Alteplase – A Life-Saving Thrombolytic Agent for Stroke and Heart Attack

 

Introduction:

*Alteplase* is a recombinant form of *tissue plasminogen activator (tPA)* used to *dissolve blood clots* in emergencies such as *acute ischemic stroke*, *pulmonary embolism*, and *ST-elevation myocardial infarction (STEMI)*. It is a *life-saving drug* when administered early, especially within the therapeutic window of stroke onset.

Brand Names: 

- *Actilyse* (by Boehringer Ingelheim)  

- *Cathflo Activase*  

- *Activase* (in the US)  

Mechanism of Action:

Alteplase binds to *fibrin* in a thrombus (clot) and converts *plasminogen to plasmin*, an enzyme that breaks down fibrin, dissolving the clot and restoring blood flow.

- *Selective activation*: It mainly acts where clots are already formed.

- It reduces ischemia and prevents permanent tissue damage.

Pharmacokinetics:

- *Route*: IV infusion   

- *Half-life*: Biphasic – Initial 5 minutes; terminal 30–45 minutes  

- *Metabolism*: Primarily hepatic  

- *Excretion*: Via liver enzymes; minimal renal involvement  

- *Onset of action*: Immediate (within minutes of infusion)

Pharmacodynamics:

- Promotes *fibrinolysis*  

- Reduces *clot burden*  

- Improves *perfusion* in ischemic tissue  

- *No direct effect* on platelets or coagulation factors

Indications:

- *Acute Ischemic Stroke*  

  - Within *4.5 hours* of symptom onset

- *Acute STEMI*  

  - When PCI is not immediately available

- *Massive Pulmonary Embolism*

- *Occluded central venous catheters* (low-dose Alteplase)

Contraindications: 

*Absolute Contraindications:*

- Active internal bleeding

- History of hemorrhagic stroke

- Recent brain or spinal surgery

- Severe uncontrolled hypertension

- Bleeding disorders

*Relative Contraindications:*

- Recent major surgery

- Pregnancy

- Recent gastrointestinal bleeding

- Age >80 years (for stroke use in some guidelines)

Side Effects:

- *Hemorrhage* (intracranial, gastrointestinal)

- *Angioedema*

- Hypotension

- Reperfusion arrhythmias

- Injection site bleeding

- Allergic reactions (rare)

Dosage Guidelines:

*1. Acute Ischemic Stroke:*

- *0.9 mg/kg IV* (max dose: 90 mg) 

- 10% as *IV bolus over 1 minute*  

  - Remaining 90% as *IV infusion over 60 minutes*

*2. STEMI (as per protocol):*

- Dosing based on *weight* and *duration since symptom onset*

*3. Pulmonary Embolism:*

- *100 mg IV over 2 hours* (standard dose)

Available Form:

- *Actilyse 20 mg & 50 mg vials* (Lyophilized powder for IV use)  

- *Cathflo Activase 2 mg* (for catheter clearance)

Price (may vary by country):

- *Actilyse 50 mg vial*: Approx. *PKR 75,000–90,000* or *USD 600–800*

Conclusion:

Alteplase is a *critical drug in emergency medicine*, especially in *stroke management*, where every minute counts. While its cost and bleeding risk are considerable, *timely administration* can save lives and prevent disability. Proper selection and monitoring of patients are essential to maximize its benefits and minimize risks.