Fondaparinux sodium is a synthetic pentasaccharide anticoagulant that selectively inhibits Factor Xa, preventing blood clot formation. It is primarily used to prevent and treat venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE). It is commonly administered to patients undergoing major orthopedic surgeries, such as hip or knee replacements, to reduce VTE risk. It is also indicated for the treatment of acute DVT and PE, often in combination with other therapies. Additionally, it is prescribed for patients with unstable angina or non-ST-segment elevation myocardial infarction (NSTEMI), typically with aspirin, to prevent thrombotic complications. The drug is given via subcutaneous injection and is favored in select cases for its predictable pharmacokinetics and lower monitoring requirements compared to unfractionated heparin.