A note on Factor 7 (rVIIa) and thrombocytopenia
Factor 7 (rVIIa - Novoseven) is now significantly use as off label in uncontrolled bleeding. It may not be efective in the presence of severe thrombocytopenia and should be corrected prior to its administration. Although there are case reports of the successful use of rVIIa in severe thrombocytopenia, a low platelet count is likely to predict a poor or partial response to rVIIa therapy.
Its haemostatic effects are mediated by the thrombin it generates by both tissue factor (TF) dependent and independent mechanisms. The TF independent mechanism requires platelets for the direct activation of Factor X on their surface by rVIIa.