What are the medications used for thrombolysis (thrombolytic therapy)?

From the Guidelines

Thrombolytic medications, including alteplase (tPA), tenecteplase, reteplase, and streptokinase, are used to dissolve blood clots in conditions like stroke, heart attack, and pulmonary embolism, with the primary goal of improving morbidity, mortality, and quality of life outcomes. The choice of thrombolytic agent and dosing regimen depends on the specific condition being treated, with alteplase being the most commonly used agent due to its efficacy and safety profile, as supported by studies such as 1.

Thrombolytic Agents and Dosing Regimens

• Alteplase (tPA) is dosed at 0.9 mg/kg (maximum 90 mg) with 10% given as a bolus and the remainder over 60 minutes for ischemic stroke, as recommended by guidelines 1.
• Tenecteplase is administered as a single weight-based bolus (0.25-0.5 mg/kg), with studies such as 1 demonstrating its efficacy in improving right ventricular dysfunction in patients with pulmonary embolism.
• Reteplase is given as two 10-unit boluses 30 minutes apart, with studies such as 1 comparing its efficacy to other thrombolytic agents.
• Streptokinase is dosed at 1.5 million units over 60 minutes, although its use has been largely abandoned due to lower efficacy and increased bleeding complications compared to other agents, as noted in 1.

Administration and Monitoring

Thrombolytic medications work by activating plasminogen to plasmin, which breaks down fibrin in clots. Major risks include bleeding complications, particularly intracranial hemorrhage, so patients require careful screening for contraindications including recent surgery, active bleeding, uncontrolled hypertension, or history of hemorrhagic stroke, as emphasized in 1. Thrombolytics must be administered within specific time windows (typically 3-4.5 hours for ischemic stroke and 12 hours for myocardial infarction) to maximize benefit while minimizing risks, with studies such as 1 highlighting the importance of timely administration.

Key Considerations

• Careful patient selection and screening for contraindications are crucial to minimize risks and maximize benefits, as noted in 1.
• Monitoring for bleeding complications and other adverse effects is essential during and after thrombolytic therapy, with studies such as 1 emphasizing the importance of close monitoring.
• The choice of thrombolytic agent and dosing regimen should be individualized based on patient-specific factors and the specific condition being treated, with guidelines such as 1 providing recommendations for different clinical scenarios.

From the FDA Drug Label

WARNINGS AND PRECAUTIONS Bleeding: Increases the risk of bleeding. Avoid intramuscular injections. Monitor for bleeding. (5.1) Thromboembolism: The use of thrombolytics can increase the risk of thrombo-embolic events in patients with high likelihood of left heart thrombus. (5.2) Cholesterol Embolization: Has been reported in patients treated with thrombolytic agents. (5. 3) Increased Risk of Heart Failure and Recurrent Ischemia when used with Planned Percutaneous Coronary Intervention (PCI) in STEMI: In patients with a large ST segment elevation myocardial infarction, physicians should choose either thrombolysis or PCI as the primary treatment strategy for reperfusion Rescue PCI or subsequent elective PCI may be performed after administration of thrombolytic therapies if medically appropriate. (5.5)

The medication used for thrombolysis (thrombolytic therapy) mentioned in the label is tenecteplase (IV), also known as TNKase 2.

• Thrombolytic agents are used to increase the risk of bleeding to break down blood clots.
• The label mentions the use of thrombolytics to increase the risk of thrombo-embolic events in patients with high likelihood of left heart thrombus.
• Thrombolytic therapies may be used for reperfusion in patients with a large ST segment elevation myocardial infarction.

From the Research

Thrombolytic Medications

The medications used for thrombolysis (thrombolytic therapy) include:

• Alteplase (recombinant tissue plasminogen activator; rt-PA) 3, 4, 5, 6, 7
• Tenecteplase, a modified version of alteplase 4, 5, 6

Comparison of Alteplase and Tenecteplase

• Tenecteplase has similar or higher efficacy and safety compared to alteplase 4, 5
• Tenecteplase has improved pharmacokinetic properties over alteplase, with a longer half-life enabling a single-bolus administration 4
• Tenecteplase appears to be a better thrombolytic agent for acute ischemic stroke when compared to alteplase 5

Dosage of Alteplase

• Different doses of alteplase (0.6 mg/kg and 0.9 mg/kg) have been studied, with both doses showing improvement in neurological function and living ability of patients 7
• The standard dose of alteplase is 0.9 mg/kg, while a lower dose of 0.6 mg/kg has also been used 7