Tenecteplase (TNKase)

Emergency & Prehospital

• Acute ischemic stroke (AIS): Disabling deficit, within 3 hr of symptom onset. That is the US label. The AcT trial (a disabling-deficit population) enrolled patients up to 4.5 hr. Door-to-needle goal: within 60 min of arrival (AHA/ASA stroke guideline). Mobile stroke units may give it before hospital arrival where protocols allow.
• ST-elevation myocardial infarction (STEMI): Give fibrinolysis when primary PCI cannot start within 120 min of first medical contact and symptoms began under 12 hr. Pharmacoinvasive use means lytic first, then transfer for angiography. Time goal: lytic within 30 min of arrival (ACC/AHA ACS guideline).

ED / ICU / Transport

• Stroke at 3 to 4.5 hr: Past the US label window, so off-label. The AcT trial (disabling deficit, enrolled within 4.5 hr) found tenecteplase non-inferior to alteplase. The 2026 AHA/ASA guideline abstract says it revisits thrombolytic eligibility. Its full text was not checked for this page, so follow the stroke protocol.
• Stroke at 4.5 to 24 hr: Imaging-selected patients only. A stroke expert decides. Off-label.
• Stroke with large-vessel occlusion: Give the lytic, and do not hold up endovascular thrombectomy (EVT) when both are indicated. A 2025 meta-analysis of five randomized trials (1,028 patients) found no significant difference between tenecteplase and alteplase in 90-day excellent recovery or symptomatic intracerebral hemorrhage in LVO (Yao et al.).

Other Uses

• Pulmonary embolism or catheter occlusion: Not labeled for tenecteplase. Alteplase carries the label for massive PE and for catheter restoration. See the fibrinolytics class page. Any tenecteplase use there is off-label and protocol-driven.

Doses vary by protocol; follow local protocols and medical direction.

Available Forms

• 25 mg and 50 mg single-dose vials: white to pale yellow lyophilized powder. Each vial is co-packaged with Sterile Water for Injection: 5.2 mL with the 25 mg vial, 10 mL with the 50 mg vial. Reconstituted to 5 mg/mL.
• Stroke doses fit the 25 mg vial, and the maximum is 25 mg. A 25 mg vial cannot supply a STEMI dose above 25 mg. STEMI stock needs the 50 mg vial.

Adult Dosing

Weight Bands

Pediatric Dosing

Preparation & Administration

• Reconstitution: use only the co-packaged Sterile Water for Injection. Direct the stream onto the powder, swirl gently and do not shake; slight foaming settles in a few minutes.
• Timing: reconstitute immediately before use. If not used at once, refrigerate the vial at 2–8 °C (36–46 °F) and use within 8 hr; the product has no antibacterial preservative.
• Bolus: inspect for particles or discoloration, connect the syringe directly to the IV port and push over 5 seconds.
• Dextrose: incompatible. Flush dextrose-containing lines with 0.9% sodium chloride before and after the bolus.
• Line and punctures: no intramuscular injections; avoid internal jugular and subclavian punctures. If an arterial puncture is unavoidable, use a compressible upper-extremity vessel and hold pressure for at least 30 min.

Contraindications

• Active internal bleeding
• Known bleeding diathesis
• Intracranial or intraspinal surgery or trauma within 2 months
• Current severe uncontrolled hypertension (stroke: BP must be below 185/110 mmHg before the bolus; see Hold / Reassess)
• Intracranial condition that raises bleeding risk: intracranial neoplasm, arteriovenous malformation or aneurysm
• AIS only: active intracranial hemorrhage
• STEMI only: history of intracranial hemorrhage; ischemic stroke within 3 months
• Suspected aortic dissection (not a label entry; a clinical absolute)

Precautions

• Stroke, relative (stroke-team decision; commonly used protocol screens): recent intracranial hemorrhage; ischemic stroke within 3 months; recent major surgery or trauma; GI or GU bleeding within 21 days; a direct oral anticoagulant (DOAC) within 48 hr; therapeutic low-molecular-weight heparin (LMWH) within 24 hr; heparin with an elevated aPTT. The label says treatment can start before coagulation results when there is no recent oral anticoagulant or heparin use. The 2026 AHA/ASA guideline text was not checked for these screens. The stroke team and local protocol decide.
• Label bleeding risk (relative): Systolic BP above 175 or diastolic above 110 mmHg. That is a bleeding-risk warning in label 5.1, not a bolus hold threshold. Also: recent major surgery, obstetric delivery, organ biopsy or noncompressible vessel puncture; recent GI or GU bleeding; recent trauma; acute pericarditis; subacute bacterial endocarditis; hemostatic defects from severe hepatic or renal disease; diabetic hemorrhagic retinopathy; advanced age; current anticoagulant use.
• Anticoagulants before the bolus: If the pretreatment INR is over 1.7 or aPTT is elevated, the tenecteplase label (section 2.1) says closely monitor patients. The Activase (alteplase) label (section 2.1) says discontinue. Stroke teams decide these cases.
• Planned PCI (STEMI): In the label trial, tenecteplase plus PCI had worse outcomes than PCI alone. Mortality was 6.7% vs 4.9%. Cardiogenic shock was 6.3% vs 4.8%. Choose one reperfusion strategy.
• Stroke, mild non-disabling deficit: Not a lytic indication. Antiplatelet therapy per guideline.

Hold / Reassess If

• Before the stroke bolus: BP must be below 185/110 mmHg. If it is higher, treat (for example labetalol or nicardipine) and recheck. Do not give the lytic while BP stays above 185/110. This is a commonly used stroke-protocol threshold from the AHA/ASA guideline lineage (2026 text not checked).
• Before the STEMI bolus: Systolic BP above 180 or diastolic BP above 110 mmHg is a relative contraindication in ACC/AHA guidance. Treat first, then recheck.
• Severe headache, nausea or vomiting, acute hypertension, or a worse neurologic exam after a stroke bolus: stop further treatment and get an emergent noncontrast CT.
• After a stroke bolus, if BP is above 180/105 mmHg, check more often and treat per protocol (for example labetalol or nicardipine).
• Serious bleeding not controlled by pressure: stop heparin and antiplatelet agents and start the bleeding steps.
• Tongue, lip or airway swelling: stop further doses and follow the angioedema steps.

Common

• Bleeding, the most frequent adverse reaction in all approved indications: puncture sites, gums, bruising, urine or stool
• Orolingual angioedema: about 1% (1.0% with tenecteplase vs 1.4% with alteplase in the label stroke trial)
• Hypersensitivity: urticaria and rash
• STEMI: reperfusion arrhythmias (accelerated idioventricular rhythm, sinus bradycardia, PVCs, VT)

Serious / Life-Threatening

Overdose & Toxicity Management

• Risk: a dose above the weight band (over 25 mg for stroke or 50 mg for STEMI), or a STEMI band given for stroke, which roughly doubles the dose, raises bleeding risk.
• Antidote: none. The half-life of 90–130 min limits ongoing exposure, but bleeding can appear 1 or more days later.
• Bleeding support: fibrinogen replacement per protocol (see fibrinogen); antifibrinolytic per protocol (see tranexamic acid); protamine if heparin is infusing.
• Report: file a medication-error report and review band charts and order entry.

• Lab artifact: Coagulation tests and fibrinogen can read falsely abnormal during therapy unless the laboratory prevents in-vitro lysis (label 7.1).
• Procedures: Avoid intramuscular injections and new punctures (label 5.1). Hold non-urgent nasogastric tubes, urinary catheters or arterial lines per stroke protocol.

Clinically Significant Interactions

IV Compatibility

• Tenecteplase: Dextrose and tenecteplase do not mix. Flush dextrose-containing lines with 0.9% sodium chloride before and after the single bolus.
• Reconstituted product: No antibacterial preservative is in the product. Use it right away, or refrigerate and use within 8 hr.
• Check against an institutional compatibility resource.

• Pediatrics: Safety and effectiveness are not established (label 8.4). No pediatric tenecteplase dose is labeled. See the Pediatric Dosing table. Pediatric lytic decisions belong to specialists only.
• Neonates: No specific adjustment is established. Not labeled for neonates.
• Pregnancy: Stroke and STEMI are life-threatening in pregnancy. Case reports of related thrombolytics show no increase in major birth defects. There are no tenecteplase pregnancy data. Rabbit studies showed no maternal or direct embryo toxicity (label 8.1). Do not withhold life-sustaining therapy. Decide with obstetrics.
• Lactation: There are no data on tenecteplase in human or animal milk, on its effect on the breastfed infant, or on milk production. Weigh the benefit of breastfeeding against the mother's clinical need (label 8.2).
• Older Adults: 72% of stroke trial patients were 65 or older, and 49% were 75 or older (label 8.5). For STEMI at 75 or older, STREAM-1 found excess intracranial hemorrhage with full-dose tenecteplase. A pooled STREAM-1 and STREAM-2 analysis of patients 75 and older found comparable ST resolution with half dose and no intracranial hemorrhage compared with primary PCI. The half dose is not in the US label, so follow local protocol. For enoxaparin at 75 or older, give no IV bolus (see the enoxaparin page).
• Renal Impairment: No labeled tenecteplase adjustment. Severe kidney disease raises bleeding risk (label 5.1). Enoxaparin dosing is reduced at creatinine clearance under 30 mL/min (label).
• Hepatic Impairment: No labeled adjustment. The liver is the major clearance route (label 12.3). Significant hepatic dysfunction raises bleeding risk (label 5.1).
• Obesity / Dosing Weight: Bands run on actual or estimated weight (label 14.1). From 90 kg up, the maximum dose applies: 25 mg for stroke, 50 mg for STEMI.

• Scope: Mobile stroke units and some paramedic programs give stroke or STEMI lytics under protocol and medical oversight. RN and critical-care transport teams manage post-lytic monitoring. Scope varies by state and agency protocol.
• Storage & Stability: Store the lyophilized powder at room temperature up to 30 °C (86 °F), or refrigerated at 2–8 °C (36–46 °F) (label 16.2). Reconstituted, use it right away, or refrigerate and use within 8 hr. Do not leave kits in a hot vehicle.
• Carried Concentration: Reconstituted tenecteplase is 5 mg/mL in both vial sizes. Read the stroke band or the STEMI band, not both. Draw the band volume.
• Infusions in Transport: None. Tenecteplase is one bolus, with no pump and no infusion to hand over. Flush dextrose lines before and after the push.
• After a Stroke Lytic (drip and ship): There is no infusion to watch. Keep neurologic and BP checks on schedule. Avoid intramuscular injections and new punctures. Hold antithrombotics until imaging and protocol allow. If the neuro exam worsens, stop and divert for CT.
• After a STEMI Lytic: Go straight to a PCI center. Defibrillator pads stay on. Watch for reperfusion arrhythmias, recurrent pain or shock.
• Handoff Essentials: agent and mg dose, weight used (measured or estimated), last known well or symptom onset, bolus time, BP trend and drugs, neuro trend, antithrombotics given, any bleeding or swelling.

Mechanism of Action

• Modified human tissue plasminogen activator (tPA): threonine 103 to asparagine, asparagine 117 to glutamine, and a tetra-alanine substitution at amino acids 296–299 (label 11)
• Binds fibrin and converts plasminogen to plasmin. That conversion is increased when fibrin is present (label 12.1).
• Plasmin cuts the fibrin. The thrombus dissolves and flow returns.
• Fibrin specificity reduces systemic plasminogen activation and fibrinogen degradation. Its effect on bleeding in clinical use is not established (label 12.1).
• STEMI doses of 30–50 mg lower circulating fibrinogen by 4–15% and plasminogen by 11–24% (label 12.2).

Pharmacokinetics

• Half-life: terminal phase 90–130 min in STEMI patients; plasma clearance 99–119 mL/min (label 12.3)
• Metabolism / Elimination: the liver is the major clearance mechanism (label 12.3)
• Distribution: central volume 4.22–5.43 L, approximating plasma volume; steady-state volume 6.12–8.01 L, suggesting some extravascular distribution (label 12.3)
• Linearity: pharmacokinetics are linear and dose-proportional across 30–50 mg (label 12.3)

Generic Name

Tenecteplase (ten-EK-te-plase)

Brand Names

TNKase (US)

Pharmacologic Class

Plasminogen activator (recombinant, modified tissue plasminogen activator)

Therapeutic Class

Thrombolytic (fibrinolytic) agent

Controlled Substance

Not controlled

ISMP High-Alert

Yes: ISMP high-alert medication (thrombolytic agents)

Look-Alike / Sound-Alike

TNKase / Activase (alteplase); tenecteplase / alteplase

Error-Prone Abbreviations to Avoid

"tPA", "TNK", "rt-PA": write the generic name