What medications are used to treat acute angioedema?

Medication Management for Acute Angioedema

For acute angioedema, treatment must be tailored to the specific type: histamine-mediated angioedema responds to antihistamines, corticosteroids, and epinephrine, while bradykinin-mediated angioedema (including hereditary angioedema) requires specific medications such as icatibant (30 mg subcutaneously) or C1 esterase inhibitor concentrates (20 IU/kg IV). 1

Classification and Treatment Algorithm

Step 1: Identify the Type of Angioedema

• Histamine-mediated angioedema:

  • Usually presents with urticaria (hives)
  • Often associated with allergen exposure
  • Responds to standard treatments

• Bradykinin-mediated angioedema:

  • No urticaria present
  • Includes hereditary angioedema (HAE), acquired C1 inhibitor deficiency, and ACE inhibitor-associated angioedema
  • Does NOT respond to standard treatments

Step 2: Treatment Based on Type

For Histamine-Mediated Angioedema:

1. H1 antihistamines: First-line treatment

   • Non-sedating second-generation antihistamines (cetirizine, fexofenadine) at 2-4 times FDA-approved doses 1
   • For post-anaphylaxis: Diphenhydramine every 6 hours for 2-3 days plus H2 antihistamine (ranitidine twice daily for 2-3 days) 1

2. Corticosteroids: Effective for reducing inflammation

3. Epinephrine: For severe reactions or anaphylaxis

   • 150 μg for body weight >10 kg
   • 300 μg for body weight >30 kg 2

For Bradykinin-Mediated Angioedema (including HAE):

1. Icatibant: 30 mg subcutaneously in abdominal area

   • May repeat at 6-hour intervals if needed
   • Maximum 3 injections in 24 hours 1, 3

2. C1 esterase inhibitor concentrate: 20 IU/kg IV 1

3. Fresh frozen plasma: Can be used if specific treatments unavailable

   • Caution: May occasionally worsen attacks 4

Important Clinical Considerations

Critical Warning

Epinephrine, corticosteroids, and antihistamines are NOT effective for hereditary angioedema (HAE) and other bradykinin-mediated angioedema 4, 1. Using these standard treatments in bradykinin-mediated angioedema wastes critical time and may lead to poor outcomes.

Airway Management

For angioedema affecting the head and neck, securing the airway is the highest priority 2. Early treatment is crucial for pharyngeal attacks to prevent progression to complete airway obstruction 1.

Self-Administration

Patients with HAE may self-administer icatibant upon recognition of an attack 3. This early intervention can significantly reduce attack severity and duration.

Special Populations

• Elderly patients: Demonstrate increased systemic exposure to icatibant, though specific dosing adjustments are not established 3
• Pregnancy: Plasma-derived C1-INH is the preferred treatment 1

Medication-Specific Considerations

Icatibant (Bradykinin B2 Receptor Antagonist)

• Indicated specifically for HAE attacks in adults ≥18 years
• Cannot be used in children under 18
• Generally safe but carries risk of injection site reactions in almost all patients (97%) 3

C1 Esterase Inhibitor Concentrates

• Available in both IV and subcutaneous formulations
• Effective for both acute treatment and prophylaxis 1
• Significantly reduces attack frequency, making attacks milder and shorter 1

Prevention Strategies

• Avoid ACE inhibitors in patients with history of angioedema 5
• Avoid estrogen-containing contraceptives in patients with HAE 1
• Consider long-term prophylaxis for patients with frequent attacks 1

Remember that early recognition and prompt treatment with the appropriate medication based on angioedema type is crucial for effective management and prevention of life-threatening complications.