How Do Thrombolytics Work?

Thrombolytic drugs are often used as emergency drugs given intravenously to dissolve life-threatening clots in blood vessels, especially in arteries that supply the heart, lungs, and brain, improve blood flow, and prevent ischemic damage to tissue and organs. They are used to treat emergency conditions such as ischemic strokes, heart attacks, pulmonary embolism, and deep vein thrombosis in the legs.

Thrombolytic treatment is also known as fibrinolytic or thrombolysis. These drugs are plasminogen activators, i.e., they convert plasminogen into active plasmin, which breaks down the blood clot, allows free flow of blood to the affected areas, and supplies oxygen and nutrients limiting the damage. Thrombolytics work effectively if given immediately after the event and as close as possible to the site of the blood clot. These drugs may be given within three hours postonset of the symptoms of a stroke and within 12 to 24 hours postonset of the symptoms of a heart attack.

Thrombolysis may be performed using X-ray imaging, and a specialized catheter may be used to discharge the drug at the site of blood clots.

Thrombolytics are used to treat:

• Ischemic stroke (damage to brain tissue caused because of lack of blood supply)
• Heart attack (pain in the chest caused because of the lack of blood supply to the heart)
• Severe pulmonary embolism (blood clots, formed elsewhere in the body, migrate and block the arteries of the lungs)
• Deep vein thrombosis (formation of blood clots in veins of lower limbs)
• Arterial thrombosis (formation of blood clots in arteries)

The side effects associated with thrombolytics include:

• Major bleeding in the brain
• Kidney damage in patients with kidney disease
• Severe hypertension (high blood pressure)
• Severe blood loss or internal bleeding
• Bruising or bleeding at the site of thrombolysis
• Damage to the blood vessels
• Fragments of the clot may migrate to other vessels and cause obstruction
• Increased risk of bleeding in pregnant woman, elderly people, and people with bleeding disorders
• Increased risk for infection
• Allergic reactions

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Drug names include:

• Activase
• Alteplase
• Cathflo Activase
• Defibrotide
• Defitelio
• Retavase
• Reteplase
• Tenecteplase
• TNK tPA
• TNKase
• TPA