Fondaparinux Sodium (2 brand names, 1 dosage form, 1 route)
Available dosage forms: SOLUTION.
Routes of administration: SUBCUTANEOUS.
Brand Names
- ARIXTRA
- FONDAPARINUX SODIUM
Related Health Topics
Boxed Warning
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 non-steroidal anti-inflammatory drugs (NSAIDs), platelet inhibitors, or other anticoagulants a history of traumatic or repeated epidural or spinal puncture a history of spinal deformity or spinal surgery Optimal timing between the administration of fondaparinux sodium and neuraxial procedures is not known. Monitor patients frequently for signs and symptoms of neurologic impairment. If neurologic compromise is noted, urgent treatment is necessary. Consider the benefit and risks before neuraxial intervention in patients anticoagulated or to be anticoagulated for thromboprophylaxis. [See Warnings and Precautions ( 5.1) and Drug Interactions ( 7).]
Contraindications
Fondaparinux sodium injection is contraindicated in the following conditions:( 4) Severe renal impairment (creatinine clearance [CrCl] <30 mL/min). [See Warnings and Precautions ( 5.3) and Use in Specific Populations ( 8.6).] Active major bleeding. Bacterial endocarditis. Thrombocytopenia associated with a positive in vitro test for anti-platelet antibody in the presence of fondaparinux sodium. Body weight <50 kg (venous thromboembolism [VTE] prophylaxis only) [see Warnings and Precautions ( 5.4)]. History of serious hypersensitivity reaction (e.g., angioedema, anaphylactoid/ anaphylactic reactions) to fondaparinux sodium injection.
Adverse Reactions
The following serious 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 <50 Kg and bleeding risk [see Warnings and Precautions ( 5.4)] . Thrombocytopenia [see Warnings and Precautions ( 5.5)] .
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. Agents that may enhance the risk of hemorrhage should be discontinued prior to initiation of therapy with fondaparinux sodium unless these agents are essential. If co-administration is necessary, monitor patients closely for hemorrhage. [See Warnings and Precautions ( 5.2).] In an in vitro study in human liver microsomes, inhibition of CYP2A6 hydroxylation of coumarin by fondaparinux (200 micromolar i.e., 350 mg/L) was 17 to 28%. Inhibition of the other isozymes evaluated (CYPs 1A2, 2C9, 2C19, 2D6, 3A4, and 3E1) was 0 to 16%. Since fondaparinux does not markedly inhibit CYP450s (CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, or CYP3A4) in vitro, fondaparinux sodium is not expected to significantly interact with other drugs in vivo by inhibition of metabolism mediated by these isozymes. Since fondaparinux sodium does not bind significantly to plasma proteins other than ATIII, no drug interactions by protein-binding displacement are expected.
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.
Overdosage
There is no known antidote for fondaparinux sodium. Overdose of fondaparinux sodium may lead to hemorrhagic complications. Discontinue treatment and initiate appropriate therapy if bleeding complications associated with overdosage occur. Data obtained in patients undergoing chronic intermittent hemodialysis suggest that clearance of fondaparinux sodium can increase by 20% during hemodialysis.