Benzonatate overdose in an infant and review of literature

Benzonatate (BZ) is a non-narcotic antitussive on the market for over 30 years. In overdose, a patient can develop seizures, cardiac dysrhythmias and death. We present a case of an infant who ingested 800 mg of BZ and a review of the literature. An 11 month old male ingested eight 100 mg BZ perles at an unknown time. When the child presented to the ED, he was in status epileptics and required multiple doses of lorazepam. He was intubated to protect his airway, placed on assisted ventilation and given AC. Initial ABGs were normal. On the 2nd day, he developed copious amounts of secretions from his mouth and worsening breath sounds with rales and wheezing. A chest x-ray revealed a upper right lobe collapse. He was started on IV Piperacillin/tazobactam therapy for aspiration pneumonia. On day 5 he was extubated and discharged on day 6. The maximum therapeutic dose of BZ in adults is 600 mg/day. Its structure is closely related to tetracaine and anesthetizes the stretch receptors of the lungs/pleura. The incidence of BZ exposure is not available in TESS. The off-label use of BZ has gained popularity as an anesthetic agent for conscious sedation, an adjunct agent for EEG and MRI procedures and for cancer patients with opioid resistant coughs. Four of 5 case reports in the literature have resulted in death. Two of 4 deaths involved unintentional overdoses in infants. Toxicology analysis is complicated and not routinely available because it contains 8 compounds. Despite the fact the FDA has deemed BZ unsafe for OTC use in 1987, its use seems to be growing and clinicians need to be aware of its potential toxicity and management.