anti-coagulant/anti-platelet_PHARM

Question 1

Anti-coagulant drugs

Answer 1

1. heparins
   - heparin
   - LMWH
2. warfarin
3. DOACs
   - Direct thrombin inhibitors (dabigatran)
   - Direct Xa inhibitors (endoxaban, rivaroxaban, apixaban)

Question 2

Platelet activation

Answer 2

• Thrombin (IIa)
• Collagen
• PAF
• TXA2
• ADP

Question 3

Anti-platelet drugs

Answer 3

1. COX inhibitors
   - ASA
2. P2Y12 Receptor Inhibitor
   - Clopidogrel
   - Prasugrel
   - ticagrelor
   - ticlopidine
3. GPIIb/IIIa inhibitor
   - ABCIXIMAB

Question 4

Heparin
MOA

Answer 4

• Bind to anti-thrombin
• increases anti-thrombin affinity for Xa and IIa
• also binds and inhibits intrinsic coagulation factors (XII, XI, IX, X, II)

Question 5

Heparin
Route, 1/2 life

Answer 5

Route: IV

1/2 life: 60-90minutes

D/C 4hours before surgery

Question 6

Heparin
Reversal agent

Answer 6

1mg protamine sulfate : 100U heparin

binds heparin-anti-thrombin complex; stronger inhibition IIa

Question 7

Heparin
Dosage and theraputic monitoring

Answer 7

aPTT
60-80 seconds

Therapeutic monitoring
- aPTT
- Platelet count

Question 8

AE Heparin

Answer 8

HIT
- heparin induced thrombocytopenia
- drop platelets > 50%
- 2-3 weeks therapy
- D/C heparin

Question 9

SE Heparin

Answer 9

GI bleeding
hematomas, hemorrhages
melena stools
haematuria
HIT

Question 10

Heparin
Contraindications

Answer 10

Hemorrhages, bleeding
HIT
anti-coagulation, anti-platelet therapy
brain, spinal, eye surgery

Question 11

Heparin
Special populations

Answer 11

reduce dosage in old people, osteoporosis

safe in pregnancy, doesn’t cross placenta

Question 12

Anti-coagulants for HIT

Answer 12

Fondaparinux*
DOAC (Argatroban, dabigatran)
danaparoid*

*safe in pregnancy

Question 13

LMWH
MOA

Answer 13

bind anti-thrombin
increase affinity for Xa > IIa

Question 14

List of LMWH

Answer 14

enoxaparin
dalteparin
fondaparinux (irreversible, no antidote)

Question 15

LMWH
reversal agent/antidote

Answer 15

protamine sulfate
1mg per 100U
only works on enoxaparin and dalteparin (IIa)

Question 16

LMWH
Dose, half life

Answer 16

dosage
- weight based

half life
- up to 6 hours

D/C
- 24 hours before procedure

Question 17

LMWH
monitoring

Answer 17

No monitoring needed

Lower risk of HIT

Can look at aPTT

Question 18

LMWH
SE and AE

Answer 18

higher risk of bleeding than heparin

decrease dosage in liver, kidney disease, old age, low body weight

Question 19

Contraindications

Answer 19

anti-platelets, anti-coagulation, bleeding disorders/conditions

Question 20

Warfarin
MOA

Answer 20

inhibits VKORC1
inhibits activation Vitamin K and formation Vitamin K dependent coagulation factors (VII, IX, X, II)

Question 21

Warfarin
route, dose

Answer 21

PO
dosing based on INR (2-3 seconds)

Question 22

Warfarin
Therapeutic monitoring

Answer 22

INR (daily, 2-3x per week, weekly, monthly)

Question 23

Warfarin
Education

Answer 23

Soft tooth brush
medic alert bracelet
electric razor
stop 5 days before surgery

Question 24

Warfarin antidote

Answer 24

vitamin K (phytonadione)
fresh frozen plasma

Question 25

warfarin Contraindications

Answer 25

pregnancy , breast feeding hemorrhage antiplatelets, anticoagulants, thrombocytopena spine, brain, eye surgery vitamin K deficiency alcoholism

Question 26

warfarin Foods/ drugs decrease effect

Answer 26

Foods - canola oil, soyabean, mayonase, leafy green drugs - oral contraceptives - vitamin K - AEDs

Question 27

Warfarin Drugs that increase bleeding

Answer 27

acetaminophen anti-platelets anti-coagulants azoles amiodarone cimetidine TMP-SMX

Question 28

Direct thrombin inhibitors

Answer 28

Dabigatran argatroban IV

Question 29

Dabigatran Route, Dose, monitoring

Answer 29

PO same dosage no monitoring

Question 30

Antidote dabigatran

Answer 30

idaricuxumab

Question 31

Dabigatran MOA

Answer 31

binds II directly - free - clot binds XIII directly - prevents insoluble fibrin

Question 32

SE Dabigatran

Answer 32

GI upset, ulcers, bleeds Rx. PPI

Question 33

Drugs that increase Dabigatran

Answer 33

P-glycoprotien (kidney) inhibitors - verapamil - amiodarone - azoles

Question 34

Contraindications Dabigatran

Answer 34

- GI - hemorrhages - pregnancy - liver disease - kidney disease

Question 35

Direct Xa inhibitors

Answer 35

apixaban rivaroxaban endoxaban

Question 36

MOA Rivaroxaban

Answer 36

binds Xa directly

Question 37

antidote rivaroxaban

Answer 37

andexanet alphaanti

Question 38

anti-platelet drugs

Answer 38

1. aspirin - COX inhibitor 2. P2Y12 inhibitors - ticagrelor - clopidogrel

Question 39

Aspirin MOA

Answer 39

< 325mg (anti-platelet function) inhibition COX1 - inhibits vasoconstrictino - inhibits platelet activation (inhibition AA to TXA2) > 325mg inhibition COX 2 - inhibits vasodilation (decrease GI and kidney blood flow, increase MI) _ decrease mucous, bicarb, increase acid - inhibits PGI2 formation (prevention vasodilation, platelet inhibition)

Question 40

Aspirin SE

Answer 40

Reyes syndrome (brain swelling, fatty liver, organ failure) < 18 years Salicylism (old age) GI bleeding, hemorrhages (Silent) Kidney damage MI, stroke Premature closure ductus arterosus and still birth

Question 41

Health teaching aspirin

Answer 41

no paediatrics < 18 years d/c old age monitor tinnitus smallest dose shortest time no BP > 150mmHg D/C last term monitor melena stools

Question 42

Clopidogrel, Ticagrelor MOA

Answer 42

inhibitioin P2Y12 receptor prevention platelet activation

Question 43

Clopidogrel SE

Answer 43

GI upset and bleeding Rx. PPI TTP Thrombotic thrombocytopenia monitor platelets

Question 44

Ticagrelor SE

Answer 44

Gout TTP