Pharmacology and controlled release of hirudin for cardiovascular disorders.

Hirudin is the most potent specific inhibitor of thrombin known. Hirudin was originally isolated from leeches, but it is now also available in synthetic form (recombinant hirudin). The inhibitor is currently undergoing clinical trials as a potential replacement for the extensively used thrombin inhibitor heparin. In this review, the biochemical and pharmacokinetic characteristics of hirudin (native and recombinant) and the efficacy of hirudin in treating and preventing cardiovascular disorders is discussed. The advantages of local controlled delivery of hirudin for treating cardiovascular disorders are then presented. Several implantable polymers applicable for controlled delivery system also are introduced. Finally, the feasibility of controlled delivery of r-hirudin for local therapy of cardiovascular disorders is addressed.