Illicit drug users seem to overwhelmingly appreciate being able to use take-home test strips to detect the extremely common presence of dangerous fentanyl in opioids and other drugs, a new study finds. More than 95% said they’d use the inexpensive strips again.
said study lead author addiction medicine specialist Sukhpreet Klaire, MD, of the British Columbia Center on Substance Use in Vancouver, in an interview.
Dr. Klaire presented the study findings at the virtual annual meeting of the College on Problems of Drug Dependence.
Researchers in Vancouver distributed take-home fentanyl test strip kits at 10 sites that allow users to test their illicit drugs. The 218 participants performed 1,680 tests, mainly (73%) for opioids, over 3 months in 2019. Of the participants, 61% were male, and the average age was 36 (interquartile range, 29-47). About 30% described themselves as indigenous Canadians (First Nations).
About 90% of the opioid samples tested at home were positive for fentanyl, about the same level as samples tested at clinics. Fentanyl is very potent and linked to the huge rise in overdose deaths in the United States.
Fentanyl test strips aren’t new. According to the Harm Reduction Coalition, they originally were developed to detect fentanyl in urine samples but were jury-rigged in Vancouver to work on samples of illicit drugs. “We literally just repurposed it,” Dr. Klaire said. “It’s the same strip.”
Users test their drugs by dissolving a small sample in water. Then then dip the test strip, which provides readings similar to those in a pregnancy test. If a sample turns up positive for fentanyl, Dr. Klaire said, users may discard the drug or “be more careful with it.”
When asked what they would do if a sample turned up positive, 27% said they’d make a “positive change,” such as using less or using more slowly (n = 45) or making sure that someone else is present in case of an overdose (n = 26). But most, 71%, reported no change in behavior.
Previously, researchers in Rhode Island and North Carolina also found that some users adopted safer behaviors – such as throwing out their drugs or using less often – after testing their drugs with the strips.
The strips cost about 75 cents, Dr. Klaire said.
Harm-reduction strategies are controversial, and fentanyl test strips aren’t any exemption. “The entire approach is based on the premise that a drug user poised to use a drug is making rational choices, is weighing pros and cons, and is thinking completely logically about his or her drug use. Based on my clinical experience, I know this could not be further from the truth,” wrote Elinore F. McCance-Katz, MD, PhD, assistant secretary for Mental Health and Substance Use with the Department of Health & Human Services, in a 2018 blog post.
But Dr. Klaire said the patients in the new study are highly dependent on opioids. “The drug supply is heavily contaminated [with fentanyl],” he said, “but even when people know it’s contaminated, they still need to go ahead and use it.”
In an interview, epidemiologist Brandon Marshall, PhD, of Brown University, Providence, R.I., who has conducted fentanyl test strip research, called the study results “compelling.”
“The researchers found that the fentanyl test strips had a very high level of acceptability – over 95% said they would use the strips again – which is remarkably similar to what we found in our work here in Rhode Island,” he said. “Taken together, these studies show that take-home test strips are a feasible, acceptable, and effective strategy for people who use drugs to reduce their risk of fentanyl overdose.”
He added that “fentanyl test strips help people make more informed decisions about their drug use and reducing their risk of overdose.”
However, he said, “one of important limitations of the strips is that they do not detect all contaminants that put persons at risk of overdose. Just because a test result is negative does not mean that the drug is 100% safe.”
Kimberly Sue, MD, PhD, medical director of the National Harm Reduction Coalition, said in an interview that the research is “important,” but noted that many drug users already have been using fentanyl test strips on their own. “We should be focusing on investing in variety of other interventions that could keep more people safe against nonfatal and fatal opioid overdoses, including structural interventions such as safe supply, housing and community with appropriate supports, low barrier access to medication for opioid use disorder, and safe consumption spaces,” she said.
No study funding was reported. Dr. Klaire disclosed participating in a research fellowship and a research in addiction medical scholars program, both funded by the National Institute of Drug Abuse. Dr. Sue reported no relevant disclosures. Dr. Marshall reported that he has collaborated frequently with one of the coauthors of the Vancouver study.