Management of NSAID-Induced Anaphylaxis
Prompt administration of intramuscular epinephrine is the first-line treatment for anaphylaxis, including NSAID-induced anaphylaxis, followed by supportive care and observation for potential biphasic reactions. 1
Immediate Management
First-Line Treatment
- Administer epinephrine 1:1000 (1 mg/mL) at a dose of 0.2-0.5 mL (0.01 mg/kg in children, maximum 0.3 mg) intramuscularly into the lateral thigh (vastus lateralis) 1
- Repeat epinephrine every 5 minutes as necessary to control symptoms and blood pressure 1
- Epinephrine autoinjectors (e.g., EpiPen 0.3 mg or EpiPen Jr 0.15 mg) may be used as an alternative 1
Positioning and Airway Management
- Place patient in recumbent position and elevate lower extremities 1
- Establish and maintain airway (endotracheal intubation or cricothyrotomy may be required in severe cases) 1
- Administer oxygen at 6-8 L/min 1
Vascular Access and Fluid Resuscitation
- Establish venous access 1
- Administer normal saline for fluid replacement (may require 1-2 L in adults) 1
- For hypotension refractory to epinephrine and volume replacement, consider vasopressors such as dopamine (400 mg in 500 mL D5W at 2-20 μg/kg/min) 1
Second-Line Treatments
Antihistamines
- Administer diphenhydramine 1-2 mg/kg or 25-50 mg parenterally 1
- Consider adding ranitidine 1 mg/kg or 50 mg IV (diluted in 5% dextrose to 20 mL, administered over 5 minutes) 1
- Note: Antihistamines are second-line therapy and should never be used alone to treat anaphylaxis 1
For Persistent Bronchospasm
- Consider nebulized albuterol 2.5-5 mg in 3 mL saline if bronchospasm is resistant to epinephrine 1
For Patients on Beta-Blockers
- Consider glucagon 1-5 mg IV (20-30 μg/kg, maximum 1 mg in children) over 5 minutes followed by infusion (5-15 μg/min) if beta-blocker therapy complicates treatment 1
Corticosteroids
- Consider systemic glucocorticosteroids for patients with history of asthma or severe/prolonged anaphylaxis 1
- IV steroids should be administered every 6 hours at a dosage equivalent to methylprednisolone 1.0-2.0 mg/kg/day 1
- Oral prednisone 0.5 mg/kg may be sufficient for less critical episodes 1
- Note: Corticosteroids are not helpful acutely but may prevent recurrent or protracted anaphylaxis 1
Management of Cardiopulmonary Arrest
- Implement cardiopulmonary resuscitation and advanced cardiac life support measures 1
- Consider high-dose IV epinephrine: 1-3 mg (1:10,000 dilution) slowly over 3 minutes, then 3-5 mg over 3 minutes, followed by 4-10 μg/min infusion 1
- For children, initial resuscitation dose is 0.01 mg/kg (0.1 mL/kg of 1:10,000 solution) 1
Post-Acute Care
Observation Period
- Monitor patients for 4-12 hours after initial reaction to observe for potential biphasic reactions 2
- Longer observation periods may be necessary for patients with risk factors for severe anaphylaxis 2
Follow-up Care
- Refer patient to an allergist for comprehensive evaluation 1
- Identify the specific NSAID trigger through history and follow-up testing 1
- Provide patient education on avoidance of the triggering medication 1
- Prescribe self-injectable epinephrine and educate on proper use 1
- Advise patient to wear medical identification (e.g., Medic Alert jewelry) 1
Special Considerations
Risk Factors for Severe Reactions
- Coexisting asthma 2
- Mast cell disorders 2
- Older age 2
- Underlying cardiovascular disease 2
- Concomitant beta-blocker therapy 1
Common Pitfalls to Avoid
- Delaying epinephrine administration (epinephrine is the drug of choice and should be given promptly) 1
- Using antihistamines or corticosteroids as first-line treatment instead of epinephrine 1
- Failing to place patient in recumbent position (may worsen hypotension) 1
- Inadequate fluid resuscitation in hypotensive patients 1
- Discharging patients too early without adequate observation for biphasic reactions 2