Volume 12, Issue 3 (2026)
Pharm Biomed Res 2026, 12(3): 187-194 |
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Arjmand M, Fazel M Y, Parvaresh A, Shamsipour F, Ghorbani R, Bagheryan A S, et al . Prolonged QT Interval in Methadone Poisoning: A 10-Year Retrospective Study of 1,000 Cases. Pharm Biomed Res 2026; 12 (3) :187-194
URL: http://pbr.mazums.ac.ir/article-1-740-en.html
URL: http://pbr.mazums.ac.ir/article-1-740-en.html
Marziyeh Arjmand1 
, Mohammad Yousef Fazel2 , Arash Parvaresh3 , Fateme Shamsipour4 , Roshanak Ghorbani5 , Amir Sajad Bagheryan6 , Seyed Ahmadreza Ziaei7 , Niloofar Deravi6 , Mehrnoush Giahi Yazdi1 , Marjan Shariatpanahi8 , Elahe Zare9 , Hamid Owliaey *10
, Mohammad Yousef Fazel2 , Arash Parvaresh3 , Fateme Shamsipour4 , Roshanak Ghorbani5 , Amir Sajad Bagheryan6 , Seyed Ahmadreza Ziaei7 , Niloofar Deravi6 , Mehrnoush Giahi Yazdi1 , Marjan Shariatpanahi8 , Elahe Zare9 , Hamid Owliaey *10
1- Department of Medical Science, Ya.C., Azad University, Yazd, Iran.
2- Department of Toxicology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
3- Department of Clinical Pharmacy, Faculty of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
4- Student Research Committee, Department of Toxicology, School of Health, Guilan University of Medical Sciences, Rasht, Iran.
5- Universal Scientific Education and Research Network (USERN), Tehran, Iran.
6- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
7- Student Research Committee, Department of Medicine, School of Medicine, Fasa University of Medical Sciences, Fasa, Iran.
8- Department of Pharmacology and Toxicology, School of Pharmacy, Iran University of Medical Sciences, Tehran, Iran.
9- Clinical Research Development Center, Afshar Hospital, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
10- Department of Forensic Medicine and Clinical Toxicology, Ya.C., Islamic Azad University, Yazd, Iran.
2- Department of Toxicology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
3- Department of Clinical Pharmacy, Faculty of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
4- Student Research Committee, Department of Toxicology, School of Health, Guilan University of Medical Sciences, Rasht, Iran.
5- Universal Scientific Education and Research Network (USERN), Tehran, Iran.
6- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
7- Student Research Committee, Department of Medicine, School of Medicine, Fasa University of Medical Sciences, Fasa, Iran.
8- Department of Pharmacology and Toxicology, School of Pharmacy, Iran University of Medical Sciences, Tehran, Iran.
9- Clinical Research Development Center, Afshar Hospital, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
10- Department of Forensic Medicine and Clinical Toxicology, Ya.C., Islamic Azad University, Yazd, Iran.
Abstract: (174 Views)
Background: Methadone overdose is increasingly recognized as a cause of acquired long‑QT syndrome and life‑threatening ventricular arrhythmias, yet the prevalence and clinical correlates of QT prolongation in poisoned patients remain incompletely characterized.
Objectives: This study aimed to determine the frequency of QT interval prolongation in patients with methadone poisoning and to identify clinical factors associated with prolonged QT in this population.
Methods: In this retrospective observational study, we reviewed 1,000 consecutive patients admitted to Shah Vali (Yazd City, Iran) and Shahid Beheshti (Taft City, Iran) hospitals for methadone overdose between January 2014 and December 2023. Demographic characteristics, reported methadone dose, comorbid cardiovascular diseases, electrolyte profiles, and electrocardiographic (ECG) measurements were extracted from medical records. QT intervals were obtained from the initial 12-lead ECG at admission and categorized as normal/borderline (<450 ms) or prolonged (≥450 ms). Associations between prolonged QT and age group (<45 vs ≥45 years), sex, comorbidity, electrolyte disturbances, and arrhythmias were assessed using chi‑square tests and crude odds ratios (OR).
Results: The mean age was 32.8±9.6 years, and the mean reported methadone dose was 75.4±2.25 mg. The mean QT interval was 478.6±32.1 ms, and QT prolongation (≥450 ms) was observed in 48.0% (n=480) of patients. Prolonged QT was significantly associated with younger age (P=0.02), female sex (P=0.05), cardiovascular comorbidity (P=0.02), and electrolyte imbalances, particularly hypokalemia (P=0.02). Patients with prolonged QT also had a higher frequency of clinically documented arrhythmias, including torsades de Pointes (TdP) (P=0.002).
Conclusion: QT interval prolongation is common among hospitalized patients with methadone poisoning and is strongly associated with younger age, female sex, cardiovascular disease, electrolyte abnormalities, and malignant arrhythmias. These findings support routine 12‑lead ECG screening, continuous cardiac monitoring, and prompt correction of electrolyte disturbances in all patients presenting with methadone overdose.
Objectives: This study aimed to determine the frequency of QT interval prolongation in patients with methadone poisoning and to identify clinical factors associated with prolonged QT in this population.
Methods: In this retrospective observational study, we reviewed 1,000 consecutive patients admitted to Shah Vali (Yazd City, Iran) and Shahid Beheshti (Taft City, Iran) hospitals for methadone overdose between January 2014 and December 2023. Demographic characteristics, reported methadone dose, comorbid cardiovascular diseases, electrolyte profiles, and electrocardiographic (ECG) measurements were extracted from medical records. QT intervals were obtained from the initial 12-lead ECG at admission and categorized as normal/borderline (<450 ms) or prolonged (≥450 ms). Associations between prolonged QT and age group (<45 vs ≥45 years), sex, comorbidity, electrolyte disturbances, and arrhythmias were assessed using chi‑square tests and crude odds ratios (OR).
Results: The mean age was 32.8±9.6 years, and the mean reported methadone dose was 75.4±2.25 mg. The mean QT interval was 478.6±32.1 ms, and QT prolongation (≥450 ms) was observed in 48.0% (n=480) of patients. Prolonged QT was significantly associated with younger age (P=0.02), female sex (P=0.05), cardiovascular comorbidity (P=0.02), and electrolyte imbalances, particularly hypokalemia (P=0.02). Patients with prolonged QT also had a higher frequency of clinically documented arrhythmias, including torsades de Pointes (TdP) (P=0.002).
Conclusion: QT interval prolongation is common among hospitalized patients with methadone poisoning and is strongly associated with younger age, female sex, cardiovascular disease, electrolyte abnormalities, and malignant arrhythmias. These findings support routine 12‑lead ECG screening, continuous cardiac monitoring, and prompt correction of electrolyte disturbances in all patients presenting with methadone overdose.
Keywords: Methadone, Poisoning, Electrocardiography (ECG), Long QT syndrome, Cardiotoxicity, Opioid-related disorders
Type of Study: Original Research |
Subject:
General
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