1. Best Practices in Urine Toxicological Screening
Timothy J. Ives, Pharm.D., M.P.H., FCCP, CPP
Eshelman School of Pharmacy, and School of Medicine
The University of North Carolina at Chapel Hill
October 22, 2016

2. Disclosure
I have no relationships with commercial interests related to the content of my presentation.

3. Today’s Learning Objectives
Recognize the factors which enhance the reliability and validity of the urine toxicology screening process.
Identify the factors which constitute barriers to successful testing.
Describe the clinical/biochemical testing options.

4. To Begin, A Few Definitions
Screen: A qualitative (positive/negative) test; usually designed to detect many drug classes; confidence in results may be poor, but depends on the assay
Confirmation: A test designed for very high confidence in identification of individual drugs/compounds; may be qualitative or quantitative (reports the amount of drug present)
Cut-off: The concentration used to distinguish between a positive and a negative result; defined by the product manufacturer, or by the limit of quantification (LOQ)

5. Why Perform UTS? Helps to detect inappropriate drug use
Identifies patients who are maintaining stability
Test to confirm the history of current drug use provided by patients
Satisfies requirement for immediate results, but:
Represents only a single point in time
Compounds are usually found post-metabolism
Results do not completely relate to patient’s current and immediate presentation

6. Some Limitations to UTS
Urine drug testing only indicates prior use
Drug concentration in urine varies greatly, based on:
Individual metabolism
Body composition
Time/Frequency of use
Drug strength
Current hydration status
Not useful for determining:
The time since the last use
Extent/frequency of drug use
Any additional use since the last positive test
Current level of impairment

7. What Specimens to Test?
Urine: Current specimen of choice for initial testing; uses a class-specific immunoassay Blood: Common tests: BAC, acetaminophen, salicylate, TCAs Saliva/Oral fluids: pH-dependent; collection device-dependent. Need to measure specific parent compounds, within a short turnaround time. Sweat: High variability, due to added electrolytes, compounds and a need for a sufficient volume Hair: Greatest variability, due to length and rate of growth Also, it is becoming more practical to explore unconventional biological matrices such as fingernails or meconium.

8. Problems That Can Occur with Collection?
Substitution: Fake urine or other yellow liquids (# 1)
Adulteration:
Detergents, bleach, salt, ammonia, acids
Glutaraldehyde
Nitrites
Chromates
Peroxide and peroxidase
Dilution: Water!
At UNC: Up to 10% of confirmed samples are “suspicious”
Adulteration
Alter pH or ionic strength
Inhibit antibody binding
Interfere with method of detection
Dilute the specimen
Creatine Monohydrate, Echinacea Purpurea Leaf Extract, Guarana Seed Extract, Milk Thistle Seed Extract, Parsley Leef, Dandelion Leaf, Trace Minerals, Whey Protein, Riboflavin (vitamin B2), Fiber, Natural Flavorings, Potassium Sorbate.

9. How Do You Collect Samples?
To reduce chances of sample dilution, adulteration, or substitution:
Do you do direct observation (aka visuals)?
Do patients leave bags, bulky outdoor clothing, empty pockets outside the collection room?
Use a designated urine sample collection area, with “blued toilet” and no access to tap water (unless cold only) until sample is handed over
If available, place a temperature strip on the specimen bottle. If not available, is the sample warm (or is it cold, like water out of the tap/toilet)?
Un-witnessed urine collections are of little or no assessment value, and also enhances denial.

10. 2-Step Process: Screenings & Confirmations
Test method = Enzyme Immunoassay (EIA)
Designed to separate negative samples from samples that are “presumptively” positive
Easy to perform and cost-effective
Specificity and cutoff concentrations vary
Immunoassay technology is drug class-specific
Does not identify individual drugs in each class, and is not quantitative.

11. Second Step: Confirmation:
Test method = Gas Chromatography/Mass Spectrometry (GC/MS)
A follow-up procedure designed to validate positive screening test results
Most drugs are eliminated as metabolites
GC/MS is more sensitive and specific than screening, with identification and quantification of both parent drug and its metabolite(s)
Cutoffs are often lower than screens

12. What are Cut-offs (c/o)?
Lowest concentration of a drug considered to be positive by screening or confirmation; thus distinguishing between a negative and a positive sample = a therapeutic “threshold”
Cutoffs provide important safeguards:
Legal protections (evidentiary admissibility)
Measured in ng/mL = ppb; concentration used depends upon the setting
Work place drug testing, etc: Defined by federal or state statutes, DOT, DOD, IOC, NFL, etc.
Most labs report results below the c/o as “negative”, and results above the c/o as “positive”

13. Cut-Off Levels (ng/mL)
Screening Confirmation
amphetamines
barbiturates
benzodiazepines
cannabinoids
cocaine (benzoyl ecognine)
opiates
heroin/6-monoacetyl morphine
phencyclidine (PCP)
alcohol
NB: Testing Methods and Cutoffs are regulated by SAMHSA (Substance Abuse and Mental Health Services Administration) – Why is this important?

14. Pharmacology: Opioids (& metabolites)
Medication What’s seen in the UTS
Codeine Norcodeine, morphine (metabolites)
Hydrocodone Hydrocodone, hydromorphone (primary metabolite), codeine, morphine
Morphine Morphine, hydromorphone (with use of higher doses of morphine)
Heroin 6-acetylmorphine (metabolite), morphine
Oxycodone* Oxycodone, oxymorphone (metabolite)
* Not commonly noted as an opiate on UTS due to low sensitivity, except with higher doses; confirmation is necessary
Oyler JM, et al. Identification of hydrocodone in human urine following controlled codeine administration. J Anal Toxicol. 2000; 24:

15. What are Target Analytes (in UTS)?
Immunoassay screenings typically target the metabolites that are primarily excreted over a reasonable time period.
GC/MS confirmations are more specific, and center on only one specific metabolite.
Immunoassay Target Analytes (highest sensitivity to lowest):
Cannabinoid (marijuana): 11-nor-Δ9-THC > 11-nor-Δ8-THC
Opiates: morphine > codeine > 6-acetylmorphine (from heroin) > hydromorphone > hydrocodone > oxycodone > oxymorphone
Benzodiazepines: 6-nordiazepam > oxazepam > 7-aminoclonazepam
Cocaine: benzoyl ecgonine
Amphetamine: methamphetamine > amphetamine

16. Example of Screening vs. Confirmation
Amphetamine <500 ng/mL -
Benzodiazepine <200 ng/mL -
Cannabinoid >20 ng/mL +
Cocaine >150 ng/mL +
Methadone <300 ng/mL -
Opiate >300 ng/mL +
Confirmation:
Benzoyl ecgonine = 4,623 ng/mL
(11- nor-)9-THC = 222 ng/mL
Hydrocodone = 1,322 ng/mL
Hydromorphone = negative (i.e., it is still < ng/mL)

17. UTS, Window of Detection, & Cut-Offs
Class
Target Drug
WOD
C-O (IA)
C-O (GC/MS)
Amphetamines
d-amphetamine
2 – 4 days
(pH dependent)
500
Barbiturates
secobarbital
days
200
100
Benzodiazepines
nor-diazepam
~72 hours 50
Cannabinoids
9-THC
days 20 3
Cocaine
benzoyl ecgonine
hours
150
Methadone
methadone
72 hours
300
Opiates
morphine
2 - 4 days

18. What could cause a positive drug test?
Indicates that a legitimate drug(s), or the metabolites tested for, was detected in the screened sample
Drug presence is above the “cut-off” level
Patient was previously prescribed the drug, or admitted past use, but disease (e.g., CKD) or time of specimen collection since drug discontinuation is insufficient for elimination
Prescription obtained from another clinic
Incorrect prescription was filled
Laboratory error
Drug detected is from an unprescribed or illegal drug

19. What could cause a negative drug test?
No drugs or metabolites were detected in the sample
Patient is not taking the medication, or ran out early (i.e., outside the period of detection)
Drug was not absorbed, or very poorly absorbed
Drug was taken incorrectly: only PRN instead of on a standard regimen, less than prescribed, less frequently than prescribed, or not at all (diversion?))
Accelerated metabolism/elimination
Urine was dilute and concentrations were below detection limits of analytical method
Inappropriate specimen handling, laboratory error

20. Interpreting UTS Results
Screening result at or above the c/o
Detected drugs belonging to the indicated class (true positive), or another similar substance that cross-reacts with antibody in the immunoassay (false positive)
Screening result below the c/o
Drug is absent (true negative)
Drug is present, but below designated c/o
Assay does not detect drug (false negative)

21. Some Excuses & Limitations with UTS
“I can’t pee” or “I just went”
“I haven’t used since the last appointment, but I took a Tylenol #3 for a headache yesterday”
The urine is cold: Did they bring it with them? Did they dilute it?
Benzodiazepines & cannabinoids persist for several weeks
All other drugs only test positive for a few days
Often, oxycodone IR or OxyContin does not test positive in most opiate immunoassay tests (sensitivity = ~70%)
No reliable commercial test for fentanyl or tramadol (yet)
Clonazepam & alprazolam test negative on immunoassay for benzodiazepines – Why?

22. Other Interpretation Cautions
Hydromorphone: minor metabolite in patients receiving chronic morphine (via alternate pathway)
Hydrocodone: minor metabolite detectable in patients taking high amounts of codeine.
With a longer t1/2 than oxycodone; a patient prescribed oxycodone may only have oxymorphone detected in urine.
Heroin is metabolized to morphine, which may be detectable after its use.
The drug dose that was taken cannot be extrapolated from drug screen results, even with a confirmation.

23. The Strongest UTS Results are when:
Confirmed by GC/MS method
Both parent drug and drug metabolites are identified
More than one sample is tested at two separate times (pattern of results)
More than one specimen source/type (i.e., urine, blood, meconium, hair, etc.) is tested
A chain of custody is maintained
Results come from a certified laboratory
Cook JD, et al. The characterization of human urine for specimen validity determination in workplace drug testing: a review. J Analytical Toxicol. 2000; 24:

24. How Do You Know That It’s Urine
How Do You Know That It’s Urine? Substitution, Adulteration, and Dilution
Visual examination: Color, froth?
Olfactory examination: Does it smell like urine?
Tactile examination: Is it warm?
Chemical evaluation:
Most common form of specimen tampering: sample dilution
If suspected, test the sample provided for a urine creatinine level to rule out intentional dilution.
Normal limit = 18 – 200 mg/dL
< 20 mg/dL is diagnostic for dilution (or for water intoxication, diabetes insipidus) – most sensitive indicator of dilution
< 5 mg/dL isn’t physiologically possible
Specific gravity: determine if urine creatinine is < 20 mg/dL Concerning level is < 1.003
Urine pH: Range = 6.5 – 8.0

25. Substitution: Synthetic Urine
Mimics normal human urine:
Creatinine
Electrolytes (Na ,K, Cl, Ca, Mg)
Urea, Phosphate
Difficult to detect by standard testing
Non-Human Urine:
Difficult to Detect

26. Substitution: Synthetic/Fake Urine
Substitution is more prevalent than adulteration

27. Interference? Another Myth
Drinking vinegar or cranberry juice will produce a “negative” urine drug test.
Theory: To cause a “pH shift”, making the urine sample acidic - altering the chemistry of immunoassay tests
Reality: The body buffers the weak acid, and dilutes it to physiological pH

28. Equipment: Urinator or Whizzinator?
Available in a variety of natural life-like skin tones
Fully adjustable latex belt
4 oz vinyl bag
One dehydrated, toxin-free urine specimen
Four organic heat pads
$150.00

29. Adulteration with Household Products
Adulterant Drug Test Affected
Chlorine bleach Cannabinoid, morphine, amphetamine
Liquid drain cleaner Morphine, amphetamine
(sodium hydroxide (Drano®)
Vinegar Amphetamine
Dubious Promotional Media (e.g., from the Internet)
Pyridinium chlorochromate Amphetamine, cocaine, morphine,
(Urine Luck®) cannabinoid, PCP
UR’n Kleen All of the above, except amphetamine
Instant Clean and Stealth Cannabinoid, PCP, cocaine
Wong R. The effect of adulterants on urine screen for drugs of abuse: detection by an on-site dipstick device. Am Clin Lab. 2002; 21: 37-9.
Paul BD, et al. Effects of pyridinium chlorochromate adulterant (urine luck) on testing for drugs of abuse and a method for quantitative detection of chromium (VI) in urine. J Anal Toxicol. 2000; 24:

30. Dilution: Two Types with Urine Specimens
Pre-collection dilution:
Consumption of large quantities of fluids (water loading, flushing, hydrating, etc.) prior to collection
Newer: Dilution with Adulteration: Flushing or detoxifying products: Gold Seal, Instant Clean, Clean & Clear, Test-Free, etc. No evidence of additional effect on drug elimination.
Post-collection dilution:
Adding fluid to specimen post collection
True medical causes for dilute urine:
Diabetes insipidus, muscle wasting syndromes, kidney disease, diuretic use, pharmaceutical toxicity (e.g., lithium)

31. Some Principles of Drug Testing
Place written UTS policies and procedures in your clinic policy, and use them consistently.
Add to your medication contract a phrase that permits urine toxicological screening and confirmation.
Perform a urine creatinine conc. to identify tampering.
Perform confirmations on all positive screening results.
Ensure that the sample collection process is effective:
random/unannounced selection
witnessed observation during sample collection
know your cut-off levels and windows of detection

32. Principles of Drug Testing
Outline a process in your clinic policy for managing patients with an inappropriate UTS. Simple dismissal avoids addressing the real problem.
Place a dilute sample prohibition in your medication contract, with sanctions for repeat offenses.
When developing and administering your drug testing program assume that the participants you are testing know more about urine drug testing than you do (even if it comes from the internet).
Beware of “opioid-only” pain clinics & their questionable UTS cut-off levels.

33. Your Final Exam!
Patient AB is prescribed Tylenol #3. What do you expect to find in the UTS, on screening & confirmation?
Patient CD is prescribed MS-Contin. What do you expect to find in the UTS, on screening & confirmation?
Patient EF is suspected of heroin use. What do you expect to find in the UTS, on screening & confirmation?
Patient GH is prescribed Vicodin (hydrocodone & acetaminophen) chronically, and is asked to provide a random UTS. On confirmation: hydrocodone = 537 ng/mL, hydromorphone = undetectable. What is going on here?
Reisfield GM, et al. Family physicians' proficiency in urine drug test interpretation. J Opioid Manag ; 3(6):

34. Time Permitting: Other Exam Questions
Patient IJ tests positive for cannabinoids on a random urine drug screen. She explains that her husband sometimes smokes pot in the bedroom (aka “passive positive”) Is this plausible?
Patient KL received an injection of procaine (Novocain) from a dentist. Will a UTS result be positive for cocaine because of it? What about the following cases?
“I tested positive for cocaine because I used Orajel or Anbesol (benzocaine) for a toothache.”, or
“I tested positive for cocaine because I got a bad sunburn and applied Solarcaine® (lidocaine).”
Reisfield GM, et al. Family physicians' proficiency in urine drug test interpretation. J Opioid Manag. 2007; 3(6):

35. Thank You
Any Questions?