What is the management for beta blocker and calcium channel blocker poisoning?

Management of Beta-Blocker and Calcium Channel Blocker Poisoning

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

Initial Assessment and Consultation

• Contact poison control or medical toxicology immediately for specialized guidance, as these cases require treatments most clinicians use infrequently and benefit from expert consultation 1, 2
• Cardiovascular symptoms typically appear within 2 hours of ingestion for immediate-release formulations, 8 hours for sustained-release formulations, and up to 12 hours for sotalol 2
• Key manifestations include bradycardia, hypotension, cardiogenic shock, and conduction disturbances 1, 3
• Highly lipophilic beta-blockers like propranolol can cause CNS effects including delirium, coma, and seizures 2
• Sotalol uniquely causes QT prolongation and torsade de pointes due to potassium channel blocking properties 2

First-Line Pharmacologic Treatment

High-Dose Insulin Euglycemic Therapy (HIET)

For both beta-blocker and calcium channel blocker poisoning:

• Administer insulin bolus of 1 U/kg followed by continuous infusion of 1 U/kg/hour, titrated to clinical effect (can increase up to 10 U/kg/hour) 1, 4, 5
• Co-administer dextrose and potassium infusions to prevent hypoglycemia and hypokalemia 1, 4, 5
• This improves cardiac contractility in cardiogenic shock and has shown favorable outcomes with lower rates of vasoconstrictive complications than vasopressor-only therapy 1, 5
• Monitor glucose concentrations regularly and continue supplementation for up to 24 hours after discontinuation of high-dose insulin 5
• Class 1 recommendation (Level B-NR) for both beta-blocker and calcium channel blocker poisoning 1

Vasopressors

• Administer vasopressors (norepinephrine and/or epinephrine) for hypotension as they are readily available and act quickly 1
• Class 1 recommendation (Level C-LD) for both beta-blocker and calcium channel blocker poisoning 1
• For calcium channel blocker poisoning with cardiotoxicity, use combination of calcium and epinephrine as initial therapy 6

Calcium Salts

For calcium channel blocker poisoning specifically:

• Administer intravenous calcium (calcium chloride or calcium gluconate) 1
• Class 2a recommendation (Level C-LD) for calcium channel blocker poisoning 1
• Avoid rapid administration to prevent vasodilation, decreased blood pressure, bradycardia, cardiac arrhythmias, and cardiac arrest 7
• Rate should not exceed 200 mg/minute in adults and 100 mg/minute in pediatric patients with ECG monitoring 7
• Note: Calcium administration may reduce response to calcium channel blockers but is still recommended 7

Second-Line Therapies

Glucagon

For beta-blocker poisoning:

• Use bolus of glucagon followed by continuous infusion for bradycardia or hypotension 1, 4
• Increases contractility and improves hemodynamics 1
• Class 2a recommendation (Level C-LD) for beta-blocker poisoning 1

For calcium channel blocker poisoning:

• Usefulness is uncertain (Class 2b, Level C-LD) 1

Atropine

• May be administered for symptomatic bradycardia in both beta-blocker and calcium channel blocker poisoning 1
• Class 2b recommendation (Level C-LD) for beta-blocker poisoning 1
• Class 2a recommendation (Level C-LD) for hemodynamically significant bradycardia from calcium channel blocker poisoning 1

Temporary Cardiac Pacing

• May be attempted for refractory bradycardia in both poisonings 1
• Class 2b recommendation (Level C-LD) for both beta-blocker and calcium channel blocker poisoning 1
• More reasonable in presence of unstable bradycardia or high-grade AV block without significant myocardial dysfunction 1

Advanced Life Support for Refractory Cases

Venoarterial Extracorporeal Membrane Oxygenation (VA-ECMO)

• Initiate VA-ECMO early for cardiogenic shock or dysrhythmias refractory to pharmacologic interventions 1, 8
• Class 2a recommendation (Level C-LD) for both beta-blocker and calcium channel blocker poisoning 1
• Because VA-ECMO implementation takes time, start the process early in patients not responding well to other therapies 1
• Associated with improved survival in severe cases, though risks include limb ischemia, thrombosis, and bleeding 8

Hemodialysis

For specific beta-blockers only:

• Consider hemodialysis for life-threatening atenolol or sotalol poisoning 1, 4
• Class 2b recommendation (Level C-LD) 1
• These agents have low protein binding (0-5%) and small volume of distribution (1.0-1.2 L/kg), making them amenable to removal 2

Therapies NOT Recommended

Intravenous Lipid Emulsion (ILE)

• NOT recommended for beta-blocker poisoning (Class 3: No Benefit, Level C-LD) 1, 4
• NOT recommended for routine use in calcium channel blocker poisoning (Class 3: No Benefit, Level C-LD) 1
• Animal studies showed benefit only in intravenous verapamil models, not oral poisoning models 8

Critical Pitfalls to Avoid

• Do not wait for laboratory confirmation of drug levels, as assays are rarely available and correlate poorly with symptoms (except sotalol) 2
• Do not underestimate severity with co-ingestions of other cardioactive drugs such as digoxin, as fatalities are more likely 2
• Do not rely solely on receptor selectivity in overdose, as it is lost and leads to overlapping manifestations among different agents 2
• Avoid administration of calcium in patients receiving cardiac glycosides due to risk of synergistic arrhythmias; if necessary, administer slowly with close ECG monitoring 7
• Monitor for tissue necrosis and calcinosis cutis with calcium administration, especially with extravasation 7
• Anticipate prolonged effects with sustained-release formulations (diltiazem, verapamil, nifedipine) or long half-life agents (amlodipine) 1

Monitoring Requirements

• Monitor serum glucose every 30-60 minutes during high-dose insulin therapy and for 24 hours after discontinuation 5
• Monitor serum potassium frequently as insulin shifts potassium intracellularly 5
• Continuous ECG monitoring is essential, especially during calcium administration 7
• Monitor for hypoglycemia and hypokalemia as major anticipated adverse events with high-dose insulin 5