Overview
11 DESCRIPTION Fondaparinux sodium injection is a sterile solution containing fondaparinux sodium. It is a synthetic and specific inhibitor of activated Factor X (Xa). Fondaparinux sodium is methyl O-2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranosyl-(1→4)-O-β-D-glucopyranuronosyl-(1→4)-O-2-deoxy-3,6-di-O-sulfo-2-(sulfoamino)-α-D-glucopyranosyl-(1→4)-O-2-Osulfo-α-L-idopyranuronosyl-(1→4)-2-deoxy-...
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action The antithrombotic activity of fondaparinux sodium is the result of antithrombin III (ATIII)-mediated selective inhibition of Factor Xa. By selectively binding to ATIII, fondaparinux sodium potentiates (about 300 times) the innate neutralization of Factor Xa by ATIII. Neutralization of Factor Xa interrupts the blood coagulation cascade and thus inhibits thrombin formation and thrombus development. Fondaparinux sodium does not inactivate thrombin (activated Factor II) and has no known effect on platelet function. At the recommended dose, fondaparinux sodium does not affect fibrinolytic activity or bleeding time. 12.
Indications
- 1 INDICATIONS AND USAGE Fondaparinux sodium injection is a Factor Xa inhibitor (anticoagulant) indicated for: Prophylaxis of deep vein thrombosis (DVT) in patients undergoing hip fracture surgery (including extended prophylaxis), hip replacement surgery, knee replacement surgery, or abdominal surgery. (1.1) Treatment of DVT or acute pulmonary embolism (PE) when administered in conjunction with warfarin. ( 1.2 , 1.3 ) 1.
Common Doses
- 2.5 mg
- 5 mg
- 7.5 mg
- 10 mg
Dosage
2 DOSAGE AND ADMINISTRATION For subcutaneous use, do not mix with other injections or infusions. ( 2.1 ) Prophylaxis of deep vein thrombosis: Fondaparinux sodium 2.5 mg subcutaneously once daily after hemostasis has been established. The initial dose should be given no earlier than 6 to 8 hours after surgery and continued for 5 to 9 days. For patients undergoing hip fracture surgery, extended prophylaxis up to 24 additional days is recommended. ( 2.2 , 2.3 ) Treatment of deep vein thrombosis and pulmonary embolism: Fondaparinux sodium 5 mg (body weight 100 kg) subcutaneously once daily.
Black Box Warning
WARNING: SPINAL/EPIDURAL HEMATOMAS Epidural or spinal hematomas may occur in patients who are anticoagulated with low molecular weight heparins (LMWH), heparinoids, or fondaparinux sodium and are receiving neuraxial anesthesia or undergoing spinal puncture. These hematomas may result in long-term or permanent paralysis. Consider these risks when scheduling patients for spinal procedures. Factors that can increase the risk of developing epidural or spinal hematomas in these patients include: use of indwelling epidural catheters concomitant use of other drugs that affect hemostasis, such as...
Contraindications
- 4 CONTRAINDICATIONS Fondaparinux sodium injection is contraindicated in the following conditions: Severe renal impairment (creatinine clearance [CrCl]
Side Effects
- 6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: • Spinal or epidural hematomas [see Warnings and Precautions ( 5.1 ) ] • Hemorrhage [see Warnings and Precautions ( 5.2 )] • Renal impairment and bleeding risk [see Warnings and Precautions ( 5.3 ) ] • Body weight
Interactions
- 7 DRUG INTERACTIONS In clinical studies performed with fondaparinux sodium, the concomitant use of oral anticoagulants (warfarin), platelet inhibitors (acetylsalicylic acid), NSAIDs (piroxicam), and digoxin did not significantly affect the pharmacokinetics/pharmacodynamics of fondaparinux sodium. In addition, fondaparinux sodium neither influenced the pharmacodynamics of warfarin, acetylsalicylic acid, piroxicam, and digoxin, nor the pharmacokinetics of digoxin at steady state.