VTE: Warfarin Drug and Diet Interactions

Question 1

Drug Interactions (Increase INR)

Answer 1

Erythromycin, Metronidazole, Alcohol
Anabolic steroids, Fluconazole, Isoniazid, Liver disease
Ciprofloxacin, Propafenone

Question 2

Drug Interactions (Decrease INR)

Answer 2

Rifampin, Cholestyramine, Carbamazepine

Question 3

FOOD-DRUG INTERACTIONS

Answer 3

Vitamin K rich foods
geen leafy vegetables

Question 4

Alcohol and Warfarin

Answer 4

Acute EtOH: increase anticoagulant effect of warfarin by inhibiting metabolism

Chronic EtOH w/o liver damage: enhances warfarin metabolism by inducing hepatic enzymes decreases the effect of warfarin

Chronic EtOH w/ liver damage: due to lack of hepatic enzymes, increases anticoagulant effect (dose reduction often needed)