Modern treatment of pulmonary embolism.

Pulmonary embolism is diagnosed over 100,000 times yearly in the United States and is the recognized primary cause of death in at least 10,000 cases. Thrombolytic therapy has been successful in reducing clot burden substantially; however, clinical data are lacking to indicate that thrombolytic therapy improves mortality rates in patients with pulmonary emboli or that the pharmacologic removal of clot will improve future quality of life. The use of thrombolytic agents has been limited by the potential for producing hemorrhagic complications. This paper discusses the pharmacology of numerous thrombolytic agents and their clinical use in research studies intended to determine the safest and most efficacious regimens. Recombinant t-PA infusions appear quite safe and produce very rapid lyses of pulmonary emboli. Innovative administration regimens of urokinase also appear promising. The availability of extremely safe and efficacious treatment regimens should allow for large epidemiologic studies to be conducted to determine whether thrombolytic therapy will improve the morbidity and mortality of pulmonary embolism.