What is the correct antidote for beta blocker overdose?

In the case of a beta blocker overdose, glucagon is considered the most effective antidote. This is due to its mechanism of action, which can counteract the effects of beta blockade. Beta blockers work by inhibiting the action of epinephrine and norepinephrine on beta-adrenergic receptors, leading to reduced heart rate, blood pressure, and myocardial contractility. Glucagon, on the other hand, increases cyclic AMP (cAMP) levels in the heart, which helps to increase heart rate and inotropy, effectively reversing the negative inotropic and chronotropic effects caused by beta blockers.

Additionally, glucagon is particularly useful in situations where standard treatment may not be effective, such as in patients with severe symptoms of bradycardia or hypotension following a beta blocker overdose. It is also worth noting that glucagon's effectiveness does not rely on the presence of beta-adrenergic receptors, making it especially valuable in these emergency scenarios.

Other options listed are not appropriate for treating beta blocker overdose. For example, calcium gluconate is primarily used for managing hyperkalemia or calcium channel blocker overdose, while amyl nitrite typically serves as an antidote for cyanide poisoning. Fomepizole is an