Metalyse (Tenecteplase)

Tenecteplase is a fibrinolytic drug used in the acute coronary syndrome pathway to dissolve occlusive thrombi.

• Acute ST‑elevation myocardial infarction (STEMI): rapid restoration of coronary blood flow and reduction of infarct size.
• High‑risk STEMI presenting within 12 hours: improves survival when administered promptly.
• Late‑presenting STEMI (12–24 hours): facilitates reperfusion in patients unsuitable for primary PCI.
• Adjunct to primary PCI when delays occur: provides early thrombolysis to limit myocardial damage.
• Bridge therapy for patients awaiting transfer to PCI‑capable centre: maintains patency of the coronary artery.

• Tenecteplase is a genetically modified variant of tissue‑type plasminogen activator that binds fibrin‑rich thrombi with high affinity. Once bound, it converts circulating plasminogen to active plasmin, which enzymatically degrades fibrin strands, leading to dissolution of the clot while sparing systemic fibrinogen. The modification reduces interaction with plasma protease inhibitors, enhancing its clot‑targeted activity and allowing a rapid, single‑dose regimen in acute myocardial infarction.

Tenecteplase may cause a range of adverse reactions, most of which are related to its fibrinolytic activity.

Common Side Effects

• Bleeding at injection site: mild to moderate bruising or hematoma.
• Hemorrhage: gastrointestinal or urinary tract bleeding.
• Hypotension: transient drop in blood pressure.
• Nausea or vomiting: mild gastrointestinal upset.
• Headache: often mild and self‑limiting.
• Fever or chills: transient pyrexia.

Serious or Rare Side Effects

• Intracranial hemorrhage: life‑threatening bleeding in the brain.
• Allergic reaction or anaphylaxis: severe hypersensitivity requiring immediate treatment.
• Myocardial rupture: rare tearing of heart muscle post‑infarction.
• Severe hypotension: profound drop in blood pressure causing shock.
• Disseminated intravascular coagulation: abnormal clotting and bleeding throughout the body.

When using Tenecteplase, clinicians should observe several precautionary measures to minimize bleeding risk and ensure safe administration.

• Assess bleeding risk: evaluate recent surgery, trauma, or active hemorrhage before administration.
• Review contraindications: avoid use in patients with known intracranial hemorrhage or uncontrolled hypertension.
• Monitor coagulation parameters: check PT/INR and platelet count during therapy.
• Observe vital signs: continuous blood pressure and heart rate monitoring after infusion.
• Use caution in elderly: dose adjustments may be required due to increased bleeding susceptibility.
• Store at 2‑8 °C: keep refrigerated, protect from light, do not freeze or shake.

Tenecteplase interacts with several agents that affect hemostasis or fibrinolysis, requiring careful management.

Major Interactions (Avoid)

• Concurrent thrombolytics: combined use markedly increases risk of severe bleeding.
• Therapeutic anticoagulants (e.g., heparin, low‑molecular‑weight heparin, warfarin): additive anticoagulant effect may cause life‑threatening hemorrhage.
• Direct oral anticoagulants (e.g., dabigatran, rivaroxaban): similar heightened bleeding risk.

Moderate Interactions (Monitor Closely)

• Antiplatelet agents (e.g., aspirin, clopidogrel, GP IIb/IIIa inhibitors): may increase minor bleeding; monitor platelet function.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs): can impair platelet aggregation, requiring observation.
• Selective serotonin reuptake inhibitors (SSRIs): may modestly raise bleeding tendency; assess risk‑benefit.