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Bleeding Complications in a Patient After the Unexpected Interaction between Valproic Acid and Phenprocoumon
André Wieringa1,2, Helle-Brit Fiebrich2,3, Fleur van Gelder1
1Department of Clinical Pharmacy, Isala Hospital, Zwolle, The Netherlands.
A drug interaction between phenprocoumon and valproic acid (VPA) can lead to dangerous bleeding. This case highlights the need for increased INR monitoring when these medications are prescribed together.
Area of Science:
- Pharmacology
- Clinical Medicine
- Drug Interactions
Background:
- Phenprocoumon is a common vitamin K antagonist used for thromboembolic events.
- Valproic acid (VPA) is an anticonvulsant and a cytochrome P450 (CYP) 2C9 inhibitor.
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