Which medication is used to treat beta blocker overdose?

Glucagon is the correct choice for treating beta blocker overdose due to its unique mechanism of action that counteracts the effects of beta-adrenergic receptor blockade. In instances of beta blocker overdose, patients may experience significant bradycardia (abnormally slow heart rate) and hypotension (low blood pressure) because the beta blockers impede the normal adrenergic response which would typically increase heart rate and contractility.

Glucagon works by stimulating the production of cyclic AMP (cAMP) in cardiac myocytes, effectively bypassing the blocked beta receptors and leading to increased heart rate and myocardial contractility. Additionally, glucagon can also improve vascular resistance, helping to ameliorate hypotension. It is particularly useful in situations where patients are non-responsive or have severe symptoms from the overdose.

Other medications mentioned, such as flumazenil and Romazicon, are used to reverse the effects of benzodiazepines and are not applicable in beta blocker overdose scenarios. N-acetylcysteine is primarily used in cases of acetaminophen toxicity and has no role in counteracting beta blocker overdose. Therefore, glucagon’s specific action of enhancing cardiac function makes it the most appropriate treatment option for this medical emergency.