5. 2), kan entakapon potentielt interferere med lægemidler med metabolisme, der er afhængig af dette isoenzym, såsom S- warfarin.
Due to its affinity to cytochrome P450 2C9 in vitro (see section 5.2), entacapone may potentially interfere with medicinal products with metabolism dependent on this isoenzyme, such as S-warfarin.