Thrombolytic drugs are used in medicine to dissolve blood clots in a procedure termed thrombolysis. They limit the damage caused by the blockage or occlusion of a blood vessel. Thrombolytic agents can be differentiated from fibrinolytic agents as they dissolve the fibrin only while thrombolysis refers to the dissolution of the entire thrombus.
Thrombolytic agents are used for the treatment of myocardial infarction (heart attack), thromboembolic strokes, deep vein thrombosis and pulmonary embolism to clear a blocked artery and avoid permanent damage to the perfused (see perfusion) tissue (e.g. myocardium, brain, leg) and death. They may also be used to clear blocked catheters that are used in long-term medical therapy.
|Condition||Prothrombin time||Partial thromboplastin time||Bleeding time||Platelet count|
|Vitamin K deficiency or warfarin||Prolonged||Normal or mildly prolonged||Unaffected||Unaffected|
|Disseminated intravascular coagulation||Prolonged||Prolonged||Prolonged||Decreased|
|Von Willebrand disease||Unaffected||Prolonged or unaffected||Prolonged||Unaffected|
|Liver failure, early||Prolonged||Unaffected||Unaffected||Unaffected|
|Liver failure, end-stage||Prolonged||Prolonged||Prolonged||Decreased|
|Factor V deficiency||Prolonged||Prolonged||Unaffected||Unaffected|
|Factor X deficiency as seen in amyloid purpura||Prolonged||Prolonged||Unaffected||Unaffected|
|Bernard-Soulier syndrome||Unaffected||Unaffected||Prolonged||Decreased or unaffected|
|Factor XII deficiency||Unaffected||Prolonged||Unaffected||Unaffected|
The thrombolytic drugs include:
These drugs are most effective if administered immediately after it has been determined they are clinically appropriate. The advantage of administration is highest within the first sixty minutes after a thrombotic event, but may extend up to six hours after the start of symptoms.
These drugs are often administered in combination with anticoagulant drugs such as intravenous heparin or low molecular weight heparin, for synergistic antithrombotic effects and secondary prevention.
Hemorrhagic stroke is a rare but serious complication of thrombolytic therapy. If a patient has had thrombolysis before, an allergy against the thrombolytic drug may have developed (especially after streptokinase). If the symptoms are mild, the infusion is stopped and the patient is commenced on an antihistamine before infusion is recommenced. Anaphylaxis generally requires immediate cessation of thrombolysis.
- "Thrombolytic therapy".
- Ellen C Keeley, Judith A Boura, Cindy L Grines (4 January 2003). "Primary angioplasty versus intravenous thrombolytic therapy for acute myocardial infarction: a quantitative review of 23 randomised trials". The Lancet 361: 13–20. doi:10.1016/S0140-6736(03)12113-7. PMID 12517460.
- Selim M. Arcasoy, MD; John W. Kreit (June 1999). "Thrombolytic Therapy of Pulmonary Embolism: A Comprehensive Review of Current Evidence". Chest Journal 115: 1695–1707. doi:10.1378/chest.115.6.1695.