What are the guidelines for prescribing an EpiPen (epinephrine) for anaphylaxis?

Prescribing EpiPen for Anaphylaxis

Prescribe an epinephrine autoinjector to any patient with a history of anaphylaxis or at risk for anaphylaxis (food allergies, insect venom allergies, drug allergies), with clear instructions to inject intramuscularly into the lateral thigh at the first sign of anaphylactic symptoms. 1

Who Should Receive an EpiPen Prescription

• Any patient with a documented history of anaphylaxis should be prescribed an epinephrine autoinjector 1
• Patients at risk for anaphylaxis including those with:
  • Food allergies (especially peanuts, tree nuts, shellfish) 1
  • Insect venom allergies 1
  • Drug allergies with prior systemic reactions 1
  • Idiopathic anaphylaxis 1

Dosing Selection by Weight

For children weighing 10-25 kg (22-55 lbs): Prescribe EpiPen Jr (0.15 mg dose) 2

For children ≥25 kg (55 lbs) and adults: Prescribe standard EpiPen (0.3 mg dose) 2

For adults and children ≥30 kg (66 lbs): FDA-approved dosing is 0.3-0.5 mg 3

The 25 kg threshold is critical because at this weight, the 0.15 mg junior dose provides only 0.006 mg/kg (an underdose), while the 0.3 mg adult dose provides 0.012 mg/kg (a slight overdose but preferable during life-threatening anaphylaxis) 2

Critical Patient Education Points

Administration technique:

• Inject into the anterolateral thigh (vastus lateralis muscle) - this is non-negotiable as it provides peak plasma levels in 8±2 minutes versus 34±14 minutes with subcutaneous deltoid injection 1, 2
• Can inject through clothing if necessary 1
• Hold firmly in place for several seconds after injection 3

Timing is everything:

• Administer at the FIRST sign of anaphylactic symptoms - delayed administration is associated with fatalities 2, 4, 5
• Do not wait for symptoms to worsen 4, 5
• Approximately 500-1000 people die annually in the US from anaphylaxis, primarily due to delayed epinephrine 1

When to use:

• Lip/facial swelling with difficulty breathing 1
• Throat tightness or sensation of closing 1
• Difficulty breathing, wheezing, or stridor 1
• Rash/hives with respiratory symptoms OR hypotension symptoms (dizziness, pallor, altered consciousness) 1
• Vomiting/diarrhea with respiratory or cardiovascular symptoms 1

Prescription Specifications

Prescribe TWO autoinjectors - 7-18% of patients require a second dose 1

Repeat dosing instructions:

• If symptoms do not improve or worsen after 5-10 minutes, administer second dose 1
• Can repeat every 5 minutes as needed until EMS arrives 1

Always call 911 immediately after first dose - even if symptoms improve, as patients may require advanced interventions (intubation, IV fluids, vasopressors) and biphasic reactions can occur 1, 2

Common Prescribing Pitfalls to Avoid

Never prescribe only one autoinjector - patients frequently need a second dose before EMS arrival 1

Do not suggest subcutaneous administration - this delays absorption significantly and is inferior to intramuscular injection 1, 2

Do not prescribe ampules/syringes instead of autoinjectors - this causes significant delays and dosing errors 2

Avoid underdosing in larger children - switch to adult dose at 25 kg, not 30 kg 2

Do not create hesitation about side effects - there are NO absolute contraindications to epinephrine in anaphylaxis, even in patients with cardiac disease, elderly, or pregnancy 2, 3

Documentation Requirements

Document in the prescription and patient chart:

• Specific allergen(s) if known 1
• Weight-based dosing rationale 2, 3
• Patient/caregiver education provided on recognition of anaphylaxis and proper injection technique 5, 6
• Instruction to carry autoinjector at all times 5
• Plan for allergy specialist referral for further evaluation and potential immunotherapy 7

Special Populations

Patients with asthma or other risk factors for fatal anaphylaxis: Consider prescribing the higher dose at lower weights and emphasize even more urgent administration 2

Pregnant women: No contraindication - maternal and fetal survival depends on prompt epinephrine administration 3

Elderly patients with cardiac disease: Still prescribe - risk of death from untreated anaphylaxis far exceeds risk of epinephrine-induced arrhythmia 2, 3

Patients on beta-blockers: Still prescribe, but warn they may require higher doses or additional interventions; beta-blockers antagonize epinephrine's effects but this is not a contraindication 3