Recombinate Disease Interactions

Hemophilic patients with cardiovascular risk factors or diseases may be at the same risk to develop cardiovascular events as non-hemophilic patients when clotting has been normalized by treatment with factor VIII. Care should be exercised when using this agent in patients with cardiovascular risk factors.

The formation of neutralizing antibodies (inhibitors) to Factor VIII may occur. Subsequent administration of either antihemophilic factor can result in anamnestic response and increased levels of inhibitor. Response to treatment with antihemophilic factor may be less than expected. Cross-reactivity between human and recombinant agents has been noted. It is recommended to carefully monitor patients for the development of factor VIII inhibitors, using appropriate clinical observations and laboratory tests. If expected plasma factor VIII activity levels are not attained, or if bleeding is not controlled, perform an assay that measures factor VIII inhibitor concentration to determine if a factor VIII inhibitor is present. Clinical assessment of patient history, severity of bleeding and inhibitor level (history and current) is necessary.

Blood group isoagglutinins (anti-A and anti-B) are present in antihemophilic factor (human) at concentrations that may not be clinically significant when used to control minor bleeds. Monitoring of hematocrit and Coombs for signs of intravascular hemolysis and falling hematocrit is recommended in patients with blood groups A, B, or AB when large or frequently repeated doses of antihemophilic factor (human) are administered. Acute hemolytic anemia may occur, resulting in increased bleeding tendency or hyperfibrinogenemia. Should this condition occur, leading to progressive hemolytic anemia, discontinue treatment and consider administering serologically compatible Type O red blood cells and providing alternative therapy.

Because antihemophilic factor (human) is made from human blood, it may carry a risk of transmitting infectious agents. The risk that such products will transmit an infectious agent has been reduced by screening plasma donors for prior exposure to certain viruses, by testing for the presence of certain current virus infections, and by inactivating and/or removing certain viruses during the manufacturing process. The risk of transmission of infectious agents cannot be eliminated completely. Some viruses, such as Parvovirus B19 virus (B19V) or hepatitis A (HAV), are particularly difficult to remove or inactivate. B19V may most seriously affect pregnant women and immune-compromised individuals. Physicians should be alert to the potential symptoms of B19V and HAV infections and should strongly consider administration of hepatitis A and hepatitis B vaccines to individuals receiving plasma derivatives. Potential risks and benefits of vaccination should be weighed by the physician and discussed with the patient.

Thromboembolic events have been reported in patients receiving antihemophilic factor/von Willebrand factor complex replacement therapy. Care should be exercised in the existence of known risk factors for thrombosis. Endogenous high levels of factor VIII have also been associated with thrombosis, but no causal relationship has been established. Caution is recommended and consider antithrombotic measures in all patients at risk who are receiving coagulation factor replacement therapy.