ANALYZING THE FACTORS AFFECTING THE DIFFERENCES IN THE RESULTS OF COMPUTING THE ORAL TOXIC AND LETHAL DOSES OF DRUGS BY THEIR CONCENTRATION IN URINE; [АНАЛИЗ ФАКТОРОВ, ВЛИЯЮЩИХ НА ИЗМЕНЧИВОСТЬ РЕЗУЛЬТАТОВ РАСЧЕТА ПЕРОРАЛЬНЫХ ТОКСИЧЕСКИХ И ЛЕТАЛЬНЫХ ДОЗ ЛЕКАРСТВЕННЫХ ВЕЩЕСТВ ПО КОНЦЕНТРАЦИИ В МОЧЕ]

Introduction. Quetiapine belongs to psychotropic drugs, i. e., neuroleptics, and is an antipsychotic. With oral narcotic, potent, and psychotropic substances, in case of suspected intentional or unintentional poisoning, the determining factor is the dosage amount of the substance taken by the sufferer, which allows assuming the use of a toxic or lethal dose. In this case, the investigative authorities can be assisted by the findings obtained in forensic-chemical or chemical-toxicological investigations. Aim. With consideration to certain factors, developing a methodological approach to calculating the doses of narcotic, psychotropic, and potent substances that have been orally (per os) administered to the sufferer, and testing the said approach within a case study. Materials and Methods. We studied the active substance quetiapine contained in pharmaceutical drugs. Biological objects studied were the liver, femoral vein blood, and urine taken from the corpse of a 24-year-old normosthenic person died of acute quetiapine poisoning. Forensic chemical examination of biological objects aimed at identifying quetiapine qualitatively and quantitatively was performed using conventional procedures. Results and Discussion. A methodological approach is proposed to calculate the doses of narcotic, psychotropic, and potent substances administered orally to the sufferers, considering certain factors and using a case study, in which quetiapine was detected in urine quantitatively. The analysis of six factors is presented, affecting the results of calculating the theoretical dose of the drug taken. Conclusions. A formula is proposed for calculating the theoretical dose with the relative error of the results obtained, not exceeding 28%. © 2024 LLC "IMC" Modern Clinical Medicine. All rights reserved.