In:
Current Drug Safety, Bentham Science Publishers Ltd., Vol. 19, No. 1 ( 2024-02), p. 142-144
Abstract:
Phenprocoumon is a vitamin K antagonist that is widely prescribed in Europe
and Latin America for the prophylaxis and treatment of thromboembolic events. Case Presentation: A 90-year-old female was admitted to our hospital with tonic-clonic seizures,
possibly due to dementia syndrome. Valproic acid (VPA) was prescribed for the treatment of seizures. VPA is an inhibitor of cytochrome
P450 (CYP) 2C9 enzymes. A pharmacokinetic interaction with phenprocoumon occurred, which is a substrate for CYP2C9 enzymes. The interaction resulted in a strong INR increase and
subsequent clinically relevant bleeding in our patient. Valproic acid is not specifically mentioned in the phenprocoumon drug label as a CYP2C9 inhibitor,
and in the Dutch medication surveillance database, no medication alert is shown when prescribing this combination, and no interaction with phenprocoumon has been reported so far. Conclusion: When prescribing this combination, the prescriber should be warned and advised to
intensify INR monitoring if the combination is to be continued.
Type of Medium:
Online Resource
ISSN:
1574-8863
DOI:
10.2174/1574886318666230310104322
Language:
English
Publisher:
Bentham Science Publishers Ltd.
Publication Date:
2024
SSG:
15,3
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