Hematological agents II Flashcards
in HIT2, antibodies are directed against what complex?
PF4 + heparin
what is the result of HIT2?
- platelets are cleared by macrophages
2. venous and arterial thrombi
what is the name for LMWH?
enoxaparin
what is the main clearance site for enoxaparin and fondaparinux?
kidney
what is the anticoagulant drug of choice in patients with long term osteoporosis?
LMWH
what is fondaparinux?
only the pentasaccharide sequence of heparin
what is fondaparinux used for?
initial treatment of established venous thromboembolism
what test is used to monitor LMWH and fondaparinux activity?
factor Xa assay
what are the benefits of direct thrombin inhibitors over heparin?
can bind and inhibit thrombin bound to fibrin
how does warfarin work?
- inhibits vitamin K epoxide reductase
2. prevents vitamin K reduction / regeneration, thus preventing carboxylation of resides on factors 10, 9, 7, and 2
where is warfarin metabolized?
liver
which test is used to monitor warfarin activity?
prothrombin time (PT) assay
what is the international normalized ratio (INR)? what is the normal target?
- way to normalize variables between different patients’ PT assay times
- 2-3
which drugs potentiate warfarin’s effects (increase INR)?
- BSAbx
- NSAIDs
- SSRIs
- statins
which drugs lessen the effects of warfarin (decrease INR)?
- rifampin
- barbiturates
- carbamazepine
how does renal insufficiency affect INR?
increase
how does Crohn’s disease - reduced vitamin K absorption - affect the INR?
increase
what is the MOA for rivaroxaban?
direct factor Xa inhibitor
what is the MOA for dabigatran?
- oral thrombin inhibitor
2. contraindicated in patients with mechanical heart valves
what are the fibrinolytic agents?
- streptokinase
- urokinase plasminogen activators
- tissue plasminogen activators
what type of drug is alteplase?
tissue plasminogen activator
what is the main use for alteplase?
STEMI within 12 hours
what class of drug are aminocaproic acid and tranexamic acid? what is the MOA?
- antifibinolytic
2. block interaction of plasmin with fibrin - prevents clot degradation