methadone overdose and its complications in patients admitted to ‎the toxicology emergency ward of baharloo hospital of tehran in ‎‎2011-2012‎

background: to date, studies on methadone overdose in adults have not been ‎reported in iran. hence, this study was performed to determine the frequency of ‎methadone overdose and its associated complications in baharloo hospital of tehran ‎between august 2011 and august 2012.‎ methods: this cross-sectional study was done on 390 cases. all patients with ‎methadone overdoses and positive urine screen test for methadone were included in this ‎case study through census method. demographic data and overdose complications, ‎such as loss of consciousness, respiratory complications, arrhythmia, hemodynamic ‎disturbances, and qtc interval, were recorded in the questionnaire. data were analyzed ‎by spss software and kolmogorov smirnov, t-test, and chi-square tests were used for ‎data analysis.‎ results: overall, 84.1% of the samples were male and the mean age of the samples ‎was 35.53±11.25 years (range: 15-84 years). mean of the methadone dose used in ‎current admissions was 96.13±52.34 mg. concomitant drug abuse and concomitant ‎uses of medications were seen in 25.9% and 36.9% of the patients, respectively. ‎respiratory depression, pulmonary edema, pneumonia, aspiration, and arrhythmia were ‎seen in 87.9%, 26.2%, 3.3%, 7.4%, and 15.4% of the patients, respectively. ‎ there were significant differences between concomitant medications, duration of ‎methadone use, and qtc interval prolongation and arrhythmia (p<0.05).‎ conclusion: based on the findings of the present study, initial screening of ecg ‎changes and qt interval prolongation as well as arrhythmias should be considered in ‎patients on methadone therapy and concurrent drug abuse and co-administration of ‎medications that lead to qt prolongation should be avoided in them. ‎