Urinary excretion of immunologically reactive metabolite(s) after intranasal administration of cocaine, as followed by enzyme immunoassay.

Using the enzyme immunoassay technique (EMIT), we determined the time course of urinary excretion of benzoylecgonine 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 1 to 4 h, peaked at about 10 to 12 h, remained positive for 18 to 27 h, and became negative after about 17 h. This information should be considered by drug dependency treatment programs in which the EMIT procedure is used to screen urines for cocaine use.