From the Guidelines
In beta blocker overdose, epinephrine is generally not the first-line treatment but may be used in severe cases with significant hypotension and bradycardia that are unresponsive to other therapies. Initial management should focus on glucagon (3-10 mg IV bolus, followed by 3-5 mg/hr infusion), which works through a non-beta receptor pathway to increase heart rate and contractility, as recommended by the 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1. If glucagon is ineffective, high-dose insulin therapy (1 unit/kg bolus followed by 0.5-1 unit/kg/hr) with glucose supplementation can be used, as suggested by the 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1. Epinephrine may be considered when these treatments fail, starting at 1-10 mcg/min IV and titrating based on response, but it has limited efficacy due to beta receptor blockade, as noted in the 2023 American Heart Association focused update on the management of patients with cardiac arrest or life-threatening toxicity due to poisoning 1. Epinephrine works primarily through alpha-adrenergic effects in this setting, causing vasoconstriction to maintain blood pressure. Other vasopressors like norepinephrine or vasopressin may be more effective. The challenge with epinephrine in beta blocker overdose is that the blocked beta receptors prevent its chronotropic and inotropic effects, making it less effective than in other shock states. Hemodialysis, lipid emulsion therapy, or mechanical circulatory support may be necessary in severe cases unresponsive to pharmacological interventions. Key considerations in the management of beta blocker overdose include:
- Initial stabilization with glucagon and high-dose insulin therapy
- Use of epinephrine as a secondary agent, with careful titration and monitoring
- Consideration of alternative vasopressors, such as norepinephrine or vasopressin
- Potential need for advanced interventions, such as hemodialysis or mechanical circulatory support, in severe cases.
From the Research
Treatment for Beta Blocker Overdose
The treatment for beta blocker overdose involves various interventions to manage the resulting cardiovascular complications.
- Gastric decontamination with activated charcoal may be considered, but its effectiveness is unclear due to concurrent use of multiple interventions 2.
- Catecholamines, such as epinephrine, may be used to improve haemodynamics, including heart rate and blood pressure 2.
- High-dose insulin euglycaemic therapy has been associated with improved haemodynamics and mortality benefit, but its use is often accompanied by hypoglycaemia and hypokalemia 2.
- Glucagon has been shown to increase heart rate and improve atrioventricular conduction, but its effectiveness in reversing beta-blocker toxicity is limited 3, 4, 2.
- Other treatments, such as calcium salts, vasopressors, and advanced therapies like ECMO, may be indicated depending on the severity of toxicity and specific agents involved 2, 5.
Specific Considerations for Epinephrine Use
Epinephrine is a catecholamine that may be used to treat beta blocker overdose, particularly in cases of severe bradycardia and hypotension.
- The use of epinephrine in beta-blocker overdose is supported by case reports and animal studies, which suggest that it can improve haemodynamics and provide a survival benefit 2.
- However, the effectiveness of epinephrine may be limited by the presence of beta-blockers, which can reduce its efficacy 2.
- Therefore, epinephrine should be used in conjunction with other treatments, such as high-dose insulin euglycaemic therapy and glucagon, to manage beta blocker overdose effectively 2.