Epinephrine
Epinephrine (adrenaline)
Brand names:EpiPen, Auvi-Q, Adrenaclick, Adrenalin
An endogenous catecholamine and the universally life-saving treatment for anaphylaxis and cardiac arrest. Epinephrine activates alpha-1, beta-1, and beta-2 adrenergic receptors, producing vasoconstriction, increased cardiac output, and bronchodilation simultaneously. Standard IM doses (0.3 mg adult, 0.15 mg pediatric) treat anaphylaxis. IV/IO doses (1 mg) drive cardiac arrest resuscitation. Wrong dose or wrong route can be lethal.
Pharmacology and Actions
Epinephrine is a non-selective alpha and beta adrenergic agonist. Alpha-1 effects: vasoconstriction, increased systemic vascular resistance, reduced mucosal edema in anaphylaxis. Beta-1 effects: increased heart rate, contractility, conduction velocity. Beta-2 effects: bronchodilation, smooth muscle relaxation, mast cell stabilization (reduces further histamine release). The combination of these three effects makes epinephrine uniquely suited for anaphylaxis - it simultaneously reverses bronchospasm, restores blood pressure, reduces edema, and stabilizes the inflammatory cascade.
Indications
- Anaphylaxis (FIRST-LINE, ESSENTIAL - no substitute exists)
- Cardiac arrest (asystole, PEA, refractory VF/VT)
- Severe bronchospasm refractory to albuterol
- Symptomatic bradycardia unresponsive to atropine (infusion)
- Severe hypotension and septic shock (infusion)
- Local hemostasis (combined with local anesthetics)
- Croup (nebulized racemic epinephrine)
Absolute Contraindications
- None in life-threatening situations (anaphylaxis, cardiac arrest) - the benefit always outweighs risk
- Relative: known hypersensitivity to epinephrine (extremely rare), narrow-angle glaucoma (topical avoid)
Precautions and Side Effects
Common: tachycardia, palpitations, anxiety, tremor, headache, pallor, sweating. Cardiovascular: hypertension (especially with IV bolus), arrhythmias, myocardial ischemia in patients with coronary disease, takotsubo cardiomyopathy (rare). Hyperglycemia. Hypokalemia. Lactic acidosis at high doses. Drug interactions: beta-blockers can produce paradoxical hypertension via unopposed alpha effect; halogenated anesthetics increase arrhythmia risk; tricyclic antidepressants and MAOIs potentiate effects; alpha-blockers reduce effect. No real contraindication in life-threatening anaphylaxis or arrest. Half-life 2 to 3 minutes - rapid metabolism by MAO and COMT, requiring repeated dosing or continuous infusion for sustained effect. Pregnancy Category C (use as indicated for life-threatening reactions). Compatible with lactation in acute use. Pediatric dosing weight-based: 0.01 mg/kg IM for anaphylaxis (max 0.3 mg single dose), 0.01 mg/kg IV/IO every 3 to 5 minutes for arrest. Monitor heart rate, blood pressure, rhythm, and clinical response. IV bolus dosing for anaphylaxis is reserved for severe shock with imminent cardiovascular collapse - IM is the standard route for anaphylaxis even when IV access is established, because IM is safer and equally effective for most cases.
Adult Dosing
Pediatric Dosing
Anaphylaxis IM: 0.01 mg/kg of 1:1,000 (max 0.3 mg single dose); 0.15 mg auto-injector (EpiPen Jr) for 15 to 30 kg children; 0.3 mg auto-injector for over 30 kg. Cardiac arrest: 0.01 mg/kg of 1:10,000 IV/IO every 3 to 5 minutes (max 1 mg single dose).
Pharmacokinetics
Peak Effect: IV: 1 to 2 minutes. IM: 5 to 15 minutes.
Duration: 5 to 15 minutes (IV bolus); 30 minutes to 2 hours (IM).
Storage and Handling
Store at room temperature (15 to 25 degrees C). Protect from light. Do not refrigerate auto-injectors. Inspect solution before use - discard if discolored (pink, brown, or yellow) or contains particulate matter; epinephrine is normally clear and colorless. Auto-injectors have expiration dates; some studies suggest residual potency past expiration but operational practice is to maintain in-date supply. Heat exposure (vehicle dashboard in summer) degrades epinephrine rapidly.
Reconstitution:
Available concentrations: 1:1,000 (1 mg/mL) for IM use; 1:10,000 (0.1 mg/mL) for IV bolus; 1:100,000 (0.01 mg/mL) for selected IV applications. Auto-injectors are prefilled and ready to use - remove safety cap, swing and press firmly against anterolateral thigh, hold for 3 to 10 seconds per device instructions. For infusion: 1 mg in 250 mL NS or D5W yields 4 mcg/mL; titrate to clinical effect.
TCCC and TECC Role
Epinephrine is core TCCC doctrine for anaphylaxis. TCCC 2026 anaphylaxis protocol: epinephrine 0.3 mg IM in anterolateral mid-thigh (EpiPen or equivalent) as first-line, repeated every 5 to 15 minutes if no response, followed by H1 blocker (diphenhydramine), H2 blocker (famotidine or cimetidine), and corticosteroid (methylprednisolone or dexamethasone). The auto-injector format is doctrine because it eliminates dose calculation under stress and ensures correct route and depth. By definition the patient is non-mission-capable once requiring epinephrine; post-anaphylaxis observation for 4 to 6 hours is required due to biphasic reaction risk.
Epinephrine is the single most important medication in any allergic or anaphylactic emergency, and one of the most important in cardiac arrest. The doctrine is unambiguous: any patient with anaphylaxis (defined as systemic allergic reaction with respiratory, cardiovascular, or two organ system involvement) gets epinephrine IM immediately - not after a trial of antihistamines, not after corticosteroids, immediately. The auto-injector format is the standard for field use because it eliminates dosing errors and dilution mistakes that have killed patients (drawing up 1:1,000 thinking it is 1:10,000, or vice versa). The 1:1,000 concentration is for IM use; 1:10,000 is for IV use in cardiac arrest. Mixing these up gives a 10-fold dosing error in either direction. Always confirm concentration before drawing up epinephrine.
Withholding or delaying epinephrine in anaphylaxis while administering antihistamines, corticosteroids, or fluids first. Epinephrine is the only intervention that reverses the immediate life-threatening physiology of anaphylaxis; everything else is adjunctive. Patients have died waiting for diphenhydramine to work while the airway closes. The other catastrophic mistake is IV bolus of 1:1,000 concentration in a non-arrest patient - the dose is 10 times what was intended and produces hypertensive emergency, severe arrhythmia, and MI. Always check concentration: 1:1,000 is 1 mg/mL (IM use, 0.3 mL = 0.3 mg adult dose); 1:10,000 is 0.1 mg/mL (IV use, 10 mL = 1 mg arrest dose).
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
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Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Epinephrine
| IV/IO | Cardiac arrest: 1 mg (10 mL of 1:10,000) IV/IO every 3 to 5 minutes, push, follow with 20 mL saline flush. Anaphylactic shock with cardiovascular collapse: 0.1 mg (1 mL of 1:10,000) IV slow push (extremely cautious - rapid IV bolus in non-arrest can cause hypertensive emergency and MI). Infusion for severe anaphylaxis or post-arrest: 0.1 to 1 mcg/kg/min titrated. Severe bradycardia: 2 to 10 mcg/min IV infusion. (Immediate) |
| IM | ANAPHYLAXIS STANDARD: 0.3 mg (0.3 mL of 1:1,000) IM in anterolateral mid-thigh (vastus lateralis), repeat every 5 to 15 minutes if needed. Adult EpiPen auto-injector delivers 0.3 mg. Anterolateral thigh absorption is faster and more reliable than deltoid IM administration. (5 to 10 minutes) |
| IN | None (None) |
| PO | None (None) |