American Society of Hirudotherapy

Fondaparinux sodium

Research article published in Drugs of today (Barcelona, Spain : 1998) (2002)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Narrative reviewClinical TrialsReverter. · Drugs of today (Barcelona, Spain : 1998), 2002

Abstract

Fondaparinux (Org-31540 / SR-90107A) is a new drug chemically synthesized for treatment and prophylaxis of thromboembolic disease. Fondaparinux is a selective inhibitor of activated factor X. Its structure is the copy of the heparin pentasaccharide sequence, the shortest chain required for antithrombin inhibition of activated factor X without antithrombin action. Fondaparinux has no effect on coagulation tests and does not bind to platelet factor 4 or promote heparin-induced thrombocytopenia. Fondaparinux inhibits thrombin generation and the growth of thrombi in in vitro and in vivo models. Phase I trials have shown a 100% bioavailability after subcutaneous (s.c.) administration, a rapid onset of action and an approximate half-life of 13.5 h. Fondaparinux is cleared as an active substance by the kidneys. In elderly patients, renal clearance is reduced and the half-life is longer. The phase II Pentathlon trial demonstrated significant dose-dependent reductions in the frequency of venous thromboembolism in total hip-replacement patients and the optimal dose was determined to be 2.5 mg s.c./24 h. Four phase III trials have evaluated fondaparinux starting 6 hours after surgery compared with enoxaparin for prevention of venous thromboembolism following orthopedic surgery in 7,344 patients. The risk of thrombosis was reduced by 50% with fondaparinux and no differences were observed in death or severe bleeding. In a phase II trial, similar efficacy and incidence of major bleeding were seen with fondaparinux s.c. compared with dalteparin s.c. in the treatment of deep venous thrombosis. In patients with acute myocardial infarction, the efficacy of fondaparinux during fibrinolytic therapy was assessed in 326 patients who had acute coronary syndromes of less than a 6 hour duration, showing a slight but statistically not significant advantage for fondaparinux over unfractionated heparin in the coronary angiographies. There is currently no antidote for fondaparinux.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleReview
Indexed MeSH termsAnimalsBlood CoagulationFibrinolytic AgentsFondaparinuxHumansOrthopedic ProceduresPolysaccharidesPostoperative ComplicationsThromboembolismThrombosisVascular DiseasesVenous Thrombosis

Summary

Peer-reviewed clinical and outcomes research relevant to medicinal leech therapy and its biology. Indexed in PubMed and verified against the NCBI record.

Why This Matters for Hirudotherapy

This review profiles fondaparinux, a chemically synthesized selective inhibitor of activated factor X modeled on the heparin pentasaccharide sequence, reporting 100% subcutaneous bioavailability, an approximate 13.5 h half-life, renal clearance, no effect on routine coagulation tests, no platelet-factor-4 binding (no heparin-induced thrombocytopenia), and phase III orthopedic-surgery data (7,344 patients) showing roughly halved thrombosis risk versus enoxaparin without excess severe bleeding. For hirudotherapy the value is contextual: fondaparinux is a synthetic factor-Xa inhibitor, not a Hirudo-derived molecule, but it exemplifies the rational drug-discovery tradition of engineering precise single-target anticoagulants — a lineage in which leech-derived hirudin (a direct thrombin inhibitor) is a historically important natural prototype that helped open the antithrombotic field. Caveat: this is an early (2002) review of a non-leech agent and explicitly notes there is currently no antidote for fondaparinux; it provides no direct evidence about medicinal-leech therapy.

Citation

Fondaparinux sodium.

Reverter. · Drugs of today (Barcelona, Spain : 1998), 2002

Added to ASH library: May 28, 2026 · Site last updated: June 18, 2026

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