Management of Beta Blocker Overdose

Treatment Approach

• The American Heart Association recommends high-dose insulin with glucose supplementation as the drug of choice for beta blocker overdose with refractory hypotension, receiving the highest level recommendation (Class 1, Level B-NR) 1
• The American Heart Association suggests initiating vasopressors immediately for hypotension due to beta blocker poisoning (Class 1, Level C-LD), as they are readily available and act quickly 1, 2
• Administer high-dose insulin for hypotension refractory to or in conjunction with vasopressor therapy (Class 1, Level B-NR), as recommended by the American Heart Association 1, 2, 3
• High-dose insulin improves myocardial inotropy in cardiogenic shock from beta blocker poisoning and demonstrates favorable outcomes with lower rates of vasoconstrictive complications compared to vasopressor-only therapy, according to the American Heart Association 1, 3

Antidote Therapy

• The American Heart Association recommends using glucagon as a reasonable alternative for bradycardia or hypotension due to beta blocker poisoning (Class 2a, Level C-LD) 1, 2, 3
• Glucagon increases contractility and improves hemodynamics by activating hepatic adenylate cyclase, bypassing the blocked beta-adrenergic receptors, as stated by the American Heart Association 3
• Atropine may be reasonable for beta blocker-induced bradycardia (Class 2b, Level C-LD), but is often ineffective due to the mechanism of beta blocker toxicity, according to the American Heart Association 1, 2, 3

Rescue Therapy

• The American Heart Association suggests utilizing VA-ECMO for life-threatening beta blocker poisoning with cardiogenic shock refractory to pharmacological interventions (Class 2a, Level C-LD) 1, 2, 3
• Hemodialysis may be reasonable specifically for life-threatening atenolol or sotalol poisoning (Class 2b, Level C-LD), as recommended by the American Heart Association 1, 2, 3

Contraindications

• The American Heart Association states that Intravenous Lipid Emulsion (ILE) is not likely to be beneficial for life-threatening beta blocker poisoning (Class 3: No Benefit, Level C-LD) 1, 2, 3

Treatment of Beta Blocker Overdose

Introduction to Glucagon Therapy

• The American College of Cardiology recommends glucagon as a reasonable treatment for symptomatic bradycardia or hemodynamic compromise due to beta blocker overdose, with a recommended dose of 3-10 mg IV followed by an infusion of 3-5 mg/h 4, 5
• Glucagon is a vasoactive polypeptide that counteracts the effects of beta blockers by activating hepatic adenylate cyclase, promoting glucogenolysis 6

Guideline Recommendations

• The ACC/AHA/HRS 2018 guidelines give glucagon a class IIa recommendation (reasonable) with a level of evidence C-LD for the treatment of bradicardia due to beta blocker overdose 7, 8

Administration Protocol

• The initial dose of glucagon is 3-10 mg IV administered over 3-5 minutes, followed by a continuous infusion of 3-5 mg/h due to the transient effects of glucagon 4, 9

Treatment of Beta Blocker Overdose

• The American College of Cardiology suggests initiating standard support measures (BLS/ACLS) and considering glucagon, calcium, or high-dose insulin therapy for refractory cases 4, 5, 10
• Glucagon can be administered at a dose of 3-10 mg IV with an infusion of 3-5 mg/h, while calcium can be given as 1-2 g of 10% calcium chloride every 10-20 minutes or as an infusion of 0.2-0.4 mL/kg/h 4, 5, 9, 11
• High-dose insulin therapy can be initiated with a bolus of 1 unit/kg followed by an infusion of 0.5 units/kg/h 4, 5, 10

Special Considerations

• For cases refractory to glucagon, temporary transvenous pacing can be considered if bradycardia persists with hemodynamic compromise 4, 9

Monitoring

• Continuous cardiac monitoring is essential to evaluate the response to treatment, and glucose and potassium levels should be controlled during glucagon therapy 10

Glucagon Therapy for Beta‑Blocker Overdose

Indications and Clinical Thresholds

• Glucagon should be started promptly in a beta‑blocker‑overdose patient who develops symptomatic bradycardia (heart rate < 50 bpm) together with hypotension (systolic < 90 mmHg) or signs of poor perfusion that persist after adequate fluid resuscitation and atropine; this is a Class IIa recommendation. 12
• The same recommendation applies when the patient shows features of cardiogenic shock despite initial supportive measures. 13

Dosing Protocol

• Initial bolus: administer 3–10 mg of glucagon intravenously over 3–5 minutes. This dose range is supported by the guideline and is considered a Class IIa recommendation. 12
• Continuous infusion: follow the bolus with an infusion of 3–5 mg per hour; the infusion is required because glucagon’s hemodynamic effects are short‑lived. This regimen also carries a Class IIa recommendation. 13

Pharmacologic Mechanism

• Glucagon reverses beta‑blocker toxicity by stimulating hepatic adenylate cyclase, thereby increasing cyclic AMP independent of blocked β‑adrenergic receptors; this leads to enhanced myocardial contractility and improved atrioventricular conduction. 12

Adverse Effects and Monitoring

• Nausea and vomiting are common adverse effects of glucagon, especially concerning when airway protection is compromised; early airway management should be considered if the patient’s mental status is altered. [12][13]

All statements are derived from cited guideline recommendations (Class IIa) as referenced in the cited sources.