FDA wants less acetaminophen in prescription painkillers

The U.S. Food and Drug Administration announced on Jan 13 that drug makers are required to use no more than 325 milligrams of acetaminophen or otherwise known as Paracetamol per tablet, capsule or other dosage unit.

The FDA Drug Safety and Risj Management Advisory Committee with Anesthetic and Life Support Drugs Advisory Committee and Nonprescription Drugs Advisory Committee earlier recommended the agency to strengthen the safety of prescription drugs containing acetaminophen such as Percocet and Vicodin because overdosing these prescription drugs has been linked with acute liver failure and deaths.

The new rule does not apply to those over-the-counter painkillers containing acetaminophen like Tylenol. The FDA said its review on the safety of OTC products is ongoing and a new rule will be made separately.

The FDA said in a safety announcement, a boxed warning is additionally required to highlight the potential risk of severe liver injury and a warning on the label is mandated to alert patients to the risk of allergic reactions caused potentially by acetaminophen-containing prescription drugs.

"FDA is taking this action to make prescription combination pain medications containing acetaminophen safer for patients to use," said Sandra Kweder, M.D., deputy director of the Office of New Drugs in FDA's Center for Drug Evaluation and Research. 

"Overdose from prescription combination products containing acetaminophen account for nearly half of all cases of acetaminophen-related liver failure in the United States; many of which result in liver transplant or death."

Media reports say drug makers are given three years to reformulate their products.

FDA advice for patients

The FDA says patients should not discontinue taking prescription painkillers unless they are advised by heath care professionals to do so.

However, caution needs to be exercised. Patients should not take more than one medicine containing acetaminophen at any time, should not take more of an acetaminophen-containing drug than indicated, and should not drink alcohol, which can cause injury to the liver, the FDA says. 

When a patient takes more acetaminophen than directed or experiences allergic reactions, he should seek medical attention immediately.

Still, the FDA advises on its website that acetaminophen-containing prescription drugs are safe and effective when used as directed although all medications carry some risks.

Acetaminophen and liver injury

According to the FDA, acetaminophen is the leading cause of acute liver failure in the United States during 1998 to 2003 and 48 percent of the cases were due to accidental drug overdose.  Overall, 1600 cases of acute liver failure are reported each year and acetaminophen-induced liver failure is the type that is most commonly seen.

Each year during 1990 to 1998, acetaminophen containing medications resulted in 56,000 emergency room visits, 26,000 hospitalizations and 458 deaths, according to the Centers for Disease Control and Prevention.

Side effects of acetaminophen

Side effects are not commonly associated with use of therapeutic doses of acetaminophen.  But even therapeutic dose in some cases could lead to some adverse effects in certain patients, according to studies.

When adverse effects do occur such as signs of an allergic reaction like hives, difficulty breathing, swelling of the face, lips, tongue or throat, patients should seek immediate medical attention.

Patients who experience serious symptoms like low fever with nausea, abdominal pain, and loss of appetite, dark urine, clay-colored stools or jaundice should stop taking acetaminophen-containing products and seek medical attention immediately.

I. Sudano and colleagues from Cardiovascular Center Cardiology University Hospital Zurich reported in the Nov 2, 2010 issue of Circulation that acetaminophen increases ambulatory blood pressure in patients with coronary artery disease.

Keep it in mind that different brands of acetaminophen containing medications may result in different adverse effects. Make sure to talk to your doctor before taking acetaminophen containing prescription drugs.

David Liu