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

Treatment of Propranolol Overdose

High-dose insulin therapy with glucose supplementation is the first-line treatment for propranolol overdose, followed by glucagon administration and vasopressors for patients in refractory shock. 1

Initial Assessment and Stabilization

• Airway, Breathing, Circulation: Ensure airway protection, provide respiratory support as needed, and establish IV access
• Monitoring: Continuous cardiac monitoring, blood pressure, blood glucose, potassium, lactate levels, and neurobehavioral status 1
• Decontamination: If ingestion is recent and airway is protected, consider gastric evacuation to prevent further absorption 2

Treatment Algorithm

First-Line Therapies

1. High-Dose Insulin Euglycemic Therapy (HIET) 1

   • Initial bolus: 1 U/kg IV
   • Continuous infusion: 1 U/kg/hour
   • Titrate based on clinical response
   • Co-administer with dextrose to maintain euglycemia
   • Monitor blood glucose every 15-30 minutes initially

2. Glucagon 1, 2

   • Dosing: 50-150 mcg/kg IV bolus (typically 5-10 mg)
   • Follow with continuous infusion of 1-5 mg/hour
   • Caution: May cause vomiting; ensure airway protection
   • Mechanism: Exerts positive inotropic and chronotropic effects

3. Vasopressors 1, 2

   • Options: Epinephrine, norepinephrine, dopamine
   • Titrate to effect based on blood pressure response
   • Note: Epinephrine may cause uncontrolled hypertension in some cases 2

Second-Line Therapies

1. Calcium Administration 1

   • Calcium chloride or calcium gluconate IV
   • May repeat every 10-20 minutes for 3-4 doses if beneficial

2. Atropine 1, 2

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

3. Isoproterenol 2

   • May be useful for bradycardia resistant to other treatments
   • Caution with dosing due to potential for hypotension

4. Intravenous Lipid Emulsion 3

   • Consider in cases unresponsive to conventional therapy
   • Initial dose: 1.5 mL/kg of 20% lipid emulsion over 1 minute
   • Follow with infusion of 0.25 mL/kg/min for 30-60 minutes

Rescue Therapy

1. Extracorporeal Life Support (VA-ECMO) 1
   • Consider for life-threatening poisoning with cardiogenic shock unresponsive to pharmacological interventions
   • Early consultation with ECMO team recommended

Special Considerations

• Severe toxicity threshold: ≥2,000 mg in isolated propranolol overdose 4
• Hemodialysis: Not recommended due to high protein binding and lipophilicity of propranolol 1
• Bronchospasm: May be treated with isoproterenol and aminophylline 2
• Hypoglycemia: Monitor closely and treat as needed, especially common with high-dose insulin therapy

Monitoring During Treatment

• Continuous cardiac monitoring
• Blood pressure and heart rate
• Blood glucose levels (every 15-30 minutes initially, then hourly)
• Serum potassium (risk of hypokalemia with insulin therapy)
• Neurological status
• Fluid balance and urine output

Treatment Tapering

• Begin tapering vasopressors and insulin therapy as the patient stabilizes
• Continue monitoring for rebound hypotension or bradycardia
• Observe for at least 24 hours after severe overdose due to risk of delayed toxicity

Pitfalls and Caveats

• Avoid using epinephrine alone as it may provoke uncontrolled hypertension 2
• Propranolol toxicity presents with cardiac, neurological, and respiratory manifestations
• Time interval between ingestion and treatment initiation is critical for prognosis 1
• Patients with liver disease are at higher risk for beta-blocker toxicity, even at therapeutic doses 1