Bivalirudin Bivalirudin Bivalirudin (Angiomax or Angiox, manufactured by The Medicines Company) is a direct thrombin inhibitor (DTI). Chemically, it is a synthetic congener of the naturally occurring drug hirudin (found in the saliva of the medicinal leech "Hirudo medicinalis"). Bivalirudin is a DTI that overcomes many limitations seen with indirect thrombin inhibitors, such as heparin. Bivalirudin is a short, synthetic peptide. It is a potent and highly specific inhibitor of thrombin. It inhibits both circulating and clot-bound thrombin, while also inhibiting thrombin-mediated platelet activation and aggregation. Bivalirudin has a quick onset of action and a short half-life. It does not bind
Hirudin nor its structure fully determined until 1976. Full length hirudin is made up of 65 amino acids. These amino acids are organized into a compact N-terminal domain containing three disulfide bonds and a C-terminal domain that is completely disordered when the protein is un-complexed in solution. Amino acid residues 1-3 form a parallel beta- strand with residues 214-217 of thrombin, the nitrogen atom of residue 1 making a hydrogen bond with the Ser-195 O gamma atom of the catalytic site. The C-terminal domain makes numerous electrostatic interactions with an anion-binding exosite of thrombin, while the last five residues are in