## **Core Concept**
Beta antagonist toxicity, also known as beta-blocker overdose, occurs when there is an excessive amount of beta-blockers in the body, leading to an overstimulation of beta receptors. This results in severe cardiovascular and respiratory symptoms. The management involves supportive care and specific antidotes.

## **Why the Correct Answer is Right**
The drug of choice for beta antagonist toxicity is **. Glucagon** because it increases heart rate and contractility, and also has a positive inotropic effect on the heart, which counteracts the effects of beta-blockade. Glucagon works by stimulating adenylate cyclase directly, bypassing the beta-adrenergic receptor, thereby increasing cyclic AMP levels and cardiac contractility.

## **Why Each Wrong Option is Incorrect**
* **Option A:** - This option is incorrect because, although is used in some cases of beta-blocker overdose, it is not the first-line treatment.
* **Option B:** - This option is incorrect as is not typically used for beta-blocker toxicity.
* **Option D:** - This option is incorrect because, while can be used in certain cases of toxicity, it is not the drug of choice for beta antagonist toxicity.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that in beta-blocker overdose, **glucagon** is the drug of choice because of its ability to increase heart rate and contractility. High-dose may also be considered in some cases. Always monitor the patient's vital signs and adjust treatment accordingly.

## **Correct Answer:** . Glucagon