What is the treatment for beta blocker overdose?

Treatment for Beta Blocker Overdose

For beta blocker overdose with refractory shock, initiate high-dose insulin with glucose as first-line therapy, followed by IV glucagon, with ECMO reserved for cases failing pharmacological management. 1, 2

Initial Stabilization and Monitoring

• Establish cardiac monitoring, secure the airway if needed, and obtain IV access as part of standard BLS/ACLS resuscitation protocols 2
• Beta blocker overdose characteristically presents with life-threatening hypotension and/or bradycardia that may be refractory to standard vasopressor infusions 1, 2
• Patients with suspected self-harm or malicious administration should be referred to an emergency department immediately regardless of reported dose 3
• Consider oral activated charcoal if available and no contraindications exist, but do not delay transportation 3

First-Line Pharmacological Therapy for Refractory Shock

High-Dose Insulin with Glucose (Class 2a Recommendation)

The American Heart Association recommends high-dose insulin with glucose as reasonable first-line therapy for refractory shock from beta blocker overdose. 1, 2

• Administer a bolus of 1 U/kg IV, followed by continuous infusion of 1 U/kg per hour, titrated to clinical effect 1
• Coadminister dextrose and potassium infusions to prevent hypoglycemia and hypokalemia 1
• Maintenance dosing ranges from 1-10 units/kg/hour of insulin based on patient response 4
• This therapy was associated with mortality benefit in 10 case series and showed clear haemodynamic improvement in multiple case reports 4
• Monitor closely for hypoglycemia and hypokalemia, which are commonly observed adverse effects 4

IV Glucagon (Class 2a Recommendation)

IV glucagon is reasonable as first-line therapy for refractory shock, as it bypasses the beta-receptor site to increase heart rate and contractility. 1, 2

• Glucagon increases heart rate, myocardial contractility, and improves atrioventricular conduction independently of beta-receptor blockade 5
• Administer 50 micrograms/kg IV loading dose, followed by continuous infusion of 1-15 mg/hour, titrated to patient response 5
• Multiple case reports and case series have reported improvement in bradycardia and hypotension after glucagon administration 1
• Monitor for side effects including nausea, vomiting, hypokalemia, and hyperglycemia 6, 5
• If dramatic increase in blood pressure occurs, phentolamine mesylate can be used for short-term control 6

Second-Line Therapies

Calcium Administration (Class 2b Recommendation)

• IV calcium may be considered in patients with refractory shock, though evidence is limited 1, 2
• Limited animal data and rare case reports suggest possible utility to improve heart rate and hypotension 1
• Three out of six case reports showed improvement in haemodynamics, though typically in association with multiple other therapies 4

Catecholamines and Vasopressors

• Norepinephrine should be used to increase blood pressure in vasoplegic shock 2
• Epinephrine can be used to increase contractility and heart rate 2
• The use of catecholamines was associated with survival benefit and improved haemodynamics in 16 case reports, 3 case series, and 2 animal studies 4
• A graduated response beginning with IV fluids, followed by single or combination catecholamine inotropes and vasopressors is reasonable depending on the type of haemodynamic compromise 4

Rescue Therapy for Pharmacologically Refractory Cases

ECMO (Class 2b Recommendation)

ECMO might be considered in patients with shock refractory to all pharmacological therapy. 1, 2

• Veno-arterial ECMO was associated with improved survival in patients with severe cardiogenic shock or cardiac arrest in observational studies and case series 4
• Early recognition of the indication for ECMO is one of the most important predictive factors for morbidity and mortality 7
• The average time on ECMO in one series was 59.25 ± 2 hours (range 48-71 hours) 7
• Four of six patients survived without sequelae when ECMO was initiated promptly, while the first two patients died of multi-organ failure due to delayed installation 7

Monitoring and Observation Periods

• Asymptomatic patients who ingested more than the referral dose should be monitored for at least 6 hours after ingestion for immediate-release products (other than sotalol), 8 hours for sustained-release products, and 12 hours for sotalol 3
• Routine 24-hour admission of asymptomatic patients who unintentionally ingested sustained-release preparations is not warranted 3
• Follow-up calls should be made to determine outcome at appropriate intervals for up to 12-24 hours 3

Critical Pitfalls to Avoid

• Never abruptly withdraw beta blocker therapy in patients on chronic therapy, as this can lead to clinical deterioration 1, 2
• Do not induce emesis in beta blocker overdose 3
• Do not delay transportation to administer activated charcoal 3
• Atropine and isoproterenol have been inconsistent in reversing the bradycardia and hypotension of beta blocker overdose 5
• Intravenous lipid emulsion therapy showed variable response in case reports and cannot be reliably recommended 4