What is the treatment for angioedema?

Treatment of Angioedema

The treatment of angioedema depends on its type, with first-line therapies for hereditary angioedema (HAE) including plasma-derived C1 inhibitor, icatibant, or ecallantide, while histamine-mediated angioedema responds to antihistamines, corticosteroids, and epinephrine. 1, 2

Immediate Assessment and Airway Management

• Assess for airway compromise immediately as this is the most critical first step in managing any patient with angioedema 3
• Patients with oropharyngeal or laryngeal involvement should be closely monitored in a medical facility capable of performing intubation or tracheostomy if necessary 3
• Consider elective intubation if the patient exhibits signs of impending airway closure, such as change in voice, loss of ability to swallow, or difficulty breathing 3

Treatment Based on Angioedema Type

Histamine-Mediated Angioedema

• Administer epinephrine (0.1%) 0.3 mL subcutaneously or by nebulizer 0.5 mL for significant symptoms or airway involvement 3
• Give IV diphenhydramine 50 mg and IV methylprednisolone 125 mg 3
• Add H2 blockers such as ranitidine 50 mg IV or famotidine 20 mg IV 3
• For chronic management, use high-dose second-generation H1 antihistamines (fourfold the standard dose), with addition of montelukast if antihistamines alone fail 2

Bradykinin-Mediated Angioedema (HAE)

• Administer plasma-derived C1 inhibitor (1000-2000 U intravenously) or icatibant (30 mg subcutaneously) if available 1, 3
• Icatibant is administered as 30 mg injected subcutaneously in the abdominal area; if response is inadequate or symptoms recur, additional injections of 30 mg may be administered at intervals of at least 6 hours (maximum 3 injections in 24 hours) 4
• Standard treatments for allergic reactions (antihistamines, corticosteroids, epinephrine) are NOT effective for hereditary angioedema 2, 5
• Fresh frozen plasma (10-15 ml/kg) may be considered if specific targeted therapies are unavailable 3

ACE Inhibitor-Induced Angioedema

• Immediately discontinue the ACE inhibitor permanently 3
• Consider bradykinin pathway-targeted therapies such as icatibant (30 mg subcutaneously) 3
• Standard treatments (antihistamines, corticosteroids, epinephrine) are ineffective for ACE inhibitor-induced angioedema 6, 5

Prophylaxis for HAE Patients

Short-Term Prophylaxis

• Before dental or surgical procedures, administer plasma-derived C1 inhibitor (1000-2000 U intravenously) 1, 3
• Alternative options include attenuated androgens (danazol 2.5-10 mg/kg) or tranexamic acid 7, 1
• For high-risk procedures when first-line therapies are unavailable, consider attenuated androgens, fresh frozen plasma, or a combination of both 7

Long-Term Prophylaxis

• For patients with frequent attacks, options include androgens (danazol 100 mg on alternate days) 2
• Tranexamic acid (30-50 mg/kg/day) should be considered as long-term prophylaxis where first-line treatments are not available 7
• Regular monitoring for side effects by blood testing and periodic hepatic ultrasounds should be implemented for patients receiving attenuated androgens 7

Special Populations

Children

• Tranexamic acid should be the preferred drug for long-term prophylaxis in children where first-line agents are unavailable 7, 3
• Fresh frozen plasma should be considered for acute treatment and short-term prophylaxis where first-line agents are unavailable 7
• Attenuated androgens may exceptionally be considered for long-term prophylaxis but side effect burden is likely to be high 7

Pregnant Patients

• C1-INH is the only recommended acute and prophylactic treatment for pregnant patients with hereditary angioedema 3

Common Pitfalls to Avoid

• Delaying epinephrine administration in cases of airway compromise with histamine-mediated angioedema 3
• Using standard angioedema treatments (epinephrine, corticosteroids, antihistamines) for bradykinin-mediated angioedema, which are ineffective 2, 5
• Discharging patients with oropharyngeal or laryngeal involvement without adequate observation 3
• Missing the relationship between ACE inhibitors and angioedema, which can occur even after long-term use of these medications 6
• Failing to recognize that laryngeal attacks are potentially life-threatening with historical mortality rates of approximately 30% or higher 2