💊 Epinephrine

Epinephrine is the single most important drug in EMS. It's first-line for cardiac arrest and anaphylaxis — two of the highest-acuity calls you'll run. On the NREMT, epinephrine shows up in pharmacology questions, cardiac arrest algorithms, and allergic reaction scenarios. You need the doses, routes, and ratios cold because the test will make you differentiate between IM (1:1,000) and IV (1:10,000) concentrations every time.

The mechanism: epinephrine is a non-selective alpha and beta agonist. Alpha-1 causes vasoconstriction (shunts blood to core during arrest). Beta-1 increases heart rate and contractility. Beta-2 dilates bronchioles — critical in anaphylaxis and severe asthma. Understanding this triad helps you predict both therapeutic effects and side effects on the exam.

For cardiac arrest per ACLS 2025: give 1 mg IV/IO every 3-5 minutes. First dose should come early — delayed administration is associated with worse survival. For anaphylaxis, 0.3-0.5 mg IM in the mid-outer thigh is standard. The thigh is preferred over the arm for better blood flow and absorption. Repeat every 5-15 minutes if no response.

Common NREMT trap: EpiPen delivers 0.3 mg IM, EpiPen Jr delivers 0.15 mg IM for pediatrics. The test also asks about racemic epinephrine nebulized for croup. Master epinephrine dosing and you've mastered the single most testable drug in NREMT pharmacology.

💉 Dosage & Administration

Adult: 1 mg (10 mL of 1:10,000) IV/IO q3-5min in arrest; 0.3-0.5 mg IM (1:1,000) for anaphylaxis

Pediatric: 0.01 mg/kg (0.1 mL/kg of 1:10,000) IV/IO q3-5min; 0.01 mg/kg IM (1:1,000) max 0.3 mg

Route: IM, IV, IO, ETT, Nebulized

Onset: Immediate IV; 5-10 min IM

Duration: 5-10 minutes

Notes: First-line for anaphylaxis and cardiac arrest. Push early in arrest — delayed epi = worse outcomes.