Drug Testing in Biological Matrices: Hair and Urine

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Drug Testing in Biological Matrices Hair and
Urine

• Charles McKay MD FACMT, FACEP, ABIM, MROCC
• Medical Toxicologist, Medical Review Officer, and
  Emergency Physician
• Division of Medical Toxicology, Department of
  Traumatology and Emergency Medicine
• Hartford Hospital
• Associate Medical Director, Connecticut Poison
  Control Center
• Associate Professor of Emergency Medicine
• University of Connecticut School of Medicine

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Biomonitoring

• Generally applied when presence of a compound or
  concentration has some meaning
• Therapeutic drug monitoring
• Quantitative
• Detection of illicit drugs
• Usually qualitative
• End-of-shift workplace monitoring
• Quantitative comparison to OSHA regulations

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Validity of Biomonitoring

• Compound has defined source of exposure
• Compound is excreted in matrix of interest
• There is a control or reference population (if
  appropriate)
• Testing is defined as
• Screening prone to false positives or false
  negatives
• Confirmatory interpretation issues related to
  clinical relevance and limit of
  detection/reporting

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Applications of Hair Testing

• Almost any drug could be detected if commercial
  reason to develop test
• For practical purposes, testing is done for
• Usual drugs of abuse similar to workplace NIDA
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• Pharmaceutical agents as research tools
• Variety of compounds in forensic or research
  setting
• Heavy metals
• Inappropriately for number of environmental
  contaminants

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Identification of Compound in Hair

• Incorporation
• Via hair follicle during
  active growth phase
• Drug in perspiration from
  sweat/sebaceous glands
• External contamination
• Specimen preparation and washing
• Varies by laboratory
• May be addressed by measurement of metabolites

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Hair Growth Cycle

• Generally gt90 of the scalp hair is in active
  growth phase
• Average growth rate is 1 cm/month

From http//www.lahairmd.com/info/hairlossm.htm
Similar to diagram found in Habif TP. Clinical
Dermatology A Color Guide to Diagnosis and
Therapy, 2nd edition CV Mosby Co, 1990
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Sampling For Drugs of Abuse

• Hair sampling generally done with 50 or more
  hairs cut at scalp level
• Sectioning the hair can be used to compare one
  period of time to another
• Does not reflect previous few days of use
• Urine tests generally identify use within last
  few hours to several days

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Example Hair Testing For Cocaine/Metabolite

• Hair Testing for Cocaine reported results
• Sample 1 Positive for cocaine (measured on whole
  length of hair) at 454 ng/10 mg hair weight
• Sample 2 (4 ½ months later) Positive for cocaine
  in 2nd (15.8 ng/10 mg hair) and 3rd segments
  (73.5 ng/10 mg hair) only
• Sample 3 (5 ½ months after 1) Positive for
  cocaine (qualitative on whole length of hair)
• Hair Testing Interpretation

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Example Hair Cocaine And Time of Cocaine Use

• Approximate Hair Growth Periods vs. Estimated
  Time of Cocaine Incorporation
• I used to use, but havent used any cocaine in
  the last 3 months
• Sequential hair samples show decreased
  concentration over time

• April 2006 March 2006 February 2006
  January 2006
• May 2006 April 2006 March 2006
  February 2006 January 2006

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Example Use of Hair and Urine Testing For
Cocaine Metabolite
0 1 2 3 4 cm
Scalp End
Tip of Hair
Sample 2
Sample 3
TIME

• Urine Testing for Cocaine Metabolite
• 1/24/06 Positive
• 1/26/06 through 6/26/06 Negative

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Case Summary

• Urine testing reliably identifies cocaine use
  within previous few days.
• In conjunction with decreasing cocaine content in
  hair over time and no cocaine present in hair
  that grew over last couple months, there is no
  clinical laboratory evidence of cocaine use since
  the positive urine test.

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CAVEATS But what about

• variability in hair growth?
• Largest variable is in the length of time in
  resting phase
• May lead to appearance of prolonged clearance
  time for the fraction of hair that is no longer
  incorporating drug, but also not falling out
• variability in hair color?
• Higher melanin (eumelanin vs. pheomelanin)
  associated with more binding of some (basic)
  drugs
• variability in hair type/treatment?
• Higher incorporation into damaged
  (chemically-treated) hair
• Oval or flat hair shafts will curl, raising
  questions about true length (e.g. stretched?)
• external contamination?
• Usually indicates significant excretion from
  pores, so not really external contaminant
• Low-level findings can be differentiated by
  proper laboratory steps

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So, Is Hair Testing A Good Idea?

• Definition of good?
• Reliable technique to identify past substance use
• Sequential testing may support abstinence and
  identify relapse
• If adequate specimen handling and preparation
• May not identify all uses and users at very low
  levels
• resulting in unintended bias
• In one study, 15 doses of codeine over 5 days
  would be detected months later (at recommended
  federal cutoffs) in
• 100 of those with black hair
• 50 of those with brown hair
• 0 of those with blond or red hair
• Not a practical concern for most cases where drug
  concentrations are much higher than reporting (or
  detection) cutoffs

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Hair Testing

• Collection
• Processing
• Analysis
• Interpretation

http//www.testcountry.com/images/hair_test_proced
ure.jpg
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And In Response To Tests

• PassYourTest
• UrineClear
• PerfectUrine
• ClearTest

• 45 Minute Chewable Tablet
• Take the chewable with 48 ounces of water.
• Wait 45 minutes.
• Urinate 2-3 times during the hour that you are
  waiting.
• The tablet is effective for up to 6 hours.
• Helpful Hints
• Avoid toxins for 48 hours before using this
  product.
• Drink water before and after using this product.

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So If Your Client Looked Like This
Then Like This
Be very suspicious!
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Take Home Messages

• GC/MS or LC/MS techniques are reliable in the
  identification of chemical compounds
• Hair analysis is a reasonable mechanism to
  evaluate long term (months) drug abstinence
• There are issues near reporting cut-offs and
  limits of detection in the interpretation of
  positive tests that might be addressed by
• Analysis of metabolites
• Sequential sectioning
• Sample washing techniques
• The laboratory and toxicologists can provide
  assistance in interpretation

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QUESTIONS?