The evolution of fentanyl-related substances: Prevalence and drug concentrations in postmortem biological specimens at the Miami-Dade Medical Examiner Department.

Since 2014, the Miami-Dade Medical Examiner Department (MDME) has observed a drastic increase in the number of fentanyl and fentanyl analog (fentanyl-related substances (FRSs)) fatalities since its introduction into the heroin and cocaine supply. Due to the prevalence of FRS in Miami-Dade County, the MDME toxicology laboratory began documenting each case in which fentanyl and/or a fentanyl analog was identified. Additional information monitored included demographics (age, race and sex), other drugs identified, cause of death (COD) and manner of death (MOD). From 2014 to 2022, the MDME toxicology laboratory analyzed a total of 1,989 cases that tested positive for FRS, of which 1,707 had detectable and/or quantifiable fentanyl concentrations in postmortem cases. The majority of decedents were white males (62%), and the predominant age range was 25-34 years. The most prevalent MOD was accident (93%) with the most common COD listed as acute combined drug toxicity of fentanyl in combination with other drugs (79%). Other drugs found in combination with fentanyl included heroin, cocaine (most prevalent), synthetic cathinones and ethanol. Of all FRS cases, 9% (170 cases) involved fentanyl alone as a COD, while 2% (38 cases) included only fentanyl analogs. Fentanyl concentrations ranged from 1.0 to 1,646 ng/mL in peripheral blood, 1.2 to 449 ng/mL in central blood, 3.2 to 28 ng/mL in donor blood (obtained during tissue harvesting), 1.1 to 108 ng/mL in antemortem blood, 8.5 to 1,130 ng/g in liver and 2.0 to 471 ng/g in brain. Drug concentrations were also reported for an additional eight fentanyl analogs. Considering the prevalence, high potency and constant evolution of FRS, it is important to continuously monitor trends and report drug concentrations in complex medical examiner casework in an effort to educate pathologists, law enforcement and local governments.

Prevalence of xylazine in overdose cases: An analysis of Miami-Dade County medical examiner case data.

Xylazine sedative, muscle relaxant, and analgesic used in a veterinary setting. Although xylazine was never approved for therapeutic use in humans, it has become popular in the street drug market as a cutting or bulking agent in the fentanyl and heroin supply. Recently, there has been a significant increase in the detection of xylazine in postmortem forensic toxicology casework. Xylazine can be identified during routine toxicology screening utilizing instrumentation such as gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. Using the Miami-Dade Medical Examiner's LIMS system, all cases received between 2015 and 2022 in which xylazine was reported were reviewed. The cases studied include accidental drug overdose deaths in Miami-Dade County as well as Collier County (Naples), Florida. In total, there are 170 cases; the majority are accidental polydrug overdoses involving White males between the ages of 25 and 44 years old. Of the 170 cases, 37% listed xylazine as the cause of death. 13% of cases contained only xylazine and fentanyl while the remaining 87% of deaths were attributed to polydrug toxicity involving two or more substances. The prevalence of xylazine can be attributed to its increasing popularity rather than an increase in caseload. In 2019, xylazine was present in only 4% of all accidental fentanyl overdoses. By 2021, this percentage has increased sixfold, with xylazine present in 24% of all accidental fentanyl overdoses. Despite a decrease in fentanyl overdoses in 2022, the percentage of xylazine detection remained the same.