CYP3A4 and Prolonged QT interval: Moreover, concomitant administration of berberine and macrolides and/or statins could enhance cardiac toxicity caused by inhibition of CYP3A4 and human ether-a-go-go related gene (hERG) channel because inhibition of CYP3A4 might elevate plasma drug concentration increasing cardiotoxicity and inhibition of hERG the potassium channel regulator might affect cardiac repolarization leading to long QT syndrome (Zhi et al., 2015; Feng et al., 2018a).