Factor Viia

What it is and how it works

Recombinant factor VIIa binds tissue factor exposed at the site of vascular injury and, at pharmacological doses, also directly activates factor X on the surface of activated platelets independently of factors VIII and IX. This generates a thrombin burst sufficient to form a haemostatic plug, bypassing inhibitors to factors VIII or IX.

Indications

Treatment of bleeding and prevention of bleeding during surgery in congenital haemophilia with inhibitors to factor VIII or IX (or expected high anamnestic response), acquired haemophilia, congenital factor VII deficiency, and Glanzmann’s thrombasthenia refractory to platelet transfusion; some regions also approve it for severe postpartum haemorrhage.

Dosage and administration (summary)

Dosing is individualised by the haemophilia/haemostasis specialist according to indication, body weight and severity of bleeding (for haemophilia with inhibitors typically 90 micrograms/kg by intravenous bolus every 2–3 hours initially), until haemostasis is achieved.

Contraindications

Known hypersensitivity to the active substance, excipients, or mouse, hamster or bovine protein.

Warnings and precautions

Arterial and venous thrombotic events, including myocardial infarction, stroke and DIC, may occur, especially in patients with atherosclerotic disease, crush injury, septicaemia or concomitant use of activated prothrombin complex concentrates; use outside approved indications is associated with increased arterial thrombosis. Patients with factor VII deficiency should be monitored for prothrombin time and inhibitor development.

Pregnancy

Use in pregnancy only if clearly needed, as data are limited.

Storage and supply

Store below 25 °C (or as stated by the manufacturer); do not freeze; protect from light; use the reconstituted solution promptly.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.