Streptokinase (Streptase) (Last Updated - 4/6/2005)

-produced by beta-hemolytic strep
-no intrinsic enzymatic activity on its own

-Mechanism Of Action:
     -forms complex w/ plasminogen --> induces plasminogen --> plasmin
     -NO fibrin (Ia) specificity (unlike t-PA) --> increased risk of serious hemorrhage

-Dosing:
     -Loading Dose: 250,000 units (2.5 mg) IV
          -to overcome plasma Ab's against it due to prior strep infex.

-1/2-Life:
     -40-80 mins. (once Ab's are depleted)

-NOT inhibited by alpha-2-anti-plasmin

-Uses:
     1) Acute MI --> coronary thrombolysis --> DOC

-Side Effex:
     1) Serious hemorrhage --> NO fibrin (Ia) specificity --> no limit to systemic plasmin formation
     2) Allergic reax. (Ex.) anaphylaxis --> rare)
     3) Fever

-t-PA vs. Streptokinase:
     -t-PA (plus Aspirin) vs. Streptokinase (plus Aspirin) for Acute MI's:
          -PTCI (Percutaneous Transluminal Coronary Intervention) is still superior to either
          -NO statistically significant differences
          -both t-PA & Streptokinase (both along w/ Aspirin) decreased death & reinfarction rates by ~30%
     -t-PA more expensive than Streptokinase (Streptase)

     -Streptokinase (Streptase) --> DOC (unless pt. has already received it in the past --> increased Ab titers --> then t-PA is DOC


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References:

Goodman & Gilman's: The Pharmacologic Basis Of Therapeutics - 10th Edition - 2001. Chapter 55.