Background. Poisoning by addictive and psychotropic substances is one of the main reasons for the admission of patients to emergency departments in most countries of the world. The purpose of this study was to investigate the current structure of toxic syndromes in patients with acute poisoning and to analyze existing approaches to the diagnosis of addictive and psychotropic substance poisoning based on the syndromic approach. Materials and methods. Medical data of 2987 patients treated with the diagnosis: “Acute drug poisoning” (ICD-10: T40.0-T40.3) in the Kyiv Toxicological Center were studied. Laboratory studies of addictive and psychotropic substances in the biological environment were performed using immunochromatographic analysis (rapid tests) and chromate-mass spectrometry (device Aligent 6850/5973N, column HP-5MS). Statistical analysis was performed using the program Statistica 12.6 (Windows 10/7). Results. According to the Center for Mental Health and Monitoring of Drugs and Alcohol of the Ministry of Health of Ukraine in 2018, the most common substances that result in abuse were: alcohol — 14.6 %, cannabis — 2.8 %, opioids — 2.1 %, sedative agents — 1.1 %, solvents — 0.9 %, amphetamine-type stimulants — 0.2 %, cocaine — 0.1 %, and hallucinogens — 0.1 %. The range of substances that caused severe poisoning in adults in 2016–2020 represented by: ethanol — 29.2 %, opioids — 42.3 %, cannabinoids — 8.4 %, sedative agents and hypnotics — 9.5 %, cocaine, and stimulants, inclu-ding caffeine — 7.4 %, hallucinogens — 5.5 %, solvents — 2.1 %. The following toxidromes were diagnosed: sedative in 46.3 % of patients, opioid — 37.6 %, sympathomimetic — 17.7 %, anticholinergic — 9.5 %, serotonin — 0.4 %, and syndrome of inappropriate diuretic hormone secretion (SIADH) — 0.2 %. During the study period, the number of combined poisonings increased 1.8 times (from 20.5 to 37.1 %), and among the combinations of addictive and psychotropic substances, the most common are methadone + ethanol, methadone + benzodiazepines, methadone + amphetamine, opioids + cocaine + ethanol, opioids + cannabis, as well as other combinations involving methamphetamine, hallucinogens, analgesics. Clinical diagnosis of combined poisonings is difficult, miosis may be absent in tramadol and meperidine poisoning, in cases of combined use of opioids and stimulants, or extremely severe cases, when the patient shows signs of deep post-hypoxic encephalopathy. Modern synthetic opioids (fentanyl and buprenorphine analogues) significantly outweigh the toxic effects of heroin, so there is a fairly common approach to using higher initial doses of naloxone in the treatment of such overdoses. However, approaches to the use of naloxone differ in various scientific sources. The practical experience in the Kyiv Toxicological Center proves that treatment can be started with standard doses of naloxone and quickly increased in the absence of side effects (agitation, convulsions, pulmonary edema). Given the fact that modern test systems are aimed at finding a small range of narcotic and psychotropic substances and do not determine their concentration, considerable attention should be paid to clinical diagnosis based on the definition of pathological symptoms and syndromes. Since the main target for narcotic and psychotropic substances is the nervous system, the identification of biomarkers of its dysfunction at different levels is key in the diagnosis of poisoning. Based on certain biomarkers, an understanding of the existing toxic syndrome (toxidrome) is formed. Today, opioids play a key role in morbidity and mortality from drug poisoning in Ukraine. A threatening trend in recent years is the increase in the proportion of combined poisonings by opioids and other substances, which complicates the determination of the toxidrome. It is important to note that the “fashion” for the use of combinations of narcotic drugs and psychotropic substances among drug users is constantly changing, so doctors try to regularly update information on available drugs and psychotropic substances in the region, which are popular among consumers and characteristic manifestations of poisoning. The universal approach ABCDE should be used in cases where there are no specific tests for toxic substances, and because more than a third of positive tests show the presence of two or more xenobiotics. Conclusions. Identification of toxidrome is important from the standpoint of diagnosis and treatment of acute poisoning. Many researchers note that its importance exceeds the value of rapid tests to determine the toxic substance, and the patient’s vital signs and careful examination are the best clues for choosing treatment tactics. In cases of combined poisoning with drugs or psychotropic substances, or in situations where it is not possible to conduct rapid testing of the patient’s urine for toxic substances, it is necessary to approach the use of antidotes (naloxone) with caution. It is important to remember that the object of medical intervention in any poisoning is the patient, not the toxin or the results of laboratory tests, which do not always correctly indicate the poison. Pharmacological interventions in the treatment of a patient with acute addictive or psychotropic substance poisoning should be aimed at correcting the underlying pathological syndrome (if possible), taking into account not to exacerbate its manifestations, but rather to minimize its severity and duration.