How should I write a prescription for epinephrine (adrenaline) auto‑injector (EpiPen) for a patient with documented severe allergy or prior anaphylaxis, specifying strength by weight, two devices, dosing instructions, refill and counseling?

How to Write an Epinephrine Auto-Injector Prescription

Prescribe two epinephrine auto-injectors with weight-based dosing (0.15 mg for 10–25 kg, 0.3 mg for ≥25 kg), include explicit instructions to inject intramuscularly into the anterolateral thigh at the first sign of anaphylaxis and repeat every 5–15 minutes if symptoms persist, provide unlimited refills, and accompany the prescription with a written anaphylaxis emergency action plan and hands-on training. 1

Prescription Components

Drug Name and Formulation

• Write "Epinephrine auto-injector" as the medication name, specifying the brand (EpiPen, Auvi-Q, or generic equivalent) if required by your institution or insurance. 1

Dosing by Weight

For patients weighing 10–25 kg (22–55 lb):

• Prescribe 0.15 mg epinephrine auto-injector. 1

For patients weighing ≥25 kg (≥55 lb):

• Prescribe 0.3 mg epinephrine auto-injector. 1

For infants weighing <10 kg:

• This presents a clinical dilemma because the lowest available auto-injector dose (0.15 mg) exceeds the recommended 0.01 mg/kg for small infants. 1
• For infants >7.5 kg, the 0.15 mg dose is acceptable when no lower-dose device is available. 1
• For infants ≤7.5 kg, consider prescribing epinephrine 1:1000 solution with a syringe for manual injection (0.01 mg/kg), though this requires more training and carries higher risk of dosing error. 1

Quantity

• Dispense: 2 auto-injectors (always prescribe two devices because approximately 10–20% of anaphylactic reactions require a second dose, and the second dose must be available before emergency services arrive). 1, 2

Specific Dosing Instructions (Write on Prescription)

"Inject 0.15 mg [or 0.3 mg] intramuscularly into the anterolateral mid-thigh (vastus lateralis) at the first sign of anaphylaxis. May inject through clothing. Repeat dose every 5–15 minutes if symptoms persist or recur. Call 911 immediately after first injection and proceed to emergency department even if symptoms improve." 1

• The anterolateral thigh is critical because it achieves peak plasma concentrations in 8±2 minutes versus 34±14 minutes with subcutaneous administration. 1
• Injection may be given through clothing, but avoid seams or items in pockets. 1

Refills

• Refills: Unlimited (or specify a large number such as 12 refills) to ensure patients can replace expired devices without delay. 1
• Epinephrine degrades over time even without visible discoloration, so patients must check expiration dates regularly and renew prescriptions promptly. 1

Indications for Prescribing

Mandatory Indications (Always Prescribe)

• Previous anaphylaxis with respiratory or cardiovascular involvement from any trigger. 1
• Food allergy combined with asthma, especially poorly controlled asthma (highest risk group for fatal anaphylaxis). 1
• Known allergy to peanut, tree nuts, fish, or crustacean shellfish (these cause the majority of fatal food-induced anaphylaxis). 1

Strong Consideration (Clinical Judgment Required)

• Any IgE-mediated food allergy, even without prior anaphylaxis, because it is difficult to predict which patients will progress to life-threatening reactions. 1, 3
• Idiopathic anaphylaxis (recurrent anaphylaxis without identified trigger). 1
• Exercise-induced anaphylaxis. 1
• Venom allergy (insect sting anaphylaxis). 1

Required Counseling and Education

Hands-On Training

• Demonstrate auto-injector technique using a trainer device and have the patient/caregiver practice until they can perform it correctly without assistance. 1
• Errors in auto-injector use are common despite the devices being relatively simple. 1
• Review manufacturer educational materials (videos, instruction sheets). 1

Written Anaphylaxis Emergency Action Plan

• Provide a personalized written plan that includes:

  • List of patient's known triggers
  • Common symptoms of anaphylaxis (skin: hives, flushing, itching; respiratory: throat tightness, wheezing, difficulty breathing; cardiovascular: dizziness, fainting, rapid pulse; gastrointestinal: vomiting, cramping)
  • Clear instructions: "Inject epinephrine immediately if [specific symptoms] occur after exposure to [specific trigger]"
  • Instruction to call 911 after injection
  • Instruction to proceed to emergency department even if symptoms improve (risk of biphasic reaction)
  • Emergency contact numbers 1

• Downloadable templates are available from the Food Allergy & Anaphylaxis Network and American Academy of Allergy, Asthma and Immunology. 1

Critical Safety Points to Emphasize

• Inject epinephrine first, at the earliest sign of anaphylaxis—delayed administration is directly linked to fatalities. 1
• Do not rely on antihistamines or asthma inhalers to treat anaphylaxis; they cannot reverse airway obstruction or cardiovascular collapse. 1
• Always seek emergency care after using epinephrine, even if symptoms resolve, because biphasic reactions (recurrence of symptoms) occur in 7–18% of cases, typically around 8 hours later but potentially up to 72 hours. 1, 4
• Carry both auto-injectors at all times; do not leave them in hot cars or direct sunlight, as heat degrades epinephrine. 1
• Check expiration dates monthly and obtain refills before devices expire. 1

When to Inject Epinephrine

• Inject immediately when symptoms occur after known exposure to a trigger that previously caused a significant reaction. 1
• For patients with idiopathic anaphylaxis, use a symptom-based approach: inject when two or more organ systems are involved (e.g., hives plus difficulty breathing, or vomiting plus dizziness). 1
• Do not wait to see if symptoms worsen—early injection reduces hospitalization rates and morbidity. 1

Additional Management Components

Trigger Avoidance and Identification

• Confirm or identify the triggering allergen through allergy testing if not already known. 1
• Provide specific avoidance instructions (reading food labels, avoiding cross-contamination, recognizing hidden allergens). 1

Medical Identification

• Recommend medical alert bracelet or wallet card listing anaphylaxis triggers. 1

Specialist Referral

• Refer to board-certified allergist-immunologist for comprehensive evaluation, trigger confirmation, and consideration of allergen immunotherapy (e.g., venom immunotherapy for insect sting allergy provides long-lasting protection). 1

School/Workplace Accommodation

• For children, work with school administrators to ensure an anaphylaxis emergency action plan is on file, staff are trained, and epinephrine is accessible. 1
• Provide a third auto-injector to keep at school (separate from the two the patient carries). 1

Common Pitfalls to Avoid

• Do not prescribe only one auto-injector—19% of pediatric food-induced anaphylaxis reactions require more than one dose, and the second dose is typically given by healthcare professionals because families run out. 2
• Do not prescribe antihistamines as a substitute for epinephrine—they treat only cutaneous symptoms and provide no protection against respiratory or cardiovascular collapse. 1
• Do not delay prescribing epinephrine for patients with "mild" prior reactions—it is impossible to predict which future reactions will be severe, and delayed epinephrine contributes to fatalities. 3
• Do not forget to review the emergency action plan regularly (at every visit)—knowledge and skills decay over time. 1
• Do not prescribe subcutaneous epinephrine—intramuscular injection in the thigh is the only recommended route for first-aid treatment. 1, 5