Dr. Francisco R. Velázquez: Xylazine is here: Why you need to know about it

The latest threat to public health and public safety is a veterinary sedative, xylazine. Also known as “tranq,” it is increasingly present in illicit drug supplies and connected to overdoses across the county, including here in Washington.

On June 30, 2023, the Centers for Disease Control and Prevention released the analysis of data collected from 2019 to 2022 showing a 276% increase in drug-related deaths where xylazine was involved. The monthly percentage of illicitly manufactured fentanyl drug products where xylazine was detected increased from 2.9% in January 2018 to 10.9% in June 2022.

According to the Drug Enforcement Agency’s laboratory system, in 2022, approximately 23% of fentanyl powder and 7% of fentanyl pills seized by the DEA in the United States contained xylazine. What is xylazine? Certainly not a new drug, but a commonly used, nonopioid veterinary sedative, analgesic, and relaxant. It was initially developed in 1962 as a potential antihypertensive agent that when tested had excessive central nervous system depressant effects. Because of these side effects, it was repurposed for veterinary use.

Xylazine was first identified as an illegal drug additive in Puerto Rico in 2001. When mixed with other drugs, it was referred to as “speed ball.” It was later identified in Philadelphia in 2006, which many consider the epicenter of the xylazine impact. In 2021, Philadelphia reported nearly 1,300 unintentional overdose deaths; one third involved xylazine. More recently, we have seen a dramatic increase in its use as a co-occurring drug – initially in the Northeast and East Coast – widely distributed across the country.

In Washington, we know xylazine is here. The Forensic Laboratory Services Bureau has identified its presence in drug samples submitted to the Washington State Patrol’s Crime Lab. In the first quarter of 2023, xylazine was detected in multiple counties, including Spokane. And, according to the Washington State Department of Health, there were seven overdose deaths in 2022 that involved xylazine.

Although these numbers are not yet at the levels seen on the East Coast, it gives us an indication that now is the time to take notice and educate our community on how dangerous xylazine can be before these numbers increase.

Why is it more frequently seen now? There are several theories. One is that its availability and relatively low cost have made it an attractive “cutting” drug for illicit drug manufacturing. The drug’s sedative effect allows for lower doses of more expensive drugs such as fentanyl or heroin to be used while still experiencing similar effects.

Additionally, there is some evidence that xylazine can prolong the effects – or the “high” – of faster acting drugs such as heroin and fentanyl, which makes it more attractive to some users. Because of these enhanced effects there is a paradoxical need for continued use to prevent the harsh symptoms of withdrawal, which continue even if the opioid withdrawal effects are contained.

Its many street names – tranq, tranq dope, sleep-cut, Philly dope and zombie drug – are well earned due to its lethal potential. Published literature demonstrates that xylazine can produce toxic effects, including lethal, over a wide range of concentrations. Because of the significant overlap between fatal and nonfatal blood concentrations identified, no defined safe or fatal concentration can be determined. This makes it more difficult to ascertain the potential for medical management of suspected overdoses. Rapid metabolism in the body may lead to quick onset of toxic effects that can potentially overwhelm the body’s ability to recover. And because xylazine is not an opioid, use of naloxone will not effectively reverse a potential overdose.

In addition to the effects on the central nervous system, the drug is also known to cause extensive and profound tissue injuries. The user can have skin ulcers, soft tissue damage and necrosis. Some of the wounds have been described as extensive chemical burns. These lesions can be very deep, exposing bones and tendons surrounded by blackened dead tissue, sometimes described as “rotting skin” – thus the monicker of “zombie drug.” Some wounds are so severe that amputation is necessary.

The reason for the skin lesions is not completely understood. These can be found in areas distant from the injection site and have been described in people who smoke the drug as opposed to injecting it. One of the theories proposed to explain skin lesions is the vasoconstrictive effect of the drug. By constricting the blood vessels, blood is unable to provide nutrients and remove cellular waste, which could lead to tissue damage and death. Chronic use can impair the wound-healing process leading to deep ulcerations.

Xylazine powder can be white like fentanyl as well as several other colors such as pink or purple, making it difficult for a person to identify just by its appearance. There are test strips that can detect the drug’s presence in a compound, but they are not as widely available as fentanyl strips.

Like with opiates, the signs and symptoms of xylazine toxicity include decreased respiration, low blood pressure and a slow heart rate. Initial administration of naloxone is still recommended, as it may reverse the effects of other drugs present. According to reports from emergency departments in the East Coast, patients need to be monitored longer than with an opioid overdose. Naloxone may revive the patient but given xylazine’s prolonged effect, the patient’s symptoms can reoccur. Currently there is no medication approved by the Food and Drug Administration that can manage xylazine withdrawal in symptomatic individuals.

Awareness, education and information are our most important prevention tools at this point in time.

Francisco R. Velázquez, M.D., S.M., FCAP, is health officer for the Spokane Regional Health District.