Can cetirizine (antihistamine) cause angioedema?

Can Cetirizine Cause Angioedema?

Yes, cetirizine can cause angioedema as an allergic reaction, although it is paradoxically more commonly used to treat angioedema rather than cause it. 1

Cetirizine and Angioedema: Evidence and Mechanisms

• Cetirizine is listed as having angioedema as a potential allergic adverse effect in medical guidelines 1
• In the Japanese Encephalitis Vaccine safety studies, a case of urticaria was reported in a patient who received the vaccine, and this patient was treated with cetirizine hydrochloride for the reaction, indicating cetirizine is typically used to treat rather than cause angioedema 1
• Cetirizine is a second-generation H1 antihistamine commonly used to treat allergic conditions including urticaria and angioedema 1

Paradoxical Nature of Cetirizine and Angioedema

• While cetirizine is primarily used to treat angioedema, rare cases of paradoxical reactions can occur where the medication itself triggers angioedema 2
• This phenomenon has been documented in patients with NSAID sensitivity, where antihistamines including cetirizine can trigger urticaria/angioedema 2
• These reactions represent an unusual subset of drug hypersensitivity where the treatment for the condition can occasionally cause the same condition 3

Clinical Management of Cetirizine-Induced Angioedema

• If angioedema occurs after cetirizine use, the medication should be discontinued immediately 3
• Alternative non-sedating antihistamines from a different chemical class may be considered (e.g., if reaction to cetirizine occurs, consider fexofenadine as an alternative) 2
• For severe angioedema with respiratory compromise, emergency management may include epinephrine, diphenhydramine, and intravenous corticosteroids 3

Risk Factors for Antihistamine-Induced Angioedema

• Patients with known NSAID sensitivity may be at higher risk for paradoxical reactions to antihistamines 2
• Cross-reactivity between different antihistamines is possible but not universal 2
• Patients with a history of multiple drug allergies may be at increased risk 3

Cetirizine's Normal Role in Treating Angioedema

• Cetirizine is actually a first-line treatment for histamine-mediated angioedema 1
• It is often used at doses of 10mg daily, though higher doses (up to 20mg daily) may be used in refractory cases 1
• Cetirizine has been shown to be effective in combination with montelukast for suppressing recurrent angioedema 4

Differential Diagnosis of Angioedema

• When evaluating angioedema, consider other more common causes:
  • ACE inhibitor-induced angioedema 3
  • Hereditary or acquired C1 esterase inhibitor deficiency 1
  • NSAID-induced angioedema 3, 2
  • Idiopathic angioedema 4

Clinical Pearls and Pitfalls

• Do not automatically rule out cetirizine as a cause of angioedema simply because it is typically used to treat the condition 2
• When treating a patient with angioedema who has been taking cetirizine, consider whether the medication might be contributing to rather than alleviating symptoms 3
• In patients with recurrent angioedema unresponsive to cetirizine alone, consider combination therapy with leukotriene modifiers 4
• Always take a complete medication history in patients with angioedema to identify potential drug triggers 3