Which adrenergic agent stimulates all receptors in the heart and is the drug of choice for cardiac arrest?

• A. Epinephrine
• B. Pilocarpine
• C. Guaifenesin
• D. Aminopentamide

Answer: (A)

In cardiac arrest, you need a drug that both boosts heart performance and increases perfusion to vital organs. Epinephrine fits this role because it is a nonselective adrenergic agonist that activates both alpha and beta receptors. On the heart, beta-1 stimulation raises heart rate and the strength of contraction, helping to increase cardiac output. In the vasculature, alpha-1 stimulation causes vasoconstriction, which raises diastolic aortic pressure and improves coronary and cerebral perfusion during CPR. This combination of supporting cardiac function while improving blood flow to essential tissues is why epinephrine is the drug of choice for resuscitation.

Pilocarpine is a muscarinic agonist and would slow the heart, not help during CPR. Guaifenesin is an expectorant with no targeted cardiovascular effect to support resuscitation. Aminopentamide is an anticholinergic for GI issues and not used to enhance cardiac arrest outcomes.