Other analyses
Cocaïne (benzoylecgonine)
A urine test for breakdown products of cocaine; shows whether cocaine has been used in the past few days.
Everything about this testWhat it measures
Cocaine itself disappears from the body within a few hours. The body breaks cocaine down into, among other things, benzoylecgonine, which stays detectable in the urine much longer. This screening test looks for benzoylecgonine and related breakdown products. The laboratory uses a cut-off of 150 µg/l: if the concentration is above it, the result is positive. The test does not measure whether someone is under the influence at this moment.
- Use of cocaine, including in the form of crack, in the past few days
Positive
A positive result means there are breakdown products of cocaine in the urine above the laboratory's cut-off. After use, cocaine is usually detectable in urine for about 2 to 4 days; according to the Trimbos Institute, with heavy and frequent use this can increase to 1 to 2 weeks. A positive result does not say when, how much or how often cocaine was used, nor whether someone was under the influence at the time of the test. Cocaine used as a local anesthetic during a medical procedure on the nose or throat and tea made from coca leaves can also give a positive result. A positive result shows that a substance is in the body; it is not a diagnosis and says nothing about dependence.
Negative
A negative result means no breakdown products of cocaine were found above the cut-off. This does not completely rule out use: within about an hour of use, or if use was more than a few days ago, the result can be negative. With one-time or light use in diluted urine, the value can stay below the cut-off.
If your result is abnormal
With a positive result that may have consequences, the laboratory has the result confirmed with a second method of analysis. The GP then looks at the context: amount, frequency, symptoms and any wish to cut down or quit, and refers to addiction care if needed.
Reliability
The test says something about use in the past few days, not about health or the extent of use. The Dutch Society for Clinical Chemistry (NVKC) states that a positive result of a screening test must be confirmed with a second, different method of analysis, because a positive result can have far-reaching consequences; for legal purposes this means confirmation with mass spectrometry (GC-MS or LC-MS). This test is not intended for an assessment or procedure of the CBR (Dutch driving license authority), an employer or the justice system: these have their own requirements for sample collection, identity checks and confirmation.
Limitations
- A screening test can give a false-positive result; according to the Trimbos Institute, quinine, for example, can give a positive result with some tests. Confirmation with a different method is needed before a result can carry weight.
- How long cocaine is detectable differs per person and depends on how much, how often and how recently it was used; alcohol taken together with cocaine can extend the window.
- Fluid intake determines how concentrated the urine is; diluted urine can give a negative result.
- Medical use of cocaine as a local anesthetic and coca tea give a positive result without recreational use.
How common is this
In 2024, 7.4 percent of adults in the Netherlands had ever used cocaine, about one million people. In the past year, 2.4 percent had used cocaine.
Who is this useful for
Useful for a medical question, for example in addiction care or with unexplained symptoms in which cocaine use may play a role, or for anyone who wants to monitor their own use. Not intended for an assessment or procedure of the CBR, an employer or the justice system: these have their own requirements. Anyone worried about their own use will get more out of help with cutting down or quitting than out of a test.
Downsides and risks
- A result without a confirmation test can wrongly be used as evidence.
- A negative result can give false reassurance if use was more than a few days ago.
Sources
Always discuss an abnormal result with your GP. If a result is strongly abnormal, we try to reach you as soon as possible. Read your result yourself as well and contact your GP if in doubt. A test does not make a diagnosis. Read more about risks and results