What is the treatment for a beta (beta blocker) overdose?

Treatment for Beta Blocker Overdose

For beta blocker overdose, first-line treatment should include high-dose insulin with glucose and IV glucagon for patients in refractory shock, with additional consideration of calcium administration and ECMO for cases unresponsive to pharmacological therapy. 1

Initial Assessment and Management

• Assess for key clinical manifestations:

  • Bradycardia
  • Hypotension
  • Altered mental status
  • Hypoglycemia
  • Cardiogenic shock
  • Bronchospasm
  • Seizures (particularly with propranolol) 2

• Immediate interventions:

  • Establish IV access
  • Continuous cardiac monitoring
  • Administer activated charcoal if within 1-2 hours of ingestion and airway is protected 3
  • Obtain ECG, blood glucose, potassium, and lactate levels 3

Pharmacological Treatment Algorithm

First-Line Therapies

1. High-Dose Insulin Therapy (Class 2a, C-LD evidence) 1

   • Initial bolus: 1 U/kg IV
   • Continuous infusion: 1 U/kg/hour, titrate up based on clinical response
   • Co-administer dextrose and monitor glucose every 15-30 minutes initially
   • May require maintenance doses of 1-10 U/kg/hour 4

2. Vasopressors/Inotropes 3, 4

   • Epinephrine, norepinephrine, or dopamine titrated to effect
   • Target improved blood pressure and cardiac output

3. IV Glucagon (Class 2a, C-LD evidence) 1

   • Dosing: 5-10 mg IV bolus over 3-5 minutes
   • Follow with continuous infusion of 1-5 mg/hour
   • Caution: May cause vomiting; protect airway

Second-Line Therapies

1. Calcium Administration (Class 2b, C-LD evidence) 1

   • Calcium chloride: 10-20 mL IV or
   • Calcium gluconate: 30-60 mL IV
   • May repeat every 10-20 minutes for 3-4 doses if beneficial

2. Atropine (Class 2b, C-LD evidence) 1, 3

   • Dose: 0.5-1 mg IV for symptomatic bradycardia
   • Note: Often has limited efficacy in beta-blocker overdose

Refractory Cases

1. Extracorporeal Life Support (VA-ECMO) (Class 2b, C-LD evidence) 1, 5

   • Consider for life-threatening poisoning with cardiogenic shock unresponsive to pharmacological interventions
   • Early consultation with ECMO team recommended

2. Hemodialysis 4

   • Limited utility for most beta blockers due to high protein binding
   • May be effective for water-soluble beta blockers (e.g., atenolol, sotalol)

Special Considerations

• Lipophilic vs. Water-soluble Beta Blockers:

  • Propranolol (lipophilic): More likely to cause seizures and CNS effects 2
  • Sotalol: Requires longer monitoring (12 hours) due to QT prolongation risk 6
  • Atenolol (water-soluble): May respond better to hemodialysis 4

• Co-ingestions:

  • Beta blocker + calcium channel blocker combinations are particularly dangerous and may require more aggressive treatment 6, 2

• Monitoring Duration:

  • Immediate-release preparations: Monitor for at least 6 hours
  • Sustained-release preparations: Monitor for at least 8 hours
  • Sotalol: Monitor for at least 12 hours 6

Monitoring Parameters

• Continuous cardiac monitoring
• Frequent blood pressure measurements
• Serial ECGs
• Blood glucose levels (every 15-30 minutes initially, then as clinically indicated)
• Potassium levels (risk of hypokalemia with high-dose insulin)
• Lactate levels to assess tissue perfusion 3

Treatment Pitfalls to Avoid

• Abrupt withdrawal of beta blocker therapy in patients on chronic therapy can lead to clinical deterioration 1
• Relying solely on atropine is often ineffective for beta blocker-induced bradycardia 7
• Delaying high-dose insulin therapy when patients are not responding to conventional treatments 4
• Failing to monitor glucose and potassium during high-dose insulin therapy 3
• Underestimating the severity of co-ingestion with calcium channel blockers 2

The evidence strongly supports high-dose insulin and glucagon as the most effective pharmacological interventions for beta blocker overdose, with ECMO providing rescue therapy for the most severe cases unresponsive to medical management 1, 4.