Drug Checking

What we are doing

Drug checking is a process that has been around in North America for decades. Drug checking identifies specific substances contained in drug samples and provides information directly back to the user. When people who use drugs (PWUD) know what substances are in their drugs, they can make informed decisions to reduce overdose risk and prevent other adverse reactions.

Our team is assisting the North Carolina Survivors Union to implement drug user-led drug checking services in North Carolina using a technique called Fourier-transform infrared spectroscopy (FTIR). FTIR machines use infrared radiation to generate a spectrum of a drug sample, allowing an analysis of what substances are present. Each sample usually takes about 15-20 minutes to run and analyze.

Another type of drug checking technology is fentanyl test strips (FTS), which is an inexpensive test that shows whether or not fentanyl is in a sample. In comparison, FTIR provides information on wide range of drugs, adulterants, and contaminants. Still, FTS are very useful. A study based in North Carolina found 43% of participants willing to use FTS and change drug use behavior following test results. Studies have shown drug checking does not lead to riskier use, but rather encourages safer practices, similar to distribution of naloxone. We expect that users will respond similarly when provided with information generated from the FTIR technique. In 2019, North Carolina enacted legislation to support drug checking.

For samples that have suspicious or unclear composition, a gas chromatography mass spectrometer (GC-MS) will be used to identify major and minor components. A Thermo Exactive GC (NIH: R35GM118055) will be used for analysis. This instrument is unique in that it provides gas chromatography separations as well as high resolution/accurate mass measurements. This allows chemical formula confirmation of opioids, byproducts, and fillers in the samples. This platform will allow for a more sensitive analysis with concrete identification of sample components. An opioid polysubstance kit supplied by Cerilliant in partnership with the CDC will be used to develop an in-house spectral library of common opioids, ensuring the most confident identifications possible.

How to use the results

Being able to get more specific information about the contents of drug batches will help people who use drugs to understand their overdose risk, as well as for other risks like abscesses or unexpected pharmacokinetic reactions. Drug checking data can also be used to help determine trends in the unregulated drug supply.

In February 2021, the drug checking group detected a substance called xylazine. This substance was found alongside heroin, fentanyl, and some sugars (a common filler). Xylazine is a veterinary tranquilizer that causes central nervous system depression. While it was assessed for human use by the FDA several decades ago, it was ultimately not approved for human use. People who inject xylazine may experience unexpected symptoms, including a slowed pulse, slowed breathing, low blood pressure, and excessive fatigue. Xylazine has also been linked to skin ulceration among people who inject xylazine. Skin ulcers may require medical care. In order to inform our community about xylazine, we developed a flyer containing background information and tips.

A Twitter thread about the history of xylazine can be found here.

FTIR drug checking has important limitations. FTIR machines provides information on what substances are in a sample, but not how much of those substances. The GC-MS analysis provides confirmatory testing for samples run through the FTIR. Because the machine does not provide information about potency, we are not offering quality control of the unregulated market. Instead, drug checking will inform users about the content of their product to enable them to make educated use decisions to prevent morbidity and mortality.

Who is conducting and supporting the project

This effort is being led by the North Carolina Survivors Union (NCSU) with assistance from the University of North Carolina Injury Prevention Research Center. NCSU is a self-support group of people with lived experience of drug use, operating within a drop-in center and harm reduction program in Greensboro, North Carolina.

The Mass Spectrometry Core Laboratory located in the Chemistry Department at the University of North Carolina at Chapel Hill (UNC-CH) will be conducting the mass spectrometry analysis.  The Mass Spectrometry Core enables innovative research at UNC-CH by providing equipment, expertise and training in small molecule applications utilizing mass spectrometry in an open-access facility. The Core is led by Dr. Brandie Ehrmann who has 15+ years of mass spectrometry and analytical chemistry experience. She is assisted by Diane Weatherspoon who holds a MS in chemistry and 5+ years of mass spectrometry and analytical chemistry experience.