Coumarins

Question 1

Example

Answer 1

Warfarin

Question 2

MoA

Answer 2

Vitamin K epoxide reductase
Inhibitor
Prevents the post-translational gamma-carboxylation of factors II, VII, IX, X
Anticoagulant effect starts when formed active factors are degraded

Question 3

Indications

Answer 3

Tx: Thromboembolic Disease (DVT/PE)
AF
Mechanical prosthetic heart valves
TIA
Rheumatoid Heart Disease

Question 4

ADR

Answer 4

Bleeding (- Vit K/Prothrombin)
Alopecia
Skin necrosis

Question 5

Prescribing Advice

Answer 5

Measure the International Normalised Ratio (INR)
= ratio of patient’s PT + control sample
X Liver Disease
X Thyrotoxicosis
X Pregnancy
Decrease w/ antibiotics, Amiodarone, Cimetidine, Clofibrate, Fluconazole, Metronidazole, Antiplatelet drugs, NSAIDs
Increase w/ Barbituates, Carbamazepine, Rifampicin, Sucralfate