Drugs Of Abuse (DOA) In Urine Screen

Clinical
Biochemistry

All results are reported according to European workplace testing thresholds.
Results above the threshold are reported as positive and results below the threshold are reported as negative.

Group screened	*Drugs measured (list is not exhaustive^)**	Threshold	Typical t_1/2	Typical positive window
Benzodiazepines
Short acting	Oxazepam Triazolam Lorazepam	200 µg/L	4 - 11 hours	Up to 24 hours
Intermediate	Temazepam Chloridiazepoxide		6 - 27 hours	Up to 4 days
Long acting	Diazepam Nitrazepam		20 - 50 hours	Up to 7 days
Amphetamines
Short acting	Amphetamine Metamphetamine 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
Opiates	Morphine Heroin (diacetylmorphine) 6-monoacetylmorphine Codeine Dihydrocodeine	300 µg/L	2 - 4 hours (morphine)	Up to 2 days
Methadone Metabolite	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.

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