XLR-11 and UR-144 in Washington state and state of Alaska driving cases

J Anal Toxicol. 2014 Oct;38(8):563-8. doi: 10.1093/jat/bku067.


The case reports for 18 driving cases positive for the synthetic cannabinoid substances XLR-11 and/or UR-144 are discussed. Eleven of these cases had drug recognition expert evaluations performed. Slurred speech, lack of convergence and body and eyelid tremors were the most consistently noted interview characteristic. Pulse and blood pressure of the subjects were within the expected range. Most of the drivers contacted demonstrated poor driving; however, their performance on the standardized field sobriety tests yielded inconsistent diagnostic information. All cases were negative for other commonly detected drugs that affect the central nervous system, although one case was additionally positive for other synthetic cannabinoids. Of the studied cases, six were positive for only UR-144, whereas eight contained only XLR-11. Four cases were found to have both.

MeSH terms

  • Adolescent
  • Adult
  • Alaska
  • Automobile Driving*
  • Cannabinoids / blood*
  • Cannabinoids / standards
  • Dose-Response Relationship, Drug
  • Female
  • Humans
  • Illicit Drugs / blood
  • Indoles / blood*
  • Indoles / standards
  • Male
  • Substance Abuse Detection / methods
  • Washington
  • Young Adult


  • (1-pentyl-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)methanone
  • Cannabinoids
  • Illicit Drugs
  • Indoles
  • XLR-11