Opioids
Loren Bonner
The opioid epidemic continues to evolve. In addition to seeing more overdose cases attributed to fentanyl, officials in some U.S. states have noticed a significant uptick in a new, dangerous street drug detected in fatal overdose cases. The drug is an animal tranquilizer called xylazine that is FDA approved for veterinary use only.
In Philadelphia—which is at the epicenter of the opioid epidemic—a research team found that the percentage of fatal overdose cases in the city with detectable levels of xylazine rose from 2% to 31% during a 10-year period.
“The Philadelphia Department of Public Health is working with community partners to notify [both] people who use drugs and providers that xylazine is currently the most prevalent adulterant in the illicit drug market,” said Jewell Johnson, MPH, lead author of the study that was published this year in Injury Prevention.
Researchers obtained their data from overdose death records due to heroin, fentanyl, or both from the Philadelphia Medical Examiner’s Office. According to the study results, xylazine was detected in 2% of 1,854 unintentional overdose deaths from heroin, fentanyl, or both between 2010 and 2015. The percentage was 11% in 2016 and jumped to 31% in 2019.
“Other states and jurisdictions have been reporting the increase in xylazine detections in fatal overdose cases, but their prevalence remains lower than [in] Philadelphia,” said Johnson, who is also a substance use epidemiologist for the Philadelphia Department of Public Health.
Other states reporting an increase in xylazine detection include Ohio, Connecticut, and Maryland. “Xylazine prevalence may be underreported in other states or jurisdictions if xylazine is not a part of the routine toxicology testing for overdose decedents,” Johnson said.
More doses of naloxone
Xylazine is an alpha‐2‐adrenergic agonist with analgesic and muscle-relaxing properties. It causes central nervous system depression and slows down a person’s breathing and heart rate. The drug was rejected by FDA for human use because of its significant impact on blood pressure and heart rate.
When it’s used in combination with fentanyl, according to Johnson, it creates a synergistic effect.
“Due to the sedating effects of xylazine, we are seeing that it’s taking more doses of naloxone to reverse an opioid overdose and longer for a person to awaken,” said Johnson. “Anecdotally, in the past it would require just one dose of naloxone for someone to revive, but now it’s taking several doses, which can lead to precipitated withdrawal.”
She said health care professionals and pharmacists should know that xylazine has been associated with skin and soft tissue infections.
“Sterile syringes should be made available to individuals who inject drugs to reduce the burden of disease related to xylazine,” Johnson said.
Other street drugs
Johnson and her research team are not aware of xylazine being mixed into other street drugs at this time. However, in analyzing their data from 2019, they did notice that nearly 50% of fatal overdose case reports indicated the presence of cocaine. Also in that same year, 28% of fatal overdose cases tested positive for benzodiazepines, and 12% tested positive for methamphetamine. All the 2019 cases with positive detections for xylazine also tested positive for fentanyl.
Xylazine has been a drug of abuse in Puerto Rico since the early 2000s, the researchers noted.
A growing substance use crisis
There’s no question that the COVID-19 pandemic has exacerbated the substance use crisis across the United States.
“We have seen a rise in alcohol use and the highest number of opioid-related overdose deaths in a single year across the U.S., likely attributed in part to the pandemic,” said Daniel Ventricelli, PharmD, MPH, assistant professor of clinical pharmacy with the Philadelphia College of Pharmacy at the University of the Sciences.
A study published in JAMA Network in 2020 found that alcohol consumption among adults increased by 14% during the COVID-19 pandemic from 2019 to 2020. The study found that the increase was more pronounced for women, with a 41% increase over a 2019 average baseline.
Stimulant-related deaths have also been increasing over the past few years—a trend that started long before the pandemic.
In a research letter published in February 2021 in JAMA, Black and colleagues wrote that for many stimulants, such as cocaine, methamphetamine, and amphetamine, the mortality rate doubled approximately every 4 years since 2010. Stimulants are often used in combination with opioids and other drugs.
A December 2020 CDC advisory to medical and public health professionals noted that drug overdose deaths accelerated during COVID-19.
“Put this all together, and we have a lot more than just the opioid crisis and its associated public health impacts to worry about,” said Ventricelli.