EACA: epsilon aminocaproic acid; FEIBA: factor eight inhibitor bypassing activity; rFVIIa: recombinant activated factor VII; RICE: rest, ice, compression, and elevation; TXA: tranexamic acid; Vd: volume of distribution.
* Most factor IX inhibitors are high responding. Determination is based on historical peak inhibitor titer (not current measurement). If a bypassing agent is used, rFVIIa is preferred; patients with a history of anaphylactoid reactions cannot receive FEIBA because it contains factor IX.
¶ Bleeding severity:Δ Calculation depends on inhibitor titer; refer to UpToDate text for details.
◊ Give the patient's own factor product if available, otherwise give recombinant factor IX. Dosing is based on target factor IX activity and Vd, which varies by factor IX product.
If there is sufficient time to do the dosing calculation, use the formula: Dose (units) = % correction × Vd × weight (kg); refer to the UpToDate table on factor IX products for the Vd of specific products.
If there is insufficient time to do the calculation, use:Measure factor IX peak (ideally, 5 to 15 minutes after the first dose) and trough (approximately 8 to 12 hours after the first dose of a standard half-life factor IX product) and plan for next dose at approximately one half-life (adjust based on peak and trough activity). Factor IX half-life is approximately 18 to 24 hours for standard half-life products and longer for extended half-life products; refer to UpToDate table on factor IX products for half-lives of individual factor IX products.