Det er påvist, at supraterapeutiske koncentrationer af fesoterodins aktive metabolit hæmmer K+- strømmen i klonede humane ether- à- go- go- related (hERG) - kanaler og forlænger aktions - potentialets varighed (70% og 90% repolarisering) i isolerede Purkinjefibre fra hunde.
Supratherapeutic concentrations of the active metabolite of fesoterodine, have been shown to inhibit K+ current in cloned human ether-à-go-go-related gene (hERG) channels and prolong action potential duration (70% and 90% repolarisation) in canine isolated Purkinje fibres.