Warfarin

Question 1

absorption

Answer 1

completely absorbed following administration

Question 2

distribution

Answer 2

has a small volume of distribution because it binds extensively to plasma proteins

Question 3

metabolism

Answer 3

hepatic metabolism through CYP450 system

Question 4

excretion

Answer 4

renal excretion by glomerular filtration

Question 5

MOA

Answer 5

1. vitamin K antagonist
2. works by competitively inhibiting the vitamin K epoxide reductase complex which is essential for activating vitamin K available in body
3. leads to depletion of functional vitamin K reserves
4. reduces synthesis of active clotting factors

Question 6

indications

Answer 6

1. prophylaxis of embolisation in heart disease and AF
2. Treatment of venous thrombosis and pulmonary embolism

Question 7

adverse effects

Answer 7

• haemmorhage
• abnormal hepatic function

Question 8

interactions

Answer 8

• aspirin
• enoxaparin

Question 9

contraindications

Answer 9

• avoid use within 48 hours postpartum
• haemorrhagic stroke
• significant bleeding