C1 Esterase Inhibitor Names
The C1 esterase inhibitors used for acute bradykinin-mediated angioedema are Berinert and Cinryze (both plasma-derived), and Ruconest (recombinant human C1INH).
Available C1 Esterase Inhibitor Products
Based on FDA-approved medications and international guidelines, there are three main C1 esterase inhibitor products:
Plasma-Derived C1 Esterase Inhibitors
Berinert (CSL Behring) 1
- FDA-approved for acute attacks of hereditary angioedema (HAE)
- Administered intravenously at 20 IU/kg body weight
- Indicated for acute abdominal, facial, or laryngeal attacks in adults and pediatric patients
- Can be self-administered by appropriately trained patients
Cinryze (ViroPharma/Takeda) 2
- FDA-approved for long-term prophylaxis of HAE
- Administered intravenously at 1000 U every 3-4 days for prophylaxis
- Also used for short-term prophylaxis at 1000-2000 U before procedures
- Can be used for acute attacks, though this is not its primary FDA indication
Recombinant C1 Esterase Inhibitor
- Ruconest (rhC1INH, Pharming) 2, 3
- Recombinant human C1 esterase inhibitor
- Administered intravenously at 50-100 U/kg for acute attacks
- FDA-approved for acute attacks in adult and adolescent patients
- Also approved in Europe for patients aged >2 years
Mechanism of Action
All C1 esterase inhibitors work by the same mechanism 2:
- Inhibit plasma kallikrein (the primary target in bradykinin-mediated angioedema)
- Inhibit coagulation factors XIIa and XIa
- Inhibit complement components C1s and C1r
- Inhibit MASP-1 and MASP-2
- Inhibit plasmin
Clinical Context
For acute bradykinin-mediated angioedema attacks, Berinert is the most commonly referenced plasma-derived C1INH with specific FDA approval for this indication 1. The guidelines emphasize that all three C1INH products (Berinert, Cinryze, and Ruconest) are safe and efficacious for treating acute HAE attacks 2.
Important distinction: While Cinryze is primarily FDA-approved for prophylaxis, it has been widely studied and used for acute attacks as well 2, 4, 5. Berinert remains the gold standard for acute attack treatment with its specific 20 IU/kg dosing 1.