11- Coagulation Related Drugs

Question 1

Definitions

Define: Thrombus

Answer 1

The actual blood clot (platelets + fibrin combination)

Question 2

Definitions

Define: Embolus (or Embolism). And provide 2 examples of what can cause them

Answer 2

A blockage caused by something moving from one place to another
- Ex –> Air (air emboli) + fat (fat emboli)

Question 3

Definitions

What are antithrombics and anticoagulants?

Answer 3

Drugs that prevent formation of blood clots/thrombi

Question 4

Definitions

Define: Antiplatelet Agents

Answer 4

• Drugs that interfere with platelet aggregation

Doesnt necessarily mean they decrease platelet production

Question 5

Definitions

Define: Thrombolytics

Answer 5

Drugs that ↑ breakdown speed of blood clots that’ve already formed

Question 6

What are the 4 categories of drugs related to coagulation?

Astronauts Always Throw Anchovies

Answer 6

1. Anticoagulants
2. Antiplatelets
3. Thrombolytics
4. Anti-Fibrinolytics

Question 7

Anticoagulants

What are uses of these drugs?

Answer 7

1. Prevent clots in cardiopulmonary by-pass machines
2. Prevent DVT formation
3. Prevent pulmonary emboli from growing
4. Prevent clotting in ABG syringes

DVT = Deep vein thrombosis
ABG = arterial blood gas

Question 8

Antigoagulants

What is a drug that falls under this category, and what the drug’s 2 categories?

Answer 8

Drug –> Heparin
- 2 categories –> Unfractioned Heparin(UFH) + Low Molecular Weight Heparin(LMWH)

Question 9

Heparin

What’s the difference between UFH and LMWH?

Answer 9

• UFH = 18 or more molecule side chain (heavier)
• LMWH = 1-17 side chain (lighter)
• Longer interacts differently vs shorter

Question 10

Heparin

How does heparin cause anticoagulation?

Answer 10

By increasing activity of Antithrombin III

Question 11

UFH

How does UFH work?

Answer 11

Forms complex w/ Antithrombin –> Combines w/ Thrombin OR factor 10a –> Inhibits their action

Question 12

Heparin

How can it be given?

Answer 12

Via injection (IV or sub-cue)

Question 13

LMWH

What does LMWH do to cause anticoagulation?

Answer 13

Increases antithrombin III (only inhibits Factor 10a)

Question 14

LMWH

What are 2 LMWH drugs?

Answer 14

1. Enoxaparin
2. Dalteparin

Question 15

Enoxaprin + Dalteparin

How are these different vs heparin?

Answer 15

Last longer + Start slower + Less potent

Question 16

Heparin

What is a Heparin-related-drugs reversal drug?

Answer 16

Protamine

More effective in UFH reversal

Question 17

Protamine

What happens when protamine admnistered?

Answer 17

Heparin (even the heparin attached to antithrombin III) goes and attaches to protamine. They create an inactive complex.

Question 18

Protamine

When might reversal be needed?

Answer 18

1. If patient overcoagulated (spontaneous bleeding)
2. If procedure is over

Question 19

Anticoagulant Drugs

What is a drug that falls under this category?

Answer 19

Coumadin (Warfarin)

Question 20

Coumadin (Warfarin)

What is it? What does it do?

Answer 20

• A drug structurally related to Vitamin K.
• It acts like a vitamin K antagonist, preventing specific clotting factors from being created

Question 21

Coumadin (Warfarin)

Where is it most used? What is its onset of action and peak time?

Answer 21

• Used –> Out of hospital (for anticoagulation needs)
• Onset –> 12-24hrs
• Peak –> 5-7 days after first dose

Question 22

Coumadin (Warfarin)

What is a warfarin reversal drug?

Answer 22

Vitamin K1

Question 23

Vitamin K1

How does it work? When would it be needed?

Answer 23

It directly antagonizes warfarin.
- Needed if excessive bleeding or related risks occur.

Requires PERSISTENT MONITORING of lab values

Question 24

Anticoagulation Drugs

What is a better substitute for Vitamin K1? Why?

Answer 24

• DOACs (Direct oral acting coagulants)
• Easier to take + Safer + no constant monitoring required

Question 25

# DOACs What are 2 examples of drugs that are DOACs?

Answer 25

1. Dabigatran (Pradaxa) 2. Rivaroxaban (Xarelto)

Question 26

# DOACs Of the 2 drugs, which one ***has*** a reversal agent?

Answer 26

Dabigatran (Pradaxa)

Question 27

# #2: Antiplatelets What is the point of these drugs?

Answer 27

To prevent platelet aggregation + platelet clumping

Question 28

# #2: Antiplatelets What is a drug that falls under this category?

Answer 28

Aspirin (Acetylsalicylic Acid)

Question 29

# Aspirin (Acetylsalicylic Acid) What is low dose aspirin good for helping prevent?

Answer 29

Recurrent myocardial infarctions (MI) - ↓Platelet clumping --> ↓Platelet plugs --> ↓MI

Question 30

# Aspirin Why does Aspirin act as an antiplatelet agent at low doses?

Answer 30

Prevents creation of thromboxane A2 - Leads to platelets unable to aggregate (including newly created ones)

Question 31

# #3: Thrombolytics How do these drugs break down already existing clots?

Answer 31

- Increase the activity of plasminogen (clot buster)

Question 32

# #3: Thrombolytics What are most thrombolytics?

Answer 32

Recombinant forms of tissue-plasminogen activator (t-PA) -↑ plasmin = ↑fibrin degraded = clot breaks down

Question 33

# #3: Thrombolytics What drug falls under this category?

Answer 33

Alteplase (rt-PA)

Question 34

# #3: Thrombolytics What is an issue with giving any thrombolytic?

Answer 34

It can break up other clots in the body (not just the ones we want) - Can lead to reoccuring bleeding we do not want in a trauma patient

Question 35

# #3: Thrombolytics What is done to prevent side effects to thrombolytics?

Answer 35

A t-PA drug is given directly to embolism via catheter

Question 36

# #4: Anti-fibrinolytics What drug is associated with this category?

Answer 36

Tranexamic Acid

Question 37

# Tranexamic acid What does it do?

Answer 37

Breaks down fibrin by plasmin. - Binds to plasmin + prevents its action

Question 38

# Tranexamic Acid When can it be used?

Answer 38

- In acute care setting, at times of severe life-threatening hemorrhage (via INJECTION)

Question 39

# Tranexamic Acid This can be considered a possible antidote to rt-PA. But what can it NOT do?

Answer 39

Reverse bleeding that's already occured b/c of rt-PA.