- The limitations of standard heparin have prompted the development of a variety of newer antithrombotic agents. In fact, a LMWH preparation has recently been approved for clinical use in North America. Of these novel preparations, LMWH, the direct thrombin inhibitors, and inhibitors of GPIIb-IIIa have been used clinically and are in advanced stages of evaluation. Not only is LMWH effective in the prevention of venous thromboembolic disease in high-risk patients, but its more predictable dose response makes it an ideal candidate for the treatment of venous thrombosis. Further studies are needed to determine whether LMWH is superior to standard heparin as adjunctive therapy in patients undergoing coronary thrombolysis or angioplasty. Particularly promising in the setting of arterial thrombosis are hirudin, hirulog, and 7E3. With the encouraging results reported to date, it is likely that these agents will soon find their way into the treatment armamentarium of arterial thrombosis.