Benzonatate Toxicity in a Teenager Resulting in Coma, Seizures, and Severe Metabolic Acidosis

Abstract

We report a benzonatate overdose in a teenager resulting in life-threatening toxicity to increase awareness of this overdose, and discuss recent pediatric warnings and labeling information provided by the US Food and Drug Administration (FDA). After an overdose of benzonatate, a 13-yr-old female presented to our emergency department with coma, seizures, hypotension, prolonged QT interval on electrocardiogram, and metabolic acidosis. Benzonatate is an antitussive medication with sodium channel-blocking properties and local anesthetic effects on the respiratory stretch receptors due to a tetracaine-like metabolite. Overdose is reported to cause coma, seizures, hypotension, tachycardia, ventricular dysrhythmias, and cardiac arrest. The FDA recently issued a Drug Safety Communication warning that accidental benzonatate ingestion in children younger than 10 years of age have increased risk of death and added the new information to the Warnings and Precautions section of benzonatate's label.