TNK-tPA

Uses

TNK-tPA is used for use in the reduction of mortality associated with acute myocardial infarction (AMI). Treatment should be initiated as soon as possible after the onset of acute myocardial infarction symptoms.
Pediatric Use: The safety and effectiveness of TNK-tPA in pediatric patients have not been established.

In elderly patients: The benefits of TNK-tPA on mortality should be carefully weighed against the risk of increased adverse events, including bleeding.

TNK-tPA is also used to associated treatment for these conditions: ST Elevation Myocardial Infarction (STEMI)

How TNK-tPA works

TNK-tPA binds to fibrin rich clots via the fibronectin finger-like domain and the Kringle 2 domain. The protease domain then cleaves the Arg/Val bond in plasminogen to form plasmin. Plasmin in turn degrades the fibrin matrix of the thrombus, thereby exerting its thrombolytic action.

Dosage

TNK-tPA dosage

TNK-tPA is for intravenous administration only. The recommended total dose should not exceed 50 mg and is based upon patient weight. A single bolus dose should be administered over 5 seconds based on patient weight. Treatment should be initiated as soon as possible after the onset of AMI symptoms.

• Patient Weight <60 kg: 30 mg TNK-tPA 
• Patient Weight ≥60 to <70 kg: 35 mg TNK-tPA 
• Patient Weight ≥70 to <80 kg: 40 mg TNK-tPA 
• Patient Weight ≥80 to <90 kg: 45 mg TNK-tPA 
• Patient Weight ≥90 kg: 50 mg TNK-tPA

1. The product should be visually inspected prior to administration for particulate matter and discoloration. TNK-tPA may be administered as reconstituted at 5 mg/mL.
2. Precipitation may occur when TNK-tPA is administered in an IV line containing dextrose. Dextrose-containing lines should be flushed with a saline-containing solution prior to and following single bolus administration of TNK-tPA.
3. Reconstituted TNK-tPA should be administered as a single IV bolus over 5 seconds.
4. Because TNK-tPA contains no antibacterial preservatives, it should be reconstituted immediately before use. If the reconstituted TNK-tPA is not used immediately, refrigerate the TNK-tPA vial at 2-8°C and use within 8 hours.
5. Although the supplied syringe is compatible with a conventional needle, this syringe is designed to be used with needleless IV systems. From the information below, follow the instructions applicable to the IV system in use.

Side Effects

The most frequent adverse reaction associated with TNK-tPA is bleeding. Should serious bleeding occur, concomitant heparin and antiplatelet therapy should be discontinued. Death or permanent disability can occur in patients who experience stroke or serious bleeding episodes. For TNK-tPA-treated patients in ASSENT-2, the incidence of intracranial hemorrhage was 0.9% and any stroke was 1.8%. The incidence of all strokes, including intracranial bleeding, increases with increasing age

Precaution

General: Standard management of myocardial infarction should be implemented concomitantly with TNK-tPA treatment. Arterial and venous punctures should be minimized. Noncompressible arterial puncture must be avoided and internal jugular and subclavian venous punctures should be avoided to minimize bleeding from the noncompressible sites. In the event of serious bleeding, heparin and antiplatelet agents should be discontinued immediately. Heparin effects can be reversed by protamine.

Readministration: Readministration of plasminogen activators, including TNK-tPA, to patients who have received prior plasminogen activator therapy has not been systematically studied. Three of 487 patients tested for antibody formation to TNK-tPA had a positive antibody titer at 30 days. The data reflect the percentage of patients whose test results were considered positive for antibodies to TNK-tPA in a radioimmunoprecipitation assay, and are highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody positivity in an assay may be influenced by several factors including sample handling, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to TNK-tPA with the incidence of antibodies to other products may be misleading. Although sustained antibody formation in patients receiving one dose of TNK-tPA has not been documented, readministration should be undertaken with caution.

Hypersensitivity: Hypersensitivity, including urticarial / anaphylactic reactions, have been reported after administration of TNK-tPA (e.g., anaphylaxis, angioedema, laryngeal edema, rash, and urticaria). Monitor patients treated with TNK-tPA during and for several hours after infusion. If symptoms of hypersensitivity occur, appropriate therapy should be initiated.

Interaction

Formal interaction studies of Tenectaplase with other drugs have not been performed. Patients studied in clinical trials of TNK-tPA were routinely treated with heparin and aspirin. Anticoagulants (such as heparin and vitamin K antagonists) and drugs that alter platelet function. (such as acetylsalicylic acid, dipyridamole, and GP IIb/IIIa inhibitors) may increase the risk of bleeding if administered prior to, during, or after Tenectaplase therapy.

Food Interaction

• Avoid herbs and supplements with anticoagulant/antiplatelet activity. Examples include garlic, ginger, bilberry, danshen, piracetam, and ginkgo biloba.

TNK-tPA Hypertension interaction

[Major] The most common complication encountered during tenecteplase therapy is bleeding.

TNK-tPA therapy in patients with acute myocardial infarction is contraindicated in patients with active internal bleeding, history of cerebrovascular accident, intracranial or intraspinal surgery or trauma within 2 months, intracranial neoplasms, arteriovenous malformations or aneurysm, bleeding diathesis or severe uncontrolled hypertension, due to an increased risk of bleeding.

Each patient being considered for therapy should be carefully evaluated and anticipated benefits weighed against potential risks associated with therapy.

TNK-tPA Drug Interaction

Major: enoxaparin, heparinModerate: aspirin, clopidogrelUnknown: alteplase, pioglitazone, albumin human, spironolactone, diltiazem, ciprofloxacin, sulfamethoxazole / trimethoprim, glucose, ethanol, arginine, metoprolol, sodium chloride, acetaminophen, tramadol, valproic acid, phytonadione

TNK-tPA Disease Interaction

Major: Tenecteplase -bleedingModerate: thromboembolism

Half Life

1.9 hours (mammalian reticulocytes, in vitro) >20 hours (yeast, in vivo) >10 hours (Escherichia coli, in vivo)

Clearance

• 99 - 119 mL/min [acute myocardial infarction patients]

Pregnancy & Breastfeeding use

Pregnancy: Tenectaplase has been shown to elicit maternal and embryo toxicity in rabbits given multiple IV administrations. In rabbits administered 0.5, 1.5, and 5.0 mg/kg/day during organogenesis, vaginal hemorrhage resulted in maternal deaths. Subsequent embryonic deaths were secondary to maternal hemorrhage and no fetal anomalies were observed. Tenectaplase does not elicit maternal and embryo toxicity in rabbits following a single IV administration. Thus, in developmental toxicity studies conducted in rabbits, the no observable effect level (NOEL) of a single IV administration of Tenectaplase on maternal or developmental toxicity (5 mg/kg) was approximately 7 times human exposure (based on AUC) at the dose for AMI. There are no adequate and well controlled studies in pregnant women. Tenectaplase should be given to pregnant women only if the potential benefits justify the potential risk to the fetus.

Nursing Mothers: It is not known if Tenectaplase is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Tenectaplase is administered to a nursing woman.

Contraindication

TNK-tPA therapy in patients with acute myocardial infarction is contraindicated in the following situations because of an increased risk of bleeding:

• Active internal bleeding
• History of cerebrovascular accident
• Intracranial or intraspinal surgery or trauma within 2 months
• Intracranial neoplasm, arteriovenous malformation, or aneurysm
• Known bleeding diathesis
• Severe uncontrolled hypertension

Storage Condition

Store lyophilized TNK-tPA at controlled room temperature not to exceed 30°C or under refrigeration 2-8°C. Do not use beyond the expiration date stamped on the vial.

Innovators Monograph

You find simplified version here TNK-tPA