Terfenadine is an antihistamine, generally completely metabolizes to the active form fexofenadine in the liver by the enzyme cytochrome P450 CYP3A4 isoform. Terfenadine ((±)-Terfenadine) is a potent open-channel blocker of hERG with an IC50 of 204 nM. Terfenadine, an H1 histamine receptor antagonist, acts as a potent apoptosis inducer in melanoma cells through modulation of Ca2+ homeostasis. Terfenadine induces ROS-dependent apoptosis, simultaneously activates Caspase-4, -2, -9.