ecallantide

Ecallantide is a recombinant protein that inhibits plasma kallikrein, an enzyme in the kinin–kallikrein system. By blocking kallikrein activity, ecallantide reduces the production of bradykinin, a mediator of increased vascular permeability that contributes to swelling in hereditary angioedema (HAE). It is approved for the acute treatment of HAE attacks in patients aged 12 years and older and is not indicated for long-term prophylaxis or for edema due to other causes.

Indications and mechanism of action: Ecallantide is used to treat an acute HAE attack in capable patients, helping to shorten the course of swelling. It targets the enzymatic step that leads to edema, rather than replacing C1 esterase inhibitor or counteracting other inflammatory pathways.

Administration and dosing: Ecallantide is given by subcutaneous injection in a clinical setting because of the risk of severe allergic reactions. The usual dose is 30 mg, administered as two 15 mg injections given in close succession. Patients are typically observed for at least two hours after administration to monitor for adverse reactions.

Safety and contraindications: The product carries a boxed warning for anaphylaxis and other hypersensitivity reactions. Common adverse effects include injection-site reactions, dizziness, and nausea. It should not be used in individuals with known hypersensitivity to ecallantide or any of its components. Appropriate emergency treatment should be available during and after administration.

Regulatory status: In the United States, ecallantide (Kalbitor) was approved by the FDA in 2009 for acute treatment of HAE attacks in patients 12 years and older. It is not approved for self-administration and must be administered in a setting with access to emergency care.