Pavel Nikolaevich Varioshkin

Acute methadone poisoning is a serious socioeconomic problem worldwide. THE AIM OF THE STUDY. was to conduct an epidemiological analysis of the prevalence of acute methadone poisoning cases in St. Petersburg from 2022 to 2024, based on data from a multidisciplinary emergency hospital. MATERIAL AND METHODS. A total of 2,812 medical records and toxicology test results of patients hospitalized with acute methadone poisoning during the specified period were reviewed. The epidemiological analysis included a quantitative assessment of the incidence of acute methadone poisoning among St. Petersburg residents per 100,000 people. RESULTS. The study revealed that over a three-year period, the incidence of acute methadone poisoning among St. Petersburg residents varied unevenly, with a predominance of cases in 2022 and 2023, and a sharp decrease in this indicator in 2024 to 10.8 per 100 thousand population, respectively (c2=36, p=0.0002). Male patients were more often hospitalized with this poisoning. An increase in cases of hospitalization with acute methadone poisoning in patients of working age (from 39 to 48 years old) was noted: from 33.8% to 45.7% by 2024. Over the period from 2022 to 2024, the total number of cases of hospitalization in toxicology departments of patients with acute mild methadone poisoning increased from 31.9% to 52.3% (c2=28.2, p=0.0003). In turn, the proportion of patients requiring assistance in the intensive care unit decreased over this period from 68.1% to 47.7% (c2=17.2, p=0.0001). The proportion of patients requiring mechanical ventilation in the intensive care unit ranged from 76.2% to 90.6% without statistically significant changes over the three-year period (c2=2.89, p=0.09). Among hospitalized patients, isolated methadone use was prevalent, accounting for 70.9% of cases. Combined use of methadone with other psychoactive substances or medications was observed less frequently, in 29.1% of cases. The mortality rate during the study period was 70 cases (case fatality rate — 2.5%). CONCLUSION. The study found a decrease in the incidence of acute methadone poisoning among residents of St. Petersburg from 19.9 to 10.8 per 100,000 people over the period from 2022 to 2024.

This report presents a case of acute severe poisoning with methadone and α-pyrrolidinovalerophenone in a 41-year-old male patient complicated by circulatory arrest. The poisoning occurred following the intravenous injection of 0.5 g of methadone and intranasal administration of α-pyrrolidinovalerophenone. The case manifested as a critical circulatory arrest with a significant depression of consciousness, reaching a coma II level, alongside cytotoxic edema affecting the white matter of the brain and corpus callosum. Notably, the serum S-100 protein concentration was increased to 152.1 ng/L. The patient also exhibited acute respiratory failure, mixed acid-base disorders, lactic acidosis, cardiotoxic effects, acute renal impairment, acute hepatic impairment, toxic encephalopathy, post-cardiac arrest syndrome, and subsequent severe neurocognitive deficits, as well as cystic gliosis and atrophy in the anterior and anterior-basic parts of the frontal lobes, along with cyst formation in the basal nuclei. The patient received intensive care, including mechanical ventilation with the Hamilton C2 device in Continuous Mandatory Ventilation (CMV) mode, inotropic support, correction of acid-base and hypoxic disturbances, and nutritional support via percutaneous endoscopic gastrostomy to address protein-energy deficiency. Additionally, antibacterial therapy was employed, along with measures to resolve intestinal obstruction. Following stabilization of the blood’s oxygen transport function, a multicomponent drug containing inosine, nicotinamide, riboflavin, and succinic acid was used, which facilitated correction of hypoxic complications and the acute psycho-organic syndrome, leading to improvements in cognitive function.

BACKGROUND: For many years, methadone poisoning has remained one of the leading causes of death among patients admitted to toxicology departments worldwide. During the COVID-19 pandemic, the number of such patients increased substantially, which may be associated with heightened anxiety, fear, sadness, adaptation difficulties, symptoms of post-traumatic stress disorder, and suicidal tendencies in both the general population and specific subgroups, thereby increasing the risk of drug and alcohol use as maladaptive coping strategies. AIM: To perform a comparative analysis and evaluate the results of methadone detection based on retrospective data from chemical toxicological and forensic chemical investigations conducted in 2020–2022. METHODS: This cross-sectional multicenter sample study employed retrospective medical data from patients who died of acute methadone poisoning. The analysis assessed features of methadone detection in fatal acute poisonings, the comparability of chemical toxicological and forensic chemical investigation results, and the frequency of circumstances affecting interpretation of the obtained findings. RESULTS: The study included data from 131 cases of fatal methadone poisoning. In all reviewed cases, screening in chemical toxicological investigations was performed using immunochromatographic assay. In 20% of cases, the assay was performed 12–48 hours after hospital admission. False-positive methadone detection results in chemical toxicological investigations were recorded in 3.4% of cases, whereas false-negative results were found in 6%. In addition, confirmatory methods were not used in 18% of cases. Moreover, in all cases with false-negative results, high concentrations of substances such as nicotine and caffeine were detected in the samples, which may have affected the reliability of immunochromatographic assay. CONCLUSION: Improving approaches to the selection of biological material, the timing of assay, and the mandatory use of confirmatory methods may minimize the risk of false-positive and false-negative methadone test results in chemical toxicological investigations. This, in turn, may improve diagnostic accuracy, optimize treatment strategy, and provide a more objective assessment of medical circumstances in subsequent forensic medical examinations.

Objective : to evaluate the effects of correcting metabolic disorders in the post-resuscitation period in a clinical case report. Materials and methods . Management and dynamic monitoring of acute poisoning in a 29-year-old patient after concomitant use of methadone and cocaine complicated by cardiac arrest and prehospital biochemical and acid-base balance alterations. Results . The bradypneic and comatose patient developing out-of-hospital cardiac arrest (OHCA) was hospitalized after effective resuscitation by emergency team. Comprehensive lab examination revealed the presence of methadone and cocaine, decompensated metabolic lactic acidosis and hyperkalemia. Patient’s condition improved after intense correction of metabolic alterations with sodium hydrocarbonate, a glucose-insulin mixture, and a pharmaceutical containing inosine + nicotinamide + riboflavin + succinate. A positive trend including recovered consciousness, switch from ventilator support to spontaneous breathing, and stable hemodynamics was documented after 3 days of treatment. However, emerging complications such as hospital-acquired pneumonia and acute kidney injury had to be managed. The patient improved significantly by the 17th day of treatment, and was discharged on day 21. Conclusion . Intensive care to promptly address decompensated metabolic lactic acidosis (sodium hydrocarbonate, a multi-component drug containing inosine + nicotinamide + riboflavin + succinate) and hyperkalemia (glucose-insulin solution), reduced the severity of metabolic alterations after cardiac arrest due to acute methadone and cocaine poisoning, favoring patient’s outcome.

Introduction. Soil is an important element of the city’s ecological system. Therefore, in the russian federation and european countries, in-depth studies are being conducted to substantiate permissible levels of soil exposure for most known metals. The level of environmental pollution varies in different parts of the city and may depend on the distance from the source of pollution, such as an industrial enterprise. The studied industrial center of the russian federation has areas that differ in functional use and purpose, including a large industrial enterprise, which is one of the key complexes of russian chemical production.The purpose of this study is to determine the content of a number of metals (mercury, lead, zinc, arsenic, chromium, nickel, cobalt, copper, manganese, barium, vanadium) in the soil of different areas of one of the industrial centers of the Russian Federation.Material and methods. The paper presents the results of determining chemical elements (metals) in the soil of different urban areas of one of the industrial centers of the Russian Federation. Soil samples taken in 10 areas of the city were analyzed for quantitative content of metals using inductively coupled plasma mass spectrometry. The samples were collected over a period of two years; the research method was inductively coupled plasma mass spectrometry.Results. The results of the study showed that in all the studied areas of the city, metal contents (Pb, Zn, Cu and As) were found that exceeded the permissible levels approved in the Russian Federation, which indicates a potential threat to the health of the population living in these territories.Limitation. The use of these research methods is possible only in a specially equipped laboratory with qualified personnel.Conclusion. The detected concentrations emphasize the importance of regular monitoring of the content of hazardous metals in the soil. An opinion has been formed on the need to take measures to reduce chemical pollution and the impact on the environment and to continue research, especially in those areas where excess exposure levels have been identified. The standards (maximum permissible concentrations) approved in the Russian Federation and similar standards (maximum permissible concentrations) of the Netherlands are compared.Compliance with ethical standards. This study does not require the conclusion of a biomedical ethics committee or other documents.Authors’ contribution: Varioshkin P.N. – concept and design of the study, collection of material and data processing, statistical processing, writing the text; Lukovnikova L.V. – data processing, writing; Reynyuk V.L. – data processing, editing; Kombarova M.Yu. – collection of material and data processing, statistical processing; Kuznetsov S.V. – collection of material and data processing, statistical processing; Yatselenko Yu.V. – data processing, editing. All co-authors – approval of the final version of the article, responsibility for the integrity of all parts of the article.Conflict of interests. The authors declare no conflicts of interest.Funding. The study was supported by the Golikov Research Clinical Center of Toxicology of the FMBA of Russia, Saint Petersburg, Russian Federation.Received: August 21, 2025 / Revised: September 03, 2025 / Accepted: October 2, 2025 / Published: November 19, 2025

BACKGROUND: The stability of trace element composition within the organism is crucial for maintaining the vital biochemical and biophysical processes. The severity of diseases associated with heavy metal accumulation is largely attributable to the irreversibility of this process and the persistent disturbances in metabolic systems. Therefore, investigating the imbalance of biogenic elements in patients with chronic heavy metal intoxication is highly relevant. AIM: The work aimed to determine the variations in the levels of biogenic metals and selenium in patients with chronic manganese chloride intoxication. METHODS: The experiments were conducted on 12 male white outbred rats weighing 180–220 g. The experimental group (n=6) received a 0.2% manganese chloride solution via automatic dispensers for 3 months, and the control group (n=6) was given tap water. The concentrations of manganese, copper, zinc, selenium, calcium, iron, and magnesium were measured in the left and right hippocampi using atomic emission spectroscopy with PerkinElmer Optima 7000 DV ICP-OES Spectrometer (USA). RESULTS: Based on the hippocampal content, the analyzed biogenic elements were arranged in the ascending order of concentration as follows: [Mn] [Cu] [Zn]=[Se] [Mg] [Fe] [Ca]. No evidence of asymmetry was observed in the levels of these metals and selenium across any of the animal groups. In rats that received the manganese solution, the hippocampal levels of manganese were more than twice as high compared to the control group (p 0.01). In the experimental group, the copper concentrations were found to be significantly higher (p 0.01), whereas the selenium levels were lower (p 0.01) compared to the control group. These effects demonstrated a bilateral pattern, affecting both the left and right hippocampi. The levels of iron, zinc, calcium, and magnesium remained unchanged. CONCLUSION: It can be hypothesized that the observed variations in biogenic elements may be responsible for the impairment of enzymatic systems, which include manganese, copper, and selenium.

The article discusses the controversial aspects of conducting medical examinations for intoxication. This work is based on a case report on determining the legitimacy of administrative license revocation, which involved a forensic medicine and toxicology expert. A detailed chronology is provided, from the moment the driver was stopped by a traffic police officer and suspended from driving for an alcohol intoxication test, to the ruling by the magistrates’ court, which was later upheld by the court of cassation. This case study illustrates errors in interpreting the findings of chemical tests for intoxication, which occur when psychoactive substances are incorrectly identified in human biological fluids. This case of γ-butyrolactone detection in a professional car driver highlights the inadmissibility of unreliable methods for chemical compound identification. Moreover, the paper emphasizes insufficient training of clinical laboratory diagnostics physicians, addresses the issue of an overly mechanistic approach to their work, and proposes potential solutions to the identified shortcomings.