Skip to main content Back to Top


FDA Approves Injectable Acetylcysteine

Cheryl A. Thompson

Acetadote, an injectable form of acetylcysteine, was recently approved for marketing as a treatment to prevent or lessen liver injury in persons who have ingested a potentially toxic amount of acetaminophen.

The product will be marketed by Cumberland Pharmaceuticals Inc., based in Nashville, Tenn.

According to the Jan. 23 approval letter from the Food and Drug Administration (FDA), acetylcysteine injection is to be administered intravenously "within 8 to 10 hours after ingestion of a potentially hepatotoxic quantity" of acetaminophen. Information on use of the drug in children age 1 month to 16 years is supposed to be provided to FDA by mid-summer.

The product's labeling labeling (PDF) states that the decision to administer acetylcysteine injection should be based on the amount of acetaminophen in the patient's circulation in the first four hours after ingestion. Acetylcysteine injection should be administered within eight hours of the patient's overdose if the acetaminophen plasma concentration, when plotted on the Rumack-Matthew nomogram, indicates probably hepatic toxicity. If the nomogram, which requires the patient's acetaminophen plasma concentration and time after ingestion of the drug, cannot be used or if more than eight hours-but not more than 24 hours-have passed since the overdose, then acetylcysteine injection should be administered immediately.

Treatment should begin with an intravenous dose of 150 mg of acetylcysteine per kilogram of patient weight infused over 15 minutes and continue with a maintenance infusion of 50 mg/kg over four hours and then 100 mg/kg over 16 hours. The labeling details the preparation of the three infusions.

Acetadote will be available in single-dose preservative-free 30-mL vials containing 200 mg of acetylcysteine per milliliter. The drug solution, once diluted with 5 percent dextrose injection, may be stored at 20-25 degrees C for up to 24 hours. Previously opened vials should not be used for intravenous administration. The solution should not be exposed to rubber and metals.

James D. Aderhold, Cumberland vice president for marketing and sales, said Acetadote will be available from drug wholesalers in the second quarter of 2004.

Approval of acetylcysteine injection came on the same day that FDA launched a national education campaign to provide consumers advice on the safe use of nonprescription pain-relief products, particularly those containing acetaminophen or a nonsteroidal antiinflammatory drug. One day earlier, FDA had asked state boards of pharmacy to require prescription-container labels to provide more information about acetaminophen-containing products.