Abstract
Methadone is a synthetic full µ-opioid receptor agonist and N-methyl-D-aspartate antagonist given to patients who have recently stopped using illicit opioids or are tapering off chronic opioid pain medication. Maintenance treatment with methadone is today the most widespread and effective way to treat opiate addiction, which achieves abstinence, decreases morbidity and mortality, improves quality of life, and reduces crime genesis, among other benefits. It is also approved by the Food and Drug Administration for treating moderate-to-severe pain that remains unresponsive to nonopioid medications. Patients sometimes abruptly discontinue the medication for several reasons and sometimes suffer distressing but non-life-threatening withdrawal symptoms. More common withdrawal symptoms include anxiety, agitation, rhinorrhea, nausea, and vomiting, like other opioid agonist medications. Psychosis has been reported in some rare cases of methadone withdrawal. However, more research is required because, although psychotic symptoms have been described in different case reports after the reduction or withdrawal of methadone, they have not been sufficient. This case report contributes to the literature on rare manifestations of psychosis in patients who abruptly discontinue the use of methadone.