Cocaine is prepared from the leaves of the tropical bush Erythroxylon coca. After use (snorting, smoking, or intravenous injection) cocaine is metabolized to benzoylecgonine (BZE) and ecgonine methyl ester (EME). The BZE metabolite is analyzed since it is the metabolite that is detectable in urine for a longer period of time.
This LC-MS/MS confirmation-only test for BZE is intended for use only in patients where an initial drug screening test has already been performed at the time of specimen collection (i.e. point-of-care drug screening cup, dipstick, etc.). The specimen will not be screened by immunoassay in the laboratory; it will only be tested by LC-MS/MS. If an initial drug screen has not been performed at the specimen collection site, it is more appropriate to order the "Cocaine Metabolite, Urine" (COC) test code which includes an initial screen.
Current Cutoff Levels for Toxicology
The cocaine metabolite benzoylecgonine can be detected up to 3-5 days after last use.