CYP3A4 and Thrombocytopenia: Tyrosine kinase inhibitors are mostly substrate and/or inhibitors of CYP3A4 and P-glycoprotein, which ensures a relatively high oral bioavailability.11,13 Despite the lower association strength of PK DDI of antineoplastic and supportive care drugs with warfarin, high protein binding rate of warfarin and tyrosine kinase inhibitors, both> 90%, which results in competition, has not been taken into account in this model.11,13,28 Also, tyrosine kinase inhibitors are associated with an increased risk of bleeding and thrombocytopenia and may interact with enoxaparin and fondaparinux.