Icatibant Aguettant (Icatibant)

Icatibant is a bradykinin B2 receptor antagonist used to treat hereditary angioedema, a disorder characterized by sudden swelling.

• Hereditary angioedema type I: provides rapid relief of swelling during acute attacks.
• Hereditary angioedema type II: reduces severity and shortens duration of attack‑related edema.
• Hereditary angioedema with normal C1‑esterase inhibitor: alleviates sudden swelling episodes in patients lacking a functional inhibitor.
• Acute airway‑involving hereditary angioedema attacks: helps prevent respiratory compromise by decreasing laryngeal edema.

• Icatibant competitively blocks the bradykinin B2 receptor on vascular endothelial cells, preventing bradykinin from binding and activating the receptor. By inhibiting this pathway, the drug stops bradykinin‑mediated vasodilation and increased vascular permeability, which are responsible for the rapid swelling seen in hereditary angioedema attacks. The antagonism is selective and reversible, allowing normal physiological signaling to resume after the drug is cleared.

Icatibant may cause a range of adverse reactions, which are generally categorized by frequency and severity.

Common Side Effects

• Injection site pain: mild to moderate discomfort at the subcutaneous injection site.
• Redness or swelling at injection site: localized erythema or edema.
• Nausea: transient feeling of queasiness.
• Headache: mild to moderate headache occurring after dosing.

Serious or Rare Side Effects

• Hypersensitivity reactions: rash, urticaria, or anaphylaxis requiring immediate medical attention.
• Severe hypotension: marked drop in blood pressure potentially leading to dizziness or syncope.
• Thrombocytopenia: low platelet count observed in rare cases.
• Acute respiratory distress: rare worsening of airway edema despite treatment.

When using Icatibant, several precautions should be observed to ensure safe administration.

• Patient assessment: confirm diagnosis of hereditary angioedema and evaluate severity before injection.
• Allergy screening: check for known hypersensitivity to icatibant or any formulation components.
• Concomitant therapy: review use of ACE inhibitors or other bradykinin‑enhancing drugs that may increase risk of angioedema.
• Monitoring: observe patients for signs of hypersensitivity or worsening edema after administration.
• Pregnancy and lactation: use only if potential benefit justifies potential risk, as safety data are limited.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake the product.

Icatibant can interact with other medicines, and awareness of these interactions helps avoid adverse outcomes.

Major Interactions (Avoid)

• ACE inhibitors: concurrent use may potentiate bradykinin‑mediated angioedema; avoid combination.
• Angiotensin receptor blockers (ARBs): may increase risk of swelling when used together; avoid.

Moderate Interactions (Monitor Closely)

• Estrogen‑containing oral contraceptives: may exacerbate hereditary angioedema frequency; monitor patient response.
• DPP‑4 inhibitors: theoretical increase in bradykinin levels; observe for enhanced edema.
• Other B2 receptor antagonists: additive pharmacologic effect; adjust dosing as clinically indicated.