Icatibant

approved

Also known as: Firazyr, HOE 140

**Mechanism of Action** Icatibant is a synthetic decapeptide that acts as a selective, competitive antagonist of the bradykinin B2 receptor. By blocking bradykinin binding, it inhibits downstream signaling pathways (e.g., nitric oxide and prostaglandin release) that mediate vasodilation, increased vascular permeability, and smooth muscle contraction. This mechanism directly counteracts the pathological bradykinin overproduction underlying hereditary angioedema (HAE) attacks. **Key Research Findings** Clinical trials (e.g., FAST-1, FAST-2, FAST-3) demonstrated that subcutaneous icatibant significantly reduces time to symptom relief in acute HAE attacks, with median onset of symptom improvement within 2 hours versus placebo. Pharmacokinetic studies show rapid absorption (Tmax ~0.75 h) and a half-life of 1–2 hours, supporting single-dose efficacy. Post-marketing data confirm consistent safety, with transient injection-site reactions as the most common adverse event. No evidence of tachyphylaxis or antibody formation has been reported. **Clinical Relevance** Icatibant is approved (FDA, EMA) for self-administered treatment of acute HAE attacks in adults. Its targeted B2 receptor antagonism offers a non-plasma-derived alternative to C1 esterase inhibitors, with comparable efficacy and favorable tolerability. Limitations include lack of efficacy in other bradykinin-mediated conditions (e.g., ACE inhibitor-induced angioedema) and the need for repeated dosing during recurrent attacks. For research purposes only — not medical advice.

Key data

Category
Clinical Therapeutics
Molecular weight
1304.5 g/mol
Molecular formula
C59H89N19O13S
CAS number
130308-48-4
Administration
subcutaneous
Research status
approved
References
770
Tags
bradykinin-antagonist, approved, angioedema

Research & studies

Icatibant
2026 · PubMed
Icatibant in viral infections
Infectious diseases (London, England) · 2023 · PubMed
The Icatibant Outcome Survey: 10 years of experience with icatibant for patients with hereditary angioedema
Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology · 2022 · PubMed

Icatibant effectiveness in real-world settings is comparable to clinical trials.; One dose is effective for the majority of attacks.; Early treatment, facilitated by self-administration, leads to faster resolution and shorter attack duration.; Effectiveness and safety are demonstrated across diverse patient subgroups, including children/adolescents and elderly patients.

ACE inhibitor-mediated angioedema
International immunopharmacology · 2020 · PubMed

ACEi-AE prevalence is 0.1-0.7% and shows ethnic predisposition, with higher rates in African-Americans and Hispanics.; Clinical manifestations include edema of face, lips, tongue, uvula, and upper airways, often requiring hospital admission.; Pathogenesis involves bradykinin accumulation from reduced ACE-mediated catabolism, with genetic polymorphisms contributing.; Corticosteroids and antihistamines are ineffective; icatibant shows conflicting efficacy, with benefit in Caucasian but not black patients.

New Treatments for Hereditary Angioedema
Skin therapy letter · 2018 · PubMed

New techniques isolate and purify human-derived C1 inhibitor.; Recombinant C1 inhibitor has been produced.; Drugs targeting the kallikrein-kinin pathway have been developed.; The paper reviews mechanisms, efficacy, and adverse reactions of these treatments.

Acquired C1 Inhibitor Deficiency
Immunology and allergy clinics of North America · 2017 · PubMed

Diagnosis requires quantitative or functional C1-INH deficiency, negative family history, and low C1q.; Common associations include autoimmunity and B-cell lymphoproliferative disorders.; C1-INH-AAE can precede lymphoproliferative disease and increases risk of non-Hodgkin lymphoma.; Treatment involves bradykinin-regulating therapies (e.g., C1-INH concentrate, icatibant) and managing underlying conditions.

The Angiotensin-Converting-Enzyme-Induced Angioedema
Immunology and allergy clinics of North America · 2017 · PubMed

Icatibant is effective for ACE inhibitor-induced angioedema but used off-label in emergencies.; Corticosteroids and antihistamines are not effective for this condition.; The effectiveness of C1-esterase-inhibitor requires verification through a double-blind study.

[Acquired angioedema]
Presse medicale (Paris, France : 1983) · 2015 · PubMed

Acquired angioedema is rare and linked to MGUS or lymphomas.; Symptoms and laryngeal risk mirror hereditary angioedema.; Biomarkers include low C4, C1Inh, and C1q levels.; Treatment involves C1Inh concentrate and icatibant; rituximab's role is uncertain.

Frequently asked questions

What is Icatibant?

**Mechanism of Action** Icatibant is a synthetic decapeptide that acts as a selective, competitive antagonist of the bradykinin B2 receptor. By blocking bradykinin binding, it inhibits downstream signaling pathways (e.g., nitric oxide and prostaglandin release) that mediate vasodilation, increased vascular permeability

How does Icatibant work?

Selective bradykinin B2 receptor antagonist decapeptide approved for acute attacks of hereditary angioedema.

What is the research status of Icatibant?

Icatibant is currently classified as approved, with 770 research references on record. This is for research purposes only and is not medical advice.

What is the molecular weight of Icatibant?

Icatibant has a molecular weight of approximately 1304.5 g/mol (formula C59H89N19O13S).

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    Icatibant — Mechanism, Research & Data | Peptides API