What is a common adverse reaction of dopamine infusion compared to norepinephrine?

Dopamine infusion is commonly associated with the potential for arrhythmias, primarily because dopamine influences both dopaminergic and adrenergic receptors. It has dose-dependent effects: at low doses, it primarily stimulates dopaminergic receptors, leading to renal vasodilation, while at moderate to high doses, it increases cardiac contractility and heart rate through beta-adrenergic receptor stimulation. This increased cardiac activity can precipitate arrhythmias, particularly in patients with underlying heart conditions or those receiving high doses.

Norepinephrine, on the other hand, primarily acts on alpha-adrenergic receptors, leading to significant vasoconstriction and an increase in blood pressure, but does not have the same degree of direct impact on heart rhythm compared to dopamine. While both agents can lead to increases in heart rate, the risk of arrhythmia is significantly higher with dopamine due to its effects on cardiac electrical activity.

Therefore, when considering the adverse reactions specific to the infusion of these drugs, arrhythmia stands out as a more common concern with dopamine relative to norepinephrine.