Emergency Medicine Drugs Practice Test

In suspected ACS, the goal is rapid and potent platelet inhibition to blunt thrombus formation as soon as possible. Aspirin does this by irreversibly inhibiting COX-1 in platelets, which decreases thromboxane A2 and prevents further platelet aggregation for the life of the platelet. Because speed matters, a single loading dose of chewable aspirin is recommended right away and should be in the 160–325 mg range. Chewing speeds absorption, so the antiplatelet effect kicks in sooner, which is crucial in the early treatment window. The common, guideline-supported approach is to give around 325 mg when available, or at least 160 mg if needed. Other dosing choices aren’t appropriate for the acute setting: a daily 81 mg is a maintenance dose and doesn’t provide the short-term antiplatelet impact needed in ACS, while 75 mg or 500 mg are not standard acute doses and don’t align with recommended practice.