Intravenous acetaminophen in the United States: iatrogenic dosing errors.

An intravenous formulation of acetaminophen was introduced to the United States in 2011. Experience from Europe indicates that serious dosing errors are likely to occur. Most events have involved a 10-fold dosing error in small children caused by calculating the dosage in milligrams, but then administering the solution in milliliters. The solution is 10 mg/mL; therefore, a 10-fold overdose occurs. Evaluation of overdose with the intravenous formulation is similar to oral overdose. A serum acetaminophen concentration should be drawn 4 hours after the infusion was started or as soon thereafter as possible. If the serum acetaminophen concentration plots above the treatment line on the Rumack-Matthew nomogram, treatment with acetylcysteine should be initiated. Health care providers are encouraged to contact their regional poison center (1-800-222-1222) so that dosing errors will be reported, and the experience with this new product can be accumulated.