session 11b Flashcards
What are common thrombolytic drugs?
- Streptokinase (Streptase)
- Alteplase (t-PA, Activase)
- Reteplase (Retavase)
- Tenecteplase (TNKase)
These drugs are used to dissolve blood clots in various medical conditions.
How do thrombolytic drugs work?
They activate the fibrinolytic system to break down clots quickly by converting plasminogen to plasmin, digesting fibrin.
This process restores blood flow to the heart muscle via coronary arteries.
What is the primary indication for the use of thrombolytic drugs?
- Acute STEMI (ST-Elevation Myocardial Infarction)
- Arterial thrombosis
- DVT (Deep Vein Thrombosis)
- PE (Pulmonary Embolism)
- Occlusion of shunts or catheters
- Acute ischemic stroke
These conditions require rapid intervention to prevent tissue damage.
What are absolute contraindications for thrombolytic therapy?
- Symptoms/signs of aortic dissection
- Active bleeding (excluding menses)
- Hemorrhagic CVA, intracranial malignancy
- Significant head or facial injury in last 3 months
These conditions greatly increase the risk of severe complications.
List the relative contraindications for thrombolytic therapy.
- Severe hypertension (SBP >180, DBP >110)
- Ischemic CVA more than 3 months ago
- Major surgery within the last 3 weeks
- Pregnancy (acceptable for PE)
- Warfarin therapy: increased risk of intracranial hemorrhage with elevated INR
These factors may require careful consideration before administering therapy.
What are the goals of fibrinolytic therapy?
- Achieve early patency of the artery
- Increase myocardial muscle salvage
- Preserve left ventricular function
- Lower mortality rate
Timely administration is crucial, ideally within 4 hours of MI onset.
What is the dosage for Streptokinase?
1.5 million IU IV over 60 minutes.
This dosage is critical for effective treatment.
What are the adverse effects of Streptokinase?
- Anaphylaxis
- Edema
- Bronchospasm
- Spontaneous or intracranial bleeding
Monitoring for these adverse effects is essential during treatment.
What is the dosage protocol for Alteplase (t-PA)?
- 15 mg IV bolus over 1-2 minutes
- 0.75 mg/kg (50 mg max) IV over 30 minutes
- 0.5 mg/kg (35 mg max) IV over 60 minutes
These specific dosages are important for maximizing efficacy and safety.
What are the adverse effects associated with Alteplase (t-PA)?
- Spontaneous bleeding
- Cerebral hemorrhage
Awareness of these risks is important for patient safety.
What is the unique characteristic of Tenecteplase (TNKase)?
It is a genetically engineered t-PA with three-point mutations.
This modification allows for a single bolus administration.
What is the dosage for Tenecteplase (TNKase)?
Single bolus IV dose over 5-10 seconds.
This rapid administration is a key feature of TNKase.
Do fibrinolytics actively breakdown fibrin clots?
True
This distinguishes them from anticoagulants, which do not.
Why is it crucial to review contraindications before starting fibrinolytics?
Due to extremely high bleed risk, potentially resulting in death.
Understanding contraindications is vital for patient safety.
