Direct thrombin and factor Xa inhibitors in children: a quest for new anticoagulants for children.

Venous thrombosis and pulmonary embolism rarely occur in children but are associated with significant morbidity and mortality. Venous thromboembolism (VTE) mostly affects children with severe underlying conditions and multiple risk factors. Newborns and adolescents are at the highest risk. Standard and low molecular weight heparins and vitamin K antagonists are routinely used for the prevention and treatment of VTE. The new anticoagulants, both parenteral such as argatroban, bivalirudin and fondaparinux and oral such as dabigatran and rivaroxaban, have favourable pharmacological properties, all are approved for clinical use in adults and are currently being investigated in children. Argatroban is the only new anticoagulant licensed for use in children so far. The role of these new anticoagulants as alternative anticoagulants for children remains to be defined. This review focuses on the characteristics of VTE in children and reviews current knowledge on the use of the new thrombin and factor Xa inhibitors in this population.