Urinary Excretion of ImmunologicallyReactive Metabolite(s) after IntranasalAdministrationof Cocaine, as Followed by Enzyme Immunoassay

Using the enzyme immunoassay technique (EMIT), we determined the time course of urinary excretion of ben-zoylecgonine in 16 surgical patients and three volunteers who received intranasal cocaine. After doses varying from 13 to 130 mg, the test for benzoylecgonine was positive in ito 4 h, peaked at about 10 to 12 h, remained positive for 18 to 27 h, and became negative after about 27 h. This information should be considered by drug dependency treatment programs in which the EMIT procedure is used to screen urines for cocaine use. AdditIonal Keyphrases: screening for drug abuse. drug assay Identification of cocaine use by means of urine drug screening depends on detection of its polar metabolite, benzoylecgonine (BE) (1-3). Although other methods for detection of BE in the urine have been published (2-8), the procedure most widely used for large-scale urine screening is EMIT.5 Using this procedure, we determined the time course of urinary excretion of BE in 16 surgical patients and three volunteers who received known doses of cocaine. This type of data, not presently available, provides guidelines for interpreting the results of this assay technique when used for drug-abuse screening. The EMIT procedure has been well described and verified (9, 10). This nonisotopic competitive binding immunoassay is rapid and yields a semiquantitativ