Southern California EMS Midterm Practice Test

Aspirin used in prehospital care for suspected ACS is a salicylate with antiplatelet action. The recommended dose is 160–325 mg taken by mouth, often as a chewable tablet to speed absorption. It works by irreversibly inhibiting the enzyme COX-1 in platelets, which lowers thromboxane A2 production and prevents platelets from clumping together. This antiplatelet effect helps reduce clot growth during an acute coronary event. Other options don’t fit because they describe different drugs or routes/doses that aren’t used for this purpose: an opioid would address pain rather than provide antiplatelet therapy, and intravenous dosing is not the standard route for aspirin in prehospital ACS care. Labeling aspirin as an NSAID with an IV dose also mismatches the typical oral antiplatelet use that EMS protocols emphasize.