BLOOD: FONDAPARINUX

Question 1

FONDAPARINUX: INDICATIONS

Answer 1

• Venous thromboembolism (VTE): low molecular weight heparin (LMWH) is the first choice agent for pharmacological VTE prophylaxis in hospital inpatients, and for initial treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE)

Question 2

FONDAPARINUX: MOA

Answer 2

• Thrombin and factor Xa are key components of the final common coagulation pathway that leads to formation of a fibrin clot. By inhibiting their function, heparins and fondaparinux prevent the formation and propagation of blood clots
• Fondaparinux is a synthetic compound that is similar to heparin. It inhibits factor Xa only
• It appears to have similar efficacy to LMWH and has become the anticoagulant of choice in the treatment of ACS in many hospitals in the UK

Question 3

FONDAPARINUX: ADVERSE EFFECTS

Answer 3

• Bleeding
• Risk lower with FONDAPARINUX than with LMWH or UFH
• Injection site rxns
• Heparin induced thrombocytopenia less likely with FONDAPARINUX

Question 4

FONDAPARINUX: WARNINGS

Answer 4

• Use in caution with patients that have an increased risk of bleeding
• Clotting disorders
• Severe uncontrolled HTN
• Recent surgery or trauma
• Renal impairment patients = Fondaparinux can accumulate and should be used at lower dose, or unfractionated heparin should be used

Question 5

FONDAPARINUX: INTERACTIONS

Answer 5

• Combining antithrombotic drugs increases the risk of bleeding
• This should usually be avoided unless there is a special reason for combined therapy, such as in the use of LMWH while initiating warfarin, or the use of antiplatelet drugs (e.g. aspirin, clopidogrel) with fondaparinux/LMWH in ACS
• In major bleeding associated with heparin therapy, protamine can be given to reverse anticoagulation. This is effective for UFH but much less so for LMWH. It is ineffective against fondaparinux.