The concomitant use of METHADOSE with all cytochrome P450 3A4, 2B6, 2C19, 2C9 or 2D6 inhibitors could lead to an increase in methadone plasma concentrations, which could trigger probably fatal respiratory despair. In addition, discontinuation of concomitantly used cytochrome P450 3A4, 2B6, 2C19, or