What is the typical maximum single-dose aspirin in EMS, and how might protocols vary?

• A. 325 mg per dose; protocols may allow up to 325 mg.
• B. 81 mg per dose.
• C. 500 mg per dose.
• D. 1000 mg per dose.

Answer: (A)

The main concept is that aspirin given in the field for suspected heart attack is dosed to rapidly inhibit platelets, typically with a single maximum dose of about 325 mg. This dose is chosen because it provides enough platelet inhibition quickly while keeping bleeding risk reasonable in the prehospital setting. In practice, this total is often delivered as a chewable tablet, or by multiple smaller tablets (for example, four 81 mg tablets) that sum to about 324 mg, to ensure fast absorption. Protocols may vary in whether they use one chewable 325 mg tablet or multiple 81 mg tablets to reach roughly the same total, but the target stays around 324–325 mg. Higher single doses (like 500 mg or 1000 mg) aren’t typical in EMS due to increased bleeding risk and no proven extra benefit. An 81 mg dose is commonly used for routine daily prevention, not as the prehospital loading dose for suspected ACS.