Discontinue use if signs of allergic reactions (including hives, generalized urticaria, chills, flushing, angioedema, chest tightness, laryngospasm, bronchospasm, dyspnea, wheezing, faintness, hypotension, tachycardia, blurred vision & anaphylaxis) occur. Nephrotic syndrome following immune tolerance induction w/ factor IX products in hemophilia B patients w/ factor IX inhibitors & history of allergic reactions to factor IX. Monitor for the development of factor IX inhibitors. Patients known to have major deletion mutations of the factor IX gene. Patients w/ liver disease, post-op, at risk of thromboembolic phenomena or disseminated intravascular coagulation. Administration by continuous infusion. Pregnancy & lactation. Childn <6 yr & neonates. Elderly ≥65 yr.