Direct oral anticoagulants

Question 1

What is it indicated for?

Answer 1

VTE- DVT and PE
AF

Question 2

What is the mechanism of action for apixaban, edoxaban and rivaroxaban?

Answer 2

Directly inhibit activated factor X (Xa), preventing conversion of prothrombin to thrombin.

Question 3

What is the mechanism of action for Dabigatran?

Answer 3

Directly inhibits thrombin

Question 4

When are antiplatelets more effective?

Answer 4

In arterial circulation where clots are largely platelet driven

Question 5

What are the side effects of this medication?

Answer 5

Bleeding- GI
GI upset
dizziness
elevated liver enzymes
anaemia

Question 6

What are the warnings for DOACS?

Answer 6

Active or clinically significant bleeding- avoid
Dose reduction in hepatic or renal disease
Contraindicated in pregnancy and breastfeeding

Question 7

What are the interactions for these drugs?

Answer 7

Risk of bleeding when used in other drugs like heparin, antiplatelets and NSAIDs

Drugs that affect DOAC metabolism or excretion, the anticoagulant effect is increased by macrolides, protease inhibitors, fluconazole

Decreased bleeding risk by rifampicin and phenytoin

Question 8

What DOAC needs to be taken with food?

Answer 8

Rivaroxaban as food affects its absorption