Occurrence of cocaine in urine of substance-abuse treatment patients

Kenzie L. Preston, Bruce A. Goldberger, Edward J. Cone

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


As part of ongoing research efforts to improve methods of monitoring drug use in treatment patients, the presence of cocaine in urine specimens was evaluated as a possible marker for recent illicit cocaine use. A total of 2327 urine specimens collected during a 17-week clinical trial of a cocaine- abuse treatment study were tested. Cocaine was measured by gas chromatography-mass spectrometry, and benzoylecgonine (BZE) equivalents were determined by fluorescence polarization immunoassay (FPIA). More than one- third of the specimens were positive (> 25 ng/mL) for cocaine (36.8%), and nearly two-thirds were positive (> 300 ng/mL) for cocaine metabolite by FPIA (62.7%). Median concentrations of cocaine and BZE equivalents were 235 and 14,900 ng/mL, respectively, and maximum concentrations were 112,025 and 1,101,190 ng/mL in cocaine- and BZE-positive specimens, respectively. There were 52 specimens that contained cocaine in equal or higher concentrations than BZE equivalents. No significant differences in cocaine or BZE concentrations between Caucasian and African-American or between male and female patients were found. Cocaine was present less frequently and at lower concentrations than BZE but more frequently than expected based on an average half-life of approximately 1 h, which suggests that cocaine may exhibit a longer terminal half-life and/or that accumulation of cocaine can occur in chronic, heavy users.

Original languageEnglish (US)
Pages (from-to)580-586
Number of pages7
JournalJournal of analytical toxicology
Issue number7
StatePublished - 1998
Externally publishedYes

ASJC Scopus subject areas

  • Analytical Chemistry
  • Environmental Chemistry
  • Toxicology
  • Health, Toxicology and Mutagenesis
  • Chemical Health and Safety


Dive into the research topics of 'Occurrence of cocaine in urine of substance-abuse treatment patients'. Together they form a unique fingerprint.

Cite this