{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,4]],"date-time":"2026-11-04T23:23:15Z","timestamp":1793834595985,"version":"4.6.1"},"reference-count":26,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2021,3,9]],"date-time":"2021-03-09T00:00:00Z","timestamp":1615248000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2021,3,9]],"date-time":"2021-03-09T00:00:00Z","timestamp":1615248000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100006108","name":"National Center for Advancing Translational Sciences","doi-asserted-by":"publisher","award":["UL1TR002529"],"award-info":[{"award-number":["UL1TR002529"]}],"id":[{"id":"10.13039\/100006108","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Advanced Diagnostics and Therapeutics","award":["Substance Abuse Discovery Fund"],"award-info":[{"award-number":["Substance Abuse Discovery Fund"]}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Harm Reduct J"],"published-print":{"date-parts":[[2021,12]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>The opioid epidemic has caused an increase in overdose deaths which can be attributed to fentanyl combined with various illicit substances. Drug checking programs have been started by many harm reduction groups to provide tools for users to determine the composition of their street drugs. Immunoassay fentanyl test strips (FTS) allow users to test drugs for fentanyl by either filling a baggie or cooker with water to dissolve the sample and test. The antibody used in FTS is very selective for fentanyl at high dilutions, a characteristic of the traditional use of urine testing. These street sample preparation methods can lead to mg\/mL concentrations of several potential interferents. We tested whether these concentrated samples could cause false positive results on a FTS.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>20 ng\/mL Rapid Response FTS were obtained from BTNX Inc. and tested against 4 different pharmaceuticals (diphenhydramine, alprazolam, gabapentin, and naloxone buprenorphine) and 3 illicit stimulants [cocaine HCl, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA)] in concentrations from 20 to 0.2\u00a0mg\/mL. The FTS testing pad is divided into 2 sections: the control area and the test area. Control and test area signal intensities were quantified by ImageJ from photographs of the test strips and compared to a threshold set by fentanyl at the FTS limit of detection.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>False positive results indicating the presence of fentanyl were obtained from samples of methamphetamine, MDMA, and diphenhydramine at concentrations at or above 1\u00a0mg\/mL. Diphenhydramine is a common cutting agent in heroin. The street sample preparation protocols for FTS use suggested by many online resources would produce such concentrations of these materials. Street samples need to be diluted more significantly to avoid interference from potential cutting agents and stimulants.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Fentanyl test strips are commercially available, successful at detecting fentanyl to the specified limit of detection and can be a valuable tool for harm reduction efforts. Users should be aware that when drugs and adulterants are in high concentrations, FTS can give a false positive result.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1186\/s12954-021-00478-4","type":"journal-article","created":{"date-parts":[[2021,3,9]],"date-time":"2021-03-09T05:03:37Z","timestamp":1615266217000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":73,"title":["High concentrations of illicit stimulants and cutting agents cause false positives on fentanyl test strips"],"prefix":"10.1186","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8988-7810","authenticated-orcid":false,"given":"Tracy-Lynn E.","family":"Lockwood","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8893-9500","authenticated-orcid":false,"given":"Alexandra","family":"Vervoordt","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3968-8044","authenticated-orcid":false,"given":"Marya","family":"Lieberman","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2021,3,9]]},"reference":[{"key":"478_CR1","unstructured":"National Institue of Health. Opioid Overdose Crisis. 2020. p. 1\u20133."},{"key":"478_CR2","doi-asserted-by":"crossref","unstructured":"Centers for Disease Control and Prevention. Opioid Overdose Data Overview. 2018;1\u20132.","DOI":"10.1007\/978-3-319-32001-4_258-1"},{"key":"478_CR3","unstructured":"Centers for Disease Control and Prevention. Understanding the epidemic: the three waves of opioid overdose deaths, combatting the opioid overdose epidemic (Internet). 2020. p. 1\u20134. https:\/\/www.cdc.gov\/drugoverdose\/epidemic\/index.html."},{"key":"478_CR4","first-page":"1","volume":"356","author":"H Hedegaard","year":"2020","unstructured":"Hedegaard H, Mini\u00f1o AM, Warner M. Drug overdose deaths in the United States, 1999\u20132018. NCHS Data Brief. 2020;356:1\u20138.","journal-title":"NCHS Data Brief"},{"issue":"12","key":"478_CR5","first-page":"1","volume":"68","author":"H Hedegaard","year":"2019","unstructured":"Hedegaard H, Bastian BA, Trinidad JP, Spencer MR, Warner M. Regional differences in the drugs most frequently involved in drug overdose deaths: United states, 2017. Natl Vital Stat Rep. 2019;68(12):1\u201315.","journal-title":"Natl Vital Stat Rep"},{"issue":"3","key":"478_CR6","doi-asserted-by":"publisher","first-page":"430","DOI":"10.2105\/AJPH.2016.303627","volume":"107","author":"CMC Jones","year":"2017","unstructured":"Jones CMC, Baldwin GT, Compton WM. Recent increases in cocaine-related overdose deaths and the role of opioids. Am J Public Health. 2017;107(3):430\u20132.","journal-title":"Am J Public Health"},{"key":"478_CR7","doi-asserted-by":"crossref","unstructured":"O\u2019Donnell J, Gladden RM, Mattson CL, Hunter CT, Davis NL. Vital signs: characteristics of drug overdose deaths involving opioids and stimulants, 24 States and the District of Columbia, January\u2013June 2019. MMWR Morb Mortal Wkly Rep (Internet). 2020;69(35):1189\u201397. http:\/\/www.cdc.gov\/mmwr\/volumes\/69\/wr\/mm6935a1.htm?s_cid=mm6935a1_w.","DOI":"10.15585\/mmwr.mm6935a1"},{"key":"478_CR8","unstructured":"Sherman S, Green T. Fentanyl overdose reduction checking analysis study (FORECAST) (Internet). 2018. http:\/\/americanhealth.jhu.edu\/assets\/pdfs\/FORECAST__Summary_Report.pdf."},{"issue":"10","key":"478_CR9","doi-asserted-by":"publisher","first-page":"2428","DOI":"10.1021\/acschemneuro.8b00174","volume":"9","author":"SM Burns","year":"2018","unstructured":"Burns SM, Cunningham CW, Mercer SL. DARK Classics in chemical neuroscience: fentanyl. ACS Chem Neurosci. 2018;9(10):2428\u201337.","journal-title":"ACS Chem Neurosci"},{"issue":"1","key":"478_CR10","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1186\/s12954-018-0276-0","volume":"16","author":"JE Goldman","year":"2019","unstructured":"Goldman JE, Waye KM, Periera KA, Krieger MS, Yedinak JL, Marshall BDL. 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