|Group screened||Drugs measured (list is not exhaustive*)||Threshold||Typical t1/2||Typical positive window|
|200 µg/L||4 - 11 hours||Up to 24 hours|
|6 - 27 hours||Up to 4 days|
|20 - 50 hours||Up to 7 days|
Ecstacy group (MDMA,MDA,MDEA)
|1000 µg/L||4 - 24 hours||Up to 3 days|
|Cocaine||Benzoylecgonine (major metabolite)||300 µg/L||2 - 5 hours||Up to 3 days|
|Cannabinoids||Δ9 Tetrahydrocannabinol and metabolites||50 µg/L||14 - 33 hours||Moderate use up to 4 days
Heavy use up to 27 days
|300 µg/L||2 - 4 hours
|Up to 2 days|
|EDDP (first major metabolite)||300 µg/L||?48 hours||Up to 9 days|
* Contact laboratory for a complete list of drug cross-reactivities. Contact the Duty Biochemist on ext. 4755/4961 if measurement of other drugs is required.
Note that while the presence of opiates in urine can be indicative of heroin use, urinary morphine may also result from over-the-counter medication (e.g. some cough syrups, kaolin-morphine mixture, co-codamol) or consumption of foodstuffs containing poppy seeds.
Most abused drugs can be detected up to 1-2 days after use. Specimens taken more than 3-4 days after use may screen negative for most substances, with the exception of cannabinoids. A urinary creatinine level of < 2 mmol/L suggests a dilute sample which may result in a false negative screen.