What is the antidote for beta-blocker overdose presenting with bradycardia and hypotension?

What is the antidote for beta-blocker overdose presenting with bradycardia and hypotension?

• A. Atropine
• B. Glucagon
• C. Calcium chloride
• D. Epinephrine

Answer: (B)

When beta-blocker overdose causes bradycardia and hypotension, the goal is to restore heart rate and contractility despite blocked beta receptors. Glucagon serves as the antidote because it works independently of those receptors. It binds glucagon receptors on heart cells and activates adenylate cyclase to raise cAMP, boosting heart rate and contractility even when beta-adrenergic receptors are blocked. In practice, give an IV glucagon bolus followed by an infusion per protocol, and monitor blood glucose and electrolytes. Side effects can include nausea and hyperglycemia. Other options like atropine or epinephrine may help or be used as adjuncts, but glucagon uniquely bypasses the blocked receptors to improve hemodynamics in this scenario.

When beta-blocker overdose causes bradycardia and hypotension, the goal is to restore heart rate and contractility despite blocked beta receptors. Glucagon serves as the antidote because it works independently of those receptors. It binds glucagon receptors on heart cells and activates adenylate cyclase to raise cAMP, boosting heart rate and contractility even when beta-adrenergic receptors are blocked. In practice, give an IV glucagon bolus followed by an infusion per protocol, and monitor blood glucose and electrolytes. Side effects can include nausea and hyperglycemia. Other options like atropine or epinephrine may help or be used as adjuncts, but glucagon uniquely bypasses the blocked receptors to improve hemodynamics in this scenario.