Elevated acetaminophen concentration measured after nasal insufflation of Percocet®

Prescription opioid products are often formulated with acetaminophen, but the pharmacokinetics of nasally administered acetaminophen are poorly characterized. We report a case of a potentially toxic acetaminophen concentration after nasal insufflation of oxycodone/acetaminophen tablets.

A 38-year-old female presented to the emergency department after 2 days of nasally insufflating a total of 50 oxycodone/acetaminophen 5/325 mg tablets. On day 3, she was evaluated for nausea and pharyngitis. She denied oral ingestion of the drug. The initial acetaminophen concentration was 14 μg/mL, although the patient had not insufflated any medication in approximately 24 h. Initial AST and ALT were normal. The patient was treated with a 21-h course of intravenous N-acetylcysteine. On hospital day 2, the measured acetaminophen concentration was < 10 μg/mL and the patient's liver enzymes remained within normal limits.

The pharmacokinetics of nasally administered acetaminophen have not been well studied, yet there is potential for significant exposure with prescription opioid abuse. Clinicians should be vigilant in evaluating patients for toxicity due to adjunct medications formulated in narcotic pain preparations used by routes other than ingestion.