P3C025: I Had a Cough and Now I Can’t Talk: A Story of a Benzonatate Ingestion in a Pediatric Patient

Introduction: Benzonatate (tessalon perles) is a widely-used antitussive medication with sodium channel-blocking properties and topical anesthetic on vagal stretch receptors. With the rising rate of intentional ingestions in the United States, it is important for medical providers to be familiar with the potential toxicities of this frequently prescribed cough suppressant. We report a case of benzonatate toxicity by intentional ingestion of a young teen resulting in cardiac arrest with sustained hypoxic brain injury leading to functional deficits.

Case Description: A 14-year-old female with history of depression and prior suicidal attempts with intentional ingestions presented in status epilepticus and status-post cardiac arrest after intentional ingestion of an unknown quantity of benzonatate capsules. Patient received CPR by EMS including 1 dose of epinephrine prior to achieving ROSC. She was transferred to a pediatric emergency department where there was concern for subclinical seizures, shock, and metabolic acidosis. She was treated with anti-epileptics, fluid resuscitation, and bicarbonate supplementation, then admitted to the pediatric intensive care unit. Her clinical course included management of acute respiratory failure due to altered mental status, seizure activity, dystonia, and continued metabolic acidosis. Brain MRI obtained on admission was normal. Once seizures resolved and respiratory status improved she was extubated, but her neurological exam remained altered. She was non-verbal, had chorea-like movements, intermittent agitation, left-sided weakness, neurogenic bowel and bladder, and oral-motor dysfunction. A repeat brain MRI 7 days post cardiac arrest showed diffuse metabolic or systemic insult. After 27 days, she was transferred to medical rehab for therapies for her function and neurological deficits. With intensive physical, occupational, and speech therapies and multi-modal medical treatment, the patient had improved cognition, but continued with severe dystonia, dysphagia requiring tube feeding, and difficulties with communication.

Discussion: Due to potentially fatal properties in overdose, the FDA has issued a Drug Safety Communication warning for children less than 10 years old. Signs and symptoms of overdose to local anesthetics are nausea, dizziness, headache and confusion. Toxicities associated with sodium channel blockers are more severe including seizures, altered mental status, agitation, hypotension, ventricular dysrhythmias, and cardiac arrest. In previous case reports, toxicity to benzonatate has occurred within 15 minutes and progressed to death within 1 hour of ingestion.

Conclusion: This case demonstrates the severity of a benzonatate ingestion. The wide availability of this medication, especially during viral respiratory season, is worrisome for risk of toxic ingestion in children. Sodium channel blockade and topical anesthetic can have devastating neurological outcomes. The FDA warns that even an appropriate adult dose (1-2 capsules) can be toxic in children under 10, but overdose can still cause detrimental effects in all ages. In this case, even 2 months after ingestion and overdose, the severe neurotoxic outcomes are demonstrated.