn of the risk of serious liver injury.

Nearly all the prescription drugs affected by the FDA action combine acetaminophen with an opioid. Popular brand names include Vicodin, Percocet, Lortab, Fioricet, and Roxicet.

Currently, the labels that pharmacies put on these prescription drugs make it hard to tell how much acetaminophen a patient is getting. Often acetaminophen is given the cryptic abbreviation "APAP," which even some doctors have a hard time interpreting.

"When taken as directed, acetaminophen is a very safe product. Our goal is to make it even safer," Sandra Kweder, deputy director of the FDA's office of new drugs, said at a news teleconference.

The FDA action comes a year and a half after an FDA advisory committee voted for much stronger action. The panel voted 20-17 to ban all combination acetaminophen/opioid pain pills. And it voted 24-13 to limit the maximum acetaminophen dosage in over-the-counter products -- an action Kweder says the FDA isn't yet ready to take.

"We have not made a decision about what action to take with over-the-counter products. We continue to consider our options," Kweder said.

Over-the-counter "extra strength" formulations of cold and cough remedies contain 500 milligrams of acetaminophen per pill or spoonful (or even more in extended-release formulations).

"It is extremely poor judgment on the part of the FDA to have failed to take action concerning this major source of acetaminophen consumption and, consequently, acetaminophen toxicity," Sidney Wolfe, MD, director of Public Citizen's Health Research Group, says in a news release.