Philadelphia has a “zombie drug” problem, and experts are concerned it is going to start rapidly spreading to other parts of the U.S.—just as the drug infiltrated the City of Brotherly Love from Puerto Rico about 5 years ago.
Xylazine is a non-opioid sedative, painkiller and muscle relaxant that is used in veterinary medicine. It can dangerously lower blood pressure, heart rate and breathing. It has also been linked to open skin ulcers.
Xylazine first became popular in Puerto Rico in the early 2000s, where the media dubbed it the “zombie drug” thanks to its heavy sedation effects. Now, it is appearing in illicit drug supplies across the U.S. at an alarming rate. Philadelphia, specifically, has seen it’s fair share—according to a new study, the vet tranquilizer is now implicated in 1/3 of fatal overdoses involving heroin and/or fentanyl in the city.
While not approved by the FDA for human use, xylazine by itself is nowhere near as deadly as fentanyl or other strong opioids. However, the combination of xylazine and heroin or fentanyl appears to be very dangerous.
The authors of the study, published in Injury Prevention, examined records from the Philadelphia Medical Examiner’s Office from 2010 to 2019. According to the data, between 2010 and 2015, xylazine was detected in just 2% of unintentional overdose deaths in which heroin and/or fentanyl also featured. But in the last five years, that figure has risen steadily. In 2016, xylazine was detected in 11% of overdose deaths; 10% in 2017; 18% in 2018; and 31% in 2019. That’s an increase of 2 % from 2015 to 2019—from 40 unintentional overdose deaths to 262.
“Harms of xylazine use in humans are not well documented, but evidence suggests that combined use of xylazine and an opioid such as fentanyl may increase the risk of overdose fatality,” write the study authors.
Indeed, seizure records and data from the Drug Enforcement Administration show that xylazine is increasingly appearing in polydrug samples, alongside heroin, fentanyl and cocaine. Between 2010 and 2013, no polydrug seizures contained xylazine. But that number jumped to 5% in 2015, 9% in 2017 and 25% in 2019.
“Some evidence suggests the combination of and fentanyl in humans may potentiate the desired effect of sedation and the adverse effects of respiratory depression, bradycardia and hypotension caused by fentanyl alone, comparable to the synergistic effects of combining benzodiazepines with heroin and/or fentanyl,” the authors explain.
In fact, there has been a decrease in the use of benzodiazepines since 2010 in Philadelphia, a decline the study authors attribute at least partially to an increasing demand for xylazine instead.
There are mixed reports as to the effectiveness of naloxone (Narcan) for preventing overdose deaths associated with xylazine. While the drug itself is not an opioid, it is often mixed with one, potentially leaving the door open for treatment with Narcan. In an October 2020 alert, the Center for Forensic Science Research & Education (CFSRE) suggested treating xylazine toxicity with multiple doses of naloxone over 4 to 8 hours. Intubation, ventilation and IV fluids are also recommended.
Both the study authors and the CFSRE recommend including xylazine in routine toxicology testing going forward. The center also suggests forensic toxicologists consider analyzing all seized drug samples taken from suspected drug overdose investigations in the hopes of providing more information that can lead to better tracking and understanding of xylazine.
Photo credit: CFSRE