Anticoagulation

Question 1

class:
Indications:
MOA:
Dosage forms:
Dosing:
Max dose:
Contraindications:
Warnings:
Side Effects:
Monitoring:
Pearls/Notes:
Drug-Drug/Food interactions:

Question 2

Notes:

Answer 2

CTA = clear to auscultation

RRR = regular rate and rhythm

Question 3

Patients at High risk for developing a clot (mechanical valve) should receive ________

Answer 3

treatment dose parenteral anticoagulation once the INR is subtherapeutic.

Question 4

High-risk condition:

Answer 4

mechanical aortic valve
+
risk factors (atrial fibrillation, prior ischemic stroke, hypertension, diabetes)

OR

mechanical mitral valve

Question 5

Warfarin is held for ______1_______ prior to surgery, which results in ________2________.

If patient was bridged with UFH, then discontinue __________3_______ before surgery.

If patient was bridged with enoxaparin, then discontinue ______4______ before surgery.

Answer 5

1) 5 days (~40 hours half-life)

2) normalization of the INR- (INR < 1.5)

3) 4-6 hours

4) 24 hours

Question 6

Macrocytic anemia is due to a __________________________________________________________

Answer 6

vitamin B12 or folate deficiency, or both

” so think of possible drugs that can cause” AND think of other comorbidities that can cause.

• Chronic use of a PPI: can cause vitamin B12 deficiency
• Long term use of metformin: Vitamin B12 deficiency
• Alcoholism

Question 7

Anticoagulants:

• are used to prevent blood clots from forming and to keep existing clots from getting bigger. They DO NOT break down clots like fibrinolytics.
• They are used in the prevention and treatment of VTE.
• they are also used in the immediate treatment of (ACS) acute coronary syndromes (UA, NSTEMI and STEMI) AND prevention of cardioembolic stroke

Answer 7

• the most common side effect with anticoagulants is bleeding, which can be fatal. For this reason, they are High alert medications.

Question 8

The coagulation cascade has two pathways that when activated lead to fibrin formation and ultimately clot formation.

1)

2)

Anticoagulants inhibit different clotting factors in the coagulation cascade and prevent (or further stop) clot formation.

Answer 8

Contact Activation Pathway (Intrinsic) - minor pathway

Tissue Factor Pathway (Extrinsic) - activated by tissue damage/trauma

Question 9

(AT) Antithrombin is one of the body’s natural anticoagulants; it inactivates _____________ and other proteases (like factor Xa) involved in blood clotting.

Answer 9

thrombin “factor IIa”

Question 10

Parenteral anticoagulants are used for:

Answer 10

• ACS treatment (UA, NSTEMI, STEMI)

-prevention/treatment of VTE

Question 11

Oral anticoagulants are used for:

Answer 11

• mainly prevention and treatment of VTE
• stroke prevention in patients with atrial fibrillation

Question 12

Vitamin K antagonist

Answer 12

warfarin

Question 13

Factor Xa (Direct) Inhibitors

Answer 13

rivaroxaban
apixaban
edoxaban
betrixaban

Question 14

Factor Xa (Indirect) Inhibitors

Answer 14

fondaparinux (Arixtra) - selective inhibition of factor Xa. - given SubQ

Question 15

Direct Thrombin Inhibitors:

Answer 15

• bind directly to factor IIa “thrombin” and block it. Which decreases the amount of fibrin available for clot formation.

IV- argatroban (Acova), bivalirudin (Angiomax)
PO- dabigatran (Pradaxa)

Question 16

IV- argatroban (Acova), bivalirudin (Angiomax) are important clinically since they DO NOT cross react with HIT antibodies.

Question 17

Drugs that must bind to (AT) antithrombin to work.

so are indirect anticoagulants:

Answer 17

UFH - inhibit factor IIa and Xa equal.
LMWH - inhibit factor Xa more specifically.

fondaparinux (Arixtra) - selective inhibition of factor Xa. - given SubQ

these drugs bind to (AT) antithrombin, which causes a conformational change and increases antithrombin activity 1000-fold.

Question 18

Coumadin / Jantoven

class:
Indications:
MOA:
Dosage forms:
Dosing:
Max dose:
Contraindications:
Warnings:
Side Effects:
Monitoring:
Pearls/Notes:
Drug-Drug/Food interactions:

Answer 18

Warfarin

class: anticoagulant
- Is a Vitamin K antagonist. Vitamin K is required for the carboxylation “activation” of clotting factors II, VII, IX, and X.

Indications:

MOA: drug competitively inhibits the C1 subunit of the Vitamin K epoxide reductase enzyme (VKORC1). This reduces the regeneration of Vitamin K epoxide and causes depletion of active clotting factors II, VII, IX, and X and proteins.

Dosage forms:

Dosing:

Max dose:

Contraindications:

Warnings:

Side Effects:

Monitoring:

Pearls/Notes:

Drug-Drug/Food interactions:

Question 19

(UFH) Unfractionated Heparin

class:
Indications:
MOA:
Dosage forms:
Dosing:
Max dose:
Contraindications:
Warnings:
Side Effects:
Monitoring:
Pearls/Notes:
Drug-Drug/Food interactions:

Answer 19

class: anticoagulant

Indications:

Prevention “prophylaxis” VTE

Treatment VTE

Treatment ACS

MOA: drug binds to antithrombin (AT) first (Indirect action), then this causes a conformational change leading to increased activity 1000-fold. It then goes on to inactivate thrombin (factor IIa) and factor Xa. Which ultimately prevents the conversion of fibrinogen to fibrin.

Dosage forms:

Dosing:

Max dose:

Contraindications:

Warnings:

Side Effects:
* bleeding, HIT, decreased platelets, increased K, osteoporosis

Monitoring:

Pearls/Notes:

Drug-Drug/Food interactions:

Question 20

If HIT is suspected, need to manage quickly.

STOP all forms of heparin and LMWH (heparin flushes too - use regional citrate)

STOP warfarin and reverse with Vitamin K

Use a non-heparin anticoagulant, a direct thrombin inhibitor, such as argatroban

Re-start warfarin at a lower dose (5mg or less) when platelets reach > or = to 150,000