Desmopressin is used for bleeding in patients with von Willebrand disease by increasing levels of which factors?

• A. Increases levels of von Willebrand factor and factor VIII
• B. Decreases levels of von Willebrand factor
• C. Inhibits platelet function
• D. Has no effect on vWF or factor VIII

Answer: (B)

Desmopressin works by triggering endothelial cells to release stored von Willebrand factor. This raises circulating von Willebrand factor and, because von Willebrand factor stabilizes and carries factor VIII, it also increases factor VIII levels. The result is improved platelet adhesion and better formation of a platelet plug, helping to control bleeding in many patients with von Willebrand disease, especially milder forms. It does not decrease von Willebrand factor or inhibit platelet function, and it does have a real effect on both vWF and factor VIII. Keep in mind its usefulness varies by vWD type, and there are risks like hyponatremia with its antidiuretic effect.