Metalyse

Indications

Tenecteplase is a clot-dissolving (thrombolytic) medicine used in emergencies to treat a heart attack (acute ST-elevation myocardial infarction) when a blocked artery cannot be opened quickly by a procedure. In some countries it is also used for certain acute strokes caused by a clot.

How It Works

Tenecteplase is a modified form of tissue plasminogen activator, a natural body protein. It binds to the fibrin in a blood clot and turns plasminogen into plasmin, an enzyme that breaks the clot down. This reopens the blocked artery and restores blood flow to the heart muscle, limiting damage. It works best when given as early as possible after symptoms start.

Dosage and Administration

Tenecteplase is given only in hospital or by trained emergency staff, as a single quick injection into a vein over about 5 to 10 seconds. The dose is based on body weight, as prescribed. It is given together with blood-thinning medicines such as Aspirin, Clopidogrel and Heparin or Enoxaparin.

Interactions

Medicines that affect clotting, including Aspirin, Clopidogrel, Heparin, Warfarin and other anticoagulants or antiplatelets, increase the risk of bleeding. The team carefully plans these combinations.

Contraindications

• Active internal bleeding or a bleeding disorder.
• Any previous bleeding stroke, or a clot stroke within recent months.
• Recent major surgery, head injury or serious trauma.
• Brain tumour or other abnormality of brain blood vessels.
• Severe uncontrolled high blood pressure.
• Recent use of anticoagulants with a high clotting test result.

Side Effects

Bleeding is the main risk, from minor oozing at injection sites to serious bleeding in the stomach, urine or brain. Irregular heart rhythms can occur as blood flow returns. Low blood pressure, nausea, fever and allergic reactions are possible.

The patient is closely monitored. Tell staff at once about a sudden severe headache, weakness, confusion, vomiting blood, black stools, blood in the urine, or any heavy bleeding.

Pregnancy and Lactation

Use in pregnancy only if the potential benefit justifies the risk, as it may cause bleeding. Breastfeeding is usually paused for 24 hours after treatment; the doctor will advise.

Precautions and Warnings

Avoid needle punctures and injections into muscles where possible. Use with special care in elderly patients, low body weight, recent minor bleeding, liver disease or diabetic eye disease. Repeat treatment may cause allergic reactions.

Overdose

Overdose increases the risk of bleeding. Bleeding is managed in hospital, which may include stopping blood thinners and giving blood products.

Therapeutic Class

Thrombolytic agent, tissue plasminogen activator (fibrinolytic).

Storage

Hospital product: store as directed on the pack, below 30°C, in the original carton to protect from light. Use the prepared solution straight away.