Recommended Cut-Offs, Metabolites, and Cross-Reactors in Urine Drug Tests
Drug (SAMHSA-5) # of Metabolites1 Metabolite name(s)1 Detection cutoff levels (ng/ml)2 "Infrequent" use detection window (days)1 "Frequent" use detection window (days)1 Cross reactants3
Marijuana 31 11-Nor-delta-9-tetrahydrocannabinol; (THC) 9 carboxylic acid; 11-Hydroxy-delta-9-tetrahydrocannabinol; 11-Nor-delta-8-tetrahydrocannabinol; (THC) 9 carboxylic acid 50-(initial)

15-(confirm)

1 – 5 1 – 35 NSAIDs, Marinol, Protonix
Cocaine 4 Benzoylecgonine 150-(initial)

100-(confirm)

1 – 2 1 – 4 ---
Opiates 3 --- --- --- --- Poppy seeds, chlorpromazine, rifampin, dextromethorphan, quinine
Heroin 6-Acetylmorphine or 6-Monoacetylmorphine 10-(initial)

10-(confirm)

1 1 – 2
Morphine Morphine-3-beta-d-glucuronide; Morphine-6-glucuronide
2000-(initial)

2000-(confirm)

1 – 2 1 – 4
Codeine Codeine-6-glucuronide; Morphine-3-glucuronide; Morphine-6-glucuronide 2000-(initial)

2000-(confirm)

1 – 2 1 – 2
Amphetamines --- --- --- --- --- Ephedrine, methylphenidate, trazodone, bupropion, desipramine, amantadine, ranitidine, phenylpropanolamine, Vicks Vapor Spray
Amphetamines Unchanged amphetamine 500-(initial)

250-(confirm)

1 - 2 2 - 4
Methamphetamine Unchanged methamphetamine 500-(initial)

250-(confirm)

1 - 2 2 - 4
MDMA Methylenedioxymethamphetamine 500-(initial)

250-(confirm)

1 - 2 1 - 2
Phencyclidine (PCP) 1 Hydroxylated PCP 25-(initial)

25-(confirm)

2 – 8 7 – 14 Chlorpromazine, thioridazine, meperidine, dextromethorphan, diphenhydramine, doxylamine
 

† No metabolites are identified for amphetamines because these substances normally pass through the body essentially unchanged in chemical structure.

Definitions:
Metabolite - a compound produced when the body processes a particular drug. These are what drug tests identify.
Cutoff level - the lowest concentration (least amount per unit volume) of a particular drug or its resulting metabolite(s) that cause a person to be identified as using a particular substance.
Initial cutoff level - level identifying “negative” results that don't need further analysis.
Confirm cutoff level - a more stringent level used to confirm "positive" results.
Detection window - time frame during which a drug can be detected as measured from the point of ingestion.
Cross reactants - other substances that may have chemical properties similar enough to produce a false positive.
Infrequent use - 'recreational' drug use.
Frequent use - 'chronic' drug use.
Cross reactants - other substances that may have chemical properties similar enough to produce a false positive.