GC-MS Quantification of Serum Opioid Concentrations in Acute Poisoning Cases

Opioid poisoning is a major worldwide public health issue, with increasing rates attributed to both traditional opiates and synthetic derivatives such as methadone. Reliable assessment of serum opioid concentrations is mandatory for clinical management and prognosis, as quantitative measurement of serum opioid concentrations determines local epidemiological patterns and identifies risk factors that guide future prevention and treatment strategies. Medical professionals at Imam Khomeini Hospital (Kermanshah, Iran) report that, in their country, and especially in western provinces such as Kermanshah, poisoning cases involving opium and its derivatives have created many challenges for emergency and treatment centers. Despite this, most studies in this province have been epidemiological and descriptive,^1,2 which, in their mind, means still insufficient research on serum opioid levels, usage patterns, and complication profiles in Kermanshah province's native populations. Moreover, data regarding differences in serum drug concentrations based on substance type, sex, age, route of administration, and clinical outcomes are lacking. Believing that such data could inform targeted treatment protocols, improve emergency care, and prevent avoidable deaths, these professionals conducted a study evaluating serum opioid levels and substance types in poisoned patients—emphasizing correlations among laboratory findings, clinical manifestations, and outcomes—to fill this gap and support targeted regional and national strategies. Serum concentrations of opioids were measured using gas chromatography-mass spectrometry (GC-MS) after administration of antidotes. A paper based on this study was published in Toxicology Reports.³

The study used fifty adult patients with confirmed opioid poisoning, which were clinically diagnosed based on the classic opioid toxidrome (decreased consciousness, miotic pupils, and respiratory depression) documented at emergency department admission. Clinical diagnosis was confirmed by positive response to naloxone administration. Demographic and clinical data, type and route of opioid use, clinical features, laboratory results, and patient outcomes were recorded. Among these patients (86 % male, mean age 33.5 ± 9.8 years), methadone was the most common cause of poisoning (72 %), followed by opium and heroin. The principal clinical findings included apnea (44 %), miosis (44 %), and weakness/lethargy (38 %), with severe symptoms observed primarily in methadone cases. Serum methadone concentrations were significantly higher in men than women (p = 0.007), and in rural residents compared to urban (p = 0.005). Higher opioid serum levels were associated with more severe clinical presentations and increased need for intensive care. Most patients recovered with medical management; no in-hospital deaths occurred. Methadone has become the leading cause of opioid poisoning in this region, with high serum concentrations predicting increased clinical severity. Measurement of serum opioid levels is a valuable tool for risk stratification and should be integrated into standard management protocols. Attention must be given to both preventive education and tighter regulation of methadone distribution, particularly among high-risk groups.³

The authors state in their paper³ that their study was the first to measure serum concentrations of the opioids consumed in Kermanshah province. “Given that methadone constituted the most significant cause of opioid poisoning among our patients,” they write, “enhanced monitoring at the MMT centers for drug distribution, supervision of drug use, and providing necessary warnings to patients regarding proper dose adjustment and storage of the medication are increasingly required. These measures could significantly reduce the incidence of poisoning, improve patient outcomes, and inform public health strategies in regions with high opioid use.”³

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References

1. Moradi, M.; Aghaei, A.; Najafi, F. et al. Epidemiology of Drug Abuse and Drug Dependence in Individuals Visiting Drug Abuse Treatment Centers in Kermanshah Province in 2013. J. Biol. Today’s World2015, 4 (7), 156-164. DOI:10.15412/J.JBTW. 01040703
2. Sharafi, K.; Nakhaee, S.; Mansouri, B. et al. Comparative Analyses of Serum Toxic Heavy Metal Ions in Opium Addicts and Healthy Controls. Iran. J. Toxicol.2025, 19 (1), 17-25. DOI: 10.32592/IJT.19.1.17
3. Sarabbadieh, A. M.; Fattahi, N.; Veisi, M. M. et al. Investigation of Serum Concentration and the Type of Opioid Used in Patients with Opium Poisoning. Toxicol Rep. 2026, 16, 102213. DOI: 10.1016/j.toxrep.2026.102213