Update 12/31/2025:
I found and added a bunch more, including a column for false positives for fentanyl assays and more for LSD and a bunch of others, new sources listed as well.
Update: a version of this is now in PubMed Central -- thanks Pik Mukherji!
Mukherji P, Sharma S. Toxicology Screening. [Updated 2018 Oct 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018 Jan-.Available from: https://www.ncbi.nlm.nih.gov/books/NBK499901/
Urine drug screens aren't completely useless, but they have a number of limitations. Here is a table where I have compiled all of the false positive causing drugs I could find (pdf updated 12/31/25):
Update 4/22/2016:
Here are my sources:
I started with this paper which was I originally heard on EM Abstracts (Jan 2011):
Brahm NC, Yeager LL, Fox MD, Farmer KC, Palmer TA.
Commonly prescribed medications and potential false-positive urine drug screens.
Am J Health Syst Pharm. 2010 Aug 15;67(16):1344-50.
Special thanks to Jon Cole from Hennepin who made this fantastic video.
Other sources include:
UMHS Guidelines for Clinical Care May 2009
Standridge JB, Adams SM, Zotos AP.
Urine drug screening: a valuable office procedure.
Am Fam Physician. 2010 Mar 1;81(5):635-40.
Reisfield GM, Haddad J, Wilson GR, Johannsen LM, Voorhees KL, Chronister CW, Goldberger BA, Peele JD, Bertholf RL.
Failure of amoxicillin to produce false-positive urine screens for cocaine metabolite.
J Anal Toxicol. 2008 May;32(4):315-8.
Ly BT, Thornton SL, Buono C, Stone JA, Wu AH.
False-positive urine phencyclidine immunoassay screen result caused by interference by tramadol and its metabolites.
Ann Emerg Med. 2012 Jun;59(6):545-7.
doi: 10.1016/j.annemergmed.2011.08.013
Swift RM, Griffiths W, Cammera P.
False positive urine drug screens from quinine in tonic water.
Addict Behav. 1989;14(2):213-5.
Updates 5/1/2016
Reordered alphabetically
Added lamotragine -> PCP
Geraci MJ, Peele J, McCoy SL, Elias B. Phencyclidine false positive induced by lamotrigine (Lamictal®) on a rapid urine toxicology screen. Int J Emerg Med. 2010 Dec; 3(4): 327–331.
Added a few more -> PCP
Phencyclidine (PCP) Test Systems Executive Summary. Chemistry and Toxicology Devices. FDA
2013 Apr 25, Link.
Update: a version of this is now in PubMed Central -- thanks Pik Mukherji!
Mukherji P, Sharma S. Toxicology Screening. [Updated 2018 Oct 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018 Jan-.Available from: https://www.ncbi.nlm.nih.gov/books/NBK499901/
Urine drug screens aren't completely useless, but they have a number of limitations. Here is a table where I have compiled all of the false positive causing drugs I could find (pdf updated 12/31/25):
Update 4/22/2016:
Here are my sources:
I started with this paper which was I originally heard on EM Abstracts (Jan 2011):
Brahm NC, Yeager LL, Fox MD, Farmer KC, Palmer TA.
Commonly prescribed medications and potential false-positive urine drug screens.
Am J Health Syst Pharm. 2010 Aug 15;67(16):1344-50.
Special thanks to Jon Cole from Hennepin who made this fantastic video.
Other sources include:
UMHS Guidelines for Clinical Care May 2009
Standridge JB, Adams SM, Zotos AP.
Urine drug screening: a valuable office procedure.
Am Fam Physician. 2010 Mar 1;81(5):635-40.
Reisfield GM, Haddad J, Wilson GR, Johannsen LM, Voorhees KL, Chronister CW, Goldberger BA, Peele JD, Bertholf RL.
Failure of amoxicillin to produce false-positive urine screens for cocaine metabolite.
J Anal Toxicol. 2008 May;32(4):315-8.
Ly BT, Thornton SL, Buono C, Stone JA, Wu AH.
False-positive urine phencyclidine immunoassay screen result caused by interference by tramadol and its metabolites.
Ann Emerg Med. 2012 Jun;59(6):545-7.
doi: 10.1016/j.annemergmed.2011.08.013
Swift RM, Griffiths W, Cammera P.
False positive urine drug screens from quinine in tonic water.
Addict Behav. 1989;14(2):213-5.
Updates 5/1/2016
Reordered alphabetically
Added lamotragine -> PCP
Geraci MJ, Peele J, McCoy SL, Elias B. Phencyclidine false positive induced by lamotrigine (Lamictal®) on a rapid urine toxicology screen. Int J Emerg Med. 2010 Dec; 3(4): 327–331.
Added a few more -> PCP
Phencyclidine (PCP) Test Systems Executive Summary. Chemistry and Toxicology Devices. FDA
2013 Apr 25, Link.
Updates 12/31/2025:
Checking for fentanyl in your drugs using fentanyl test strips
What drugs are likely to interfere with urine drug screens?
Drug information Group, Retzky College of Pharmacy, University of Illinois Chicago
Monthly FAQs, May 2021
Lockwood, TL.E., Vervoordt, A. & Lieberman, M.
High concentrations of illicit stimulants and cutting agents cause false positives on fentanyl test strips.
Wang BT, Colby JM, Wu AH, Lynch KL
Cross-reactivity of acetylfentanyl and risperidone with a fentanyl immunoassay.
J Anal Toxicol. 2014 Nov-Dec;38(9):672-5. doi: 10.1093/jat/bku103. Epub 2014 Sep 23. PMID: 25248490.
Wang D, Sun Q, Schneider R, Cunningham SL
Understand the FDA-cleared fentanyl testing: A clinical evaluation of the SEFRIA fentanyl immunoassay.
Bergh MS, Øiestad ÅML, Baumann MH, Bogen IL
Selectivity and sensitivity of urine fentanyl test strips to detect fentanyl analogues in illicit drugs.
Thanks for the work. Is it possible to create a PDF of your table.
ReplyDeleteGood idea, thanks. PDF link added above
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