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
• Administer activated charcoal if available and no contraindications exist, but do not delay transportation 3
• Provide IV fluids for hypotension during transport 3

First-Line Pharmacological Therapy for Refractory Shock

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

High-dose insulin with glucose is reasonable as first-line therapy for refractory shock from beta blocker overdose. 1, 2

• Administer a bolus of 1 U/kg insulin, followed by continuous infusion of 1-10 U/kg/hour titrated to clinical effect 1, 4
• Coadminister dextrose and potassium infusions to prevent hypoglycemia and hypokalemia 1
• This therapy was associated with mortality benefit in multiple case series and showed clear haemodynamic improvement in timeframes consistent with insulin administration 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 from beta blocker overdose. 1, 2

• Glucagon bypasses the beta-adrenergic receptor site, making it effective despite beta-blockade 5
• Administer 50 micrograms/kg IV loading dose, followed by continuous infusion of 1-15 mg/hour, titrated to patient response 5
• Glucagon increases heart rate, myocardial contractility, and improves atrioventricular conduction 5
• Monitor for side effects including nausea, vomiting, hypokalemia, and hyperglycemia 6, 5
• If dramatic increase in blood pressure occurs, phentolamine mesylate can lower blood pressure 6

Second-Line Therapies

Calcium Administration (Class 2b Recommendation)

• Calcium may be considered in patients with refractory shock, though evidence is limited 1, 2
• Intravenous calcium was associated with haemodynamic improvement in three out of six case reports and two animal studies 4

Catecholamines and Vasopressors

• Norepinephrine increases blood pressure in vasoplegic shock 2
• Epinephrine increases contractility and heart rate 2
• Catecholamines most likely provide survival benefit and improved haemodynamics based on multiple case reports and series 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 4
• Early recognition of the indication for ECMO is one of the most important predictive factors for morbidity and mortality 7
• The first two patients in one series died of multi-organ failure due to delayed ECMO installation, while four others survived without sequelae when ECMO was initiated promptly 7
• Average time on ECMO is approximately 59 hours (range 48-71 hours) 7

Monitoring Duration

• Asymptomatic patients require monitoring for at least 6 hours after ingestion for immediate-release preparations (other than sotalol) 3
• Monitor for 8 hours if sustained-release preparation was ingested 3
• Monitor for 12 hours if sotalol was ingested 3
• Routine 24-hour admission of asymptomatic patients who unintentionally ingested sustained-release preparations is not warranted 3

Critical Pitfall to Avoid

Never abruptly withdraw beta blocker therapy in patients on chronic treatment, as this can lead to clinical deterioration. 1, 2

• If patients develop fluid retention with mild symptoms during chronic therapy, continue the beta blocker while increasing diuretic dose 1
• Only halt or significantly reduce beta blocker temporarily if deterioration involves hypoperfusion or requires IV positive inotropic drugs 1
• Once stabilized, reintroduce the beta blocker to reduce subsequent risk of clinical deterioration 1