Which medication may help increase heart rate in cases of suspected beta-blocker overdose leading to bradycardia?

In cases of suspected beta-blocker overdose resulting in bradycardia, glucagon is particularly effective because it has a unique mechanism of action that bypasses the usual adrenergic receptor pathways that are inhibited by beta-blockers. Glucagon acts to increase heart rate and myocardial contractility by increasing intracellular cyclic AMP levels, leading to enhanced cardiac performance. This is crucial in situations where standard treatments, such as atropine, may not be effective due to the presence of beta-blockers, as beta-blockers primarily block the effects of catecholamines on the heart.

Additionally, glucagon's ability to increase heart rate can be particularly beneficial in treating the severe bradycardia associated with beta-blocker overdose, as it provides a direct means of countering the cardiovascular depressant effects of the overdose. This makes glucagon a preferred choice in the management of bradycardia from beta-blocker toxicity.

In contrast, while atropine is often used in bradycardia situations, its efficacy is limited in cases of beta-blocker overdose because the primary mechanism of slowing heart rate is blocked by the beta-blockers themselves. Adrenaline (epinephrine) could be useful, but it is generally reserved for more severe cardiac situations like