Anticoagulants & thrombolytics-Mata Flashcards
(41 cards)
1
Q
Heparin
A
MOA: binds to endogenous antithrombin III and irreversibly inactives thrombin
- Given parenterally
- Speeds up antithrombin action 1000x
2
Q
Unfractionated heparin
A
- Begins working immediately
- Used in combo w/thrombolytics for revascularization
- Does NOT cross placental barrier so ok for preggos
- IV or SC to avoid hematoma
- Speeds up activity on factor XA
- Prophylaxis for DVT
3
Q
Low Molecular Weight (LMW) Heparin & Foundparinux
A
- Binds antithrombin and has same inhibitory effect on XA as unfractionated heparin
- More selective (no effect on thrombin)
- IV or SC (longer half-life after SC)
4
Q
Heparin toxicity
A
- Increased bleeding time is common adverse effect of heparin and related molecules
- Can lead to hemorrhagic stroke
5
Q
Protamine
A
- Lessens risk of serious bleeding w/heparin
6
Q
Major Side Effects of Heparin
A
- Non-immune mediated Heparin–associated thrombocytopenia (HAT) Type I - common; direct run b/n heparin and platelets
- Immune-mediated Heparin-induced thrombovytopenia (HIT) Type II - FATAL
7
Q
Rivaroxaban
A
- MOA: direct inhibitor of factor XA that inhibits both free and clot bound factor XA
- Uses: prophylaxis for DVT, reducing stroke risk
- Risk of thrombotic events upon premature discontinuation
8
Q
Lepirudin
A
- Direct thrombin inhibitor
- Recombinant form of hirudin
- Alternative to heparin
- Irreversibly binds and inhibits free and fibrin bound thrombin
- Cons: prolonged half-life in renal compromised pts
9
Q
Desirudin & Bivalirudin
A
- Direct thrombin inhibitor
- Modified forms of hirudin
- Bivalrudin also inhibits platelet activation
10
Q
Direct thrombin inhibitors
A
Based on leech protein hirudin that directly binds to thrombin to prevent thrombin-mediated activation of fibrinogen and factor XIII
11
Q
Argatroban
A
- Small molecule direct thrombin inhibitor (binds only to active site of thrombin)
- Used for treatment of patients with heparin-Induced thrombocytopenia (HIT)
- Safe to be given in renal insufficiency (excrete via biliary route)
12
Q
Dabigatran
A
- Small molecule direct thrombin inhibitor (binds only to active site of thrombin)
- No need to monitor blood levels
- Greater predictive PK and PD
- No dose adjustments
- No significant drug-interactions
13
Q
Warfarin
A
- MOA: inhibits Vitamin K epoxide reductase needed for coagulation cascade
- Affects factor II, VII, IX & X
- Mimics Vitamin K (Vit K can also reverse it)
- SE: bleeding, transient period of hypercoagulaility, inhibition of protein C
- Narrow therapeutic range
14
Q
Tissue Plasminogen Activator (tPA) (aka - Thrombolytic Agents)
A
- An enzyme that binds to fibrin in a newly formed clot and directly converts plasminogen to plasmin
- Toxicity can cause cerebral hemorrhage
- Increases risk of bleeding with warfarin, heparin, aspirin
15
Q
Alteplase
A
- Thrombolytic (fibrinolytic) Agent
- Normal human tPA
16
Q
Reteplase
A
- Thrombolytic (fibrinolytic) Agent
- Mutated tPA w/similar effects but faster onset of action and longer duration of action
17
Q
Tenecteplase
A
- Thrombolytic (fibrinolytic) Agent
- Mutated form of tPA w/longer half life
18
Q
Anistreplase
A
A preformed complex of streptokinase and plasminogen
19
Q
Platelet Activation
A
Mediated by release of soluble platelet factors (ADP, TxA2)
20
Q
Aspirin
A
- Irreversible inhibitor of COX1 (which makes TxA2)
- Efficacy is not dose related
- High doses can lead to GI bleeding and ulceration
- So prescribe baby aspirin!
21
Q
Thienopyridines
A
- MOA: irreversible inhibitors of platelet ADP receptors
- BBW: bleeding
22
Q
Ticlopidine
A
- Thienopyridine
- Converts to thiol metabolites that accumulate (therefore delay in action)
- Takes 8-11 days for max effect
- Shorten delay w/aspirin or loading dose
- BBW: life threatening hematological adverse runs including neutropenia, TTP, and aplastic anemia
23
Q
Clopidogrel
A
- Thienopyridine
- Metabolized by CYP2C19
- Poor metabolizers may show higher rates of CV SEs
- BBW: diminished effectiveness in poor metabolizers
24
Q
Prasugrel
A
- Thienopyridine
- More effectively metabolized than clopidogrel so greater P2Y ADP antagonism
- Metabolized via CYP3A4
25
Ticagelor
- Thienopyridine
- Parent drug and major metabolite reversibly interact w/P2Y12 ADP receptor
- Both parent and metabolite are equipotent
- Metabolized via CYP3A4
- BBW: bleeding risk
26
Abciximab
- Platelet glycoprotein IIb/IIIa receptor blocker
- MOA: bind to IIb/IIIa and prevent interaction w/fibrinogen
- Chimeric mouse/human monoclonal Ab
27
Eptifibatide & Tirofiban
- Platelet glycoprotein IIb/IIIa receptor blockers
- MOA: bind to IIb/IIIa and prevent interaction w/fibrinogen
- Small molecule inhibitors
28
Phosphodiesterase Inhibitors
2 MOAs:
1. Block uptake of adenosine which stimulate platelet adenylyl cyclase
2. Inhibits platelet phosphodiesterase which leads to increased intracellular cAMP and decreased platelet aggregation
29
Cilostazol
- Phosphodiesterase Inhibitor
- Used to treat intermittant claudication (manifestation of peripheral arterial disease)
- Not for pts w/CHF!
30
Dipyridamole
- Phosphodiesterase Inhibitor
- Used + Warfarin to prevent thrombus on prosthetic heart valves
- Used + Aspirin to lower incidence of thrombotic diathesis
31
Fibrinolytic Inhibitors
MOA: lysine analog that blocks plasmin fibrin interaction
32
Aminocaproic Acid
- Fibrinolytic Inhibitor
- Used to reduce bleeding in hemophiliacs after prostatic surgery or tooth extractions
- Thrombi that form during drug treatment do not get lysed
33
Tranexamic Acid
- Fibrinolytic Inhibitor
| - Used to control heavy menstrual bleeding
34
Vitamin K
- Hemostatic agent
- MOA: essential cofactor required in γ-carboxylation of several clotting factors (II, VII, IX and X)
- Used in reversing bleeding episodes induced by oral anticoagulants
- Caution: fast IV infusion can lead to dyspnea, chest pain and death
35
Which drugs are anticoagulants? (4)
1. Heparin
2. Unfractionated Heparin
3. LMW Heparin & Foundparinux
4. Rivaroxaban
36
Which drugs are Direct Thrombin Inhibitors? (4)
1. Lepirudin
2. Desirudin & Bivalrudin
3. Argatroban
4. Dabigatran
37
Which drugs are Thrombolytic Agents? (3)
1. Ateplase
2. Reteplase
3. Tenecteplase
38
Which drugs are Thienopyridines? (4)
1. Ticlopidine
2. Clopidogrel
3. Prasugrel
4. Ticagelor
39
Which drugs are Platelet Glycoprotein IIb/IIIa receptor blockers? (2)
1. Abciximab
| 2. Eptifibatide & Tirofiban
40
Which drugs are Phosphodiesterase Inhibitors? (2)
1. Cilostazol
| 2. Dipyridamole
41
Which drugs are Fibronlytic Inhibits? (3)
1. Aminocaproic Acid
2. Tranexamic Acid
3. Vitamin K
