Thrombin inhibiting drugs can block its action by binding to three domains: the active site, the catalytic site, and 2 exosites.
Bivalent direct thrombin inhibitors block thrombin at both the active site and exosite 1.
Univalent inhibitors bind only to the active site.
Lepirudin, bivalirudin and argatroban require parenteral administration.
Dabigatran etexilate is a oral direct thrombin inhibitor.