The clinico-epidemiological, diagnostic, and therapeutic aspects of methadone poisoning: a registry-based clinical study.

Objectives: Methadone is a long-acting synthetic agonist of opioid receptors, which is used as an analgesic and as an alternative treatment in opioid-dependent patients. Clinical manifestations of methadone poisoning include miotic pupils, low levels of consciousness (LOC), respiratory depression or apnea, and coma and death. Considering the high consumption of methadone in society and the prevalent instances of overdose and poisoning, whether accidental or intentional, the authors decided to investigate the clinico-epidemiological, diagnostic, and therapeutic characteristics of methadone poisoning in the Mazandaran province, northern Iran, from 2020 to 2022.

Methods: This study was a retrospective and descriptive cross-sectional registry-based study, wherein data was collected from the Mazandaran Registry Center of Opioids Poisoning (MRCOP), on patients with methadone poisoning. Data based on various parameters such as individual characteristics, ingestion motivation, and clinical outcomes were collected in a checklist.

Results: Of the 385 patients, who entered the study, 264 were men and 121 were women. The mean age of the patients was 29.02 years. Two hundred forty-four patients had intentionally consumed methadone. The most common symptoms observed among individuals with methadone poisoning were decreased arterial blood oxygen (225 patients) and decreased LOC (173 patients). The length of hospitalization for most patients was less than 1 week. Except for seven of them who died, most of them were discharged in good general condition.

Conclusion: The study identified sex, age, marital and employment status, and suicidal intent as the most significant factors influencing methadone poisoning, which should be considered in the design and implementation of public education and prevention programs.