factor VIII + von willebrand factor: clinical use

Prescribing considerations

• Initiate and supervise treatment through a clinician experienced in haemostatic disorders.
• For von Willebrand disease, prescribe and monitor according to VWF activity; for haemophilia A, use factor VIII activity.
• Assess thrombotic and cardiovascular risk, particularly where factor VIII levels may remain excessively raised.
• Consider plasma-derived-product precautions, hepatitis A and B vaccination for repeated recipients, sodium content and central-line complications.
• Permit home use only after appropriate training, with periodic review and batch traceability.

Contraindications and cautions

• Hypersensitivity to factor VIII, von Willebrand factor or a formulation excipient.

Monitoring

• Clinical control of bleeding and peri-procedural haemostasis.
• VWF activity and factor VIII activity as clinically appropriate.
• Factor VIII accumulation during continuing treatment of von Willebrand disease.
• Factor VIII or VWF inhibitors when recovery is inadequate or bleeding remains uncontrolled.
• Hypersensitivity, thrombosis and catheter-related infection or thrombosis where applicable.

Clinical pharmacology

Plasma-derived VWF restores platelet adhesion and stabilises endogenous factor VIII. The accompanying factor VIII supports intrinsic-pathway coagulation and thrombin generation.

Formulation and product differences

• Wilate has an approximately equal VWF-to-factor VIII activity ratio; Voncento contains proportionally more VWF, with an approximate factor VIII-to-VWF ratio of 1:2.4.
• Both are plasma-derived powder-and-solvent products for intravenous use, but their reconstitution devices, sodium content, storage requirements and infusion instructions differ.
• Product selection and prescribing units must reflect whether VWF or factor VIII replacement is primarily required.

Injection

Route: Parenteral

Strengths: 500 units + 1200 units, 1000 units + 2400 units