CASE STUDY – Cardiovascular system II. – warfarin
Patient: Tibor, 65 years old
Personal history: arterial hypertension, osteoarthritis (after total hipp replacement surgery),
uses warfarin for 12 months without any problems, last term of INR monitoring: 4,6.
Drug history: Warfarin 5mg 0 – 0 – 1
Atenolol AL 50mg 1 – 0 – 0
Ramil 5mg 1 – 0 – 0
Tasks:
1. Describe principle of anticoagulant warfarin therapy, its risks.
2. Perform an analysis of prescription drugs, give active substance classification
according to ATC classification, a brief mechanism of action of individual medicines,
check the dosage and method of use (morning / evening, before / after meals, etc.)
3. Find out possible drug interactions. Describe all possible warfarin interactions
(warfarin – other drugs, warfarin – food supplements, warfarin – herbal products).
4. What is INR monitoring, what INR value tells us? What are therapeutic INR values for
patients taking blood thinners? What are terms (intervals) of regular INR monitoring?
5. Is necessary to adjust dose of warfarin?
6. What symptoms of increased anticoagulant effect of warfarin (signs of bleeding)
patient should watch?
7. What factors (except of drug interactions) should increase risk of bleeding in patients
with warfarin?