Nitazenes are a class of synthetic drugs that have gained attention in the United States and other countries in recent years. The prevalence of nitazenes in the illegal drug supply has been on the rise since 2019. Recent evidence suggests nitazenes may be more potent than fentanyl and may require a higher dose of naloxone in case of overdose. In the same study several individuals who overdosed on nitazenes were unaware that their drugs contained it.¹

Since 2019, the prevalence of NPS opioid subclass known as 2-benzylbenzimidazoles or 'nitazenes' began to rise, causing concern due to suspected high potency. Originally discovered in the late 1950s by the pharmaceutical company CIBA, this potent opioid subclass entered the recreational drug market following the scheduling of fentanyl-class drugs in 2018, marked by the fatalities in the United States alone. It dominated the U.S. novel synthetic opioid market for approximately a year, eventually leading to its classification under Schedule I control by the U.S. drug Enforcement Administration (DEA).

This class of substances contains a benzimidazole ring with an ethylamine at its 1-position and a benzyl group at its 2-position. Small structural modifications to this scaffold can produce a series of analogous substances. Nitazenes are ultra-high potency synthetic opioids, Isotonitazene and Protonitazene are up to 8 times stronger than fentanyl, while etonitazepyne and protonitazepyne surpass fentanyl’s potency by a staggering 20 times.

Nitazene opioids generally display high levels of opioid activity, with potencies and efficacies often exceeding that of fentanyl. Etonitazene, the prototypical nitazene drug that is the most potent analogue, was found to be at least 20 times more potent than fentanyl in vivo. Nitazene opioids have become a growing threat to public health and security worldwide.²

Nitazene-associated intoxications were primarily related to individuals purchasing these substances online. Nitazene-adulterated street drug samples have increasingly been detected often mixed with heroin or with other opioid or non-opioid drugs. Individuals are often unaware of nitazene adulteration and puts them at a high risk of unintentional overdose. The entry of new illicit substances and their presence in a variety of drug mixtures emphasizes the important need for harm reduction approaches to mitigate the effects and harm to public health.²

Ghent University Study

The Laboratory of Toxicology Department of Bioanalysis, Ghent University study is the first to independently assess in a laboratory setting using drug standards and the potential of the first commercially available BTNX Rapid Response® Nitazene Test Strip for drug checking purposes. The results indicate that the test strips are capable of detecting the presence of a wide range of nitazene analogues. 

Read the study

The Center for Forensic Science Research & Education (CFSRE) Study

The Center for Forensic Science Research & Education (CFSRE) conducted an independent evaluation of the Rapid Response® Nitazene Test Strip. To test its effectiveness in detecting nitazene analogues, various compounds were introduced into water at a concentration of 3000 ng/mL. The outcomes are detailed in the following tables:

In a separate assessment, the Chicago Recovery Alliance analyzed the strip’s performance with real-world street drug samples. With a dilution factor of 10mg per 1mL (one scoop in 1mL of water), the strip achieved 100% sensitivity and specificity. When diluted to 10mg per 5mL (one scoop in 5mL of water), sensitivity was observed at 89%, and specificity remained at 100%. The investigation continues, with the preliminary findings shown in the table below:

The Rapid Response® Nitazene Test Strip is specifically designed for the swift screening of nitazenes in liquid or powder samples. This test incorporates an antibody that selectively identifies nitazenes. Similar to other harm reduction test strips, it operates on the competitive binding principle. If nitazene is present in the sample at a concentration surpassing the designated cut-off, a singular-colored line will appear in the test. 

The test strip can detect related compounds including Isotonitazzene, Protonitazene, N-pyrrolidino Etonitazene, and Etonitazene. 

Analytical Sensitivity

A drug-free urine pool was supplemented with Isotonitazene at various concentrations: 0% cutoff, -50% cutoff, -25% cutoff, cutoff, +25% cutoff, +50% cutoff, and 3X cutoff. The results showcase over 99% accuracy, both 50% above and 50% below the cut-off concentration. The summarized data is presented below:

Analytical Specificity

The following compounds were spiked into water, respectively, to examine the ability of the test strip for detecting nitazene analogues. The cutoff listed in the table represents the concentration at which a substance will begin to show a mix of positive and negative results.

The following compounds were spiked into water, respectively, to examine possible cross-reactivity. No false positives were observed at the concentrations listed in the table.

Packaging

Each test kit comes with individually sealed test strips in pouches for easy distribution and transportation. A result interpretation card is also included as a guide for reading the results where users can align and match the test strip with the illustration on the card. QR codes to external resources are printed on every packaging for a user-friendly experience.

Rapid Response^® Nitazene Test Strip (Liquid / Powder) is available to purchase under the product code NTZ-18S26-100 from Lochness Medical Supplies in the USA and BTNX Inc. in Canada and the international market.

Buy now: Canada, USA

1. Amaducci A, Aldy K, Campleman SL, et al. Naloxone Use in Novel Potent Opioid and Fentanyl Overdoses in Emergency Department Patients. JAMA Netw Open. 2023;6(8):e2331264. doi:10.1001/jamanetworkopen.2023.3126
2. Forensic Magazine. (n.d.). New Synthetic Opioid is 20x More Potent than Fentanyl. Retrieved January 13, 2025, from https://www.forensicmag.com/576984-New-Synthetic-Opioid-is-20x-More-Potent-than-Fentanyl/