This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autonomic nervous system, Subject name: Pharmacology
[{'content': 'Which of the following is used in beta-blocker overdose? \nSelect and explain. \nA. Atropine, B. Nor-Epinephrine, C. Glucagon, D. Calcium chloride', 'role': 'user'}, {'content': "Answer: C \nExplanation: Glucagon increases hea rate and myocardial contractility and improves atrioventricular conduction. These effects are unchanged by the presence of beta-receptor blocking drugs. This suggests that glucagon's mechanism of action may bypass the beta-adrenergic receptor site. Because, it may bypass the beta-receptor site, glucagon can be considered as an alternative therapy for profound beta-blocker intoxications. The dose of glucagon required to reverse severe beta-blockade is 50 micrograms/kg iv loading dose, followed by a continuous infusion of 1-15 mg/h, titrated to patient response.", 'role': 'assistant'}]