CLINICAL PRACTICE GUIDELINES
Hemophilia and von Willebrand’s Disease: 2. Management
(Edition 2, Update 2 [1999-07-07])

Side effects
The potential for allergic reactions, and for viral transmission has been discussed. In a minority (up to 6%) of patients receiving Factor IX therapy, inhibitors may also develop <50> , and, in rare cases associated with gross factor IX gene deletions or derangements, the inhibitor can result in anaphylactic reactions when factor IX is infused.<51> The development of thrombosis and disseminated intravascular coagulation may be associated with the use of prothrombin complex concentrates #60;52> and may be related to zymogen overload and the presence of small amounts of activated factors (e.g., Factor Xa) or other thrombogenic contaminants (e.g., phospholipids).<53,54> The thrombotic risk is not predictable but is particularly significant when the product is used in large, repeated doses (e.g., more than 75 U/kg for more than three to four doses at intervals of less than 12 hours) or in the treatment of neonates, patients with bone fractures, crush injuries, extensive intramuscular bleeding, or hepatocellular dysfunction.