Fentanyl test strips (FTS) are increasingly recommended for non-heroin drugs due to overdose clusters from stimulants and counterfeit pharmaceutical pills. Misuse of FTS can lead to false positive FTS results.
We report here on results from two studies. First, a cross-sectional survey was administered from January to May 2021 to 86 participants of a syringe service program in Philadelphia, PA who had ever used a FTS on a non-heroin drug. In a follow-up qualitative study conducted between September-October 2023, 40 participants conducted a mock use of FTS on a simulated drug in a real-world environment and interpreted photos of FTS results. Data were analyzed in RedCap, SPSS and Nvivo.
Among survey participants, 70.9% reported a positive result the last time they had used a FTS on a non-heroin drug. During the simulation study, none used FTS as recommended. Most under-diluted the sample (e.g., using less than a full teaspoon of water) or used in another manner not indicated. Forty-five percent correctly interpreted a positive test, 55.0% a negative test with clear lines, and 29.5% a negative test with a faint second line.
FTS were used incorrectly by every study participant during the simulation, errors that would likely lead to false positive test results when using FTS in real world settings. Findings highlight the need to develop educational approaches to ensure people use FTS properly to optimize the harm reduction impact of FTS.