The concomitant usage of METHADOSE with all cytochrome P450 3A4, 2B6, 2C19, 2C9 or 2D6 inhibitors may well result in a rise in methadone plasma concentrations, which could result in most likely fatal respiratory melancholy. In addition, discontinuation of concomitantly used cytochrome P450 3A4, 2B6, 2C19, or 2C9 inducers may additionally result in