Using our interactive charts
Anesthetics began appearing in the Washington state drug supply in 2024, following their introduction east of the Rockies earlier. They are often added alongside or in place of other analgesics (e.g., acetaminophen) to bulk out the main drug, often a fentanyl, and enhance the feeling of pain relief. While these substances may be commonly used in surgery, dental practice, and other health arenas for local anesthesia, their effects in the quantities associated with frequent fentanyl use and the modes of ingestion involved with unregulated drug use may be dangerous. The vast majority of the anesthetics seen in Washington are lidocaine, but we have also seen (in descending order of prevalence as of July 2025) procaine, benzocaine, tetracaine, and ethyl 3-aminobenzoate (tricaine).
First, we show community drug checking samples positive for anesthetics by quarter, broken out by those found with fentanyls and those not found with fentanyls (which is rare). Initially, "all other samples" is hidden to focus on anesthetic-positive samples, but if you click on that entry in the legend, you can see the relative prevalence of anesthetics over time. Hover over a data point to see the percentage of all samples (if all other samples is in the graph) or of anesthetic-positive samples (if all other samples is hidden).
The graphs below show the data in a different way: Among samples positive for anesthetics, what were they reportedly sold or given as. Here, in addition to our usual key "sold as" categories, which are not mutually exclusive, we add an indicator for being sold as none of these key categories.
Below we present the drugs found alongside anesthetics in confirmatory testing results. Most anesthetics are found with fentanyl and/or related substances (analogues or precursors). Note that "fentanyl precursors" are fentanyl-specific impurities, while the substances in the "impurities" category repesent chemicals or compounds that remain after processing or synthesis of other drugs, such as heroin (e.g., noscapine and papaverine) or methamphetamine (e.g., N-acetylmethamphetamine) or versatile chemicals used in multiple chemical reactions not specifically linked to a given drug outcome. Results are cumulative.
Drug testing sites can do little about potential cross-contamination: The container a client used may or may not have been used before. Therefore, any unusual combination may be due to cross-contamination and not represent drugs actually sold together. For more details on drug categories named above, click here. Counts by quarter do not show the current quarter but shares do, as the percentages are not likely to change very much once the quarter is complete.