What is the antidote for beta-blocker overdose?

• A. Glucagon
• B. Librium
• C. Atropine
• D. Flumazenil

Answer: (A)

The antidote for beta-blocker overdose is glucagon. This is due to glucagon’s ability to increase heart rate and contractility through its action on the heart’s adrenergic receptors. In cases of beta-blocker overdose, the primary concern is bradycardia and reduced cardiac output caused by the blockade of beta-adrenergic receptors. Glucagon can effectively counteract these effects by bypassing the beta receptors, stimulating adenylate cyclase through a different mechanism, and thereby increasing intracellular cAMP levels, which leads to increased heart rate and improved cardiac function.

In contrast, the other options are not effective for this specific scenario. Librium is a benzodiazepine used primarily for anxiety and alcohol withdrawal, while atropine is an anticholinergic agent that can increase heart rate but is not a preferred treatment for beta-blocker overdose. Flumazenil is a benzodiazepine antagonist used in cases of benzodiazepine overdose, but it has no role in managing beta-blocker toxicity. Therefore, glucagon stands out as the specific and effective antidote for addressing the complications arising from beta-blocker overdose.