Anticoagulants Flashcards
What is an embolus?
A clot that is free and flowing through the vessel
What is a thrombus?
a clot that is attached to a vessel wall
What are thrombi composed of?
platelet aggregates
fibrin
trapped blood cells
Which type of anti-thrombotic agents disrupt the coagulation cascade?
anticoagulants
Which type of anti-thrombotic agents inhibit aggregation and activation platelets?
anti-platelets
Which type of anti-thrombotic agents degrade clots?
Fibrinolytic Agents
What do anticoagulants, anti-platelets & fibrinolytic agents all have in common?
They all increase the risk of bleeding
The more potent the anti-thrombotic agent, the __________ the risk of bleeding.
A. Higher
B. Lower
A. higher
What is thrombosis?
alterations that favor coagulation
What are the 2 MOA’s of anticoagulants?
- inhibit the function of coagulation factors, directly or indirectly (activating anti-clotting factors)
- interfere with the synthesis of coagulation factors
What are 3 parenteral anticoagulants?
unfractionated heparin (UFH)
low molecular weight heparin (LMWH)
Fondaparinux (Arixtra®)
What is the MOA of parenteral anticoagulants?
they bind to and enhance the action of antithrombin
(they indirectly inhibit thrombin and factor Xa)
List 3 LMWH drugs.
Enoxaparin (Levonox)
Dalterparin (Fragmin)
Tinzaparin (Innohep)
What drug class is derived from chemical or enzymatic degradation of UFH into fragments that are about 1/3 the size of UFH?
LMWH (Low Molecular Weight Heparin)
What is the average molecular weight of LMWH?
4500-5000
True or false. NSAIDs + oral anticoagulant increase bleeding risk.
True
[SATA] Rivaroxaban is a \_\_\_\_\_\_\_\_ substrate. A. 3A5 B. Pgp C. OATP D. 2C9 E. 3A5
A, B, E
How is Rivaroxaban eliminated?
Renal and hepatic (3A4, 3A5, Pgp substrate)
SATA: Use with caution in liver and kidney impairment.
A. Rivaroxaban
B. Apixaban
C. Dabigatran
A, B,
C (just kidney)
Which oral anticoagulant is NOT a direct factor Xa inhibitor?
Dabigatran (direct thrombin inhibitor)
How is apixaban (Eliquis) eliminated?
renal and hepatic (3A & Pgp substrate)
metabolite is eliminated in urine and bile
Which oral anticoagulant is dosed QD?
rivaroxaban (Xarelto)
Which oral anticoagulant has an adverse effect of dyspepsia?
Dabigatran (Pradaxa)
Food, H2 blockers or PPIs may help
How is Dabigatran eliminated?
10% glucuronidated into active metabolite
80% eliminated in urine
Which oral anticoagulant is a prodrug?
Dabigatran
Adverse effects of UFH?
Bleeding
Thrombocytopenia (HIT)
hypersensitivity reaction
Long term use: osteoporosis & fractures, decreased effectiveness
What is the antidote for UFH?
protamine 1%
Counseling points for Rivaroxiban (Xarelto)?
take with LARGEST meal of the day
Which anticoagulants have an increased risk of epidural or spinal hematoma when receiving spinal puncture or anesthesia and this anticoagulant?
LMWH
Rivaroxaban
Dabigatran
[SATA] Apixaban is a \_\_\_\_\_\_\_\_ substrate. A. 3A B. Pgp C. OATP D. 2C8
A, B
True or False. Dabigatran is MOSTLY RENALLY cleared.
True (80%)
Disadvantages of Oral anticoagulants?
EXPENSIVE no antidote no monitoring (hard to know if pt is compliant) Drug-drug interactions (CYPs, Pgp)
Advantages of Oral anticoagulants?
Oral, more consistent dosing, no monitoring
