Anticoagulants - Direct thrombin inhibitors

Question 1

Direct thrombin inhibitors - groups/drugs and adm

Answer 1

Hirudin derivatives - parenterally (IV)

Dabigatran - orally

Question 2

Hirudin derivatives

Answer 2

Hirudin
Lepirudin
Bivalirudin
Argatroban

Question 3

Hirdurin derivatives - adverse effects

Answer 3

Bleeding

Do not cause thrombocytopenia

Question 4

Lepirudin - indications

Answer 4

Replace heparin after HIT.

Question 5

Hirudin derivatives - indiactions

Answer 5

Prevent thrombosis in unstable angina, acute MI, stent insertions and coronary angioplasty.

Question 6

Argatroban - indications

Answer 6

Prophylaxis and treatment of thrombosis in pts with HIT.

Pts undergoing percutaneous coronary interventions for MI.

Question 7

Dabigatran - interactions

Answer 7

Few interactions with drugs and food.
Renal impairment decreases elimination (reduce dose).
The drug (bot not the active metabolite) is a substrate for P-glycoprotein (Pgp) transporter --> contraindicated with rifampin (inducer of Pgp transporter.

Question 8

Dabigatran - MOA

Answer 8

Potent, competitive and reversible inhibition of thrombin.

Question 9

How can the effect of dabigatran be monitored?

Answer 9

Thrombin clotting time (TT). However, monitoring is not usually necessary.

Question 10

Dabigatran - indications

Answer 10

Nonvalvular atrial fibrillation (reduce risk of stroke and embolism).
Hip/knee replacements - prevent thromotic complications.

Question 11

Dabigatran - adverse effects

Answer 11

Bleeding.

Dyspepsia, gastritis-like symptoms (reduced with food or H2 blocker).

Question 12

Hemorrhage associated with dabigatran - treatment

Answer 12

There is no antidote. Give plasma or RBCs.

Question 13

Active factor X inhibitors - 2 drugs

Answer 13

Apixaban

Rivaroxaban

Question 14

Rivaroxaban - indications

Answer 14

Hip/knee replacement: prevent DVT, blood clots, pulmonary embolism

Question 15

Rivaroxaban - interactions

Answer 15

Metabolized by P450 isoenzymes (esp 3A4).

Increased levels bu Pgp transporter inhibitor.

Question 16

Rivaroxaban - adverse effects

Answer 16

Bleeding

Careful in pregnancy.

Question 17

Apixaban - indications

Answer 17

Atrial fibrillation when warfarin cannot be used.

Prevent venous thromboembolism and cardiovascular events in MI.

Question 18

Rivaroxaban - antidote

Answer 18

Active factor VII or prothrombin complex concentrate.