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Essentials for physicians and health care professionals ordering and interpreting urinary
screens for drugs of abuse.
Dr. Edward Randell
Disclosure of Potential for Conflict of Interest
FINANCIAL DISCLOSURE Grants/Research Support: CIHR and others. Speakers Bureau/Honoraria: None Consulting Fees: None Other: Employee of Memorial University
Learning Objectives
• Describe why urine is the preferred sample for drug of abuse screening
• Describe common interfering substances • Identify factors to consider when interpreting
positive and negative drug screens • Describe the strengths and limitations of
common techniques used for urine drug screening
Why are UDS important to clinical practice?
• Can identify more non-adherent patients than monitoring behavior and self-reporting alone
• Identify new or recurrent drug misuse • Support clinical decisions • Assist diagnosis • Deterrent and provide objective evidence of
abstinence in high risk patients
Why is interpreting UDS correctly important?
• UDS screen interpretation carries significant potential for harm if done incorrectly
• False accusations of drug abuse or diversion based on misinterpretation of UDS results carry potential medicolegal consequences.
Health care professionals who effectively employ UDS have a good understanding of the pharmacology of commonly encountered drugs and work closely with lab professionals when ordering and interpreting these tests
Drug Screens
Common Drug of Abuse
Amphetamines and Methamphetamine
Opiates
Benzodiazepines
Cocaine
Barbiturates
Methadone
Phencyclidine
Marijuana
Oxycodone
Introduction
Check out discuss of similar case at: http://paindr.com/two-puffs-too-bad-demystifying-marijuana-urine-testing/
A 40 years old female receiving Oxycodone, presents to a pain clinic for routine follow-up visit. A random urine drug screen is done by immunoassay and she tests positive for Marijuana (cannabinoids positive). When asked, she admits “I only smoked two puffs five days ago”. Fact or Myth?
Quiz: 7 UDS questions What is detected in the urine following:
1. Acetaminophen/Codeine administration 2. Morphine administration 3. Heroine use 4. Poppy seed consumption 5. 2nd hand exposure to Marijuana smoke
6. Explain a negative drug screen result for a patient on chronic opioid therapy… 7. On receiving a negative result on an opiate screen for a patient you prescribed hydromorphone you would…
• To determine level of UDS interpretative knowledge of physicians who use UDS to monitor adherence on chronic opioid therapy
• 7 question survey given to 114 physicians • 77 who use UDS regularly • 37 who didn’t
Reisfield, G. M., Bertholf, R., Barkin, R. L., Webb, F., & Wilson, G. (2006). Urine drug test interpretation: what do physicians know?. Journal of opioid management, 3(2), 80-86.
Reisfield, G. M., Bertholf, R., Barkin, R. L., Webb, F., & Wilson, G. (2006). Urine drug test interpretation: what do physicians know?. Journal of opioid management, 3(2), 80-86.
Reisfield, G. M., Bertholf, R., Barkin, R. L., Webb, F., & Wilson, G. (2006). Urine drug test interpretation: what do physicians know?. Journal of opioid management, 3(2), 80-86.
• 99 internal medicine residents • Compared personal confidence with
interpreting drug screens vs. measured performance.
Starrels, J. L., Fox, A. D., Kunins, H. V., & Cunningham, C. O. (2012). They don’t know what they don’t know: Internal medicine residents’ knowledge and confidence in urine drug test interpretation for patients with chronic pain. Journal of general internal medicine, 27(11), 1521-1527.
Starrels, J. L., Fox, A. D., Kunins, H. V., & Cunningham, C. O. (2012). They don’t know what they don’t know: Internal medicine residents’ knowledge and confidence in urine drug test interpretation for patients with chronic pain. Journal of general internal medicine, 27(11), 1521-1527.
There was no significant differences in interpreting drug screens among medical residents stating confidence in their ability versus those acknowledging lack of confidence.
Brief History of Drug screening 1950’s blood “tox screens”
1960’s TLC 1970’s IA and
POC testing
1980’s IA + GC-MS
21st Century LC-MS/MS
1950’s Emergency Rooms and Death
investigations
1970’s: Addiction treatment & criminal justice
1970’s Methadone maintenance/Opioid
Treatment/Military Workplace/Industry/Govt.
Highway safety
How are DOAs screened?
Immunoassay GC-MS (Gas Chromatography coupled to Mass
Spectrometry) LC-MS (Liquid Chromatography coupled to Mass
Spectrometry)
Actually the following list is more accurate Method Common Abbreviation
Cloned enzyme donor immunoassay CDIA
Enzyme-linked immunosorbent assay ELISA
Enzyme-multiplied immunoassay technique EMIT
Fluorescence polarization immunoassay FPIA
Radioimmunoassay RIA
Point of care testing methods POCT
Gas Chromatography Mass Spectrometry GC-MS
Liquid Chromatography Ultraviolet Detection HPLC-UV
Liquid Chromatography High Resolution Mass spectrometry LC-hrMS
Liquid Chromatography tandem mass spectrometry LC-MS/MS
Liquid Chromatography time-of-flight mass spectrometry LC-TOF
Thin Layer Chromatography TLC
Immunoassay Urine Drug Screens (UDS) • Uses antibodies specific for drug or common
metabolite target • Detection of a drug depends on antibody
specificity, cut-off, and drug concentration. • Immunoassay-based Lab Methods
• Automated on laboratory analyzers
• Immunoassay-based POCT devices • Presence of band indicates a positive result
GC-MS
Barbosa, S. S., Leal, F. D., Padilha, M. C., Silva, R. S., Pereira, H. M. G., Aquino Neto, F. R., & Silva Júnior, A. I. D. (2012). Specificity and selectivity improvement in doping analysis using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry. Química Nova, 35(5), 982-987.
LC-MS/MS
20 Eichhorst, J. C., Etter, M. L., Rousseaux, N., & Lehotay, D. C. (2009). Drugs of abuse testing by tandem mass spectrometry: a rapid, simple method to replace immunoassays. Clinical biochemistry, 42(15), 1531-1542.
UDS techniques are targeted or untargeted
Targeted drug screens - identify specific drugs to screen excluding most others.
• Most common: Immunoassay & LC-MS/MS • All UDS commonly used in NL are targeted. Untargeted drug screens – are broad drug
screens without exclusion. • GC-MS and LC-hrMS methods are untargeted.
Comparison of UDS techniques Screening Screening/Confirmatory
Analysis Immunoassay GC-MS or LC-MS/MS
Ability to detect drug class (Sensitivity)
Low to nil for synthetic opioids but fair for others
High
Ability to discriminate drug from similar compounds (Specificity)
Variable-false positives and false negatives
High
Use Qualitative screen Quantitative confirmation
Cost Variable Variable
TAT rapid Many days
Application Works best for screening drug-free population; may be less useful in pain-management.
Definitive & Legally defensible
Interpretation Complex Complex
Why is urine the most used sample?
• Easy to obtain • Minimal preparation • Most drugs of interest & their metabolites
concentrate in urine • Good sensitivity and specificity for recent use • Wider window of detection compared to blood
Positivity in urine indicates exposure ...But
• Does not correlate with clinical status • Can miss very recent exposure • Positivity means different things depending on
the screening method used.
Interpreting urine drug screens
Urine Drug Test Positive Negative
Patie
nt re
port
s ta
king
the
drug
Yes
True Positive 1. Patient is taking the drug as
reported. 2. Test detects the substance
reported
False Negative 1. Patient may be mistaken about
taking the drug. 2. Last dose too low or too long ago to
be detected.
No
False Positive 1. Interfering substance 2. Unreported self-
administration of a cross-reacting substance
True Negative 1. Patient is not taking the drug as
reported. 2. UDS does not detect the substance.
UDS Interpretation
Factors Affecting UDS interpretation
Time since ingestion
Duration of use
Administration Route Urine volume Hydration
Status
Amount of drug ingested
Diet
Urine pH
Concurrent Medications
Urinary frequency
Testing Method
Dosage Intervals
Disease State Body Weight
Individual metabolism
Interpreting UDS
• Unexpected interferences • Target Compounds • Cut-offs • Windows of Detection • Importance of considering drug metabolism
Common Immunoassay Interferences Target Drugs Interfering Drugs
Amphetamines Diet Pills, Vicks inhaler (US), Trazodone, Aripiprazole, Promethazine and Phentermine
Marijuana Efavirenz (Antiretroviral), baby shampoo and soap, pantoprazole and possibly other proton pump inhibitors
Hydromorphone Hydrocodone
Methadone Quetiapine
Fentanyl Trazodone
TCAs Quetiapine
Opiates/Morphine Poppy Seeds, Quinolone antibiotics
Benzodiazepines Sertraline
PCP Venlafaxine
Agents that can cause positive results on amphetamine immunoassay.
Moeller, K. E., Lee, K. C., & Kissack, J. C. (2008, January). Urine drug screening: practical guide for clinicians. In Mayo Clinic Proceedings (Vol. 83, No. 1, pp. 66-76). Elsevier
Cross-reactivity is a common problem for UDS relying on immunoassay technique.
Different methods have different targets
Drug/Class Immunoassay Screen Mass Spectrometry Benzodiazepines Oxazepam Specific Drugs: Diazepam,
Oxazepam, Loraxepam, Temazepam, Alprazolam, Clonazepam…
Opiates Morphine Specific Drugs: Morphine, Codeine, Oxycodone, Fentanyl, Hydromorphone….
Cocaine Cocaine Metabolite Cocaine and Benzoeconine Marijuana THC metabolite THC and THC-COOH Amphetamine & Methamphetamine
Amphetamine & Methamphetamine
Specific Drugs: Amphetamine, MDA, MDMA, metamphetamine…
Some Mass Spectrometry methods are non-targeted – meaning that they detect “everything” and both suspected and unsuspected can be explored.
Moeller K E et al. Mayo Clin Proc. 2008;83:66-76
For both Morphine and Codeine
Different methods have different cutoffs.
Cutoffs determine the drug concentration at which a positive result is reported. This is not the same as a detection limit.
For how will a UDS remain positive?
Most- 1 to 3 days Some (marijuana, diazepam, ketamine, PCP) may
be detected for a week or more Depends of urine concentration of drug and assay
cutoff
Excretion pattern of Cocaine
0
2000
4000
6000
8000
10000
12000
0 10 20 30 40 50 60
Cocaine (base) 42 mg smoked BenzoyleconineEcgonine Methyl esterCocaine
Cone, E. J., Sampson-Cone, A. H., Darwin, W. D., Huestis, M. A., & Oyler, J. M. (2003). Urine testing for cocaine abuse: metabolic and excretion patterns following different routes of administration and methods for detection of false-negative results. Journal of analytical toxicology, 27(7), 386-401
Detected by immunoassay (300 µg/L)
Marijuana (Heavy use) (Moderate use)
Benzodiazepines (Long acting)
Barbiturate (long acting)
Window of detection in urine
2 days 4 days 6 days 1 week 2 weeks
(Short acting)
(Short)
(Single use)
Amphetamine & Metamphetamine
Alcohol and Phencyclidine
Moeller K E et al. Mayo Clin Proc. 2008;83:66-76
Cocaine
Meperidine
Window of detection in urine
1 days 2 days 3 days
Methadone
Oxycodone
Morphine from Heroine
Morphine
Moeller K E et al. Mayo Clin Proc. 2008;83:66-76
Codeine
4 days
Up to 6 days if metabolite tested
Heroine only a few hours
Often missed
Often missed
Window of detection based on sample type.
Minutes Hours Days Weeks Months Years
Blood
Saliva
Urine
Sweat
Hair
Implication of cutoffs and cross-reactivity to immunoassay.
Smith, M. L., Shimomura, E. T., Summers, J., Paul, B. D., Nichols, D., Shippee, R., ... & Cone, E. J. (2000). Detection times and analytical performance of commercial urine opiate immunoassays following heroin administration. Journal of Analytical Toxicology, 24(7), 522-529.
Drugs detected by opioid screens using mass spectrometry
Drug Mass Spectrometry
Heroine 6 monoacetyl morphine Morphine
Codeine Codeine Morphine Hydrocodone
Oxycodone Oxycodone Oxymorphone Hydrocodone
Poppy Seeds Morphine
Hydrocodone Hydrocodone Hydromorphone
Fentanyl Fentanyl Norfentanyl
Most drug screens identify opiates not opioids
Opioid • Chemicals that work by
binding opioid receptors • Opiates + semisynthetic • Heroin, hydrocodone,
Hydromorphone, oxycodone, Fentanyl, Meperidine,…
Opiate • Natural alkaloids derived
from opium poppy • Codeine and Morphine
Many Opioids and Benzodiazepines are missed by routine immunoassay UDS.
Interpretation
Negative for prescribed medication
Diversion
Patient run out of medication
Patient not taking full amount
Sample tampering
Immunoassay testing (false negative)
Interpretation
Positive for un-prescribed medication
Drug Abuse
Testing error: False Positive (poppy seeds)
Laboratory error: testing or clerical
Variability: within and between patients
Immunoassay testing
Open communication with lab is required…
1. The clinical value of UDS depends on the level of interaction between the ordering physician and testing lab.
2. Appropriate lab use requires consideration of: 1. The purpose of the UDS 2. Why, who, and when the test is done 3. The limits of the lab results 4. What is meant in lab reporting terminology 5. The significance of screening cutoffs
How people beat drug tests
1. Substitution with synthetic urine or “purchased” drug free urine
2. Flush out with commercially available product 3. Adulteration by adding reactive or masking
substance to the urine 1. Visine eye drops, Salt, Oxidizing agents, Potassium
Nitrite, glutaraldehyde.
Finding Cheats: A few simple tests
Sample Temperature • 90 to 100 for first 4 minutes
pH • Should be 4.5 to 8
Creatinine • Should be >3 mmol/L
Nitrite • Negative
Quiz: 7 UDS questions What is detected in the urine following:
1. Acetaminophen/Codeine administration 2. Morphine administration 3. Heroine Use 4. Poppy seed consumption 5. 2nd hand exposure to Marijuana smoke
6. Explain a negative drug screen result for a patient on chronic opioid therapy. 7. On receiving a negative result on an opiate screen for a patient you prescribed hydromorphone you would…
(Codeine & Morphine)
(Morphine)
(6 monoaceylmorphine & Morphine)
(Morphine)
(Nothing)
(Which opioid? Screen may not measure.)
(Most screens do not measure hydromorphone. Request confirmatory procedure)
Effective UDS use depends on:
Good relationship with Lab
Know which test lab is using
Insure screening results are
confirmed before serious action
Choose testing strategy based on purpose of testing
Know recent medication history
Insure proper collection and
labelling
References Dowell, D., Haegerich, T. M., & Chou, R. (2016). CDC guideline for prescribing opioids for chronic pain—United
States, 2016. JAMA, 315(15), 1624-1645. Moeller, K. E., Lee, K. C., & Kissack, J. C. (2008). Urine drug screening: practical guide for clinicians. In Mayo Clinic
Proceedings (Vol. 83, No. 1, pp. 66-76). Elsevier Hammett-Stabler, C.A., Weber, L.R. (2008) A Clinical Guide to Urine Drug Testing. CME monograph available at
http://ccoe.rbhs.rutgers.edu/online/ARCHIVE/endurings/09MC07.pdf Reisfield, G. M., Bertholf, R., Barkin, R. L., Webb, F., & Wilson, G. (2006). Urine drug test interpretation: what do
physicians know?. Journal of opioid management, 3(2), 80-86. Starrels, J. L., Fox, A. D., Kunins, H. V., & Cunningham, C. O. (2012). They don’t know what they don’t know: Internal
medicine residents’ knowledge and confidence in urine drug test interpretation for patients with chronic pain. Journal of general internal medicine, 27(11), 1521-1527.
Pesce, A., West, C., Egan-City, K., & Clarke, W. (2012). Diagnostic accuracy and interpretation of urine drug testing for pain patients: an evidence-based approach. In Toxicity and drug testing.