The FDA Recommends Dispensing No More Than 325 Milligrams Of Acetaminophen
By Cyndi Root
The Food and Drug Administration has issued a MedWatch Safety Alert to all consumers and healthcare professionals. The advisory recommends that medical personnel prescribe no more than 325 mg of acetaminophen per dosage. The agency states that no data suggests or proves that taking more than 325 mg provides any benefit that outweighs the risk of liver damage. The FDA believes that limiting the dose will reduce risks of overdose and resulting complications of liver transplant, liver failure, and even death.
Acetaminophen
Acetaminophen is an over-the-counter (OTC) pain medication. The drug is prescribed for common types of pain like dental procedures, surgery, or acute and chronic injuries. The medication is combined with other ingredients to treat other symptoms like fever, cough, and cold. This advisory only concerns pure acetaminophen capsules, tablets, or other dosage units. The FDA will address combination products in other advisories.
Many manufacturers have complied with the FDA’s 2011 request to limit dosage to 325 mg, but many products still remain on the market. The reason for the 2011 request is the same as the reason for this advisory—the risk of liver damage. Because products are still on the market, the FDA wants consumers to know the risks. The FDA intends to withdraw of all acetaminophen products from the market with more than 325 mg per dosage.
Risks of Liver Injury
The acetaminophen mechanism of action involves the central nervous system (CNS). The drug increases the person’s pain threshold by inhibiting or blocking isoforms of cyclooxygenase enzymes in prostaglandin synthesis. Acetaminophen is broken down in the liver where most of the drug is metabolized and excreted in the urine. However, a small amount remains and is harmful to liver cells. Severe liver injury has occurred to patients who took more than 325 mg in a dose, who took more than the prescribed dose in a 24-hour time period, took two or more types of acetaminophen products, and who drank alcohol with the drug.
FDA Recommendation
The FDA recommends that healthcare professionals prescribe doses of less than 325 mg of acetaminophen. Pharmacists should contact prescribers of more than 325 mg and recommend a lower dose. Prescribers and pharmacists should also consider other ingredients like opioids when dispensing acetaminophen. Consumers and healthcare providers are encouraged to call the Division of Drug Information at 888.INFO.FDA (888-463-6332) for more information and to report adverse events to the FDA's MedWatch Safety Information and Adverse Event Reporting Program.