Icatibant (Icatibant Acetate)

Icatibant is used to treat hereditary angioedema, a bradykinin‑mediated swelling disorder.

• Hereditary angioedema acute attacks: provides rapid reduction of swelling and pain during an attack.
• Hereditary angioedema type I attacks: shortens the duration of edema episodes.
• Hereditary angioedema type II attacks: alleviates symptoms and improves patient comfort.

• Icatibant acts as a competitive antagonist at the bradykinin B2 receptor, a G‑protein‑coupled receptor on vascular endothelial cells. By binding to this receptor, it blocks bradykinin‑induced vasodilation and increased vascular permeability, which are responsible for the swelling seen in hereditary angioedema. The inhibition is selective and reversible, leading to a rapid decrease in edema after subcutaneous administration. The drug reaches peak plasma concentrations within minutes, allowing early symptom control.

Icatibant may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Injection site pain: mild to moderate discomfort at the injection site.
• Redness or swelling at injection site: localized erythema or edema.
• Headache: transient headache occurring shortly after dosing.
• Nausea: occasional feeling of nausea without vomiting.

Serious or Rare Side Effects

• Hypersensitivity reactions: rash, urticaria, or anaphylaxis requiring medical attention.
• Severe abdominal pain: persistent abdominal discomfort that may need evaluation.
• Thrombocytopenia: rare decrease in platelet count observed in some patients.
• Angioedema unrelated to HAE: rare swelling of face or throat not caused by hereditary angioedema.

When prescribing Icatibant, clinicians should consider several safety and handling precautions.

• Confirm diagnosis: verify hereditary angioedema before initiating therapy.
• Monitor for hypersensitivity: observe patients for rash, urticaria, or anaphylactic signs after injection.
• Assess cardiovascular status: bradykinin blockade may affect blood pressure in susceptible individuals.
• Use with caution in pregnancy: safety data are limited; weigh potential benefits against unknown risks.
• Observe renal/hepatic function: no dose adjustment required, but clinical response should be monitored in impairment.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Icatibant can interact with other medicines that influence bradykinin pathways or affect injection site reactions.

Major Interactions (Avoid)

• ACE inhibitors: may increase bradykinin levels and heighten risk of angioedema.
• DPP‑4 inhibitors: potential additive effect on bradykinin metabolism.
• Other B2 receptor antagonists: concurrent use may lead to excessive blockade.

Moderate Interactions (Monitor Closely)

• NSAIDs: may increase risk of localized injection site inflammation.
• Antihistamines: can mask early signs of hypersensitivity reactions.
• Corticosteroids: may alter immune response, requiring observation for infection or delayed healing.