Drug Testing in Biological Matrices: Hair and Urine Charles McKay MD FACMT, FACEP, ABIM, MROCC Medical Toxicologist, Medical Review Officer, and Emergency.

Drug Testing in Biological Matrices:

Hair and Urine

Charles McKay MD FACMT, FACEP, ABIM, MROCC

Medical Toxicologist, Medical Review Officer, and Emergency PhysicianDivision of Medical Toxicology, Department of Traumatology and Emergency Medicine

Hartford HospitalAssociate Medical Director, Connecticut Poison Control Center

Associate Professor of Emergency MedicineUniversity of Connecticut School of Medicine

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

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

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 5”

– Pharmaceutical agents as research tools– Variety of compounds in forensic or research

setting• Heavy metals

– Inappropriately for number of “environmental contaminants”

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

Hair Growth Cycle

• Generally >90% 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

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

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:

Tip of HairScalp End

0 1 2 3 4 cm

Sample 1

Sample 2

Sample 3

Example: Hair Cocaine And Time of Cocaine Use

April 2006 March 2006 February 2006 January 2006

May 2006 April 2006 March 2006 February 2006 January 2006

Tip of HairScalp End

0 1 2 3 4 cm

Sample 2

Sample 3

Approximate Hair Growth Periods vs. Estimated Time of Cocaine Incorporation

• “I used to use, but haven’t used any cocaine in the last 3 months”• Sequential hair samples show decreased concentration over time

Example: Use of Hair and Urine Testing For Cocaine Metabolite

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

Tip of HairScalp End

0 1 2 3 4 cm

Sample 2

Sample 3

Positive Urine

Sample

Urine Samples done every 3-6 days (yellow=negative; black=positive)

TIME

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.

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

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

Hair Testing

• Collection

• Processing

• Analysis

• Interpretation

http://www.testcountry.com/images/hair_test_procedure.jpg

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.

So If Your Client Looked Like This… …Then Like This

Be very suspicious!

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

QUESTIONS?