Urinary excretion of cocaine, benzoylecgonine, and ecgonine methyl ester in humans

John Ambre, Tsuen Ih Ruo, John Nelson, Steven Belknap

Research output: Contribution to journalArticlepeer-review

97 Scopus citations


The excretion kinetics of cocaine (C) and its two major metabolites, benzoylecgonine (BZ) and ecgonine methyl ester (EME), were determined by collecting all urine for 30 h from 5 cocaine users (subjects C, D, E, F, and G) given bolus doses followed by exponential cocaine infusions that delivered doses of 253 (subject C), 444 (subjects D, E, and F), and 700 mg (subject G). Plasma cocaine, urine cocaine, BZ, and EME were measured by gas chromatography, with a nitrogen detector. Elimination half-times for EME and BZ, estimated from semilog plots of excretion rates vs. time, averaged 3.1 and 4.5 h respectively, in agreement with our previous report. Urinary recovery in D, E, and F was 27-41% of the dose, with 14-17% as BZ, 12-21% as EME, and 2% as cocaine. Subject C excreted very little EME-5-6-fold less than the mean for the other subjects and amounting to only 3% of the dose. Cocaine disposition in subject G, who received the largest dose and attained plasma levels of 3000 ng/mL, showed some characteristics of a nonlinear process.

Original languageEnglish (US)
Pages (from-to)301-306
Number of pages6
JournalJournal of Analytical Toxicology
Issue number6
StatePublished - Nov 1988

ASJC Scopus subject areas

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


Dive into the research topics of 'Urinary excretion of cocaine, benzoylecgonine, and ecgonine methyl ester in humans'. Together they form a unique fingerprint.

Cite this