From the FDA Drug Label
Desmopressin acetate should not be used to treat patients with Type IIB von Willebrand’s disease since platelet aggregation may be induced. The drug desmopressin can act as an agonist for platelet aggregation, particularly in patients with Type IIB von Willebrand’s disease.
- Key points:
- Desmopressin acetate induces platelet aggregation in Type IIB von Willebrand’s disease.
- It should not be used to treat this condition due to this effect. 1
From the Research
Agonists for platelet aggregation include thromboxane A2, ADP, thrombin, collagen, and epinephrine, which are the primary substances that trigger platelet activation and aggregation. These substances bind to specific receptors on platelets, triggering intracellular signaling cascades that lead to platelet activation and aggregation. Thromboxane A2 works through the TP receptor, while ADP activates platelets via P2Y1 and P2Y12 receptors. Thrombin is a potent agonist that acts through protease-activated receptors (PARs), particularly PAR-1 and PAR-4. Collagen binds to glycoprotein VI and integrin α2β1, initiating platelet activation. Epinephrine acts through α2-adrenergic receptors, though it's a relatively weak agonist on its own but synergizes with other agonists.
Key Agonists
- Thromboxane A2
- ADP
- Thrombin
- Collagen
- Epinephrine In laboratory settings, these agonists are used at varying concentrations to induce platelet aggregation for diagnostic testing of platelet function. Understanding these agonists is important for developing antiplatelet therapies, as many current drugs target these pathways to prevent unwanted clot formation in cardiovascular disease, as noted in studies such as 2. The use of desmopressin, as discussed in 3, can also influence platelet function, particularly in patients with von Willebrand disease or other bleeding disorders, by increasing the levels of von Willebrand factor and factor VIII. However, its direct role as an agonist for platelet aggregation is less clear, and its effects may be more related to its ability to increase the levels of these coagulation factors, as seen in studies like 4 and 5.