Urine Drug Screen Test Characteristics
Amphetamines ...

Urine Drug Screen Test Characteristics

Amphetamines - 1-2d after use (2-4d for chronic exposure)

 • False Positives: bupropion, labetalol, trazodone, ranitidine, pseudoephedrine, selegiline

 • False Negatives: Ritalin & atomoxetine won’t test +

Barbiturates - 2-20d after use 

 • False Positives: Fioricet (contains butalbital)

Benzodiazepines - 1-5d (most), 2-30d after diazepam 

 • False Positives: oxaprozin (NSAID) 

 • False Negatives: lorazepam, clonazepam <1mg/day

Cannabinoids - 1-7d after use, up to 1mo heavy chronic use 

 • False Positives: hemp products, Marinol 

 • False Negatives: synthetic cannabinoids

Opiates (NOT methadone, fentanyl, meperidine) - 1-3d after use, 6-8d after heavy use

 • False Positives: poppy seeds (unlikely); At MGH, methadone, naloxone, fluoroquinolones do NOT interfere

 • False Negatives: oxycodone, oxymorphone, Suboxone

Cocaine - 2-4d after use, 1-3wks after heavy use 

 • False Positives: NONE

Phencyclidine (PCP) - 7-14d after use 

 • False Positives: Lamictal, Effexor, Tramadol, dextromethorphan, doxylamine

Buprenorphine - 5-10d 

 • False Positives: high doses of opiates/methadone/tramadol; quinine, hydroxychloroquine, naltrexone

Methadone - 1-5d 

 • False Positives: quetiapine, diphenhydramine, doxylamine

Oxycodone - 2-4d 

 • False Positives: substances that change urine color (e.g., Flagyl) will cause refusal

#Urine #DrugScreen #UDS #testing #laboratory #toxicology #falsepositives #falsenegatives
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MGH White Book Manual
Account created for the MGH Internal Medicine Housestaff Manual "White Book" - https://stk10.github.io/MGH-Docs/WhiteBook-2019-2020.pdf

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