Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
28 Cards in this Set
- Front
- Back
|
Three treatment strategies to inhibit coagulation
|
thrombolytics
anticoagulants anti-platelets |
|
|
3 things that thrombolytics drugs are used for
|
acute MI
PE DVT |
|
|
Within how many hours can you use a thrombolytic?
|
6 hours for MI
3 hours for stroke |
|
|
How do tPA's work
(tissue plasminogen activator) |
-at physiological concentrations they are inhibited by Plasminogen Activator Inhibitor (PAI).
-at pharmacological concentrations they over come the PAI |
|
|
What are the Thrombolytics?
|
Streptokinase
Urokinase Alteplase Reteplase Tenecteplase ("plase" = tPA) |
|
|
Streptokinase
|
-causes conformational change in plasminogen so that is can convert easier to plasmin and lyse the clot
-isolated from bacteria |
|
|
Urokinase
|
-directly converts plasminogen to plasmin
-no anaphylaxis like in streptokinase |
|
|
mechanism of tPA's
|
1) selective activation of plasminogen when it is bound to fibrin
2) this localizes the fibrolysis to the area of the thrombus |
|
|
Anticoagulant Drugs?
|
Heparin - inc ATIII
Hirudin - DTI Warfarin - dec Vit K dependents Drotracogin Alfa - aProtein C |
|
|
Drugs that activate anticlotting factors
|
Heparin
Fondaparinux (pentasacchride) Dalteparin (LMW) Enoxaparin (LMW) |
|
|
Heparin mechanism
|
-binds to ATIII to complex with activated factors of the intrinsic pathway
-coats blood vessel wall to decrease platelet binding and increase its permeabililty |
|
|
Pharmacokinetics of Heparin family?
|
-adjust dose to double PTT
-doesn't cross placenta -instantaneous |
|
|
HMW vs LMW Heparin family drugs
|
HMW: Xa, more predictable, decrease dose
LMW: IIa, less inhibition, more SE, less plasma protein bound, antidote not as effective |
|
|
Adverse effects of Heparins
|
-bleeding (duh)
-anaphylaxis (duh) -HIT (antibody mediated thrombocytopenia) |
|
|
Protamine Sulfate
|
-basic peptide that forms an ionic bond with heparin to inactivate it
-doesn't work with FONDAPARINUX |
|
|
Direct Thrombi Inhibitors (DTI's)
(name the drugs) |
Bivalirudin
Hirudin Lepirudin Argatroban |
|
|
DTIs
(mechanism, metabolism) |
-interact directly with thrombin, there is no HIT
"Rudins" bind irreversible, kidney "Agratroban bind reversible, liver -no reversal agents |
|
|
When do you want to use DTI's
|
-patients with HIT
-Bivalirudin for angioplasty |
|
|
Inhibitor of Zymogen synthesis
|
Warfarin (Coumadin)
|
|
|
Mechanism of Warfarin
|
-inhibits epoxide reductase which recycles Vit K
-affects factors II, VII, IX and X -affects Protein C and S (side effects) |
|
|
Pharmacokinetics of Warfarin
|
-narrow TI
-racemic mixture where S is the active enantiomer -S is metabolized by Cyp2C9 |
|
|
Gene mutations involved with Warfarin
|
Cyp2C9 (slows metabolism)
VKOR (decreases effectiveness) Factor V Leiden (can't stop cascade) |
|
|
What is another name for the Warfarin drug?
|
Rodenticides
|
|
|
Three uses of Warfarin
|
DVT
MI AFIB |
|
|
*IMPORTANT*
3 general features of Warfarin |
-narrow therapeutic index
-99% plasma protein bound -elminated in the liver by Cyt P450 |
|
|
Things that increase the interactions of Warfarin
|
1) inhibit CYT P450
2)Decrease Plasma Protein Binding 3) Decrease plaetelet/clotting factors 4)Decrease Vit K availability |
|
|
Phytonadione
(three purposes) |
Vitamin K1
1) prevents hemorrhagic disorders in new borns 2) corrects Vit K deficiency 3) Warfarin overdose |
|
|
What can you give to counter act Warfarin?
|
Vit K
fresh-frozen plasma |
