Linezolid is a weak, nonselective monoamine oxidase inhibitor (MAOI). A recent FDA Drug Safety Communication released in March 2016 noted reports of serotonin syndrome associated with certain opioids, particularly fentanyl and methadone. Development of serotonin syndrome after concomitant administration of linezolid with other serotonergic agents has been reported. Due to a potential risk of serotonin syndrome, a patient on chronic methadone should not be started on concomitant linezolid unless they will be monitored.
