IC3 Thrombolytics Flashcards
What is the thrombolytic agent we need to know?
alteplase
Which stage of hemostasis & thrombosis does thrombolytics work on?
clot stabilization
What is the drug class of thrombolytics?
Recombinant tissue plasminogen activators (tPA)
Describe the general mechanism of action of thrombolytics
Thrombolytics break down the fibrin crosslinking that stabilizes the clot
Explain the mechanism of action of thrombolytics
recombinant tPA activates plasminogen into plasmin, which mediates the DEpolymerization and breakdown of fibrin meshwork, allowing RBCs and platelets to be slowly released into the bloodstream
When can we use thrombolytics and why?
only to break down life threatening clots eg. PE
cannot use in DVT as
- if fibrin meshwork is broken down too quickly, the clot can break up too fast in CLUMPS instead of gradually releasing RBCs and platelets into the bloodstream
- the clumps may embolize elsewhere (eg. smaller vessels)
How does alteplase (recombinant tPA) differ from endogenous tPA?
longer half life which allows for convenient IV dosing
What is an advantage of -teplases over -kinases (eg. urokinase, streptokinase)?
-teplases bind preferentially to clot-associated plasminogen, activating plasmin at the clot
What are the side effects of alteplase?
- bleeding
- ventricular arrhythmia
- hypotension
- edema
- cholesterol embolization, VTE
- hypersensitivity, anaphylaxis (rare)
What are the reversal agents for alteplase?
- tranexamic acid
- aminocaproic acid
What are the contraindications for alteplase?
- active bleeding
- prior ICH
- intracranial/intraspinal surgery within the past 3 months
- serious head injury
- stroke
When do we need to be cautious when giving alteplase?
- major surgery within the past 10 days
- risk of bleeding (eg. peptic ulcer)
- cerebrovascular disease
- AF
What drugs ↑ risk of bleeding when used with alteplase?
Antithrombotics
What drug ↓ alteplase conc?
nitroglycerin
