The concomitant usage of METHADOSE with all cytochrome P450 3A4, 2B6, 2C19, 2C9 or 2D6 inhibitors may cause a rise in methadone plasma concentrations, which could lead to possibly fatal respiratory depression. Additionally, discontinuation of concomitantly used cytochrome P450 3A4, 2B6, 2C19, or 2C9 inducers might also lead to an increase in methad