Editing Fentanyl (section)

=== Detection for harm reduction purposes ===
[[File:Fentanyl-test-strip.jpg|thumb|Image of testing strip instructions from the harm reduction organization Dance Safe]]
Fentanyl and fentanyl analogues can be qualitatively detected in drug samples using commercially available fentanyl testing strips or spot reagents. Following the principles of harm reduction, this test is to be used directly on drug samples as opposed to urine. To prepare a sample for testing, approximately 10&nbsp;mg of the drug should be diluted into 1 teaspoon, or 5&nbsp;mL, of water.<ref>{{cite web | vauthors = Cunningham C | date = 22 March 2023 | title = Fentanyl Test Strip Guidance | url = https://oasas.ny.gov/system/files/documents/2023/03/fentanyl_test_strip_guidance_0.pdf | access-date = 3 October 2023 | publisher = State of New York | archive-date = 19 April 2023 | archive-url = https://web.archive.org/web/20230419163310/https://oasas.ny.gov/system/files/documents/2023/03/fentanyl_test_strip_guidance_0.pdf | url-status = live }}</ref> Research in Dr. Lieberman's lab at the University of Notre Dame has reported false positive results on BTNX fentanyl testing strips with [[methamphetamine]], [[MDMA]], and [[diphenhydramine]].<ref>{{cite journal | vauthors = Lockwood TE, Vervoordt A, Lieberman M | title = High concentrations of illicit stimulants and cutting agents cause false positives on fentanyl test strips | journal = Harm Reduction Journal | volume = 18 | issue = 1 | page = 30 | date = March 2021 | pmid = 33750405 | doi = 10.1186/s12954-021-00478-4 | pmc = 7941948 | doi-access = free | title-link = doi }}</ref> The [[sensitivity and specificity]] of fentanyl test strips vary depending on the concentration of fentanyl tested, particularly from 10 to 250&nbsp;ng/mL.<ref>{{cite journal | vauthors = Bergh MS, Øiestad ÅM, Baumann MH, Bogen IL | title = Selectivity and sensitivity of urine fentanyl test strips to detect fentanyl analogues in illicit drugs | journal = The International Journal on Drug Policy | volume = 90 | page = 103065 | date = April 2021 | pmid = 33333419 | doi = 10.1016/j.drugpo.2020.103065 | doi-access = free | title-link = doi }}</ref>