Icatibant
Hereditary angioedema agents
Hereditary angioedema agents
A synthetic peptide that blocks the bradykinin B2 receptor; injected under the skin, it treats acute attacks of hereditary angioedema in adults.
Quick facts
- Group
- Hereditary angioedema agents
- Target
- Bradykinin B2 receptor (G-protein–coupled)
- Used for
- Acute attacks
- Key effects
- Injection-site reactions · Fever · Dizziness
- Monitor
- Airway and breathing during · Response of the swelling
- ATC
- B06AC02
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows icatibant itself (a short peptide chain) bound to the human bradykinin B2 receptor (cryo-EM); as a peptide it has no small-molecule ligand.
Icatibant is a synthetic decapeptide containing five non-natural amino acids. It competes with bradykinin for the B2 receptor on blood vessels, so bradykinin can no longer open the vessel wall, and the swelling of a hereditary angioedema attack recedes.
- In an attack, bradykinin floods the tissues
- Icatibant occupies the B2 receptor instead
- Vessels stop leaking and the swelling recedes
Indications
- Acute attacks of hereditary angioedema in adults Urticaria and angioedema →
Adverse effects
Common
- Injection-site reactions (bruising, redness, swelling, warmth, pain) in almost all patients
- Fever
- Dizziness, drowsiness, headache
- Nausea, rash
- Raised liver enzymes
Contraindications
- None listed on the label beyond allergy to the product
- Caution in acute coronary ischaemia, unstable angina and the weeks after a stroke (theoretical risk from blocking bradykinin)
Key interactions
- ACE inhibitors
- Icatibant may weaken their blood-pressure–lowering effect; ACE inhibitors themselves can trigger bradykinin angioedema
What is monitored
- Airway and breathing during and after the attack
- Response of the swelling
- Number of injections used per day
Administration and safety
- Subcutaneous injection into the abdomen at the start of an attack; patients can self-inject after training
- The solution should be clear and colourless, without particles
- There is a limit on repeat doses within 24 hours, as the label states
- With throat swelling, emergency care is sought immediately after the injection
Pregnancy and breastfeeding
Published data have not shown a clear risk of major birth defects; use in pregnancy is weighed by the treating team.
Nursing care
- Assess the airway first; prepare for airway support in laryngeal attacks
- Teach injection technique and the warning signs that need emergency care
- Warn about drowsiness and dizziness: no driving until the effect is known
- Ask about ACE inhibitor use
Pharmacokinetics
- Absorption
- Subcutaneous; bioavailability about 97%, peak in under 1 hour
- Metabolism
- Broken down by proteolytic enzymes, not by cytochrome P450
- Elimination
- Mainly in urine as inactive fragments; under 10% unchanged
- Half-life
- About 1.4 hours
Test yourself
Think of the answer, then tap the question to see it.
Which receptor does icatibant block?
The bradykinin B2 receptor.
What is its most common adverse effect?
A reaction at the injection site.
Is icatibant used to prevent attacks?
No, it treats acute attacks.
Connections
← Back to the class: Hereditary angioedema agents
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Icatibant injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); DailyMed - ICATIBANT injection (DailyMed (U.S. National Library of Medicine), 2026).
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Representative model, for educational purposes only.