Fondaparinux: a new antithrombotic agent.

Area of Science:

• Pharmacology
• Thrombosis Research
• Drug Efficacy Studies

Background:

• Venous thrombosis often results from low-flow states, common after orthopedic surgery.
• Antithrombotic agents are crucial for preventing such events.
• Fondaparinux, a novel factor Xa inhibitor, is FDA-approved for preventing venous thromboembolism in specific surgical patients.

Purpose of the Study:

• To review the clinical pharmacology of fondaparinux.
• To summarize data from existing clinical trials of fondaparinux.

Main Methods:

• Searched MEDLINE and Current Contents/Clinical Medicine (1996-2002) using terms: fondaparinux, SR90107A/ORG31540, factor Xa.
• Included English-language human studies.
• Incorporated unpublished data from the manufacturer and conference abstracts.

Main Results:

• Fondaparinux, a synthetic pentasaccharide, enhances anti-factor Xa activity via antithrombin III.
• Phase III trials indicate superior efficacy of fondaparinux over enoxaparin in preventing venous thromboembolism post-hip/knee surgery.
• Preliminary data suggest potential in treating deep vein thrombosis and acute coronary syndromes, though bleeding risks (major and minor) were significantly higher than with enoxaparin.

Conclusions:

• Fondaparinux demonstrates efficacy in preventing venous thromboembolism in hip/knee replacement patients.
• Ongoing trials are evaluating its use in deep vein thrombosis and acute coronary syndromes.
• Individual risk-benefit assessment is crucial due to potential increased bleeding risk; routine replacement of low-molecular-weight heparin is not yet advised.