Fibrinolytics Flashcards
What are the synthetic tPA drugs?
Alteplase
Reteplase
Tenecteplase
shortest to longest duration <5 minutes thru 20-25 minutes.
What is alteplase
recombinant tPA -activates plasminogen to plasmin
What is Reteplase
Recombinant tPA with the fibrin binding domain removed.
Acts more rapidly and lasts about 15 minutes instead of 5.
What is Tenecteplase
Recombinant tPA that is PAI-1 resistant.
What are the antidotes to the fibrinolytics
Aminocaproic Acid - competitive inhibitor of plasminogen activator proteins. Competes with plasminogen for binding site.
Aprotinin - plasmin, trypsin, kallekrein, general serine protease inhibitor
Fresh Frozen Plasma
Cryoprecipitate
Coagulation factor concentrates
What are the non-tPA fibrinolytics?
Streptokinase
Anistreplase
Staphylokinase
Urokinase
What is Anistreplase
A bound complex of streptokinase and plasminogen together
Also acts to activate endogenous plasminogen
half life 1.5 hours
What is the half life of streptokiase?
30 minutes. given i.v. (all thrombolytics are given i.v.)
What is Staphylokinase
Same effects and mech as streptokinase but slightly less effective and less antigenic
What is Urokinase
Human enzyme isolated from urine.
Not immunogenic,
half life 15 minutes.
What are the indications for fibrinolytic treatment
Acute MI if PCI is unnavailable within 2 hours
Severe DVT of PE with hemodynamic instability
Ischemic stroke, within 4.5 hours of symptom onset.
Contraindications for fibrinolytis
Any active internal bleeds
Significant trauma or surgery within the past 10 days, especially head trauma
Significant GI or Cranial bleeding within the past 3 months
Severe hypertension
Aortic dissection or Aortic pericarditis.
Fibrinolytic SEs
Bleeding, especially intracranial bleeding.
- Bleeding complications as high as 15% of patients.
- Lethal bleeding in 0.5%
Allergic and anaphylactic reactions possible to Streptokinase, Anistreplase, and Staphylokinase
Drugs used in bleeding disorders
Local:
- Vasoconstrictors, Epinephrine, NE, Desmopressin
- Collagen, Gelatin, Fibrin meshes
- Injections/sclerotherapy to vericose veins/hemorrhoids
Systemic:
- Vitamin K orally
- Fresh Frozen plasma
- Cryoprecipitates of concentrated cotting factors
- Aminocaproid acid and its derivatives
antidote for fibrinolytics
When is amiocaproic acid used?
In fibrinolytic overdose
Prophylactic therapy for hemophilia
Post-surgical bleeding
Prophylaxis for intracranial aneurysm rebleeding.