What are the antidote doses for beta blocker overdose?

Beta Blocker Overdose Antidote Dosing

For beta blocker overdose, high-dose insulin therapy should be initiated with a bolus of 1 U/kg IV followed by an infusion of 0.5-1 U/kg/hour as the first-line antidote, with concurrent glucose administration to maintain euglycemia. 1

First-Line Treatment: High-Dose Insulin Therapy

High-dose insulin is now considered the first-line antidote for beta-blocker overdose with refractory hypotension, as it improves cardiac contractility and provides superior outcomes compared to vasopressor-only therapy.

• Initial bolus: 1 U/kg IV regular insulin
• Maintenance infusion: 0.5-1 U/kg/hour, titrated to hemodynamic response
• Concurrent glucose: 0.5 g/kg IV bolus initially, then 0.5 g/kg/hour infusion
• Target glucose: 100-250 mg/dL
• Monitoring: Check glucose every 15 minutes initially, then every 30-60 minutes; monitor potassium levels frequently

Second-Line Treatment: Glucagon

Glucagon is considered second-line therapy after high-dose insulin for beta-blocker overdose.

• Initial dose: 3-10 mg IV bolus (adult) 2, 1
• Maintenance infusion: 3-5 mg/hour 2, 1
• Caution: Glucagon commonly causes vomiting, which is concerning in patients with altered mental status 1

Additional Pharmacological Interventions

Calcium

• Indication: For refractory shock despite insulin and glucagon
• Dosing: 1-2 g IV calcium chloride (10%) every 10-20 minutes or infusion at 0.2-0.4 mL/kg/hour 2
• Alternative: 3-6 g IV calcium gluconate (10%) every 10-20 minutes or infusion at 0.6-1.2 mL/kg/hour 2

Vasopressors

• Begin with epinephrine or norepinephrine for immediate blood pressure support
• Epinephrine: 2-10 mcg/min IV or 0.1-0.5 mcg/kg/min IV titrated to effect 2
• Dopamine: 5-20 mcg/kg/min IV, starting at 5 mcg/kg/min and increasing by 5 mcg/kg/min every 2 minutes 2

Atropine

• Dosing: 0.5-1 mg IV every 3-5 minutes to a maximum of 3 mg 2
• Note: May be ineffective in severe beta-blocker toxicity

Treatment Algorithm for Beta-Blocker Overdose

1. Initial stabilization:

   • Secure airway, breathing, circulation
   • Initiate cardiac monitoring
   • Establish IV access (preferably central)
   • Consider activated charcoal if recent ingestion and patient alert

2. First-line interventions:

   • IV fluids for volume resuscitation
   • Atropine for symptomatic bradycardia
   • Initiate vasopressors for hypotension

3. Escalate to high-dose insulin therapy when hypotension persists:

   • Bolus 1 U/kg IV regular insulin
   • Start infusion at 0.5-1 U/kg/hour
   • Administer dextrose to maintain euglycemia
   • Monitor glucose and potassium frequently

4. Add glucagon if inadequate response to insulin:

   • 3-10 mg IV bolus
   • Continue with 3-5 mg/hour infusion

5. Consider calcium for refractory shock:

   • Calcium chloride 1-2 g IV or calcium gluconate 3-6 g IV

6. For refractory cases:

   • Consider VA-ECMO for life-threatening poisoning unresponsive to pharmacological therapy 2
   • Consider hemodialysis for water-soluble beta-blockers (e.g., atenolol, sotalol) 1

Important Monitoring Considerations

• Continuous cardiac monitoring
• Frequent assessment of mental status and peripheral perfusion
• Regular monitoring of serum glucose (every 15 minutes initially)
• Monitor potassium levels (expect moderate hypokalemia with insulin therapy)
• Monitor calcium levels
• Arterial blood gases as needed
• End-organ perfusion (urine output, mental status)

Common Pitfalls to Avoid

• Delaying insulin therapy while trying other less effective treatments
• Inadequate glucose monitoring during high-dose insulin therapy
• Aggressive potassium repletion (moderate hypokalemia is expected with insulin therapy)
• Overlooking the need for central venous access for concentrated dextrose solutions
• Relying solely on atropine, which is often ineffective in severe beta-blocker toxicity
• Using Class IA, IC, or III antiarrhythmics, which may worsen cardiac toxicity

High-dose insulin therapy has emerged as the most effective antidote for beta-blocker overdose based on the most recent evidence, with glucagon serving as an important second-line agent when needed.