For example, a sizeable proportion of sertindole-associated TdP cases have been reported in the context of overdoses; whereas tolterodine, as a CYP2D6 and CYP3A4 substrate, is a potential candidate for drug–drug-interactions that could contribute to TdP risk, although it remains to be seen if this drug has a potential to cause TdP when exposure magnitudes do not surpass therapeutic levels [36, 37]. The gene discussed is CYP3A4; the disease is torsades de pointes.