Resuscitation Council UK (RCUK) Advanced Life Support (ALS) Practice Exam

Phentolamine is the correct choice for reversing coronary vasoconstriction caused by cocaine. Cocaine leads to vasoconstriction primarily through the blockade of norepinephrine reuptake, resulting in increased sympathetic activity and vasoconstriction of coronary arteries. Phentolamine is an α-adrenergic antagonist that can counteract the effects of elevated adrenergic activity, thereby promoting vasodilation and improving blood flow to the coronary tissues.

In the context of treating cocaine-induced coronary vasoconstriction, phentolamine can help alleviate the excessive constriction of coronary vessels, making it a preferred choice in this scenario. It directly opposes the pathway that cocaine activates, helping to restore normal coronary blood flow.

Adrenaline is primarily a vasopressor and may exacerbate the condition by further increasing heart rate and myocardial oxygen demand, making it less suitable for reversing vasoconstriction induced by cocaine. Aspirin, while beneficial in preventing thrombotic complications, does not have a direct effect on coronary vasoconstriction. Propranolol, a non-selective β-blocker, could worsen coronary perfusion by reducing heart rate and myocardial contractility and might exacerbate vasoconstriction in the context of cocaine