Test Catalog

Test ID: COKEU    
Cocaine and Metabolite Confirmation, Random, Urine

Useful For Suggests clinical disorders or settings where the test may be helpful

Detecting and confirming drug abuse involving cocaine


This test is not intended for employment-related testing.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Cocaine is a drug of current health concern because of its proliferation among recreational drug abusers.


Freebase and crack increase the potential for major cocaine toxicity. Cocaine use is declining across the nation according to the National Institute of Drug Abuse.


Increasingly, laboratory results are disputed or there are medical/legal overtones. Therefore, physicians are finding an increased need to confirm positive results before informing or confronting the patients.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.


Positive results are reported with a quantitative GC-MS result.

Cutoff concentrations:


<50 ng/mL



<50 ng/mL

Interpretation Provides information to assist in interpretation of the test results

Reports will specifically indicate the presence or absence of cocaine and benzoylecgonine.


The presence of cocaine, or its major metabolite, benzoylecgonine, indicates use within the past 4 days.


Cocaine has a 6-hour half-life, so it will be present in urine for 1 day after last use.


Benzoylecgonine has a half-life of 12 hours, so it will be detected in urine up to 4 days after last use.


There is no correlation between concentration and pharmacologic or toxic effects.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

No significant cautionary statements

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Disposition of Toxic Drugs and Chemicals in Man. Tenth edition. Edited by RC Baselt. Foster City, CA: Biomedical Publications, 2014

2. Langman LJ, Bechtel L, Holstege CP: Chapter 35: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Edited by CA Burtis, ER Ashwood, DE Bruns. WB Saunders Company, 2011, pp 1109-1188