The new antithrombotic agents
Research article published in Presse medicale (2005)
Abstract
Current antithrombotic agents include anticoagulants (unfractionated and low-molecular-weight heparin, and antivitamin K) and platelet aggregation inhibitors (aspirin, ticlopidine, clopidogrel). Two areas are under particular investigation: specific inhibition, direct or indirect, of factor Xa and factor IIa. Pentasaccharide, an indirect anti-Xa, has proved effective in curing deep-vein thrombosis and more effective than enoxaparin for prophylactic treatment after orthopedic surgery. Administered in a single subcutaneous injection daily, it has no risk of thrombocytopenia; laboratory surveillance is based on anti-Xa activity. Hirudin and melagatran act by direct thrombin inhibition. Unlike hirudin (which requires monitoring of active coagulation time or ecarin clotting time), melagatran requires no laboratory monitoring. It is not associated with an increased risk of hemorrhage. But there is no true antidote at this time. If its efficacy is confirmed, ximelagatran, the orally active prodrug of melagatran, may facilitate the long-term treatment now reserved for antivitamin K. Three antagonists of the tissue factor-factor VIIa complex are also under development: rNAPc2 (Recombinant Nematode Anticoagulant Protein C2), ASIS (Active Site Inhibitor Factor Seven) and recombinant TFPI (Tissue Factor Pathway Inhibitor). Antiplatelet drugs are the reference antithrombotic agents for the prevention and treatment of arterial thrombosis. Aspirin remains in first place (75 to 300 mg/d) but the modest superiority of the thienopyridines (clopidogrel and ticlopidine) is established. Hemogram monitoring is no longer necessary for clopidogrel. Use of aspirin + a thienopyridine after placement of a coronary stent has been validated. Laboratory monitoring of antiplatelet treatments has not been codified.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
The new antithrombotic agents.
Why This Matters for Hirudotherapy
This article compares emerging antithrombotic agents, including the indirect factor Xa inhibitor pentasaccharide, the direct thrombin inhibitors hirudin and melagatran, and tissue factor–FVIIa complex antagonists. The abstract notes that hirudin acts by direct thrombin inhibition and, unlike melagatran, requires laboratory monitoring of active coagulation time or ecarin clotting time. For ASH, the article is relevant for placing hirudin within the contemporary landscape of antithrombotic therapies and highlighting its operational requirements relative to alternatives. However, the scope is broad, covering multiple drug classes without examining live leeches or the broader leech secretome, and the abstract provides no new primary data.
Citation
Added to ASH library: May 27, 2026 · Site last updated: June 18, 2026