What is the protocol for beta (beta blocker) reversal in cases of overdose or toxicity?

Beta Blocker Overdose Management Protocol

High-dose insulin therapy is the first-line antidote for beta blocker overdose, with glucagon and vasopressors recommended for refractory cases. 1

Initial Assessment and Stabilization

• Recognize clinical presentation: Bradycardia, hypotension, cardiogenic shock, heart block, and altered mental status
• Secure airway and breathing: Provide supplemental oxygen and ventilatory support as needed
• Establish IV access: Preferably central venous access for medication administration

Pharmacological Management Algorithm

First-Line Treatment: High-Dose Insulin Therapy

• Initial bolus: 1 U/kg regular insulin IV 1, 2
• Maintenance: 1-10 U/kg/hour continuous infusion 1, 2
• Concurrent dextrose: Administer 0.5 g/kg dextrose bolus followed by continuous infusion
• Monitoring: Check glucose every 15-30 minutes initially, then hourly; maintain 100-250 mg/dL
• Potassium monitoring: Expect moderate hypokalemia; don't aggressively replace unless <2.5 mEq/L

Second-Line Treatment: Glucagon

• Initial dose: 2-10 mg IV bolus over 3-5 minutes 1, 3
• Maintenance: 1-15 mg/hour infusion 1, 3
• Caution: Protect airway before administration as vomiting is common
• Availability: Ensure adequate supply as large quantities may be needed

Vasopressor Support (Concurrent with Above)

• Initial vasopressors: Epinephrine and norepinephrine are more effective than dopamine 1
• Dosing: Standard vasopressor dosing, titrated to effect
• Indication: For immediate blood pressure support while other therapies take effect

Additional Interventions for Refractory Cases

• Calcium administration:

  • Calcium chloride: 20 mg/kg (0.2 mL/kg of 10% solution) IV over 5-10 minutes 1
  • If beneficial, continue infusion at 20-50 mg/kg/hour 1
  • Preferably administer through central venous access

• Atropine for bradycardia:

  • 0.5-1.0 mg IV every 3-5 minutes up to 3 mg (adult) 1
  • 0.02 mg/kg (pediatric) 1

Refractory Shock Management

• Consider VA-ECMO: For life-threatening beta blocker poisoning with cardiogenic shock refractory to pharmacological interventions 1
• Hemodialysis: May be reasonable for life-threatening atenolol or sotalol poisoning 1

Important Considerations and Pitfalls

• Avoid Class IA, IC, or III antiarrhythmics: These may exacerbate cardiac toxicity 1
• Intravenous lipid emulsion therapy: Not likely to be beneficial for beta blocker poisoning 1
• Treatment duration: Continue therapy until clinical improvement and drug elimination (may require 24+ hours depending on the specific beta blocker)
• Electrical pacing: May be reasonable for refractory bradycardia but often ineffective due to myocardial depression 1
• Glucagon limitations: Requires large quantities which may not be readily available; vomiting is a common side effect 1, 3

Monitoring During Treatment

• Continuous cardiac monitoring: ECG, heart rate, blood pressure
• Frequent laboratory assessment: Glucose, potassium, calcium, arterial blood gases
• End-organ perfusion: Urine output, mental status, peripheral perfusion

This protocol provides a systematic approach to managing beta blocker overdose, focusing on interventions that improve morbidity and mortality outcomes through targeted pharmacological therapy and supportive care.