Da oxybutynin metaboliseres af cytokrom P 450 isoenzym CYP3A4, kan interaktioner med lægemidler, der hæmmer dette isoenzym, ikke udelukkes.
As oxybutynin is metabolised by cytochrome P 450 isoenzyme CYP 3A4, interactions with drugs that inhibit this isoenzyme cannot be ruled out.