Icatibant
Also known as: Firazyr, Sajazir, HOE 140
A synthetic decapeptide bradykinin B2 receptor blocker, FDA-approved in 2011 as Firazyr for acute hereditary angioedema attacks. Prescription medication.
Last updated
Mechanism of Action
Icatibant is a synthetic 10-amino-acid peptide containing five non-natural amino acids that make it resistant to the enzymes that break down bradykinin. It competitively blocks the bradykinin B2 receptor on blood vessel cells. In hereditary angioedema, C1-inhibitor deficiency leads to excess bradykinin, which acts through B2 receptors to increase vascular permeability and cause swelling; blocking the receptor treats the attack regardless of how the bradykinin was made.
- Half-life
- ~1-2 hours
- Administration Routes
- Subcutaneous
- Research Status
- Clinical
Reported Benefits
- FDA-approved for acute attacks of hereditary angioedema in adults
- Faster symptom relief than placebo in the FAST-3 phase 3 trial
- Label allows self-administration after training by a healthcare professional
- Generic versions available in the US since 2019
Potential Side Effects
- Injection-site reactions (redness, swelling, pain) in nearly all patients
- Fever
- Elevated liver transaminases
- Dizziness
- Rash
Common Dosing
Labeled dosing is a single 30 mg subcutaneous injection in the abdomen for an attack, with repeat doses allowed at intervals of at least 6 hours and a maximum of three doses in 24 hours. Anyone with a laryngeal attack should seek emergency care after the injection. Dosing is set and supervised by the prescribing clinician.
The dosing information above is aggregated from research literature and anecdotal community reports for educational purposes only. It is not a recommendation, prescription, or medical advice. Peptides are sold as research chemicals only and are not intended for human use.
Contraindications
- Known hypersensitivity to icatibant
- Caution in acute ischemic heart disease or unstable angina, since bradykinin may have protective effects
- Laryngeal attacks still require emergency medical evaluation
No documented stacking partners for Icatibant yet.