π§ tPA (Alteplase) Stroke Dose Reference
0.9 mg/kg, 10% bolus, 60-minute infusion.
Hospital use only. Thrombolysis is given by stroke teams after hemorrhage is excluded by imaging.
Total alteplase dose
For informational purposes only, not medical advice.
Alteplase for acute ischemic stroke is dosed at 0.9 mg per kilogram, capped at 90 mg: 10 percent as a bolus over one minute, the remaining 90 percent infused over 60 minutes. An 80 kg patient receives 72.0 mg total, 7.2 mg bolus and 64.8 mg infusion. It is given within 4.5 hours of symptom onset, only after a CT scan excludes bleeding, and only by a stroke team.
Thrombolysis dissolves the clot blocking the brain artery, and every minute of delay kills about 1.9 million neurons. That urgency is why stroke systems are built around door-to-needle times, and why the dosing is standardized to the point of ritual.
How This Reference Works
Enter weight to see the total dose split into bolus and infusion. This is a look-up of the standard regimen for education, not an order, and it assumes every eligibility check has already passed.
Enter the patient's weight in kilograms.
Read the total dose, the 10 percent bolus, and the 60-minute infusion amount.
Confirm the 4.5-hour window and the exclusion checklist below. Dosing without eligibility is meaningless.
The Dosing Scheme
The 90 mg cap means patients over 100 kg all receive the same dose, a deliberate ceiling from the trials. The bolus-then-infusion split gets drug to the clot fast while maintaining exposure for the hour. Tenecteplase, increasingly used as an alternative, is a single weight-based bolus instead, a different drug with a different sheet.
Eligibility is the real gate: measurable deficit, no intracranial hemorrhage on imaging, no recent surgery or bleeding, blood pressure controlled, glucose not mimicking stroke, and onset within 4.5 hours. The dose is the easy part; the decision is the hard one.
Worked Example
An 80 kg patient, 2 hours from onset, CT negative for bleed: total dose 0.9 times 80 equals 72.0 mg. Bolus 7.2 mg IV push over one minute, then 64.8 mg infused over the next hour. Blood pressure and neuro checks run on protocol throughout, watching for the feared complication, symptomatic intracranial hemorrhage, around 6 percent in the trials.
A 120 kg patient: 0.9 times 120 would be 108 mg, but the cap holds it at 90 mg, bolus 9 mg, infusion 81 mg. The cap is not negotiable; trial safety data stops at 90.
Reading Your Result
| Element | Standard |
|---|---|
| Total dose | 0.9 mg/kg up to 90 mg. |
| Bolus | 10 percent over 1 minute. |
| Infusion | Remaining 90 percent over 60 minutes. |
| Time window | Within 4.5 hours of last known well. |
My take: the public's job in stroke is not dosing but speed, recognizing FAST symptoms and calling emergency services immediately. Every minute saved before the needle matters more than any decimal in the dose.
Limits
This page reproduces one dosing regimen for one indication. It does not cover myocardial infarction or pulmonary embolism dosing (different regimens), tenecteplase, wake-up strokes with unknown onset (see our wake-up stroke guide), or any contraindication judgment. Thrombolysis is a hospital-team decision made with imaging in hand.
Related Tools
For unknown-onset strokes see the wake-up stroke eligibility guide. The blood pressure checker covers the pressure control that precedes thrombolysis.
For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
What is the tPA dose for stroke?
Alteplase 0.9 mg/kg IV, maximum 90 mg: 10% as a bolus over 1 minute, then 90% infused over 60 minutes. Given within 4.5 hours of symptom onset after CT excludes hemorrhage.
What is the time window for tPA in stroke?
Up to 4.5 hours from last known well for standard eligibility. Wake-up strokes with unknown onset may qualify under imaging criteria (DWI-FLAIR mismatch) per the WAKE-UP trial.
How is tPA given?
As a small IV bolus over one minute followed by a one-hour infusion, with blood pressure and neurological monitoring throughout. It is administered by stroke teams in emergency departments, never at home.
What are the risks of tPA?
Symptomatic intracranial hemorrhage in roughly 6% of treated patients in trials, plus systemic bleeding. The benefit, better odds of independent recovery, outweighs the risk in eligible patients, which is why selection is strict.
Who cannot receive tPA for stroke?
Patients with intracranial hemorrhage, recent intracranial surgery or head trauma, active bleeding, very high blood pressure, low platelets or clotting abnormalities, very mild or rapidly improving symptoms, and onset beyond the window, among other exclusions.
What is the difference between tPA and tenecteplase?
Both are clot-busting drugs; tenecteplase is given as a single weight-based bolus rather than bolus-plus-infusion and is increasingly used for stroke where protocols allow. Dosing and eligibility differ by agent.
Does tPA work after 4.5 hours?
Standard IV thrombolysis eligibility ends at 4.5 hours, but mechanical thrombectomy for large vessel occlusion extends much later, up to 24 hours in selected patients with favorable imaging. Late presenters need immediate evaluation anyway.
What does FAST mean in stroke?
Face drooping, Arm weakness, Speech difficulty, Time to call emergency services. Public recognition and fast transport matter more than any dosing detail.
Can tPA be given for wake-up strokes?
When onset time is unknown, MRI showing DWI-FLAIR mismatch can identify patients likely within the window, and trials support thrombolysis in that selected group. It requires emergency MRI and specialist judgment.
Is this page a dosing order?
No. It is an educational reference reproducing the standard regimen. Real thrombolysis dosing is ordered by the stroke team after imaging and eligibility checks, with weight verified at the bedside.