What is the treatment for anaphylaxis?

Treatment of Anaphylaxis

Intramuscular epinephrine is the first-line treatment for anaphylaxis and should be administered immediately upon recognition of symptoms. 1, 2

Immediate Management

1. Epinephrine Administration:

   • Dose: 0.01 mg/kg of 1:1000 concentration (1 mg/mL) to a maximum of:
     • Adults: 0.5 mg (0.5 mL)
     • Children: 0.3 mg (0.3 mL) 2
   • Route: Intramuscular injection into the anterolateral thigh 1, 2
   • Timing: Administer immediately; delay increases risk of mortality 1
   • Repeat dosing: If symptoms persist, repeat dose after 5-15 minutes 2

2. Emergency Response:

   • Activate emergency response system/call 911 1
   • Position patient appropriately (supine with legs elevated if hypotensive) 2
   • Monitor vital signs continuously 2

3. Airway Management:

   • Assess airway, breathing, and circulation
   • Administer supplemental oxygen if needed 2

Secondary Interventions (after epinephrine)

• Fluid Resuscitation: Rapid IV fluid bolus with crystalloids (1-2 L in adults) for hypotension 2
• H1 Antihistamines: (e.g., diphenhydramine 25-50 mg IV/IM) for cutaneous symptoms 2
• H2 Antihistamines: (e.g., ranitidine 1 mg/kg IV) may be used as adjunct therapy 2
• Corticosteroids: (e.g., methylprednisolone 1-2 mg/kg IV) may help prevent protracted or biphasic reactions 2
• Bronchodilators: Albuterol 2.5-5 mg via nebulizer for persistent bronchospasm 2

Management of Refractory Anaphylaxis

• For hypotension unresponsive to initial epinephrine and fluids:
  • Consider epinephrine infusion (5-15 μg/min) 2
  • Consider IV epinephrine (1:10,000 concentration) for profound shock 1, 2
  • Glucagon 1-5 mg IV may be considered, especially in patients on beta-blockers 2

Observation Period

• All patients should be observed for at least 4-6 hours after symptom resolution 2
• Extended observation (8-24 hours) for:
  • Severe reactions
  • Patients requiring multiple epinephrine doses
  • History of biphasic reactions
  • Cardiovascular comorbidities 2

Follow-up Care

• Prescribe epinephrine autoinjectors (2) and provide training on proper use 2
• Develop an anaphylaxis emergency action plan 2
• Refer to an allergist for identification of triggers and long-term management 2
• Consider medical identification jewelry or wallet card 2

Important Considerations

• No absolute contraindications exist for using epinephrine to treat anaphylaxis, even in elderly patients or those with cardiac disease 1, 2
• Biphasic reactions can occur up to 72 hours later, with 17% of patients experiencing delayed deterioration 1, 2
• Epinephrine autoinjectors should be stored properly and replaced before expiration 2
• Common pitfalls include:
  • Delaying epinephrine administration while using antihistamines
  • Improper dosing or route (subcutaneous instead of intramuscular)
  • Failure to repeat dose when symptoms persist
  • Inadequate observation time after apparent resolution

Remember that anaphylaxis is a life-threatening emergency, and prompt administration of epinephrine is the most critical intervention that can save lives.