Clinical guidelines for treating von Willebrand disease patients who are not candidates for DDAVP — a survey of European physicians.

While certain plasma-derived factor VIII/von Willebrand factor (FVIII/vWF) concentrates have proven to be quite useful in preventing or controlling bleeding in persons with von Willebrand disease who are not candidates for DDAVP, most of the information concerning dosage and effectiveness has been anecdotal. Additionally, the laboratory tests used to quantify vWF (the vWF:RCoF assay and collagen binding assay) are not well standardized. Thus, the US Food and Drug Administration (FDA) has been reluctant to grant licensed indication for use of these products in von Willebrand disease. This brief report describes a survey of non-US physicians (from major centres) who are recognized experts in haemophilia and von Willebrand disease. Twenty-four of 27 questionnaires were completed, returned and analysed. Products thought to be effective in von Willebrand disease included Haemate P®, Facteur von Willebrand®, Alphanate®, and the UK’s BPL ‘8Y’®. In calculating dosage to stop or prevent bleeding, most aim for a certain level of both FVIII and vWF:RCoF. Postoperatively, 16/24 respondents follow both of these laboratory tests once daily. Twenty-two of 24 would follow FVIII levels once daily. It is noteworthy that FVIII assay results are generally the only test results readily available to guide the respondents’ clinical decisions. For treatment of significant mucous membrane bleeding, respondents often individualize dosage and monitoring, depending on the type, location and extent of bleeding. Gastrointestinal bleeding is generally treated more aggressively. Patient monitoring varies between merely looking for cessation of bleeding, to a battery of laboratory tests, including haemoglobin and haematocrit. Seven out of 24 would monitor BT as well. In addition to FVIII content, 22/24 respondents noted that they would find it helpful to have vWF:RCoF listed on the label, while 15/24 would like to know the vWF multimeric composition. [ABSTRACT FROM AUTHOR]