Icatibant

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 the binding of bradykinin—a potent vasoactive peptide—to its receptor, icatibant inhibits downstream signaling pathways that promote vascular permeability, vasodilation, and smooth muscle contraction. This antagonism directly counteracts the pathological accumulation of bradykinin in hereditary angioedema (HAE), thereby reducing edema formation and associated symptoms. **Key Research Findings** Clinical trials (e.g., FAST-1, FAST-2, and FAST-3) demonstrated that subcutaneous icatibant significantly reduces time to symptom relief in acute HAE attacks compared to placebo, with median onset of symptom improvement within 2 hours. Pharmacokinetic studies show rapid absorption (Tmax ~0.75 h) and a half-life of 1–2 hours, supporting single-dose administration. Post-marketing surveillance confirmed efficacy across multiple attack sites (abdominal, laryngeal, cutaneous) and a favorable safety profile, with transient injection-site reactions being the most common adverse event. **Clinical Relevance** Icatibant is approved for self-administration in acute HAE attacks, offering a non–plasma-derived alternative to C1 esterase inhibitors. Its rapid onset and targeted mechanism reduce hospitalization rates and improve quality of life. However, it is not indicated for prophylactic use or for other bradykinin-mediated conditions (e.g., ACE inhibitor–induced angioedema) due to limited evidence. For research purposes only — not medical advice.

Key data

Research & studies

Frequently asked questions

Related peptides