Increase in fentanyl -- responsible for 44 percent of New York City overdose deaths -- has led to apprehension and caution

The findings, published in the International Journal of Drug Policy, demonstrate a high level of understanding among people who use drugs regarding ways to prevent an overdose and some adoption of these methods, but the researchers assert that more needs to be done to prevent overdoses.

Fentanyl, a category of synthetic opioids that is 50 to 100 times more potent than morphine, is increasingly being added to heroin in the United States. Between 2015 and 2016, the number of illicit drug seizures by the Drug Enforcement Administration that contained fentanyl increased by 694 percent.

People who use heroin or other illicit drugs are often unaware that their drugs are being "cut" or mixed with fentanyl; as a result, the use of heroin and other drugs containing fentanyl has been linked to sharp increases in opioid mortality.

Prior to 2015, fentanyl accounted for less than 3 percent of New York City overdose deaths annually; in 2016, fentanyl accounted for 44 percent of overdose deaths. Further, while the majority of overdose deaths involving fentanyl in New York City were mixed with heroin (61 percent) in 2016, 37 percent were a combination of cocaine and fentanyl (without heroin), an increase from just 11 percent in 2015. Further, recent drug seizure data indicate that, in addition to heroin and cocaine, fentanyl has been detected as an additive in methamphetamine, ketamine, and counterfeit opioid analgesics and benzodiazepines. This suggests that fentanyl may be reaching individuals who are opioid naïve, which could further increase overdose risk.

In this study, the researchers conducted in-depth interviews with 55 people who use drugs at three New York City syringe exchange programs. The researchers asked about drug use, perceptions of fentanyl, overdose experiences, and whether they have adapted their drug-using practices in response to the increased prevalence of fentanyl.

Study participants reported apprehension about the potency of fentanyl and the need to use drugs more cautiously in case they contain fentanyl. As a result, many people who use drugs reported using a variety of harm reduction strategies to prevent overdose, including test shots, buying drugs from a consistent source, reducing drug use, using fentanyl test strips, carrying naloxone (a medication used to reverse opioid overdoses), and using drugs in the presence of others.

The most common behavioral change reported was doing a test shot, or injecting a small amount of a drug to gauge its strength. A handful of people reported using test shots every time they injected, whereas others only used them if something about their drugs looked different or if they were warned that their heroin was new or potent.

Some participants reported using fentanyl test trips, a relatively new opioid overdose prevention approach, although the number of programs currently distributing fentanyl test strips is limited.

Some people reported using drugs in the company of others to prevent overdose, while others said they still preferred to use alone. Regardless, for most people who use drugs, their living situation often dictates where they use -- for instance, whether they have stable housing, or are homeless and/or live in a shelter.

Experience with naloxone was widespread among people in the study. Over two-thirds reported carrying naloxone with them at least half of the time and several people reported being revived with it or using it on others. However, some people reported difficulty carrying naloxone due to judgment from others or homeless shelter policies that prohibit certain forms of naloxone.

"While nearly all study participants were knowledgeable about minimizing their risk for overdose and many reported using methods to reduce their risk, most were not consistent in applying these methods," said CDUHR researcher Courtney McKnight, DrPH, clinical assistant professor at NYU College of Global Public Health and the study's lead author. "Using methods to reduce the risk of overdose was often complicated by structural factors such as stigma, poverty, and homelessness, which were further complicated by dependence and the increased prevalence of fentanyl."

Given that an estimated 100,000 people inject drugs in New York City, the researchers note that no single intervention is likely to reverse the persistent increase in mortality from drug overdoses. However, they stress the importance of employing all evidence-based methods to reduce mortality, including increasing access to medication-assisted treatment and increasing naloxone distribution.

"Supervised injection sites, like those New York City plans to open, are another method that can prevent overdose deaths. These sites provide a medically supervised space with readily available naloxone, sterile injecting equipment, and safe disposal of used syringes, as well as increased access to health education services and substance use treatment," said study co-author Don C. Des Jarlais, PhD, associate director of CDUHR's infectious disease epidemiology and theory core and professor of epidemiology at NYU College of Global Public Health.

"Like other interventions to decrease opioid mortality, supervised injection sites alone will not provide a magic bullet, but may help to address some of the structural factors that could increase the risk of overdose deaths."

The research was supported by the National Institute on Drug Abuse (grants P30DA011041 and 5R01DA003574-34) as well as a pilot project award from CDUHR.