False-positive urine opiate screening associated with fluoroquinolone use

Ann Pharmacother. 2004 Sep;38(9):1525-8. doi: 10.1345/aph.1D632. Epub 2004 Jul 13.


Objective: To review the literature regarding false-positive urine opiate screens associated with the use of fluoroquinolones.

Data sources: Literature was identified using MEDLINE (1966-February 2004), EMBASE, and all EBM Reviews with the terms quinolones, substance abuse detection, opiates, cross-reactions, false-positive reactions, and each fluoroquinolone. Article references were also reviewed.

Data synthesis: Various settings utilize the practice of screening for drugs of abuse, such as opiates. These screening procedures can impact aspects of one's life, such as employment; therefore, accuracy is of the utmost importance. Two clinical trials were evaluated which showed that certain fluoroquinolone antibiotics cross-react with some of the commonly used urine opiate screening immunoassays. This suggests the importance of verifying positive results in instances where one's livelihood can be affected.

Conclusions: Fluoroquinolones can cause false-positive urine opiate screens. Clinicians should be aware of this potential interaction and may need to verify positive results.

Publication types

  • Review

MeSH terms

  • Cross Reactions
  • False Positive Reactions
  • Fluoroquinolones / urine*
  • Humans
  • Immunoassay
  • Opioid-Related Disorders / diagnosis*
  • Opioid-Related Disorders / urine
  • Substance Abuse Detection / methods*


  • Fluoroquinolones