Drug Monograph

TNKase (Tenecteplase)

tenecteplase (genetically modified recombinant tissue plasminogen activator)
Fibrinolytic / serine protease · Single 5-second IV bolus · Time-critical therapy
Pharmacokinetic Profile
Terminal Half-Life
90–130 minutes (in STEMI patients)
Plasma Clearance
99–119 mL/min
Volume of Distribution
Vc 4.2–5.4 L (≈ plasma volume); Vss 6.1–8.0 L
Metabolism
Hepatic (major clearance mechanism)
Disposition
Biphasic; linear PK across 30–50 mg dose range
Fibrinogen Reduction
4–15% at STEMI doses (per FDA PI Section 12.2)
Clinical Information
Drug Class
Tissue plasminogen activator (tPA), genetically modified third-generation fibrinolytic
Available Forms
25 mg vial; 50 mg vial (each reconstituted to 5 mg/mL)
Route
IV bolus over 5 seconds (only)
Renal Adjustment
None specified in PI
Hepatic Adjustment
Caution — significant hepatic dysfunction increases bleeding risk
Pregnancy
Use only when benefit outweighs risk; do not withhold for life-threatening AIS / STEMI
Lactation
No human or animal milk data
Schedule / Legal Status
Rx only, non-controlled
Generic Available
No (single brand: TNKase in U.S.; Metalyse outside U.S./Canada/Japan)
Rx

Indications

IndicationApproved PopulationTherapy TypeStatus
Acute ischemic stroke (AIS)Adults; initiate as soon as possible and within 3 hours of symptom onset (per FDA label); active intracranial haemorrhage excluded by imagingMonotherapy with concomitant supportive careFDA Approved (2/2025)
Acute ST-elevation myocardial infarction (STEMI)Adults — to reduce the risk of death associated with acute STEMIWith concomitant aspirin and IV heparin (per ASSENT-2 evidence)FDA Approved (2000)

Tenecteplase is a genetically modified recombinant human tissue plasminogen activator developed to retain the fibrin-binding properties of native t-PA while increasing fibrin specificity, prolonging plasma half-life, and reducing inhibition by plasminogen activator inhibitor-1. These pharmacological modifications enable single-bolus dosing rather than the prolonged infusion required for alteplase. Initial U.S. approval for STEMI was 2000. The acute ischemic stroke indication was added in February 2025 on the basis of the AcT non-inferiority trial (Menon BK et al, Lancet 2022). TNKase is currently the only single-bolus thrombolytic FDA-approved for both acute STEMI and AIS in the United States.

Off-Label and Guideline-Endorsed Extended Uses

AIS within the 3 to 4.5-hour window — the FDA AIS label restricts the approved indication to within 3 hours of symptom onset. Per the FDA prescribing information, the AcT trial enrolled patients up to 4.5 hours, but only the 0–3 hour subset (n = 1147) was used to assess efficacy because the comparator (alteplase) is approved only for that window. The ATTEST-2 trial (UK, 2024; n = 1858) confirmed non-inferiority between 0 and 4.5 hours, and AHA/ASA stroke guidelines support tenecteplase as an alternative to alteplase in selected patients within 4.5 hours of symptom onset; verify the current AHA/ASA guideline recommendation in force at the time of practice. Evidence quality: high (multiple non-inferiority RCTs).

AIS in patients eligible for endovascular thrombectomy — single-bolus tenecteplase as the bridging thrombolytic before mechanical thrombectomy is widely used and was tested in EXTEND-IA TNK; logistical advantages over alteplase include faster administration and simpler interhospital transfer. Off-label per the strict 0–3 hour FDA AIS window but supported by published RCT evidence and registry data. Evidence quality: moderate to high.

AIS in the 4.5 to 9-hour window with imaging selection — investigational/off-label use guided by perfusion-imaging selection (CT perfusion or MRI mismatch). Recent AHA/ASA updates have introduced extended-window thrombolysis recommendations; confirm the current guideline at the time of practice. Evidence quality: moderate.

Massive / submassive pulmonary embolism — tenecteplase has been tested in PE (e.g., the PEITHO trial in intermediate-risk PE) but is not FDA-approved for this indication. PEITHO showed reduced haemodynamic decompensation but increased major bleeding without overall mortality benefit. Evidence quality: moderate (single RCT; not approved).

Dose

Dosing

Tenecteplase is administered as a single intravenous bolus over 5 seconds. Dose is weight-tiered and indication-specific, with different maximum doses for AIS (25 mg) and STEMI (50 mg). The AIS regimen targets approximately 0.25 mg/kg, and the STEMI regimen targets approximately 0.5–0.6 mg/kg (about twice the AIS dose). Both vial strengths reconstitute to a final concentration of 5 mg/mL. Tenecteplase is incompatible with dextrose-containing solutions; flush dextrose lines with 0.9% sodium chloride before and after the bolus. Reconstitute immediately before use; if not used immediately, the reconstituted solution may be refrigerated at 2–8 °C and used within 8 hours.

Acute Ischemic Stroke — Maximum Dose 25 mg

Patient WeightTNKase DoseVolume to AdministerNotes
< 60 kg15 mg3 mLConfirm no intracranial haemorrhage on imaging before bolus
Pretreatment BP must be < 185/110 mm Hg (per AHA/ASA standards)
60 to < 70 kg17.5 mg3.5 mLNo antiplatelet or other antithrombotic agents within 24 h after bolus (per AcT trial protocol and FDA PI)
70 to < 80 kg20 mg4 mLInitiate as soon as possible and within 3 hours of symptom onset
80 to < 90 kg22.5 mg4.5 mLIf pretreatment INR > 1.7 or aPTT elevated in patients without recent anticoagulant use, monitor closely (per FDA PI Section 2.1)
≥ 90 kg25 mg5 mLMaximum recommended AIS dose; do not exceed

Acute STEMI — Maximum Dose 50 mg

Patient WeightTNKase DoseVolume to AdministerNotes
< 60 kg30 mg6 mLInitiate as soon as possible after onset of STEMI symptoms
Concomitant aspirin 150–325 mg loading and IV heparin per ASSENT-2 protocol
60 to < 70 kg35 mg7 mLFor weight ≤ 67 kg in ASSENT-2: heparin 4000-unit IV bolus then 800 U/h infusion
70 to < 80 kg40 mg8 mLFor weight > 67 kg in ASSENT-2: heparin 5000-unit IV bolus then 1000 U/h infusion; aPTT target 50–75 s
80 to < 90 kg45 mg9 mLPatients should not have received GP IIb/IIIa inhibitors in the prior 12 h (per ASSENT-2 exclusion)
≥ 90 kg50 mg10 mLMaximum recommended STEMI dose; do not exceed
Choose either thrombolysis or primary PCI as the reperfusion strategy — do not routinely combine

Population-Specific Considerations

PopulationAdjustmentRationale
Geriatric (≥ 65 years), AISNo formal dose adjustment72% of AcT TNKase patients (426/592) were ≥ 65 yr; 49% (290/592) were ≥ 75 yr; no overall safety differences observed (FDA PI Section 8.5), but greater sensitivity in some older individuals cannot be excluded
Geriatric (≥ 65 years), STEMINo formal dose adjustment; counsel on increased riskIn ASSENT-2, 41% (3500/8458) of TNKase-treated STEMI patients were ≥ 65 yr; this group had higher rates of 30-day mortality, stroke, ICH, and major bleeds than younger patients (per FDA PI Section 8.5)
Renal impairmentNo specified adjustmentClearance is hepatic; severe renal disease may increase bleeding risk via uraemic platelet dysfunction (FDA PI Section 5.1)
Hepatic impairmentUse with cautionSignificant hepatic dysfunction is listed by the FDA PI Section 5.1 as a condition that increases bleeding risk; weigh against anticipated benefit
Pediatric AIS / STEMINot establishedPer FDA PI Section 8.4, safety and effectiveness in paediatric patients have not been established
Clinical Pearl — Single-Bolus Logistics

Tenecteplase’s single 5-second bolus is its principal practical advantage. Both vial strengths are supplied as lyophilised powder under partial vacuum, co-packaged with the appropriate volume of Sterile Water for Injection (5.2 mL for the 25 mg vial, 10 mL for the 50 mg vial). Reconstitute only with the supplied diluent (no preservative); both vials yield a final concentration of 5 mg/mL. Slight foaming is normal — let the bubbles settle, then swirl gently (do not shake). Withdraw the weight-based volume into a syringe and connect directly to the IV port. Flush dextrose-containing IV lines with 0.9% sodium chloride before and after the bolus — tenecteplase precipitates in dextrose. Discard any unused reconstituted solution after 8 hours of refrigerated storage.

Critical — TNKase ≠ Activase ≠ Cathflo Activase

Three Genentech thrombolytics are commonly confused: TNKase (tenecteplase, single 5-second IV bolus, weight-tiered to 25 mg max for stroke or 50 mg max for STEMI), Activase (alteplase 50 / 100 mg vials, IV bolus + 60-minute infusion for stroke or weight-banded 90-minute infusion for STEMI), and Cathflo Activase (alteplase 2 mg vial, intracatheter only). The FDA has issued specific medication-error alerts about confusion between these products. Verify the product name, vial strength, indication, and weight band on every order.

PK

Pharmacology

Mechanism of Action

Tenecteplase is a 527-amino-acid glycoprotein produced by recombinant DNA technology in a Chinese hamster ovary cell line (per FDA PI Section 11). It was bioengineered from native human tissue plasminogen activator by introducing three deliberate substitutions: threonine 103 to asparagine and asparagine 117 to glutamine in the kringle 1 domain, and a tetra-alanine substitution at amino acids 296–299 in the protease domain. Its molecular weight is 58,742 daltons and biological potency is expressed as 200 tenecteplase specific units per milligram. These modifications increase the molecule’s resistance to plasminogen activator inhibitor-1, prolong its plasma half-life, and increase fibrin specificity. Like alteplase, tenecteplase binds to fibrin within a thrombus and converts entrapped plasminogen to plasmin, which then degrades the fibrin matrix and lyses the clot. In vitro studies show enhanced relative conversion of plasminogen to plasmin in the presence of fibrin compared with alteplase. The FDA prescribing information explicitly notes that the clinical significance of this fibrin specificity for safety (e.g., bleeding) or efficacy has not been established.

ADME Profile

ParameterValueClinical Implication
AbsorptionIV administration only — single 5-second bolus reconstituted to 5 mg/mLNo oral bioavailability (large glycoprotein); precipitates in dextrose-containing solutions — flush lines with normal saline
DistributionBiphasic disposition; central Vd 4.2–5.4 L (≈ plasma volume); steady-state Vd 6.1–8.0 L (~50% greater, suggesting some extravascular distribution)Local fibrin-bound action at the thrombus; modest extravascular distribution
MetabolismHepatic clearance is the major elimination mechanism; degraded as a proteinSignificant hepatic dysfunction increases bleeding risk and warrants caution
EliminationTerminal phase half-life 90–130 min in STEMI patients; plasma clearance 99–119 mL/min for 30–50 mg doses (linear PK); body weight explains 19% of clearance variability and 11% of Vd variabilityLonger terminal half-life than alteplase enables single-bolus dosing rather than continuous infusion
Pharmacodynamic comparison with alteplase

At STEMI doses (30–50 mg bolus), tenecteplase produces only a 4–15% reduction in circulating fibrinogen and an 11–24% reduction in plasminogen (per FDA PI Section 12.2). For comparison, alteplase at a 100 mg dose reduces fibrinogen by 16–36%. The lesser systemic fibrinogen depletion is a direct consequence of tenecteplase’s enhanced fibrin specificity. Whether this translates into a clinically meaningful difference in bleeding risk is not established by either label, although large randomised trials (ASSENT-2, AcT, ATTEST-2) have shown comparable safety profiles overall.

Immunogenicity

In a study of patients with STEMI, four of 625 (0.64%) patients tested for anti-drug antibodies had a positive antibody titre at 30 days (FDA PI Section 12.6). The clinical relevance of this low-frequency finding is unclear; tenecteplase is administered as a single dose, so chronic immunogenicity is not a practical concern.

SE

Side Effects

The FDA prescribing information identifies bleeding as the most frequent adverse reaction across both approved indications. Adverse-reaction rates are drawn directly from FDA PI Table 3 (AcT trial, AIS) and Table 5 (ASSENT-2 trial, STEMI). Because tenecteplase has been tested head-to-head against alteplase in both indications, the figures below include the comparator rates from those trials.

≥10% Very Common (AIS pivotal trial — AcT, n = 592 TNKase)
Adverse EffectIncidence (TNKase)Clinical Note
Death (90-day) — AIS cohort15.0%Identical to alteplase comparator (15.0%) per FDA PI Table 3; reflects underlying stroke severity rather than drug toxicity
No other ≥ 10% non-bleeding adverse reaction is enumerated in the FDA prescribing information for tenecteplase.
< 10% Common (Pivotal Trials)
Adverse EffectIncidenceClinical Note
Death or non-fatal stroke at 30 days (STEMI — ASSENT-2)7.1%Alteplase 7.0%; relative risk 1.01 (95% CI 0.91–1.13); composite endpoint per FDA PI Table 5
30-day mortality (STEMI — ASSENT-2)6.2%Identical to alteplase 6.2%; relative risk 1.00 (95% CI 0.89–1.12) per FDA PI Table 5
Symptomatic intracerebral haemorrhage (AIS — AcT)3.4%Alteplase 3.1% in the same trial; defined per FDA PI as ICH temporally related to and directly responsible for neurological worsening
Any stroke at 30 days (STEMI — ASSENT-2)1.8%Alteplase 1.7%; relative risk 1.07 (95% CI 0.86–1.35)
Orolingual angioedema (AIS — AcT)1.0%Alteplase 1.4% in the same trial; higher risk reported with concomitant ACE inhibitors
Extracranial bleeding requiring blood transfusion (AIS — AcT)1.0%Alteplase 0.7%; per FDA PI Table 3
Intracranial haemorrhage at 30 days (STEMI — ASSENT-2)0.9%Alteplase 0.9%; relative risk 0.99 (95% CI 0.73–1.35)
Serious Serious Adverse Events
Adverse EffectEstimated FrequencyTypical OnsetRequired Action
Symptomatic intracerebral haemorrhage (AIS)3.4% in AcTUsually first 24–36 hUrgent CT; cryoprecipitate ± antifibrinolytic (tranexamic acid or aminocaproic acid); platelet transfusion if low or on antiplatelet; neurosurgery consult
Major systemic bleedingIncreased over baseline; varies by siteDuring or after bolus; can occur 1+ days later if anticoagulatedDiscontinue any concomitant heparin or antiplatelet immediately; pressure on compressible sites; cryoprecipitate; transfusion as needed
Hypersensitivity reactions (urticarial / anaphylactic)Reported (frequency not quantified in PI)During and for several hours after bolusAntihistamines, corticosteroids, epinephrine; manage airway; includes anaphylaxis, angioedema, laryngeal oedema, rash, and urticaria
Cholesterol embolisationReported (incidence unknown)Days after exposureRecognise (livedo reticularis, purple toes, AKI, gangrenous digits, pancreatitis); supportive care; can be fatal
Reperfusion arrhythmias (STEMI)Common during STEMI thrombolysisMinutes to hours after bolusSinus bradycardia, AIVR, PVCs, VT — manage with standard antiarrhythmic measures; have antiarrhythmic therapy available at the bedside (per FDA PI Section 5.5)
Thromboembolism (left heart thrombus lysis)ReportedDuring or after bolusHigher risk in mitral stenosis or atrial fibrillation; consider risk-benefit before administration
Heart failure / recurrent ischaemia (STEMI + planned PCI)Worse vs PCI alone (ASSENT-4 PCI)Within 90 days of strategyDo not routinely combine TNKase with planned primary PCI; choose one reperfusion strategy (per FDA PI Section 5.6)
Discontinuation Single-Bolus Therapy — No “Discontinuation” in the Conventional Sense
Administration
5-second IV bolus single dose
Note: Unlike alteplase (60-minute or 90-minute infusion), tenecteplase is given as a single 5-second bolus. Once the bolus has been administered, there is no infusion to terminate — clinical management of bleeding or hypersensitivity focuses on stopping any concomitant anticoagulants and treating the complication.
Action on Adverse Event
Stop adjuncts
Action: for serious bleeding, immediately discontinue concomitant heparin and any antiplatelet agents; treat haemorrhage, hypersensitivity, or cholesterol embolisation per protocol.
Reason to Withhold or ReverseIncidenceContext
Suspected intracranial haemorrhagePer protocolAcute neurological deterioration after bolus → urgent CT, stop concomitant anticoagulation, reverse with cryoprecipitate ± antifibrinolytic
Major extracranial bleedingPer protocolStop all concomitant anticoagulants/antiplatelets; supportive transfusion; mechanical compression for accessible sites
Hypersensitivity / angioedemaPer protocolSecure airway; antihistamines, corticosteroids, epinephrine
Pretreatment INR > 1.7 or aPTT elevated (AIS)Per protocolIf labs return after bolus in patients without recent anticoagulant use, monitor closely (per FDA PI Section 2.1)
Management Pearl — Suspected Symptomatic ICH after Tenecteplase

Sudden neurological deterioration, severe headache, acute hypertension, nausea or vomiting after a tenecteplase bolus mandates urgent non-contrast CT. Discontinue any concomitant heparin or antiplatelet immediately. While imaging is pending, send fibrinogen, platelets, PT/aPTT, and type and crossmatch. If ICH is confirmed, administer cryoprecipitate (typically 10 units; target fibrinogen ≥ 150 mg/dL), consider an antifibrinolytic (tranexamic acid 1 g IV or aminocaproic acid), correct platelets if needed, and consult neurosurgery and haematology promptly. Reversal protocols vary by institution — follow local guidance. Note that the longer terminal half-life of tenecteplase (90–130 min) compared with alteplase means circulating drug may still be present at the time of recognition.

Int

Drug Interactions

The FDA prescribing information for TNKase has a brief Drug Interactions section (Section 7.1) that addresses primarily an in vitro coagulation-test artifact rather than direct drug–drug interactions. Clinically relevant interactions, however, are well established through the Warnings and Precautions section and through general antithrombotic pharmacology, and are summarised below.

Major Heparin / LMWH (therapeutic dosing)
MechanismAdditive antithrombotic effect on top of fibrinolysis
EffectIncreased bleeding risk, including intracranial haemorrhage
ManagementIn AIS, do not give heparin or aspirin within the first 24 h after the bolus (per FDA PI Section 5.1). In STEMI, concomitant heparin is part of the regimen — use ASSENT-2 weight-based heparin dose with aPTT 50–75 s
FDA PI 5.1, 14.2
Major Direct oral anticoagulants (DOACs) and warfarin
MechanismActive anticoagulation compounding the lytic state
EffectSignificantly increased bleeding risk
ManagementFor AIS, current AHA/ASA guidelines suggest avoiding thrombolysis if a DOAC has been taken within ~48 h (longer in renal impairment) unless reversed. The FDA TNKase label lists “patients currently receiving anticoagulants” as a bleeding precaution (Section 5.1)
FDA PI 5.1; AHA/ASA
Major GP IIb/IIIa inhibitors (within prior 12 h)
MechanismStrong platelet inhibition compounding the lytic state
EffectIncreased bleeding risk; ASSENT-2 trial excluded patients who had received GP IIb/IIIa inhibitors in the prior 12 h
ManagementAvoid recent GP IIb/IIIa exposure when possible; if combination is unavoidable in STEMI / PCI, the optimal antithrombotic strategy is unknown (per FDA PI Section 5.6)
FDA PI 5.6, 14.2
Major Other antiplatelet agents (aspirin, P2Y12 inhibitors)
MechanismAdditive haemostatic impairment
EffectIncreased bleeding risk, including intracranial
ManagementIn AIS, defer all antiplatelets (including aspirin) for 24 h after the bolus. In STEMI, aspirin and IV heparin are co-administered per the ASSENT-2 protocol
FDA PI 5.1, 14.2
Moderate ACE inhibitors
MechanismBradykinin-mediated angioedema potentiated by fibrinolytic-induced kinin generation (class effect for tPA-class agents)
EffectHigher reported risk of orolingual angioedema, especially in AIS — angioedema rate of 1.0% in AcT
ManagementMonitor airway during and for several hours after bolus; have antihistamines, corticosteroids, and epinephrine available at the bedside
Class effect / AHA/ASA
Minor Dextrose-containing IV solutions
MechanismChemical incompatibility — precipitation when mixed with dextrose (per FDA PI Section 2.5)
EffectDrug precipitation in the IV line, potentially reducing delivered dose
ManagementFlush dextrose-containing IV lines with 0.9% sodium chloride before and after the bolus
FDA PI 2.5
Coagulation tests during therapy

The FDA prescribing information cautions that coagulation tests and measures of fibrinolytic activity may be unreliable during tenecteplase therapy because circulating drug remains active in vitro and can degrade fibrinogen in blood samples after collection (Section 7.1). Specific precautions (rapid sample handling and inhibitor addition) are required for accurate post-treatment fibrinogen measurement.

Mon

Monitoring

Tenecteplase requires intensive bedside monitoring after the bolus. The dominant priorities are early detection of bleeding (especially intracranial), tight blood-pressure control, airway assessment for hypersensitivity, and — for STEMI — surveillance for reperfusion arrhythmias. AHA/ASA stroke guidelines specify a structured neurological- and BP-monitoring schedule for the first 24 hours after AIS thrombolysis, summarised below.

  • Blood Pressure (AIS) Every 15 min × 2 h, then q 30 min × 6 h, then q 60 min × 16 h
    Routine
    Goal < 180/105 mm Hg for the first 24 h after AIS thrombolysis (AHA/ASA standards). Treat with IV labetalol, nicardipine, or clevidipine per institutional protocol. Pretreatment BP must be < 185/110 mm Hg before the bolus.
  • Neurological Exam Same schedule as BP for first 24 h
    Routine
    NIHSS or focused neurological check; any acute deterioration mandates urgent CT to exclude ICH and immediate cessation of any concomitant anticoagulant.
  • Bleeding Surveillance Continuous after bolus; clinical monitoring ≥ 24 h
    Routine
    Inspect arterial puncture sites, mucous membranes, urine, and stool. Avoid IM injections, urinary catheters, NG tubes, and central venous access during the first 24 h unless essential. The FDA PI specifically advises against internal jugular and subclavian venous punctures because these sites are not amenable to manual compression.
  • Airway / Hypersensitivity During and for several hours after bolus
    Routine
    Inspect tongue and oropharynx; observe for urticaria, rash, and hypotension. Have antihistamines, corticosteroids, and epinephrine available. Higher angioedema risk in patients on ACE inhibitors.
  • Cardiac Rhythm (STEMI) Continuous telemetry
    Routine
    Watch for reperfusion arrhythmias (sinus bradycardia, AIVR, PVCs, VT) and mechanical complications. Have antiarrhythmic therapy available at the bedside per FDA PI Section 5.5.
  • Repeat CT (AIS) At 24 h or sooner if deterioration
    Routine
    Required before initiating antiplatelet or anticoagulant therapy after AIS thrombolysis; sooner if any neurological worsening, severe headache, or BP surge.
  • Coagulation Panel Baseline; repeat with bleeding
    Trigger-based
    Pretreatment INR, aPTT, platelets, type and screen. In AIS without recent anticoagulant use, treatment can begin before results return; closely monitor if INR > 1.7 or aPTT elevated.
  • Fibrinogen If clinical bleeding
    Trigger-based
    In the event of significant bleeding, send fibrinogen and target ≥ 150 mg/dL with cryoprecipitate; remember that in vitro degradation in untreated samples can artifactually lower the measured value.
  • Glucose (AIS) At presentation
    Trigger-based
    Hypoglycaemia and severe hyperglycaemia can mimic stroke; the AHA/ASA guideline recommends correcting glucose abnormalities before treatment but does not categorically exclude eligible patients once glucose is corrected.
CI

Contraindications & Cautions

Absolute Contraindications — Both AIS and STEMI (FDA PI Section 4)

  • Active internal bleeding
  • Intracranial or intraspinal surgery or trauma within 2 months
  • Known bleeding diathesis
  • Current severe uncontrolled hypertension — generally interpreted clinically as BP that cannot be lowered to < 185/110 mm Hg with antihypertensives prior to thrombolysis
  • Presence of intracranial conditions that may increase the risk of bleeding — e.g., intracranial neoplasm, arteriovenous malformation, or aneurysm

Additional Contraindication — AIS Only

  • Active intracranial haemorrhage — confirm absence by non-contrast CT before bolus

Additional Contraindications — STEMI Only

  • History of intracranial haemorrhage (any prior — not just recent)
  • History of ischaemic stroke within 3 months

Relative Contraindications (Specialist Input Recommended) — FDA PI Section 5.1

The FDA PI Section 5.1 lists conditions in which the bleeding risks of TNKase therapy for the approved indications are increased and should be weighed against the anticipated benefits:

  • Recent major surgery or procedure — coronary artery bypass graft, obstetric delivery, organ biopsy, previous puncture of non-compressible vessels
  • Cerebrovascular disease
  • Recent intracranial haemorrhage (where not already an absolute contraindication)
  • Recent gastrointestinal or genitourinary bleeding
  • Recent trauma
  • Hypertension — systolic BP above 175 mm Hg or diastolic BP above 110 mm Hg
  • Acute pericarditis
  • Subacute bacterial endocarditis
  • Hemostatic defects, including those secondary to severe hepatic or renal disease
  • Significant hepatic dysfunction
  • Pregnancy
  • Diabetic haemorrhagic retinopathy or other haemorrhagic ophthalmic conditions
  • Septic thrombophlebitis or occluded AV cannula at a seriously infected site
  • Advanced age — increased bleeding and ICH risk in older patients (especially in STEMI per ASSENT-2 sub-analyses)
  • Patients currently receiving anticoagulants (e.g., warfarin)
  • Any other condition in which bleeding constitutes a significant hazard or would be particularly difficult to manage because of its location

Use with Caution

  • Concomitant ACE inhibitor — higher reported risk of orolingual angioedema (class effect for tPA agents); monitor airway during and after bolus.
  • High likelihood of left heart thrombus — mitral stenosis, atrial fibrillation; risk of systemic embolisation as the lytic state acts on the thrombus (FDA PI Section 5.3).
  • Planned primary PCI for STEMI — do not routinely combine TNKase with planned PCI; ASSENT-4 PCI showed worse outcomes versus PCI alone (FDA PI Section 5.6). Choose one reperfusion strategy.
  • Pediatric use — safety and effectiveness not established (FDA PI Section 8.4).
  • Pregnancy — animal data showed no maternal or developmental toxicity at ~7× human STEMI exposure; limited human data in case reports of related thrombolytics. The FDA PI explicitly states that life-sustaining therapy in pregnancy should not be withheld for STEMI or AIS because of potential fetal effects.
  • Lactation — no human or animal milk data; risk-benefit decision based on the acuity of indication.
FDA Warnings & Precautions (Section 5) Bleeding, Hypersensitivity, and Reperfusion Risks

TNKase can cause significant, sometimes fatal, internal or external bleeding, especially at arterial and venous puncture sites. Concomitant drugs that impair haemostasis increase the risk further. Avoid intramuscular injections; minimise venipunctures; if arterial puncture is required during therapy, use an upper-extremity vessel accessible to manual compression and apply pressure for at least 30 minutes. There is no FDA boxed warning, but the bleeding caution is the central theme of the prescribing information.

Hypersensitivity reactions (urticarial / anaphylactic — including anaphylaxis, angioedema, laryngeal oedema, rash, urticaria) have been reported. Monitor patients during and for several hours after the bolus and treat with antihistamines, corticosteroids, and epinephrine if symptoms occur.

Coronary thrombolysis may produce reperfusion arrhythmias; have antiarrhythmic therapy available. Do not routinely combine TNKase with planned primary PCI for STEMI — ASSENT-4 PCI showed worse outcomes (mortality, cardiogenic shock, congestive heart failure, recurrent MI, and repeat revascularisation) versus PCI alone. Cholesterol embolisation has been rarely reported with thrombolytic agents.

Pt

Patient Counselling

Purpose of Therapy

Tenecteplase is an emergency, single-bolus therapy. Most patients (or surrogate decision-makers) receive it under acute, time-pressured conditions for either acute ischaemic stroke or ST-elevation myocardial infarction. Counselling typically occurs in two phases: a brief consent conversation before the bolus (when feasible) covering the trade-off between potential benefit and bleeding risk, and a more thorough post-treatment conversation about ongoing observation, recovery, and follow-up.

Before the Bolus (where time permits)

Explain in plain language that the medicine works by dissolving the clot blocking a brain artery (in stroke) or a heart artery (in STEMI). Earlier treatment increases the chance of a good outcome. The most important risk is bleeding — including bleeding into the brain, which in the AcT stroke trial occurred symptomatically in around 3 of every 100 patients treated and is sometimes fatal. Despite this risk, the trial evidence shows that tenecteplase is at least as effective as alteplase, with the practical advantage of a single 5-second injection rather than a 60-minute infusion. Allergic reactions, including swelling of the tongue and lips, are uncommon but possible, especially in patients on certain blood-pressure medicines.

Bleeding — What to Watch For
Tell patient For at least 24 hours and up to several days after the injection, you are at higher risk of bleeding. You will be observed in hospital. Avoid blowing your nose forcefully, brushing teeth too vigorously, or shaving with a razor while admitted. Tell staff if you notice unusual bruising, blood in urine or stool, coughing up blood, vomit that looks like coffee grounds, or new headache.
Call prescriber After discharge: any unexpected bleeding, dark or tarry stools, blood in vomit or urine, coughing up blood, severe headache, sudden weakness, or speech change — call emergency services immediately. The FDA prescribing information notes that bleeding can occur one or more days after administration.
Stroke Recovery and Recurrence
Tell patient Recognise stroke warning signs using the FAST acronym: Face drooping, Arm weakness, Speech difficulty, Time to call emergency services. Stroke can recur. Take prescribed prevention therapy (typically antiplatelet therapy, blood-pressure medicine, and a statin) as directed once the team confirms it is safe to start, usually 24 hours after the tenecteplase bolus.
Call prescriber Any new neurological symptom — call emergency services immediately. Do not wait to see if it resolves.
Lip / Tongue Swelling (Hypersensitivity)
Tell patient A small number of patients develop swelling of the lips or tongue, hives, or other allergic-type reactions during or shortly after the injection. The team will watch closely. If you notice tongue thickening, lip swelling, hives, or trouble speaking, tell staff immediately.
Call prescriber After discharge: any new tongue, lip, or facial swelling, especially with difficulty breathing — call emergency services. Mention you recently received tenecteplase and (if applicable) take an ACE inhibitor.
After STEMI Treatment
Tell patient Heart attack therapy continues with aspirin and other heart medicines, and the team will discuss longer-term prevention (statins, beta-blockers, ACE inhibitors, dual antiplatelets, lifestyle changes). You may also undergo coronary angiography or stenting at some point during your admission. Cardiac rehabilitation is strongly recommended.
Call prescriber Worsening chest pain, severe shortness of breath, palpitations, leg swelling, or fainting after discharge — seek emergency assessment.
Why a Different Medicine Was Used
Tell patient You may have heard about “tPA” or “alteplase” being used for strokes and heart attacks. Tenecteplase is a related medicine in the same family that can be given as a single 5-second injection rather than a 60-minute infusion. Studies show it works just as well as alteplase for both strokes and heart attacks. Hospitals are increasingly using tenecteplase because it is faster to give, especially when patients need to be transferred between hospitals quickly for further treatment.
Call prescriber Any questions about the medicine you received or any new symptoms after discharge.
Follow-up and Recovery
Tell patient Stroke and heart attack recovery often involve rehabilitation (physical therapy, occupational therapy, speech therapy). Address vascular risk factors: blood pressure, cholesterol, diabetes, smoking, weight, and physical activity. Take the prescribed medicines exactly as directed, even if you feel well.
Call prescriber Any new neurological, cardiac, or respiratory symptom; medication side effects; or questions about the medicines you are now taking.
Ref

Sources

Regulatory (PI / SmPC)
  1. TNKase® (tenecteplase) US Prescribing Information. Genentech, Inc. Revised February 2025 (Reference ID: 5540622). accessdata.fda.gov Primary FDA label; source for indications, weight-based dosing tables, contraindications, adverse-reaction Tables 3 and 5, and pharmacokinetic values cited throughout this monograph.
  2. FDA Approves Genentech’s TNKase® in Acute Ischemic Stroke in Adults. Genentech press release, March 3, 2025. gene.com Documents the February 2025 FDA approval of TNKase for acute ischemic stroke and the introduction of the new 25 mg vial configuration.
Key Clinical Trials
  1. Menon BK, Buck BH, Singh N, et al. Intravenous tenecteplase compared with alteplase for acute ischaemic stroke in Canada (AcT): a pragmatic, multicentre, open-label, registry-linked, randomised, controlled, non-inferiority trial. Lancet. 2022;400(10347):161-169. doi.org/10.1016/S0140-6736(22)01054-6 Pivotal AcT non-inferiority trial that supported FDA approval of tenecteplase for AIS; source of the 0–3 hour subgroup analysis (n = 1147) summarised in FDA PI Tables 3 and 4.
  2. Assessment of the Safety and Efficacy of a New Thrombolytic (ASSENT-2) Investigators. Single-bolus tenecteplase compared with front-loaded alteplase in acute myocardial infarction: the ASSENT-2 double-blind randomised trial. Lancet. 1999;354(9180):716-722. doi.org/10.1016/S0140-6736(99)07403-6 Pivotal STEMI non-inferiority trial (n = 16,949) demonstrating equivalence of single-bolus tenecteplase to accelerated alteplase for 30-day mortality; basis for FDA PI Table 5.
  3. Cannon CP, McCabe CH, Gibson CM, et al; TIMI 10A Investigators. TNK-tissue plasminogen activator in acute myocardial infarction: results of the Thrombolysis in Myocardial Infarction (TIMI) 10A dose-ranging trial. Circulation. 1997;95(2):351-356. doi.org/10.1161/01.cir.95.2.351 Phase 1 dose-ranging pharmacokinetic / pharmacodynamic study of tenecteplase in STEMI patients that established the basis for subsequent dose-finding.
  4. Muir KW, Ford GA, Ford I, et al; ATTEST-2 Investigators. Tenecteplase versus alteplase for acute stroke within 4·5 h of onset (ATTEST-2): a randomised, parallel group, open-label trial. Lancet Neurology. 2024;23(11):1087-1096. doi.org/10.1016/S1474-4422(24)00377-6 UK non-inferiority trial (n = 1858) extending the AcT findings up to 4.5 hours after stroke onset; supports off-label use in the extended window.
  5. Assessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention (ASSENT-4 PCI) Investigators. Primary versus tenecteplase-facilitated percutaneous coronary intervention in patients with ST-segment elevation acute myocardial infarction (ASSENT-4 PCI): randomised trial. Lancet. 2006;367(9510):569-578. doi.org/10.1016/S0140-6736(06)68147-6 Trial that demonstrated harm with routine combination of full-dose tenecteplase plus planned PCI versus PCI alone, underpinning FDA PI Section 5.6.
Guidelines
  1. Powers WJ, Rabinstein AA, Ackerson T, et al; American Heart Association Stroke Council. Guidelines for the early management of patients with acute ischemic stroke: 2019 update to the 2018 guidelines for the early management of acute ischemic stroke. Stroke. 2019;50(12):e344-e418. doi.org/10.1161/STR.0000000000000211 2019 AHA/ASA AIS guideline update — basis for the BP and post-thrombolysis monitoring targets cited in this monograph.
  2. American Heart Association / American Stroke Association. Most recent guideline for the early management of patients with acute ischemic stroke (published 2025/2026). Stroke. ahajournals.org/journal/str Most recent AHA/ASA AIS guideline addressing tenecteplase 0.25 mg/kg as an alternative to alteplase 0.9 mg/kg in selected patients within 4.5 hours, and the extended-window thrombolysis recommendation. Confirm the published citation (authors, journal, year, DOI) at the time of publication.
  3. O’Gara PT, Kushner FG, Ascheim DD, et al; American College of Cardiology Foundation / American Heart Association Task Force. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction. J Am Coll Cardiol. 2013;61(4):e78-e140. doi.org/10.1016/j.jacc.2012.11.019 ACC/AHA STEMI guideline — context for fibrinolytic therapy when timely PCI is not available, including weight-based tenecteplase dosing.
Pharmacokinetics / Special Populations
  1. TNKase® (tenecteplase) US Prescribing Information, Section 12.3 (Pharmacokinetics) and Section 8 (Use in Specific Populations). Genentech, Inc. accessdata.fda.gov Primary source for the terminal half-life (90–130 minutes), plasma clearance (99–119 mL/min), volume of distribution, hepatic clearance, body-weight covariate effects, geriatric data, and absence of paediatric and lactation data.