The concomitant usage of METHADOSE with all cytochrome P450 3A4, 2B6, 2C19, 2C9 or 2D6 inhibitors may end in a rise in methadone plasma concentrations, which could trigger potentially fatal respiratory melancholy. Also, discontinuation of concomitantly utilized cytochrome P450 3A4, 2B6, 2C19, or 2C9