Anticoagulants Flashcards

1
Q

Which drug is a Natural anticoagulant produced by mast cells & basophils?

A

Unfractionated heparin

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2
Q

Unfractionated heparin MOA?

A

increases the activity of antithrombin III by 1000 folds → inhibits factor 2 ,10, 9

in a past exam it tries to trick u by putting “directly acts on Factor Xa” which is not true bc it inhibits it thru acting on Antithrombin III

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3
Q

why is Unfractionated heparin not absorbed orally?

A

bcuz of its big size and negative charge

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4
Q

methods of administrating Unfractionated heparin?

(2)

A
  1. IV
  2. Subcutaneously
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5
Q

Under which circumstance does UFH’s half-life prolong? and why?

A

UFH is metabolized in the liver into inactive products

liver damage → UFH doesn’t metabolized → longer half-life

such as liver cirrhosis

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6
Q

Uses of Unfractionated heparin?

Mostly used for short-term immediate anticoagulation.

A

In thromboembolic events:
1. Acute MI
2. DVT
3. Atrial fibrillation
4. PE

Preventing blood clotting during:
1. Open heart surgery
2. Kidney dialysis
3. Blood transfusion

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7
Q

You accidentally overdosed a p/x w/ Unfractionated heparin, how would u treat that?

A

i’d give them Protamine sulfate

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7
Q

Side effects of UFH?

(6)

A
  1. Bleeding
  2. hypersensitivity
  3. Thrombocytopenia
  4. Osteoporosis
  5. Abdominal and joint pain
  6. Headache
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8
Q

what is an example of Low molecular weight heparin?

A

Enoxaparin

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9
Q

How is Enoxaparin prepared?

(LMWH)

A

Prepared from UFH by chemical or enzymatic depolymerization

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10
Q

How is Enoxaparin (LMWH) better than Unfractionated heparin?

(6)

A
  1. less protein binding, better bioavailability
  2. reduced risk of osteoporosis and bone fracture
  3. predictable activity
  4. no need to monitor APTT
  5. lower risk of thrombocytopenia
  6. longer half life and duration of action
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11
Q

Enoxaparin MOA?

(LMWH)

A

Activates antithrombin III and inhibits activated factor Xa only

compared to UFH which inhibits IIa, IXa, Xa

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12
Q

Can u treat Enoxaparin (LMWH) overdose the same way you would treat UFH overdose?

(with Protamine sulfate)

A

Yes, however Protamine only partially neutralizes its activity

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13
Q

What kind of drug is Warfarin?

A

Vitamin k antagonist → inhibits the formation of active forms for factors (2,7,9,10)

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14
Q

How is warfarin given?

A

orally

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15
Q

Warfarin MOA?

A

Inhibits Vit. K epoxide reductase

(converts vit. k to its reduced form which is used for the formation of active forms)

16
Q

Warfarin is metabolized where?

A

Liver

17
Q

Uses of Warfarin?

(6)

A
  1. DVT
  2. PE
  3. MI
  4. Atrial fibrillation
  5. Recurrent stroke
  6. Cardiac valve replacement
18
Q

you should NEVER give warfarin to who?

A

Pregnant Women

19
Q

Side effects of Warfarin?

(2)

A
  1. Bleeding
  2. Teratogenesis (nasal hypoplasia, depressed nasal bridge)

bleeding is controlled by giving vit. K

20
Q

Which anticoagulants require INR monitoring and which one of those dont?

A

Require INR monitoring:
- Warfarin

Don’t require INR monitoring:
- Dabigatran
- Rivaroxaban

21
Q

Compare Dabigatran & Rivaroxaban to Warfarin?

(4 differences)

A
  1. Directly inactivate coagulation factors
  2. More potent and predictable
  3. Less bleeding
  4. Doesn’t need INR monitoring
22
Q

Dabigatran & Rivaroxaban are both direct oral anticoagulants, compare their MOA?

A
  • Dabigatran:
    Direct and reversible inhibition of thrombin (factor IIa) → inhibits thrombin-mediated platelet aggregation (Anti-platelet activity)
  • Rivaroxaban:
    Direct and selective inhibitor of factor Xa

Rivaroxaban inhibits xa

23
Q

True or False?

“Rivaroxaban is fully metabolized in the liver then excreted by the kidneys”

A

False

60% is metabolized in the liver, the 40% left is excreted unchanged by the kidneys

24
Q

Uses of Directs Oral Anticoagulants?

Dabigatran & Rivaroxaban

A
  1. DVT
  2. PE
  3. Non-valvular atrial fibrillation
25
Q

Adverse effects of Dabigatran?

A
  1. bleeding
  2. 4 Ds → Dyspepsia, dizziness, diarrhea, dyspnea
  3. Headache and edema
26
Q

How would u treat a Dabigatran overdose?

A

Antidote: Idarucizumabmonoclonal antibody that binds dabigatran and reduces its activity

27
Q

Adverse effects of Rivaroxaban?

A
  1. Bleeding
  2. Breathing and swallowing difficulty
  3. Bowel or bladder dysfunction
  4. Leg weakness
28
Q

How would u treat Rivaroxaban overdose?

A

Antidote:
Andexanet

29
Q

What antidotes would u give patients overdosed on these anticoagulants?

  1. Heparin
  2. Dabigatran
  3. Rivaroxaban
A
  1. Heparin → Protamine Sulfate
  2. Dabigatran → Idarucizumab (monoclonal Ab)
  3. Rivaroxaban → Andexanet