DRE – Drug Recognition Expert


What happens to a DRE sample when it reaches the laboratory?

The sample is first tested for alcohol. If the alcohol concentration is over 0.100 g/100 mL, drug testing will be canceled according to WSLH policy. (An exception to this policy is when there is a crash resulting in injury or death. In these circumstances drug testing will be completed even if the ethanol result is greater than 0.100 g/100 mL.)

In cases where the drug testing has been canceled, calling the laboratory and discussing the particular circumstances that make this testing necessary may reinstate the testing.


Is urine a suitable DRE sample?

Urine is used only for DRE training purposes. If a urine sample is submitted from a driver for routine testing, drug testing will not be performed. The specimen will be tested for alcohol only.


Do I need to include my DRE evaluation?

It is very helpful to the lab, and important, to include a copy of your DRE evaluation. A list of suspected drugs is particularly useful. There are some drugs that we may not see unless we specifically look for them.


What should I do if I am unable to include my eval with the sample?

Please email your facesheet to DRE@slh.wisc.edu


Can I call for results on a DRE sample that I have sent in?

Yes, but please allow a few months for analysis of your sample. Keep in mind that in some instances, sample analysis can take up to four to six months.


What drugs can the WSLH detect?

We are able to look for hundreds of drugs. The main drug classes are THC, opiates, cocaine, methamphetamine, PCP, barbiturates and benzodiazepines. Drugs in these classes are detected by routine procedures. It is helpful to list any suspected drugs to ensure comprehensive testing is performed.


What drugs can the WSLH not detect?

Synthetic cannabinoids, GHB, LSD, mushrooms, Viagra, certain prescription medications and most antimicrobial drugs. Private laboratories outside of the WSLH are sometimes able to test for these drugs. Please contact the Toxicology section to determine if sending the specimen to a private laboratory for further testing is appropriate.


I submitted a sample for CNS depressants (or THC, CNS stimulants, etc.), but the report came back negative. Why?

We are able to detect drugs at very low levels. However, if the drug falls below our detectable limit, we will call that sample “Not detected.” If you feel that the subject’s symptoms of impairment suggest that a drug is present at a high concentration, please call the laboratory to discuss your concerns.


What do the units mean on my laboratory report?

Most drugs are reported in ng/mL (nanograms per milliliter), others can be reported as mcg/mL (micrograms per milliliter).


What is a metabolite?

A metabolite is a form of the drug after it has been chemically changed from its original dosage form. After a person is exposed to a drug, chemical processes occur that change the drug and remove it from the body. The changed form of the drug may be active or inactive. The laboratory measures these metabolites to better assess the effects of the drug.