Anti-platelets and Thrombolytics Flashcards
within the anti-clotting group of drugs are two classes of drugs - what are they?
anti-coagulants and anti-thrombolytics
within the anti-clotting group of drugs which drug is typically used to treat arterial disease? (the other is typically used to treat both arterial and venous thrombosis)
anti-coagulants
what happens to aPTT time when the drug effect is deemed adequate?
it is prolonged
what is the name of the endogenous anti-clottting protein that irreversibly inactivates thrombin - its actions are increased by heparin
antithrombin III
this is the laboratory test used to monitor the anticoagulant effect of warfarin; it is prolonged when drug effect is adequate
Prothrombin Time (PT)
true or false: heparin is highly acidic and can be neutralized by basic molecules
true
true or false: it is safe to give heparin via IV, subcutaneously and IM
false - not safe IM due to risk of hematoma
what is the advantage of fractioned (LMW) heparin over un-fractioned heparin?
LMW has greater bioavailability and longer duration of action - this also means it can be given less frequently
which one cannot be used during pregnancy? warfarin or heparin?
warfarin
which is more fast acting? warfarin or heparin?
heparin
true or false: aPTT test does not reliably measure anti-coagulation effect of LMW and other unfractioned heparins (like fondaparinux)
true
heparin is used in combination with ____ for re-vascularization
anti-thrombolytics
heparin is used in combination with ______ during angioplasty and placement of coronary stents
glycoprotein IIb/IIIa
what is the most common adverse side effect of heparin?
increased bleeding which may end in hemorrhagic stroke
what is the name of the drug that can lessen the risk of serious bleeding that can result from excessive un-fractioned heparin?
protamine
unfractioned heparin can cause moderate transient ____ in many patients.
thrombocytopenia
these are used as an alternative to heparin primarily in pts with heparin induced thrombocytopenia.
direct thrombin inhibitors
warfarin is approximately what percent bound to plasma proteins?
99%
how does warfarin get eliminated from the body?
depends on CYP450 for its metabolism
how can you reverse the actions of warfarin?
vitamin k, but remember that the reversal requires synthesis of new normal clotting factors which can take several hours
how can you quickly reverse the effects of warfarin ?
transfusion of FFP that contains the normal clotting factors
which anti-coagulant will actually give you a brief period hyper-coagulability?
warfarin - this is most likely b/c of the deficiency of protein c
which of the anti-coag drugs should you be more concerned about drug-drug interactions?
warfarin - again namely b/c its metabolism is by CYP450
what is the effect that CYP450 inducing drugs will have on warfarin therapy?
increase warfarin clearance and reduce the anticoagulation effect of the drug - note then that on the opposite side (CYP450 inhibitors), these drugs would reduce clearance and increase the anti-coagulation effects of the drug.
