Inhibitor Management

Always refer to the Haemophilia Treatment Centre Physician's Instructions

Please refer to the Section on: Products Available in South Africa
Please Note: Patients with Inhibitors require Special Treatment
Factor VIII Inhibitor Management
Haemophilia A

Factor VIII Inhibitor Management

1. Acute bleeding episodes

  • Ice/cold pack – 5 minutes on, 10 minutes off
  • Immobilise joint with a splint
  • Low Responder (< 5 BU)
    • Give Factor VIII at 2 – 3 times the normal dose
    • Monitor response clinically
    • Frequent factor recovery levels
  • High Responder (> 5 BU)
    • Both APCC and rVIIa are effective for treatment of acute bleeding episodes in patients with Factor VIII inhibitors.
      • Activated Prothromibin Complex Concentrate (APCC)
        • Dose: 50 – 100 IU/kg q12 – 24h for 3 days or until clinical improvement
        • Infuse at 2 IU/kg/min
        • Do not exceed a single dose of 200 IU/kg
          • Do not use antifibrinolytic drugs (e.g. tranexamic acid) concurrently because of the risk of thromboembolism
      • Recombinant Factor VIIa (rFVIIa)
        • 90 μg per kg q2 – 3 h or by continuous infusion (at 20 μg/kg/hr) until clinical improvement. Factor VIIa activates Factor X and leads to the formation of a haemostatic plug.
        • New single dose of 270 μg/kg may be used
      • Tranexamic acid 15 – 25 mg/kg/dose po/IV q6- 8h may be used concurrently with recombinant Factor VIIa.

2. Long term Management - Immune tolerance (IT)

  • IT should be initiated at a Haemophilia Treatment Centre.
  • Successful therapy (eliminating the inhibitor) may take months.
  • Several regimens are effective – the Dutch regime
    • (25 IU Factor VIII/kg 3 times per week) is the most affordable.

Factor IX Inhibitor Management
Haemophilia B

Factor IX Inhibitor Management

Treatment of haemophilia B with inhibitors

  • An aPCC should be carefully monitored for anaphylaxis and anamnestic reaction. Therefore patients with haemophilia B and inhibitors are best treated with rFVIIa, the only bypassing agent that does not contain FIX.
  • There is no evidence to guide tolerisation procedures in patients with haemophilia B and inhibitors. Plasma-derived FIX may be used for tolerisation with careful monitoring of anaphylactic reactions

Treatment with rFVIIa:

  • Give dose of 90 – 120 μg/kg IV every 2 – 3 hours as bolus or 20 IU/kg/hour as continuous infusion. Single dose of 270 μg/kg may be used.
  • Antifibrinolytic can be given concurrently with rFVIIa.