What is the standard EMS aspirin dose for suspected ACS, and how should it be administered?

• A. 81 mg swallowed with water
• B. 162–325 mg chewed, unless contraindicated
• C. 500 mg chewed and swallowed
• D. 1000 mg swallowed with water

Answer: (B)

Aspirin is given in suspected ACS to act as an antiplatelet and help prevent further clot formation. The fastest, most practical effect comes from a single dose in the range of 162–325 mg that is chewed before swallowing. Chewing increases surface area and speeds absorption, leading to quicker onset of the antiplatelet action. This is why the recommended approach is to give a chewable dose within that 162–325 mg window and then swallow, unless there’s a contraindication (such as allergy or active GI bleeding). Doses like 81 mg are too small for ACS, and 500 or 1000 mg are not standard in EMS due to increased GI risk without added benefit.