An 88-year-old patient with slow heart rate and hypotension is bradycardic; which drug should be administered first?

• A. Atropine
• B. Adenosine
• C. Dopamine
• D. Epinephrine

Answer: (A)

Symptomatic bradycardia with hypotension is best treated first with an anticholinergic that blocks vagal influence on the heart. Atropine increases heart rate by blocking acetylcholine at the SA and AV nodes, removing the parasympathetic brake and allowing faster pacing. Its effect is rapid when given IV, making it the preferred initial intervention to improve perfusion in unstable bradycardia. Typical dosing is an IV bolus of 0.5 mg, repeat every 3–5 minutes as needed up to about 3 mg total. If atropine doesn’t yield a sufficient response (or if a high-grade AV block is present where atropine is less effective), escalate to options like dopamine or epinephrine infusions to support heart rate and blood pressure. Adenosine is reserved for certain tachycardias and would not help a slow, ineffective rhythm; it can even worsen situations by further slowing conduction.