A 58-year-old woman is brought to the emergency department after she is found unconscious in her bedroom. The patient recently had an argument with her husband, and her family suspects a drug overdose. They last saw her 4 hours ago. The patient has multiple medical conditions, including major depression for which she takes several medications. Temperature is 35.5 C (95.9 F), blood pressure is 82/46 mm Hg, pulse is 40/min, and respirations are 12/min. Pulse oximetry is 84% on room air. Pupils are 4 mm and reactive. Jugular veins are flat. Lung sounds are normal. Heart sounds are muffled. Capillary refill is 3 seconds. Finger-stick blood glucose is 52 mg/dL. Overdose of which of the following medications is the most likely cause of this patient's symptoms?

Question

A 58-year-old woman is brought to the emergency department after she is found unconscious in her bedroom.  The patient recently had an argument with her husband, and her family suspects a drug overdose.  They last saw her 4 hours ago.  The patient has multiple medical conditions, including major depression for which she takes several medications.  Temperature is 35.5 C (95.9 F), blood pressure is 82/46 mm Hg, pulse is 40/min, and respirations are 12/min.  Pulse oximetry is 84% on room air.  Pupils are 4 mm and reactive.  Jugular veins are flat.  Lung sounds are normal.  Heart sounds are muffled.  Capillary refill is 3 seconds.  Finger-stick blood glucose is 52 mg/dL.  Overdose of which of the following medications is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

11ec25c8_d1cd_e0b2_bc81_db0b46ee0e1b_MD0003_00 This patient with bradycardia, hypotension, and hypoglycemia most likely has a beta blocker overdose, which also commonly presents with cardiogenic shock, bronchospasm, altered mental status, and seizures. Beta blockers act as competitive antagonists for endogenous catecholamines by binding to catecholamine receptors throughout the body. As a result, beta blockade prevents catecholamines from inducing hepatic glucose production and glycogen breakdown, which causes hypoglycemia. Unlike other overdoses, beta blocker poisoning is diagnosed clinically based on the patient's history and initial presentation. Virtually all patients develop symptoms within 6 hours of ingestion. Serum levels of beta blockers are not diagnostically helpful. Treatment consists of airway management, followed by correction of hypotension and hypoglycemia. Intravenous fluids, atropine, and glucagon are the first-line treatment. (Choice A) Overdose of tricyclic antidepressants (eg, amitriptyline) presents with altered mental status, sedation, tachycardia, and signs of anticholinergic toxicity (eg, mydriasis, urinary retention, dry mucous membranes). Hypoglycemia and bradycardia are not seen. (Choice B) Clonidine is an alpha-2 agonist used to treat hypertension. Overdose involves marked suppression of sympathetic activity and can mimic opioid overdose, presenting with bradycardia, pinpoint pupils, and altered mental status. Although hypotension and bradycardia are seen with clonidine toxicity, hypoglycemia is not. In addition, this patient's 4-mm pupils make the diagnosis unlikely. (Choice C) Digoxin toxicity presents with nausea, vomiting, confusion, and changes in color vision. Patients specifically report xanthopsia, in which all objects and the environment appear yellow. Hypoglycemia is not typical. (Choice D) Bradycardia and hypotension are typical of overdose with calcium channel blockers (eg, diltiazem); however, unlike beta blocker overdose, altered mental status is not usually seen. In addition, patients who overdose on calcium channel blockers have hyperglycemia (due to impaired pancreatic insulin secretion) rather than hypoglycemia. Educational objective: Beta blocker overdose presents within 6 hours of ingestion with bradycardia, hypotension, cardiogenic shock, bronchospasm, altered mental status, and seizures. Hypoglycemia is often seen. Treatment consists of airway management, gastric decontamination, intravenous fluids, intravenous atropine, and intravenous glucagon. References: Calcium channel antagonist and beta-blocker overdose: antidotes and adjunct therapies. (http://www.ncbi.nlm.nih.gov/pubmed/26344579) Treatment for beta-blocker poisoning: a systematic review. (http://www.ncbi.nlm.nih.gov/pubmed/32310006)

A 58-Year-Old Woman Is Brought to the Emergency Department After