From the FDA Drug Label
Risk of Thrombosis with Concomitant Use of Factor IX: Avoid concomitant use. (5.1) The FDA drug label does not answer the question about hematuria in factor 9 deficiency, as it only mentions the risk of thrombosis with concomitant use of factor IX, but does not provide information about hematuria.
From the Research
Hematuria in Factor IX deficiency (Hemophilia B) requires prompt treatment with Factor IX concentrate replacement therapy, as evidenced by the most recent study on current factor IX replacement options 1. For active bleeding with hematuria, an initial dose of 40-50 IU/kg of Factor IX concentrate should be administered, followed by maintenance doses of 20-25 IU/kg every 12-24 hours until bleeding resolves, typically for 2-3 days. The goal is to achieve Factor IX levels of 30-50% for mild to moderate bleeding and 50-100% for severe bleeding, as supported by the review of hemophilia B treatment principles 2. Patients should also be advised to:
- Increase fluid intake to 2-3 liters daily to prevent clot formation in the urinary tract
- Rest until bleeding subsides
- Avoid medications with antiplatelet effects like aspirin or NSAIDs Aminocaproic acid (Amicar) at 50-100 mg/kg every 4-6 hours (maximum 24 g/day) may be used as adjunctive therapy to stabilize clots, but should be avoided if there's evidence of upper urinary tract bleeding to prevent obstructive uropathy, as noted in the review of tranexamic acid evidence and controversies 3. Hematuria occurs in Factor IX deficiency because the lack of this essential clotting factor impairs the intrinsic coagulation pathway, leading to prolonged bleeding even with minor trauma to the urinary tract, as explained in the systematic review of human coagulation factor IX characteristics 4. Recurrent hematuria episodes warrant comprehensive urological evaluation to identify and address any underlying structural abnormalities, highlighting the importance of ongoing therapeutic innovation for hemophilia B prophylaxis 5. The recent introduction of recombinant extended half-life FIX products has represented a major advance in the therapeutic management of hemophilia B patients, permitting both a reduction of treatment burden and improving patients' compliance to prophylaxis and, ultimately, quality of life 1.