B P11 C95 Hemostasis, Thrombosis, Fibrinolysis and Cardiovascular Disease

Question 1

Usual dose of Aspirin

Answer 1

75 - 325 mg daily

There is no evidence that higher-dose aspirin is more effective than lower doses, and some meta-analyses suggest reduced efficacy with higher doses

Question 2

To reduce the risk for bleeding, thienopyridine therapy must be stopped approximately ________ before surgery.

Answer 2

5 days

Question 3

Usual dose of Clopidogrel

Answer 3

75 mg once a day

Because its onset of action is delayed for several days, 300- to 600-mg loading doses of clopidogrel are given when rapid ADP receptor blockade is desired

Question 4

Usual dose of Prasugrel

Answer 4

10 mg once a day

After a loading dose of 60 mg, prasugrel is given once daily at a dose of 10 mg. 38 Patients older than 75 years or weighing less than 60 kg should receive a daily prasugrel dose of 5 mg

Contraindicated those with a history of cerebrovascular disease.

Question 5

Usual dose of Ticagrelor

Answer 5

90 mg twice a day

Ticagrelor is initiated with an oral loading dose of 180 mg followed by 90 mg twice daily.

Question 6

Usual dose of Heparin for
1. Prophylaxis
2. ACS
3. VTE

Answer 6

1. Prophylaxis - 5000 units subcutaneously two or three times
2. ACS - 5000 units or 70 units/kg, a heparin infusion rate of 12 to 15 units/kg/hr
3. VTE - 5000 units or 80 units/kg, followed by an infusion of 18 units/kg/hr (fibrin content of extensive deep vein thrombi is greater than that of coronary thrombi)

Question 7

Usual dose of Heparin for
1. Prophylaxis
2. ACS
3. VTE

Answer 7

1. Prophylaxis - 5000 units subcutaneously two or three times
2. ACS - 5000 units or 70 units/kg, a heparin infusion rate of 12 to 15 units/kg/hr
3. VTE - 5000 units or 80 units/kg, followed by an infusion of 18 units/kg/hr (fibrin content of extensive deep vein thrombi is greater than that of coronary thrombi)

Question 8

_____________ Antibody-mediated process triggered by antibodies against n antigens on PF4

Typically occurs _______ days after initiation

More common among ________, ____________

Answer 8

Heparin-induced thrombocytopenia (HIT)
5 - 14 days
Surgical, females
Venous > arterial thrombosis
UFH than LMWH

Question 9

Dosing of LMWH for
1. Prophylaxis
2. VTE
3. ACS

Answer 9

1. Prophylaxis - once daily subcutaneous doses of 4000 to 5000 units; 2500 to 3000 units 2x a day
2. VTE - 150 to 200 units/kg OD; 100 units/kg BID
3. ACS - 100 to 120 units/kg BID

Question 10

Dosing of Fondaparinux for
1. Prophylaxis
2. VTE
3. ACS

Answer 10

1. Prophylaxis - 2.5 mg once daily
2. VTE - 7.5 mg once daily. The dosage can be reduced to 5 mg once daily for those weighing less than 50 kg and increased to 10 mg for those heavier than 100 kg
3. ACS - 2.5 mg once daily

Question 11

Dosing of Dabigatran for
1. Stroke prevention
2. VTE
3. Thromboprophylaxis

Answer 11

1. Stroke prevention - 150 mg twice daily, with a reduction to 75 mg twice daily in those with a creatinine clearance of 15 to 30 mL/min
2. VTE - 150 mg twice daily provided the creatinine clearance is over 30 mL/min after a 5 days course of parenteral anticoagulant
3. Thromboprophylaxis - 220 mg once daily

Question 12

Dosing of Rivaroxaban for
1. Stroke prevention
2. VTE
3. Prophylaxis

Answer 12

1. Stroke prevention - 20 mg once daily, with a reduction to 15 mg once daily in patients with a creatinine clearance of 15 to 49 mL/min
2. VTE - 15 mg twice daily for 21 days and is then reduced to 20 mg once daily
3. Prophylaxis - 10 mg once daily

For secondary prevention of adverse cardiac or limb events in patients with coronary or peripheral artery disease, rivaroxaban is given at a dose of 2.5 mg twice daily on top of aspirin (81 or 100 mg once daily).

Question 13

Dosing of Apixaban for
1. Stroke prevention
2. VTE
3. Thromboprophylaxis

Answer 13

1. Stroke prevention - 5 mg twice daily, with a reduction to 2.5 mg twice daily for patients with at least two of the “ABC” criteria (i.e., age over 80 years, body weight under 60 kg, and creatinine over 1.5 g/dL)
2. VTE - 10 mg twice daily for 7 days and is then reduced to 5 mg twice daily
3. Thromboprophylaxis - 2.5 mg twice daily

Question 14

Dosing of Edoxaban for
1. Stroke prevention
2. VTE
3. Thromboprophylaxis

Answer 14

1. Stroke prevention - 60 mg once daily for patients with a creatinine clearance of 50 to 95 mL/min and with a reduction to 30 mg once daily for patients with any one of the following criteria: creatinine clearance 15 to 50 mL/min body weight of 60 kg or less, or use of potent P-glycoprotein inhibitors, such as verapamil or quinidine.
2. VTE - same as above after a 5 day course of parenteral anticoagulation
3. Thromboprophylaxis - edoxaban is not licensed for this indication except in Japan

Question 15

Give the reversal agent for
Dabigatran
Rivaroxaban
Apixaban
Edoxaban

Answer 15

Dabigatran - Idarucizumab

Rivaroxaban, apixaban, edoxaban and heparins - Andexanet Alfa