Misuse of acetaminophen in the management of dental pain.

PURPOSE: We highlight the risk associated with acetaminophen misuse in patients having dental pain in France based on a series of cases of unintentional acetaminophen overdose reported by the Emergency Dental Service of Nancy over a 9-month period.

METHODS: Data were collected by querying the French Pharmacovigilance database. Each retrieved clinical data were reviewed by a clinician.

RESULTS: Thirteen cases of acetaminophen overdose were reported to the Regional Pharmacovigilance Center of Lorraine, Nancy, France. Most cases (10/13) concerned men aged 20-40 years old. Mild, unspecific clinical symptoms were observed in seven of 13 patients. The median value of the supposed ingested dose was 137 mg/kg/24 h. Liver enzyme activity was tested in 10 patients and was abnormal in four patients. N-acetylcysteine treatment was administered to four patients.

CONCLUSIONS: We propose that even patients with mild clinical symptoms with a supposed ingested dose of acetaminophen greater than 150 mg/kg/24 h should be referred to an emergency department and that liver enzyme activity should be analyzed. No case of liver failure was observed during our short survey. However, hepatotoxicity of repeated supratherapeutic ingestion of acetaminophen was suspected in four patients. Patients and practitioners should thus be better informed about the risk of unintentional acetaminophen overdose following supratherapeutic acetaminophen ingestion.