Management of Patients on Blood Thinners

Question 1

what are the two types of blood thinning therapies

Answer 1

antiplatelet and anticoagulant

Question 2

what risk is increased with these pts

Answer 2

higher risk for hemorrhage during oral surgical proceudres

Question 3

are patients recommended to dc medications prior to minor OS procedures and why

Answer 3

no because this increases their risk of developing a thrombo-embolic episode

Question 4

what is used for pts who do not dc meds

Answer 4

local measures

Question 5

what do you do if pt on these meds needs major OS procedure

Answer 5

consult with physician and medication is withheld from pt a few days prior to surgery

Question 6

who makes the decision on stopping meds

Answer 6

only physician

Question 7

what are the commonly used antiplatelet meds

Answer 7

aspirin and plavix

Question 8

what is aspirin

Answer 8

• cyclooxygenase inhibitor
• an acetylated salicylate (acetylsalicylic acid) classified amount the NSAIDs

Question 9

what does aspirin do

Answer 9

• reduce the signs and symptoms of inflammation and exhibit a broad range of pharmacologic activities, including analgesic, antipyretic and antiplatelet properties

Question 10

what is the MOA of aspirin

Answer 10

• irreversibly inactivates cyclooxygenase
• platelets cannot synthesize protein so cannot make thromboxane until new platelets are made
• the lack of thromboxane markedly diminishes platelet activation and aggergation

Question 11

what makes aspirin different from other NSAIDs

Answer 11

other NSAIDs are not irreversible
- they inhibit cyclooxygenase but are effective only while drug is present

Question 12

what does low dose aspirin do and what is the dosage

Answer 12

• 81mg/day
• irreversibly acetylates serine 530 of cyclooxygenase (COX-1) which inhibits platelet generation of thromboxane A2 resulting in antithrombotic effect

Question 13

what does an intermediate dose of aspirin do and what is the dosage

Answer 13

• 650 mg to 4g/day
• inhibits COX-1 and COX-2, blocking prostaglandin production and have analgesic and antipyretic effects

Question 14

what are the indications for low dose aspirin treatment

Answer 14

• low dose prophylaxis
• one children aspirin
• more doesnt work and can be harmful
• at low dose very small chance of GI bleed
• decreases incidence of MI by 2%
• cheap and safe

Question 15

what is plavix used for and whats its chemical name

Answer 15

• clopidogrel bisulfate
• used to prevent MI and cerebro vascular accidents in people with cardiac disease, recent stroke or those with peripheral vascular disease
• works by blocking platelets from sticking together and prevents them from forming harmful clots

Question 16

patients with what medical conditions take oral anticoagulants

Answer 16

• prosthetic heart valves
• atrial fibrillation
• valvular heart disease
• previous deep vein thrombosis
• pulmonary embolism
• congestive cardiomyopathy

Question 17

what was the brand name for the generic drug warfarin sodium

Answer 17

coumadin

Question 18

what is the new brand name for warfarin sodium

Answer 18

jantoven

Question 19

what is the MOA of warfarin sodium

Answer 19

• warfarin is a vitamin K antagonist
• it affects clotting factors II, VII, IX, and X and makes them biologically inactive
• it affects factor VII first and this increases the prothrombin time
• it then affects factors IX, X and II and thereby increases the partial thromboplastin time

Question 20

the coagluation status of a patient taking warfarin is assessed with:

Answer 20

an international normalized test (INR)

Question 21

the INR is a:

Answer 21

standardized prothrombin time test

Question 22

what was the INR developed for

Answer 22

to normalize the PT test based on the sensitivity of different thromboplastins

Question 23

what is the formula for INR

Answer 23

(PT/mean normal PT) ^ISI

Question 24

what is mean normal PT

Answer 24

the PT time based on geometric mean of 20 fresh plasmas of healthy ambulent patients

Question 25

what is ISI

Answer 25

the international sensitivity index

Question 26

what is a normal INR value

Answer 26

0.8-1.2

Question 27

what is the name for dabigatran

Answer 27

pradaxa

Question 28

what is dabigatran used for

Answer 28

to reduce stroke and systemic embolization risk in patients with non valvular atrial fibrillation

Question 29

does dabigatran need to be monitored and why

Answer 29

at a fixed dose, no, due to predictable pharmacokinetics

Question 30

which is more effective dabigatran or warfarin

Answer 30

equal in preventing embolic events in patients with atrial fibrillation

Question 31

dabigatran is a:

Answer 31

direct thrombin inhibitor

Question 32

what are the most sensitive tests for quantifying the anticoagulant effects of dabigatran

Answer 32

thrombin clotting time (TT) and ecarin clotting time (ECT)

Question 33

when is dabigatran prescribed

Answer 33

postoperatively once a stable clot is formed so pt takes it the day after surgery

Question 34

what is the name for rivaroxaban

Answer 34

xarelto

Question 35

what is rivaroxaban and what is it used for

Answer 35

an orally-administerde, selective, reversible, direct inhibitor of activated factor X (factor Xa) and is currently indicated for prophylaxis of venous thromboembolism VTE in adults after hip or knee replacement surgery

Question 36

what is the half life of warfarin

Answer 36

20-60 hours

Question 37

what is the half life of dabigatran

Answer 37

12-17 hours and up to 28 hours in severe renal impairment

Question 38

what is the half life of rivaroxaban

Answer 38

5-13 hours

Question 39

what are the local post op hemostatic measures

Answer 39

• pressure guaze; 5-10 minutes until a stable clot initiates
• sutures, attempt primary closure
• absorbents

Question 40

what are the absorbents

Answer 40

• surgicel
• gel foam
• collagen plug
• fibrin glue