Toxic effects of xylazine on endothelial cells in combination with cocaine and 6-monoacetylmorphine

Necrotic Upper-Extremity Infections in People Who Inject Drugs: A Case Series

PURPOSE

Our institution has noted an increase in severe upper-extremity infections within the last 2 years. These patients have required transhumeral amputation. This case series demonstrates some of the catastrophic outcomes of these infections in people who inject drugs, which has been postulated to be related to the addition of xylazine to injectable drugs in our community.

METHODS

The study included patients presenting with severe upper-extremity infections resulting from intravenous drug use and requiring upper-extremity amputation between January 1, 2020 and September 30, 2022 at a single, urban, level 1 trauma center. Patient information and clinical images were collected through retrospective chart review.

RESULTS

Eight patients were identified at our institution with extensive necrosis of the skin and soft tissues in the forearm and hand, resulting in exposure of the radius and ulna. None of these patients had viable motor function in the hand and presented with a lack of sensation. All underwent transhumeral amputations, including bilaterally in one case.

CONCLUSIONS

The patients in this case series self-reported injection of tranquilizer-containing drugs, and xylazine has been reported to be present in 91% of heroin and fentanyl samples in our community. Although more studies are needed to confirm that xylazine is the definitive cause of the extensive tissue necrosis seen in these patients, we have found the severity of these infections to be noteworthy, given the likely expansion of xylazine to drug samples beyond our region.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Xylazine Adulteration of the Heroin-Fentanyl Drug Supply : A Narrative Review

Xylazine is an animal sedative, approved by the U.S. Food and Drug Administration, that is commonly used in veterinary medicine and is not approved for human use. Since 2016, xylazine has consistently appeared in the illicitly manufactured fentanyl supply and has significantly increased in prevalence, likely due to its low cost, easy availability, and presumed synergistic psychoactive effect. Clinical experience along with the available pertinent research were used to review xylazine adulteration of the drug supply and provide guidance on the care of patients exposed to xylazine. This review discusses xylazine pharmacology, animal and human clinical effects, and what is known to date about care of patients experiencing acute overdose, xylazine-fentanyl withdrawal, and xylazine-associated wounds.

Nanocoral-like Polyaniline-Modified Graphene-Based Electrochemical Paper-Based Analytical Device for a Portable Electrochemical Sensor for Xylazine Detection

A portable electrochemical device for xylazine detection is presented for the first time. An electrochemical paper-based analytical device (ePAD) was integrated with a smartphone. The fabrication of the ePAD involved wax printing, low-tack transfer tape, and cutting and screen-printing techniques. Graphene ink was coated on the substrate and modified with nanocoral-like polyaniline, providing an electron transfer medium with a larger effective surface area that promoted charge transfer. The conductive ink on the ePAD presented a thickness of 25.0 ± 0.9 μm for an effective surface area of 0.374 cm². This sensor was then tested directly on xylazine using differential pulse voltammetry. Two linear responses were obtained: from 0.2 to 5 μg mL^-1 and from 5 to 100 μg mL^-1. The detection limit was 0.06 μg mL^-1. Reproducibility was tested on 10 preparations. The relative standard deviation was less than 5%. The applicability of the sensor was evaluated with beverage samples spiked with trace xylazine. Recoveries ranged from 84 ± 4 to 105 ± 2%. The developed sensor demonstrated excellent accuracy in the detection of trace xylazine. It would be possible to develop the portable system to detect various illicit drugs to aid forensic investigations.

Xylazine as a drug of abuse and its effects on the generation of reactive species and DNA damage on human umbilical vein endothelial cells

Human xylazine (XYL) abuse among addicts has received great interest due to its potential toxic effects upon addicts and the need to understand the mechanism of action associated with the potential health effects. XYL is an alpha-2 agonist restricted to veterinarian applications, without human medical applications. Our previous work demonstrated that XYL and its combination with cocaine (COC) and/or 6-monoacetylmorphine (6-MAM) induce cell death through an apoptotic mechanism. The aim of this study was to determine the effect of xylazine on the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) as well as DNA damage on endothelial cell. Human umbilical vein endothelial cells (HUVEC) were treated with XYL (60 μM), COC (160 μM), 6-MAM (160 μM), camptothecin (positive control, 50 μM), XYL/COC (50 μM), XYL/6-MAM (50 μM), and XYL/COC/6-MAM (40 μM) for a period of 24 hours. Generation of intracellular ROS, RNS, and DNA fragmentation were analyzed using a fluorometric assay. Results reveal that XYL and 6-MAM increase levels of ROS; no induction of RNS production was observed. The combination of these drugs shows significant increase in DNA fragmentation in G2/M phase, while XYL, COC, and 6-MAM, without combination, present higher DNA fragmentation in G0/G1 phase. These findings support that these drugs and their combination alter important biochemical events aligned with an apoptotic mechanism of action in HUVEC.