Most people are now aware of fentanyl testing strips, which were decriminalized last year in Tennessee. But with the rise of xylazine (also known as tranq) as a contaminant in the fentanyl supply, many have been asking about whether or not there are comparable testing strips for xylazine, and if these would be significantly useful in curbing overdose fatalities.
Currently, two companies manufacture and sell xylazine test strips. W.H.M.P. recently became the second distributor on the market to produce these strips, following Canadian-based BTNX. Both companies’ xylazine test strips have been cleared by the FDA for forensic and public use. However, they are not approved for clinical use by the FDA, meaning providers in emergency departments or hospitals cannot use these test strips for diagnostic or treatment reasons. Such a barrier also exists with fentanyl test strips, which still lack approval for clinical use despite widespread public availability and approval for forensic use.
There are some important concerns about the accuracy of these xylazine test strips. BTNX’s initial batches of test strips were known to cause false positives with the presence of lidocaine. W.H.P.M.’s strips also have a chance of delivering false positives due to a cross-reaction with ketamine and . In the context of the current wave of the overdose crisis, which is defined by polysubstance use (meaning multiple drugs), such interactions are important factors.
On the one hand, the number of overdoses involving both opioids and hallucinogens (like ketamine) remains small. This is relevant to xylazine because tranq is usually found contaminating the opioid supply. In Tennessee, overdose deaths involving both opioids and hallucinogens are so rare as to be nearly non-existent: the 2021 Annual Overdose Report does not even contain the words hallucinogen, psychedelic, or ketamine. Ketamine and xylazine are not likely to be used together. However, as lidocaine and levamisole are common cutting agents in cocaine, these are more likely to be an issue because stimulant overdoses are on the rise due to the increasing trend of pairing stimulants with synthetic opioids. Furthermore, one study found that cocaine was also present in over 45 percent of all deaths involving xylazine.
In early July 2023, the White House released a response plan to target fentanyl associated with xylazine. Part of this plan includes actions to standardize forensic testing practices and the need for real-time xylazine and fentanyl tests intended for clinical point-of-care testing. Such a need for rapid, accurate clinical testing is urgent, and many do not realize how limited healthcare providers are when it comes to testing for drugs in emergency settings.
In the meantime, xylazine test strips are available to be used by the general public in the same way as fentanyl test strips. However, the law that decriminalized fentanyl test strips in Tennessee only identifies equipment that tests for synthetic opioids. Being that xylazine is not a synthetic opioid, xylazine test strips may still be treated as drug paraphernalia by law enforcement.
This is not to say that xylazine testing should be neglected. Xylazine is indeed a major threat. Testing for xylazine is certainly an important forensic and public health objective, especially as deaths involving xylazine continue to grow. However, because it is still essentially always found in combination with fentanyl, and there are major accuracy and legal concerns with the existing tests, it is difficult to recommend spending a lot of money on the currently available products – at least for the present time. Due to a wider availability and the fact that they are definitively decriminalized in Tennessee, harm reduction organizations should consider prioritizing the purchase of fentanyl testing strips over these new xylazine test strips.
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Jeremy C. Kourvelas, MPH, SMART Initiative Substance Use Program Coordinator
Channie Cretsinger, MPH, SMART Initiative Program Associate