From the Guidelines
Beta blocker overdose or severe side effects should be treated primarily with glucagon, which works through a non-beta receptor pathway to increase heart rate and contractility. The initial dose is 5-10 mg IV given over 1 minute, followed by an infusion of 1-5 mg/hour titrated to clinical response 1. If glucagon is unavailable or ineffective, high-dose insulin therapy (1 unit/kg bolus followed by 0.5-1 unit/kg/hour infusion) with concurrent glucose administration can be used. This works by improving cardiac metabolism and contractility. For patients with significant hypotension, vasopressors like epinephrine (starting at 0.05-0.1 mcg/kg/min) or norepinephrine may be required. Atropine can help manage bradycardia at 0.5-1 mg IV every 3-5 minutes up to 3 mg total. Calcium gluconate (10%) or calcium chloride (10%) at 10-20 mL IV may improve contractility in severe cases. Hemodialysis is generally ineffective for most beta blockers due to their large volume of distribution, though it may help with certain water-soluble agents like atenolol. Supportive care including airway management, ventilation support, and correction of electrolyte abnormalities remains essential throughout treatment.
Key Considerations
- The management of beta blocker overdose or severe side effects prioritizes the restoration of adequate heart rate and contractility.
- Glucagon is the first-line treatment due to its mechanism of action independent of beta receptors.
- The 2022 AHA/ACC/HFSA guideline for the management of heart failure emphasizes the importance of continuing beta blockers in patients with heart failure unless there are clear contraindications, such as advanced degree atrioventricular block or cardiogenic shock 1.
- In cases of beta blocker overdose, the focus is on supportive care and the use of pharmacological agents to counteract the effects of the overdose rather than immediate discontinuation of the drug.
Treatment Approach
- Initial treatment with glucagon or high-dose insulin therapy aims to improve cardiac function.
- Vasopressors may be necessary for managing hypotension.
- Atropine can be used for bradycardia.
- Calcium gluconate or calcium chloride may help in severe cases by improving contractility.
- Hemodialysis may be considered for certain beta blockers but is generally not effective due to their large volume of distribution.
Clinical Decision Making
- The decision to treat beta blocker overdose or severe side effects should be based on the clinical presentation and the potential risks and benefits of the treatment options.
- Continuation of beta blockers is crucial in patients with heart failure unless contraindicated, as discontinuation can lead to increased risk of mortality and clinical deterioration 1.
- The choice of treatment should prioritize the restoration of cardiac function and the management of symptoms, with a focus on supportive care and the judicious use of pharmacological agents.
From the Research
Beta Blocker Reversal Approach
The approach for beta blocker reversal in cases of overdose or severe side effects involves the use of glucagon therapy.
- Glucagon increases heart rate and myocardial contractility, and improves atrioventricular conduction, which can help reverse the cardiovascular depression caused by beta-blocker overdose 2, 3.
- The doses of glucagon required to reverse severe beta-blockade are 50 micrograms/kg iv loading dose, followed by a continuous infusion of 1-15 mg/h, titrated to patient response 2.
- Glucagon-treated patients should be monitored for side effects of nausea, vomiting, hypokalemia, and hyperglycemia 2.
Alternative Therapies
Other therapies, such as phosphodiesterase inhibitors, may also be used in certain cases.
- Phosphodiesterase inhibitors, such as milrinone, can relieve symptoms and improve hemodynamics in patients with advanced congestive heart failure, and can be used as a bridge to beta blockade in severe heart failure 4, 5.
- The combination of milrinone and beta-blockers can be an effective treatment for heart failure, and may allow for the initiation of beta-blocker therapy in patients who would otherwise be unable to tolerate it 4, 5.
Important Considerations
It is essential to note that the use of glucagon and other therapies for beta blocker reversal should be guided by the specific clinical context and patient needs.