Week 7 - Pharmacological Treatment of Clotting Disorders

Question 1

What are the 3 drug classes used to treat clients who are at risk for blood clots, or clients who have formed blood clots?

Answer 1

• anticoagulants
• antiplatelets
• thrombolytics

Question 2

What are the 3 anticoagulants?

Answer 2

• heparin
• enoxaparin
• warfarin

Question 3

What are the 2 antiplatelet drugs?

Answer 3

• aspirin
• clopidogrel

Question 4

What is one thrombolytic?

Answer 4

alteplase (tPA)

Question 5

Which routes can heparin be given

Answer 5

• Injection or IV only (must be in hospital to receive heparin IV)

Question 6

How does heparin work as an anticoagulant?

Answer 6

• inactivates 2 major clotting factors in the blood (Xa and thrombin)
• this causes clotting action to be suppressed

so it pretty much interrupts the clotting cascade to increase the time to clot. Then, the body can go in to destroy the clots

Question 7

Why is heparin used? (2)

Answer 7

• used to prevent formation of clots, OR extension of DVT or pulmonary embolism so that those clots do not enlarge or break off into emboli
• it is also fast acting (works within minutes of IV administration)

Question 8

Heparin needs close monitoring. Which lab will we use to measure its effectiveness?

Answer 8

• aPTT 9if IV every 6-8 hours so it stays within therapeutic window)

Question 9

What are the adverse effects of heparin? (2)

Answer 9

• risk of bleeding
• possible hypersensitivity reactions

Question 10

What is the antidote in case of a heparin overdose?

Answer 10

protamine sulfate

Question 11

How does enoxaparin work? (3)

Answer 11

• a form of heparin that is chemically altered to have shorter molecule chains
• this makes a “low molecular weight” heparin
• Inactivates one important clotting factor Xa

Question 12

Why is enoxaparin used? (4)

Answer 12

• works well with heparin, but safer and easier to use
• highly predictable side effects
• used to prevent and treat DVT and PE
• longer half-life than heparin, so lasts longer

Question 13

How can enoxaparin be administered? (3)

Answer 13

• given by injection
• does not require monitoring of aPTT
• can be administered at home (no hospitalization required)

Question 14

What is the adverse effect of enoxaparin? What is the antidote?

Answer 14

• risk of bleeding
• protamine sulfate

Question 15

What is the MOA of warfarin? (3)

Answer 15

• suppresses 4 clotting factors that are made using vitamin K
• inhibits vitamin K being activated in the body, so those clotting factors cannot be made in normal amounts
• decreases those factors by 30-50% in the body

Question 16

How long does it take warfarin to reach therapeutic levels?

Answer 16

• highly protein bound, so it takes days

Question 17

In what instances would warfarin be used? (2)

Answer 17

• used for long-term clot prevention (such as DVT and PE)
• taken as PO

Question 18

How can we monitor warfarin? (2)

Answer 18

• INR (minimum monthly)
• must be frequently monitored to ensure therapeutic levels

Question 19

What are the side effects of warfarin? (2)

Answer 19

• drug interactions with many other medications
• risk of bleeding

Question 20

What is the antidote for warfarin overdose?

Answer 20

Vitamin K
- that is why you should watch you dark, leafy greens intake bc you can quickly get out of therapeutic range

Question 21

What does “bridging to warfarin” mean? (2)

Answer 21

• some people are on enoxaparin fo thrombus, and are also on warfarin
• they are on enoxaparin for blood thinning until warfarin works in the therapeutic range