Jan. 23, 2024  – Chemists refer to this category of drugs as “nitazenes,” even though the term is incorrect; it should be “benzimidazole-based opioids.” The Swiss drug maker CIBA, now part of Novartis, developed the first nitazenes in the late 1950s as potential pain treatments. 

In 2020, the World Health Organization reported that isotonitazene (which drug users call “iso” or “tony”) began appearing in forensic toxicology reports in six European countries, Canada and the United States. In 2022, the Tennessee Department of Health reported that overdose deaths from synthetic opioids classified as nitazeneshave increased fourfold in just two years. 

Just recently, the British news media reported that the United Kingdom has experienced a “big influx” of nitazenes. London’s Metropolitan Police seized more than 150,000 nitazene tablets in a single drug haul last fall.