The Food and Drug Administration has asked manufacturers of prescription pain products containing acetaminophen to include no more than 325 mg of the drug in each capsule, tablet, or other dosage unit.
According to a safety announcement issued Jan. 13 by the agency, the action was taken to address the ongoing problem of acetaminophen overdose, a leading cause of severe liver injury in the United States.
In addition, the FDA requests that manufacturers of these combination products –including Vicodin and Percocet – add a boxed warning to product labels about the potential risk of severe liver injury if acetaminophen is taken in excessive doses or with alcohol.
Manufacturers have until January 2014 to comply with the recommendations, so a shortage of these medications is not anticipated, according to the agency.
The FDA is also asking clinicians to educate their patients about the dangers of acetaminophen overdose and to advise patients to take no more than the maximum daily dose of acetaminophen (4,000 mg).
"For physicians and other health care providers, we want to emphasize that it’s important to talk to patients and make sure that they are aware of the risks of using prescription pain medicines with acetaminophen," Dr. Sandra Kweder said during a press briefing.
"Health care professionals should also make sure their patients know how much acetaminophen is contained in any prescription product," added Dr. Kweder, deputy director of the Office of New Drugs, in the FDA’s Center for Drug Evaluation and Research. By limiting the amount of acetaminophen contained in each dose, "we don’t believe we are making these products less effective," she said, noting that the doses of the drug in these products have gradually "crept up" over the past few decades.
Currently, prescription acetaminophen products contain up to 750 mg of acetaminophen per dosage unit, but there are no data indicating that more than 325 mg of acetaminophen per unit provides greater pain relief, according to the FDA.
The agency’s request does not apply to over-the-counter products, which can contain as much as 500 mg per tablet or capsule in the products marketed as extra strength. Information about the risk of liver injury already is required on the label for OTC products containing acetaminophen. The FDA announcement noted that the agency continues to evaluate ways of reducing the risk of acetaminophen-related liver injury from OTC products.
Almost half of acetaminophen-related cases of liver failure in the United States are caused by overdoses from prescription opioid-acetaminophen products, which are among the most commonly prescribed products in the United States, accounting for almost 200 million prescriptions dispensed per year.
More information is available at www.fda.gov/Drugs/DrugSafety/InformationbyDrugClass/ucm165107.htm. Serious adverse events associated with acetaminophen or products that contain acetaminophen should be reported to the FDA’s MedWatch program online or at 800-332-1088.