What is the treatment for beta blocker poisoning?

Treatment of Beta-Blocker Poisoning

High-dose insulin euglycemic therapy should be initiated early as first-line treatment for life-threatening beta-blocker poisoning, combined with vasopressors and supportive care. 1

Initial Assessment and Stabilization

• Cardiovascular symptoms typically appear within 2 hours of ingestion and are unlikely to occur in asymptomatic patients after 6 hours for immediate-release formulations, 8 hours for sustained-release formulations, and 12 hours for sotalol 1
• Key manifestations include bradycardia, hypotension, dysrhythmias, and cardiogenic shock, with potential for decreased consciousness, bronchospasm, hyperkalemia, and hypoglycemia 1
• Highly lipophilic agents like propranolol can cause CNS effects including delirium, coma, and seizures 1
• Sotalol uniquely causes QT prolongation and torsade de pointes due to potassium channel blocking properties 1
• Contact poison control or medical toxicology immediately for specialized guidance, as these cases require treatments most clinicians use infrequently 1

Decontamination

• Administer activated charcoal if available and no contraindications exist, but do not delay transportation to the emergency department 2
• Do not induce emesis with syrup of ipecac 2
• Gastric lavage has limited evidence and should not be routinely performed 3

Pharmacologic Treatment Algorithm

First-Line Therapy

High-Dose Insulin Euglycemic Therapy (HIET):

• Administer a bolus of 1 U/kg insulin followed by continuous infusion of 1 U/kg/hour, titrated to clinical effect 4
• Co-administer dextrose and potassium infusions to prevent hypoglycemia and hypokalemia 4
• This improves cardiac contractility in cardiogenic shock and is recommended early in life-threatening cases 1, 4
• Maintenance dosing may range from 1-10 units/kg/hour depending on response 3
• Monitor closely for hypoglycemia and hypokalemia, which are commonly observed adverse effects 3

Vasopressors and Inotropes:

• Vasopressors are recommended for hypotension (Class 1 recommendation) 4
• Catecholamines, inotropes, and vasopressors provide survival benefit and improve hemodynamics 3
• Use single or combination therapy depending on the type of hemodynamic compromise (bradycardia, left ventricular dysfunction, vasodilation) 3

Second-Line Therapies

Glucagon:

• Consider glucagon for bradycardia or hypotension (Class 2a recommendation) 1, 4
• Dosing: 50 mcg/kg IV loading dose, followed by continuous infusion of 1-15 mg/hour, titrated to patient response 5
• Glucagon increases heart rate and myocardial contractility by bypassing beta-receptor blockade 5, 6
• Monitor for nausea, vomiting, hypokalemia, and hyperglycemia 5
• High cost and limited availability may limit use 5

Calcium:

• Intravenous calcium improved hemodynamics in some case reports, though evidence is limited 3
• More established for calcium channel blocker toxicity than pure beta-blocker poisoning 6

Atropine:

• May be used for bradycardia (Class 2b recommendation), though evidence shows variable response 1, 4
• Multiple IV boluses were associated with improvement in heart rate and blood pressure in limited case reports 3

Electrical Pacing:

• Consider temporary cardiac pacing for bradycardia (Class 2b recommendation) 1, 4
• Particularly useful for preventing arrhythmias in sotalol toxicity 3

Therapies NOT Recommended

Intravenous Lipid Emulsion:

• Do NOT use intravenous lipid emulsion for beta-blocker poisoning (Class 3: No Benefit recommendation) 4
• Variable and inconsistent responses reported in case series 3

Advanced Life Support

Venoarterial Extracorporeal Membrane Oxygenation (VA-ECMO):

• Consider VA-ECMO for cardiogenic shock or dysrhythmias refractory to pharmacologic interventions (Class 2a recommendation) 1, 4
• VA-ECMO was associated with improved survival in severe cases in observational studies 3
• Initiate the process early in patients not responding to other therapies, as implementation takes time 1

Hemodialysis:

• Consider hemodialysis for potentially life-threatening atenolol or sotalol poisoning (Class 2b recommendation) 4
• These water-soluble beta-blockers are dialyzable, though survival benefit is not definitively established 3
• Atenolol has low protein binding (0-5%) and small volume of distribution (1.0-1.2 L/kg), making it amenable to removal 1

Supportive Care

• Administer supplemental dextrose for hypoglycemia as part of standard care 4
• Provide intravenous fluids for hypotension 2
• Continuous cardiac monitoring is essential given risk of dysrhythmias 7

Monitoring and Disposition

• Asymptomatic patients require observation for at least 6 hours (immediate-release), 8 hours (sustained-release), or 12 hours (sotalol) 2
• Ambulance transportation is recommended for patients requiring emergency department referral due to potential for life-threatening complications 2
• Any ingestion with self-harm intent or malicious administration warrants immediate emergency department referral 2
• Co-ingestion with calcium channel blockers or presence of serious cardiovascular disease warrants emergency department referral regardless of dose 2

Key Clinical Pitfalls

• Do not wait for laboratory confirmation of beta-blocker levels, as assays are rarely available and correlate poorly with symptoms (except sotalol) 1
• Fatalities are more likely with co-ingestion of other cardioactive drugs such as calcium channel blockers 1
• Receptor selectivity is lost in overdose, leading to overlapping manifestations among different beta-blockers 1
• The evidence base is primarily low-quality case reports and series, but the graduated approach described represents consensus expert opinion 3
• Multiple treatments are often given simultaneously in severe cases, making it difficult to attribute benefit to individual interventions 3