In suspected acute coronary syndrome, which medication should be given immediately?

• A. Nifedipine
• B. Metoprolol
• C. Hydralazine
• D. Aspirin

Answer: (D)

In suspected acute coronary syndrome, the immediate priority is to inhibit platelet aggregation at the site of a ruptured plaque. Aspirin fits this role best because it irreversibly inhibits COX-1 in platelets, lowering thromboxane A2 and preventing further platelet clumping. This antiplatelet effect happens quickly if aspirin is chewed, and it reduces mortality when given early in the course of ACS. The recommended approach is a chewable, non-enteric-coated dose so absorption is rapid, typically around 162–325 mg, unless there’s a contraindication like allergy or active GI bleeding.

Nifedipine is a calcium channel blocker that can cause hypotension and reflex sympathetic activation, which may worsen myocardial ischemia, so it isn’t used as the immediate therapy in ACS. Metoprolol, a beta-blocker, has a beneficial role after stabilization and when there are no contraindications, but it’s not the first-line, universally appropriate immediate treatment. Hydralazine is not used to treat the acute event itself and doesn’t address the primary issue of clot formation in ACS.

So the best immediate step is to give aspirin to rapidly disrupt platelet aggregation and reduce the risk of ongoing thrombosis and death.