C1-esterase inhibitor

How it works

It replaces the deficient or dysfunctional C1-esterase inhibitor, restoring regulation of the complement and contact (kallikrein-kinin) systems and thereby reducing the bradykinin generation responsible for angioedema attacks.

Prescribing in practice

• As a blood-derived product it carries a theoretical risk of transmitting infective agents and may provoke hypersensitivity reactions, so observe the patient and have facilities to manage anaphylaxis available during administration.
• It is given by intravenous injection or infusion, with some preparations licensed for acute treatment and others for routine prophylaxis of hereditary angioedema attacks.
• Thromboembolic events have been reported, particularly with higher exposure and in patients with risk factors for thrombosis, so weigh the benefit against this risk.

Monitoring

Monitor clinically for hypersensitivity and infusion reactions during and after administration and for signs of thromboembolism in at-risk patients.

Counselling the patient

• Report any rash, swelling, breathlessness or other reaction during or after the infusion.
• Patients trained for self-administration should follow the technique and storage instructions provided.
• Carry information about your hereditary angioedema and treatment in case of emergency.

Evidence & guidelines

Use is supported by controlled trials in hereditary angioedema and by long-standing clinical guidance for managing this condition.