ARIXTRA

What it is

ARIXTRA is fondaparinux sodium solution for injection, available in pre-filled automatic safety syringes containing 2.5 mg in 0.5 mL, 5.0 mg in 0.4 mL, 7.5 mg in 0.6 mL or 10.0 mg in 0.8 mL. Fondaparinux is a synthetic and specific inhibitor of activated Factor X (Xa) with no animal sourced components, and its anti-thrombotic activity results from antithrombin III (ATIII) mediated selective inhibition of Factor Xa.

Approved indications

— Prevention of venous thromboembolic events (VTE) in patients undergoing major orthopaedic surgery of the lower limbs such as hip fracture, major knee or hip replacement surgery. — Prevention of venous thromboembolic events (VTE) in patients undergoing abdominal surgery who are at risk of thromboembolic complications. — Treatment of acute deep venous thrombosis (DVT) and acute pulmonary embolism (PE). — Treatment of unstable angina or non-ST segment elevation myocardial infarction (UA/NSTEMI) in patients for whom urgent (≤120 min) invasive management (PCI) is not indicated. — Treatment of ST segment elevation myocardial infarction (STEMI) in patients who are managed without any form of initial reperfusion therapy.

Dosing overview

For VTE prophylaxis, the recommended dose is 2.5 mg once daily by subcutaneous injection, with the initial dose given 6 hours following surgical closure, and treatment continued for at least 7 ± 2 days. For orthopaedic surgery cases where the risk of VTE persists, treatment can be extended for as long as indicated up to a maximum of 31 days of therapy.

Key safety warnings

ARIXTRA must not be administered intramuscularly. ARIXTRA must be used with caution in patients who have an increased risk of haemorrhage, such as those with congenital or acquired bleeding disorders, active ulcerative gastrointestinal disease, recent intracranial haemorrhage, shortly after brain, spinal or ophthalmic surgery, and in patients treated concomitantly with anti-platelet drugs. Administration before 6 hours has been associated with an increased risk of major bleeding. In STEMI patients undergoing primary PCI, the use of fondaparinux prior to and during PCI is not recommended. Similarly, in UA/NSTEMI patients with life threatening conditions that require urgent revascularisation, the use of fondaparinux prior to and during PCI is not recommended. In UA/NSTEMI and STEMI patients undergoing non-primary PCI, the use of fondaparinux as the sole anticoagulant during PCI is not recommended due to an increased risk of guiding catheter thrombus, and adjunctive UFH should be used during non-primary PCI according to standard practice. Epidural or spinal haematomas may occur with concurrent use of ARIXTRA and spinal/epidural anaesthesia or spinal puncture, and such complications can result in long-term or permanent paralysis. The needle shield of the pre-filled syringe may contain dry natural latex rubber that has the potential to cause allergic reactions in latex sensitive individuals.

Contraindications

ARIXTRA is contraindicated in severe renal impairment (creatinine clearance <30 mL/min), as fondaparinux is eliminated primarily by the kidneys and the risk of haemorrhage may increase with renal impairment. ARIXTRA is also contraindicated in active major bleeding, known hypersensitivity to fondaparinux sodium, and acute bacterial endocarditis.

PBS listing

ARIXTRA fondaparinux sodium 2.5 mg in 0.5 mL single dose pre-filled syringe is listed on the PBS with streamlined restriction at an ex-manufacturer price of A$26.78.

Regulatory history

ARIXTRA fondaparinux sodium 2.5 mg/0.5 mL solution for injection syringe was first registered on the ARTG on 2002-03-25. The 5.0 mg/0.4 mL, 7.5 mg/0.6 mL and 10.0 mg/0.8 mL strengths were registered on the ARTG on 2004-11-29.