Cardiac Arrest Due to Benzonatate Overdose

Abstract

Patient: Female, 37 Final Diagnosis: Cardiac arrest due to Benzonatate overdose Symptoms: Cardiac arrest • respiratory deterioration • seizure Medication: Benzonatate Clinical Procedure: Intubation • hypothermia protocol Specialty: Critical Care Medicine Objective: Unknown ethiology Background: Benzonatate is one of the most widely prescribed nonnarcotic antitussives to relieve cough symptoms. As a structurally similar agent to other local anesthetics, including tetracaine and procaine, the risk to the public is not fully appreciated. Case Report: A 37-year-old female presented to the Emergency Department (ED) status post cardiac arrest. Advanced cardiac life support (ACLS) protocol was performed, and return of spontaneous circulation (ROSC) was achieved. Total downtime was 30 minutes. The patient was intubated, sedated, and hypothermia protocol was initiated. The patient developed bradyarrhythmia and mild coagulopathy suspicious for disseminated intravascular coagulation (DIC), thus hypothermia protocol was terminated later. A review of laboratory data showed acidosis with pH of 6.87, mixed acidosis secondary to high anion gap metabolic and respiratory acidosis with elevated liver enzymes. It was reported that approximately 2 hours prior to her presentation; the patient had ingested less than 30 pills of benzonatate 200 mg capsules with alcohol. Conclusions: Ingestion of benzonatate, a widely prescribed antitussive, may pose a risk to patients due to the potential for rapid development of life-threatening adverse events and limited treatment options in the overdose setting, not only in children but also in adults. Rational prescribing and patient education are needed.

A description of the clinical course of severe benzonatate poisonings reported in the literature and to NPDS: A systematic review supplemented with NPDS cases

“…Published cases had a greater than 60% survival. In general, onset of effects is rapid and within minutes after ingestion, although some cases may have been delayed up to 2 h. 4,7,8 However, when evaluating the pharmacokinetics of benzonatate, this timeframe does not make sense.…”

“…2 Sporadic cases of severe benzonatate poisoning are reported in the literature. [3][4][5] This was a descriptive study using the National Poison Data System (NPDS) fatalities module in combination with a systematic review to describe the S40 Human and Experimental Toxicology 40(12S) course of severe poisoning and deaths from benzonatate.…”

Updates in our understanding of local anaesthetic systemic toxicity: a narrative review

“…Of the reported in-hospital cases of LAST, 68% occurred in the operating room and 32% occurred in off-site locations (ward, labour and delivery suites, interventional radiology, intensive care unit and echocardiography laboratory). Two cases involving overdose occurred at home and one to a volunteer at an awake tracheal intubation course [11,26,38]. Local anaesthetic was identified as being delivered in 50% of the events by anaesthetists, 39% by surgeons or other proceduralists, 5.5% by dentists and 5.5% were selfadministered.…”

“…Sixty-four percent of patients received some form of infusion of lipid emulsion, however, the dosing varied among cases. Two patients (0.6%) died from anoxic brain injury [26,29], neither of whom received lipid emulsion. A 33-year-old woman suffered cardiac arrest 2 h after liposuction of the thighs during which she received a total of 5000 mg of subcutaneous lidocaine.…”

“…Between December 2017 and May 2020, there were a further 36 cases of LAST reported in 34 peer‐reviewed published articles [6–39]. These data indicated 30% of patients were older than 65 y, and 6% were younger than 5 y. Sixty‐one percent of cases occurred in the hospital; 17% in outpatient surgery centres; and 14% in outpatient clinics (e.g.…”