Which statement about thrombolytic therapy is true?

• A. They may lyse other clots and cause bleeding
• B. They do not increase bleeding risk
• C. They are safe in active bleeding
• D. They only lyse the clot causing MI

Answer: (A)

Thrombolytic therapy dissolves fibrin in clots throughout the circulation, not just the one causing the MI. Because of this systemic effect, these drugs can break down clots elsewhere in the body and markedly increase the risk of bleeding, including serious intracranial or gastrointestinal bleeding. That’s why the statement that they may lyse other clots and cause bleeding is true.

They do increase bleeding risk, so saying they do not would be incorrect. They are not safe in active bleeding, which is why active bleeding is a major contraindication. And they are not limited to the clot causing the MI; their action is not exclusively selective for one clot.