Ximelagatran (Exanta or Exarta, H 376/95) is an anticoagulant that has been investigated extensively as a replacement for warfarin that would overcome the problematic dietary, drug interaction, and monitoring issues associated with warfarin therapy. In 2006, its manufacturer AstraZeneca announced that it would withdraw pending applications for marketing approval after reports of hepatotoxicity (liver damage) during trials, and discontinue its distribution in countries where the drug had been approved (Germany, Portugal, Sweden, Finland, Norway, Iceland, Austria, Denmark, France, Switzerland, Argentina and Brazil). Ximelagatran is a prodrug that is rapidly converted after oral administration to the active compound melagatran. Melagatran is able to inhibit thrombin activity directly and quickly. The melagatran molecule binds to the arginine side pocket of thrombin, inactivating the thrombin. Following oral administration of ximelagatran, oral bioavailability (measured as melagatran) is 18% to 25%. Peak melagatran levels after a ximelagatran dose of 48 mg twice daily are achieved within approximately 2 hours. Ximelagatran is rapidly and extensively converted to melagatran in the liver and other tissues. This conversion is achieved by ester hydrolysis and reduction via two intermediate metabolites, hydroxymelagatran, and ethylmelagatran. The predominant compound in plasma is the active drug, melagatran. The elimination half-life of melagatran after an oral dose of ximelagatran is 2.5 to 4.3 hours.