blood meds Flashcards
heparin nature
large polysaccharide, water soluble. hepatic metabolism.
is heparin safe for pregnancy?
yes. it is large and does not cross the barrier
heparin mechanism
binds to antithrombin III and facilitates its binding to factors II, X, IX, XI, XII. this causes rapid inactivation of these factors.
how do we monitor heparin function
PTT
what is the antidote for heparin
protamine sulfate. this is chemical antagonism with fast onset.
what are the uses for heparin
rapid anticoagulation for thromboses, emboli, unstable angina, DIC and open heart surgery
what is the toxicity of heparin
bleeding, osteoporosis, HIT. HSR
what is the nature of warfarin
small molecule, lipid-soluble, derivative of vitamin K. t
is warfarin safe for pregancy
no. it can cross the barrier
mechanism of warfarin
decreases hepatic synthesis of vitamin K dependent factors. including protein C and S. prevents gamma-carboxylation of clotting
how do we monitor warfarin
PT and INR
antagonist for warfarin (antidote)
vitamin K or fresh frozen
uses of warfarin
long-term anticoagulant. for thromboses, post-MI, emboli, heart valve damage, atrial arrhythmia.
what are the toxicites of warfarin
bleeding, skin necrosis (use heparin to start), drug interactions. teratogenic
what is the antidote for HIT
argatroban
what is the alternative to warfarin. what are the positives to using it
dabigatran. no checking the INR.
what are the two thrombolytics
streptokinase and alteplase
streptokinase
bacterial formulated plasminogen activator. it is cheap so used.
what is the downfall of streptokinase
it acts on free plasminogen, so it is not clot specific. there is HSR.
alteplase
plasminogen activator and thrombolytic. this acts on clots specifically, not on free plasminogen. only works on fibrin-bound plasminogen. there is no allergy since it is human
complications to the thrombolytics
bleeding, intracerebral hemorrhage.
what are the antidotes to the thrombolytics
aminocaproic acid, tranexamic acid.
aspirin
low dose for anticoagulant. prevent MI and recurrance in A fib and TIA. there are no SE for low dose use
ticlopimide/clopidigrel
blocks ADP receptors on platelets and decreases their activation. alternative for aspirin. used in TIA, post-MI, unstable angina.
SE of ticlopimide/clopidigrel
hemorrhage, leukopenia, thrombocytopenic purpura.
Abciximab/eptifibatide/tirofiban
binds and blocks glycoprotein IIb/IIIa receptors decreases platelet aggregation. and preventing cross-linking. used in coronary syndromes and post-angioplasty.
