Discontinue all<unk>  products
Do not give platelets (may precipitate thrombosis)
Start anticoagulation with no<unk>  based compound such as a direct thrombin inhibitor: [lepirudin (unless renal failure), argatroban (unless hepatobiliary disease), bivalirudin] or direct Xa inhibitor (fondaparinux, danaparoid)
Avoid warfarin until platelets >100K-150K
Heparin-Induced Thrombocytopenia 
Marrow infiltration 
Disseminated intravascular coagulation
Viral infections 
Liver disease induced coagulopathy
Marrow suppression 
Vitamin K deficiency
Congenital thrombocytopenia