Selvom tolcapon er kraftigt proteinbundet, er det vist i in vitro undersøgelser, at tolcapon i terapeutiske koncentrationer ikke fortrænger warfarin, tolbutamid, digitoxin og phenytoin fra deres bindingssteder.
Although tolcapone is highly protein bound, in vitro studies have shown that tolcapone did not displace warfarin, tolbutamide, digitoxin and phenytoin from their binding sites at therapeutic concentrations.