Anticoagulation and antiplatelet therapy

Question 1

Supplement that can interact with DOACs

Answer 1

St. John’s wart

Question 2

Heparin and LMWH targets in the clotting cascade

Answer 2

Xa and IIa (thrombin) (predominately Xa effects)

Question 3

LMWH drugs

Answer 3

Enoxaparin
*Dalteparin

Question 4

Clotting factors affected by warfarin

Answer 4

II, VII, IX, X
*also protein C and S

Question 5

Other subcutaneous AC

Answer 5

Fondaparinux

Question 6

Fondaparinux contraindication

Answer 6

CrCl <30

Question 7

Heparin reversal agent

Answer 7

protamine sulfate

Question 8

heparin SE’s

Answer 8

HIT
*osteoporosis (with long term LMWH usage)
*skin necrosis

Question 9

LMWH reversal agent

Answer 9

• no great reversal agent, can use protamine sulfate

Question 10

fondaparinux mechanism

Answer 10

Inhibits Xa alone

Question 11

fondaparinux dosing schedule

Answer 11

once daily

Question 12

Warfarin mechanism

Answer 12

Inhibits vitamin K epoxide reductase (VKORC1) leading to less reduced vitamin k, deactivating y-glutamyl carboxylase

Question 13

Pathway responsible for drug interactions with DOACs

Answer 13

P glycoprotein transport system

Question 14

DOAC clearance and metabolism

Answer 14

• renally cleared
• some hepatic metabolism

Question 15

other DOAC reversal agent

Answer 15

4 factor PCC (off label)

Question 16

Status of data for NOACS in obesity

Answer 16

• data suggest xarelto and eliquis adequate for VTE treatment regardless of weight/BMI
• more data for rivaroxaban than apixaban
• insufficient data for dabigatran and edoxaban for BMI >40

Question 17

Status of DOACS for CKD

Answer 17

• Pts with CrCL <30 were excluded from trials
• caution with LMWH
• eliquis has least renal clearance

Question 18

Status of DOACs and lovenox for chronic liver disease

Answer 18

• DOACs avoided with active, clinically significant liver disease
• retrospective studies and meta-analysis have not shown clear concerns with DOACs
• ## lovenox may be considered, especially if baseline INR over 2