Thrombolytics safe for treating moderate pulmonary embolism

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.

In a self-funded study, researchers at Arizona Cardiovascular Consultants, USA, found that using half the usual dose of the thrombolytic drug tissue plasminogen activator (t-PA) not only effectively dissolved clots in patients with moderate pulmonary embolism, but also led to earlier hospital discharge and reduced the rate of pulmonary hypertension and recurrent pulmonary embolism without causing bleeding or other major side effects.

Currently, only about 5% of pulmonary embolism cases are considered severe enough to be given thrombolytic agents at full dose. While these drugs are effective in dissolving blood clots, they carry a 2% to 6% risk of causing dangerous bleeding inside the brain. The vast majority of pulmonary embolism cases are considered moderate, and thus are typically treated with anticoagulants (anti-clotting agents). However, even moderate cases can lead to recurring pulmonary embolism, pulmonary hypertension and other dangerous complications.