Xylazine, commonly referred to as “Tranq” or “Zombie Drug” is a non-opiate sedative and analgesic which was developed as a tranquilizer for veterinary use. Decades later, it has become popular for human use in the illicit drug market. Drug dealers use xylazine to cut their dope in order to extend the high of their product. As the dealers enjoy their higher profit margins, users continue to experience horrible wound infections and an increasing rate of overdose.
History
Discovered in 1962 by researchers at the German pharmaceutical company Farbenfabriken Bayer AG, xylazine was initially investigated for its antihypertensive properties¹.
However, due to its excessive and life-threatening effects in human subjects, it was not approved for human use¹. Instead, xylazine was adapted for veterinary medicine, where it serves as a sedative, analgesic, and muscle relaxant¹. Its use in animals was first reported in the late 1960s¹.
Is Xylazine Legal Or Illegal?
Xylazine is approved exclusively for veterinary use and is not legal for human consumption².
In the United States, it is not classified as a controlled substance but is regulated by the Food and Drug Administration (FDA) for veterinary applications². Its detection in illicit drug supplies has raised concerns, leading to increased monitoring and regulatory scrutiny².
Internationally, the legal status varies, with some countries imposing strict regulations due to its potential for misuse².
Appearance and Odor
In its pure form, xylazine hydrochloride appears as a white to off-white crystalline powder. It is odorless and has a bitter taste. When being used for veterinary use, it is found in liquid form either in vials or pre-loaded syringes. When included as an adulterant in illicit drug mixtures, its appearance may vary, often being indistinguishable from other powdered substances.
How Is Xylazine Made?
Xylazine is synthesized through a chemical process involving the reaction of 2,6-dimethylaniline with thiophosgene, followed by cyclization to form the thiazine ring³.
This process requires specialized chemical knowledge and equipment, typically available in pharmaceutical manufacturing settings³. Due to the complexity of its synthesis, xylazine is not commonly produced illicitly but is diverted from legitimate veterinary sources³.
Pharmacokinetics
Xylazine is rapidly absorbed following administration, with effects typically manifesting within minutes⁴.
It is metabolized primarily in the liver and excreted through the kidneys⁴.
Studies have shown its metabolites are detectable in blood and urine samples, with the parent compound having a relatively short half-life⁴. The exact pharmacokinetic parameters can vary depending on the route of administration⁴.
Pharmacodynamics
As an α₂-adrenergic receptor agonist, xylazine inhibits the release of norepinephrine and dopamine in the central nervous system, leading to sedation, analgesia, and muscle relaxation⁵. Its action on these receptors results in decreased sympathetic outflow, contributing to its hypotensive effects⁵.
Additionally, xylazine has been reported to activate κ-opioid receptors, which may further contribute to its analgesic properties⁵.
Routes of Administration
In veterinary practice, xylazine is commonly administered via intramuscular, intravenous, or subcutaneous injection⁶. The chosen route depends on the desired onset and duration of action, as well as the species being treated⁶.
In cases of human misuse, xylazine has been reported to be injected intravenously, often in combination with other substances such as opioids⁶.
Effects
In animals, xylazine produces sedation, analgesia, and muscle relaxation, facilitating surgical and diagnostic procedures⁶.
In humans, unintended exposure or misuse can lead to central nervous system depression, respiratory depression, bradycardia, hypotension, and hyperglycemia⁶. Chronic misuse may result in severe health complications, including skin ulcers and abscesses at injection sites⁶.
Why Does Xylazine Cause Infections?
A high prevalence of abscesses and painful skin ulcers are known to develop on the body due to xylazine use. This is thought to be caused by its vasoconstricting effect on local blood vessels, hypotension, bradycardia, and respiratory depression. This decrease in skin perfusion leads to lower tissue oxygenation and eventually severe soft tissue infections, abscesses, cellulitis, and skin ulceration. It also leads to impaired healing of wounds and a higher chance of infection of these ulcers16.
These serious skin conditions can appear zombie like, though less exaggerated than those in Hollywood. Nevertheless, this is why xylazine has become nicknamed the “Zombie Drug”
Speed of Onset
Xylazine’s onset of action varies depending on the route of administration.
When administered intravenously, the effects are typically observed within minutes, reaching peak sedation rapidly⁷.
Intramuscular injection produces a slightly slower onset, usually within 10 to 15 minutes⁷.
These rapid effects contribute to its popularity in veterinary anesthesia but also to its potential for misuse in humans seeking immediate sedative effects.
How Long Does It Last?
The duration of xylazine’s effects depends on the dose and route of administration.
In animals, sedative effects can last from 1 to 4 hours⁸.
In humans, the duration is less predictable due to the unregulated nature of misuse, but it generally lasts between 2 to 6 hours⁸.
The depressant effects, including respiratory depression and hypotension can pose significant health risks⁸.
How Long Does Xylazine Stay In Your System?
Xylazine is not routinely included in standard drug panels but can be detected using advanced analytical methods such as gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS)⁹.
In blood, xylazine can be detected within hours of administration. Urine tests may identify metabolites for up to 2 days⁹.
Due to its increasing misuse, some forensic laboratories have begun including xylazine in expanded toxicology panels⁹.
Supply Chain, Precursors, Sources, and Locations
Xylazine is legally manufactured for veterinary use and is primarily sourced from pharmaceutical companies in countries like China and Mexico¹⁰. However, it is frequently diverted into the illicit drug market.
In the U.S., it is commonly found as an adulterant in opioids like fentanyl and heroin¹⁰. Its widespread availability and low cost contribute to its use as a cutting agent to enhance the potency and duration of opioid effects¹⁰.
There are test strips available that can detect whether a batch of dope has been cut with xylazine. It works by dipping a test strip into a sample of water that has been mixed with a small amount of drug residue. Typically, 2 lines mean it’s negative and 1 line means positive.
Street Prices
Xylazine is typically sold as an adulterant rather than a standalone drug. Street prices vary based on location and purity. Xylazine powder can be bought for $6 – $20 per kilo from online Chinese suppliers. Its low cost compared to other sedatives makes it an attractive option for dealers seeking to maximize profit margins.
How Much Is a Typical Dose?
There is no standardized dose for xylazine in humans, as it is generally consumed unknowingly as an adulterant in opioids.
In veterinary settings, doses are calculated based on the animal’s weight, whereas recreational users lack dosing control, putting them at risk of overdose and adverse reactions¹².
User Demographics and Statistics
Xylazine misuse is most prevalent in the Northeastern United States, particularly among individuals with opioid use disorder¹³.
Studies show that it is disproportionately affecting marginalized populations in urban areas such as Philadelphia and Baltimore¹³.
According to the CDC, xylazine was involved in nearly 31% of fentanyl-related overdose deaths in Philadelphia in 2019¹³.
Feedback on User Satisfaction and Experiences
User experiences with xylazine are mixed.
Some report enhanced euphoria when combined with opioids, while others experience severe adverse effects such as memory loss, confusion, and painful skin ulcers at injection sites¹⁴.
The unpredictability of its effects and the severity of side effects contribute to overall negative user experiences¹⁴.
Comparison to Similar Drugs
Xylazine is often compared to other central nervous system depressants and sedatives such as clonidine and dexmedetomidine due to its mechanism as an α₂-adrenergic agonist¹⁵.
Unlike opioids, it does not respond to naloxone, complicating overdose treatment¹⁵. Its sedative effects are more potent than many benzodiazepines, contributing to its high risk of respiratory depression¹⁵.
Conclusion
Xylazine, has emerged as a dangerous adulterant in the illicit drug market, particularly in the U.S. Its potent CNS effects, rapid onset, and unpredictable duration pose significant public health risks. Unlike opioids, xylazine is not reversible with naloxone, increasing the fatality rate in overdose cases. The growing prevalence of xylazine-laced opioids underscores the need for enhanced drug monitoring, regulation, and public health interventions. Continued research is crucial to understand its pharmacological impact, epidemiology, and strategies for effective prevention and treatment.
References
- U.S. Centers for Disease Control and Prevention. (2022). “Notes from the Field: Xylazine Detection and Involvement in Drug Overdose Deaths — United States, 2019.” Retrieved from https://www.cdc.gov/mmwr/volumes/70/wr/mm7037a5.htm
- National Institute on Drug Abuse. (2023). “Xylazine: What You Need to Know.” Retrieved from https://nida.nih.gov/research-topics/xylazine
- Substance Abuse and Mental Health Services Administration (SAMHSA). (2023). “Emerging Drug Trends: Xylazine.” Retrieved from https://www.samhsa.gov/resource/emerging-trends/xylazine
- Journal of Analytical Toxicology. (2020). “Xylazine Involvement in Drug Overdose Deaths in Philadelphia.” Retrieved from https://academic.oup.com/jat/article/44/6/484/5890544
- U.S. Drug Enforcement Administration (DEA). (2023). “Xylazine: An Emerging Threat.” Retrieved from https://www.dea.gov/documents/2023/2023-06-22/xylazine-emerging-threat
- National Center for Biotechnology Information (NCBI). (2023). “Pharmacology of Xylazine.” Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK594271/
- U.S. Food and Drug Administration (FDA). (2023). “Xylazine Information for Veterinarians.” Retrieved from https://www.fda.gov/animal-veterinary/product-safety-information/xylazine-information
- National Institute on Drug Abuse. (2023). “Xylazine: What You Need to Know.” Retrieved from https://nida.nih.gov/research-topics/xylazine
- Journal of Analytical Toxicology. (2021). “Analytical Detection of Xylazine in Drug Mixtures.” Retrieved from https://academic.oup.com/jat/article/45/7/760/6324712
- U.S. Drug Enforcement Administration (DEA). (2023). “Xylazine: An Emerging Threat.” Retrieved from https://www.dea.gov/documents/2023/2023-06-22/xylazine-emerging-threat
- Substance Abuse and Mental Health Services Administration (SAMHSA). (2023). “Emerging Drug Trends: Xylazine.” Retrieved from https://www.samhsa.gov/resource/emerging-trends/xylazine
- National Center for Biotechnology Information (NCBI). (2023). “Pharmacology of Xylazine.” Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK594271/
- U.S. Centers for Disease Control and Prevention (CDC). (2022). “Xylazine Detection and Involvement in Overdose Deaths.” Retrieved from https://www.cdc.gov/mmwr/volumes/70/wr/mm7037a5.htm
- Harm Reduction Journal. (2022). “User Experiences and Harms Associated with Xylazine Use.” Retrieved from https://harmreductionjournal.biomedcentral.com/articles/10.1186/s12954-022-00617-8
- European Journal of Pharmacology. (2023). “Comparative Pharmacology of Xylazine and Similar Sedatives.” Retrieved from https://www.sciencedirect.com/science/article/pii/S0014299923001234
- National Center for Biotechnology Information (NCBI). (2022). “Xylazine-Induced Skin Ulcers in a Person Who Injects Drugs in Philadelphia, Pennsylvania, USA.” Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC9482722/#:~:text=Thus%2C%20chronic%20use%20of%20xylazine,of%20these%20ulcers%20%5B15%5D.
- U.S. Drug Enforcement Administration (DEA). (2022). “The Growing Threat of Xylazine and its Mixture with Illicit DrugsAn Emerging Threat.” Retrieved from https://www.dea.gov/sites/default/files/2022-12/The%20Growing%20Threat%20of%20Xylazine%20and%20its%20Mixture%20with%20Illicit%20Drugs.pdf
