Data SummaryÂ
FDA continues to monitor reports of toxicity with the use of prescription oral viscous lidocaine and over-the-counter (OTC) benzocaine to treat teething pain in infants and young children.
A search of FDA’s Adverse Event Reporting System (FAERS) database and the medical literature through December 2013 identified 22 cases of toxicity with the use of prescription oral viscous lidocaine 2 percent solution in infants and young children 5 months to 3.5 years of age. Fifteen cases were identified in FAERS and seven additional cases were noted in the literature.2-7
Of the 22 cases, 6 cases resulted in death, 3 were categorized as life-threatening, 11 required hospitalization, and 2 required medical intervention without hospitalization.
The root cause of the overdose in 7 of the 22 cases was the administration technique by caregivers, who did not follow prescriber directions for application of the product or gave additional doses beyond what was prescribed. Accidental ingestion occurred in seven additional cases, and four cases involved overdose due to a prescribing error. The root cause of the error could not be identified in the remaining four cases.
The reported reasons for use of lidocaine in these 22 cases were teething pain (n=5), oral stomatitis (n=6), fever blister (n=1), thrush (n=2), oral ulcer/lesion (n=3), and sore throat due to croup (n=1). In four cases, the reason for use was not reported.
Of the 22 cases, multiple doses of lidocaine taken prior to the onset of the adverse event occurred in 11 cases. In six cases, the toxicity manifested following the accidental ingestion of a single dose. In five cases, it was not reported whether a single dose or multiple doses were taken prior to the onset of symptoms.
Viscous lidocaine solution continues to be dispensed for infants and young children 2 years and younger (see Table). In 2012, infants and young children 2 years and younger accounted for approximately 4 percent of all patients who received dispensed prescriptions in the outpatient retail setting for oral viscous lidocaine solution. The number of patients aged 2 years and younger decreased by approximately 28 percent between 2008 and 2012 as shown in the following table:8
Nationally estimated number of total patients and patients aged 0-2 years receiving dispensed prescriptions for lidocaine 2 percent oral viscous products from U.S. outpatient retail pharmacies8
On April 7, 2011, FDA issued a Drug Safety Communication (DSC) warning that use of OTC benzocaine gels and liquids applied to the gums or mouth to reduce pain was associated with methemoglobinemia, mainly in children aged two years and younger. Since the issuance of that DSC, FDA has received reports of 6 new cases of methemoglobinemia in infants and young children, 2 years and younger, associated with OTC benzocaine gels and liquids, bringing the total to 27 cases. Hospitalization was required in all six new methemoglobinemia cases, and three were categorized as life-threatening. No new cases were identified in the literature.Â