Pharmaceutical Pulmonary embolism - the sudden blockage of an artery in the lung - is estimated to cause over 100,000 deaths each year in the US Although thrombolytics, or clot-buster drugs, are currently reserved to treat only the most severe cases of pulmonary embolism, new data suggest that when used at lower doses, these drugs are also safe and effective for more common, moderate cases of pulmonary embolism, according to research presented today at the American College of Cardiology 61st Annual Scientific Session. 28 March 2012