Appendix I

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National Roadside Survey Pilot Test

Oral Fluid and Blood Analytic Procedures

Introduction

Within the criminal justice system, urine has traditionally been used as the biological specimen for analysis.  However, there are numerous products available which are designed to render a urine drug test inaccurate (gluteraldehyde, oxidants, nitrites etc.) as well as simple dilution of the specimen by the donor, with tap or toilet water.  Unless a collection is observed, the possibility of a diluted, adulterated or substituted urine specimen is increased.  While laboratories are able to test for some of these adulterants, obviously further testing increases overall costs.

As a result, interest in an alternative specimen for testing has increased.  Advancing technology has allowed laboratories to measure lower amounts of drug in biological specimens, allowing drug testing programs to incorporate the unique benefits offered by alternative biological fluids, at a comparable cost. 

When drugs are ingested, smoked, or injected, they travel through the body, and over time, convert into drug metabolites, which are subsequently excreted from the body.  The highest concentrations of these drugs and metabolites is in the urine, but they are also present in measurable quantities in blood, saliva, sweat, tears, hair and even finger and toenails. Improved instrumentation has allowed laboratories to measure drugs in these “alternative” matrices.

Due to its ease of collection, oral fluid has emerged as the specimen of choice to replace urine in many applications of testing for drugs of abuse

Advantages of Oral Fluid Testing

  1. Collection
    Saliva is easy to collect, handle, transport and store.  Since the collection is observed, the chance of adulteration or substitution of the sample is minimized, and there is no embarrassment or requirement for a same sex observer as there is with urine.  The entire collection process is rapid, taking perhaps 2-3 minutes.

Applications specifically based on ease of collection include: 

  1. Criminal justice, parole and probation testing where often observed urine collection is required. There is no same sex observation requirement using saliva, and the dignity of the donor is preserved.
  2. Drug court, where a high number of specimens are often required to be collected, handled, and shipped in a short space of time.
  3. Staffing agencies, requiring a rapid specimen collection for pre-employment purposes.
  1. Adulteration

Since collection is observed, there is a limited opportunity for the donor to adulterate or substitute the sample. It is difficult to hold in the mouth anything which may affect the test for any length of time, particularly if engaged in conversation when filling out drug testing forms, providing personal information and interacting with the collector.

In contrast to urine, the drug concentration in saliva is unaffected by liquid intake.

  1. Window of detection

For most drugs, the detection time after use, using urine as the specimen, is approximately 2-4 days. (Note: An exception is marijuana, where in some cases, chronic marijuana smokers can be detected up to 2-3 weeks after last use). 

For oral fluid, the detection window is generally shorter, although for some drugs it can approach 2 days, overlapping the urine window. The advantage of this is that very recent drug use can be detected by employing saliva as the test specimen.  Since saliva is thought to reflect blood levels at a given time point, the presence of a parent drug (for example, cocaine) can be interpreted as an indication of being “under the influence” of cocaine at that specific time.  It is generally not possible to interpret a urine test result as being “under the influence” of a drug, and this critical information would be lost using urine as the test specimen.

Applications specifically based on the ability of saliva to show a person to be “under the influence” of a drug include:

  1. Probation and Parole settings, where using illegal drugs is a violation of parole
  2. “Reasonable suspicion”, “For cause” or “Post accident” testing, when there is an incident or a suspicious activity in the workplace, which may be due to drug or alcohol use
  3. Methadone maintenance and pain management centers, requiring a rapid answer as to whether the individual recently ingested the prescription drug
  1. Profile of drugs

The profile of drugs analyzed using saliva is somewhat wider, and considerably more useful than those in the standard urine panel. 

  • Opiates: Recent data has shown a very high prevalence of 6-acetylmorphine (a metabolite of heroin) in saliva specimens testing positively for morphine.  The selection of oral fluid as the test specimen increases the opportunity of identifying heroin users.  Under the urine program, 6-AM is not even tested for unless over 2000 ng/ml of morphine are present, severely reducing the number of heroin users identified by urinalysis. 
  • Marijuana: Marijuana metabolites take 3-6 hours after smoking to be detectable in urine. However, the active compound, tetrahydrocannabinol (THC) will be present almost immediately in saliva, likely due to its presence in the mouth following marijuana smoking, therefore very recent use can be identified.
  • Cocaine: In urine testing, only a metabolite, benzoylecgonine is detectable using the SAMHSA guidelines. A positive urine finding gives no information on the state of the individual donor.  In contrast, for oral fluid analysis, both parent cocaine and benzoylecgonine are identified. The presence of cocaine in the sample can be interpreted as very recent use of cocaine and possibly “under the influence” of the drug. The detection of benzoyecgonine lengthens the window of detection for cocaine use in saliva.
  • Amphetamines: Under proposed guidelines for both urine and oral fluid, the inclusion of Ecstasy and its metabolite will be allowed in the amphetamine panel.
  1. Cost savings:

The major cost saving in converting from urinalysis to oral fluid testing is in the collection:

  • No same sex observers are required
  • No special facilities or conditions are needed (for example, “blueing” agent in toilet water)
  • The cost of specimen transport and storage is significantly reduced
  • There are no added costs to determine “adulteration” of the specimen
  • In workplace settings, there is a significant reduction in time wasted travelling to and from the collection site, since collections can be performed anywhere
  1. On-site” tests

Oral fluid lends itself very well to “on-site” testing, in terms of obtaining a rapid result, with no requirement for skilled personnel or special facilities. Rapid tests have been reported to perform well for opiates, methadone, amphetamines, and to some extent, cocaine.  However, the main problem with all “on-site” oral fluid tests at this time, is the difficulty of achieving the required sensitivity for marijuana testing.

The proposed “cut-off” levels can be achieved using laboratory based testing, which also has the added advantages of improved quality control, confirmed results using GC/MS or MS/MS techniques and formal reporting.

Disadvantages of Oral Fluid Testing

Of course, nothing is perfect, and there are disadvantages to using oral fluid as a test specimen. 

  1. Collection Devices:

There are several variations in collection device and it has been reported that the method of collection influences the test result.  Some devices consist of a pad attached to a stick (like a popsicle) which is placed into the mouth for a given time (e.g. Intercept ™). The saliva absorbs onto the pad and is then placed into a buffer for transport to the laboratory.  The problem with this is that it is not known exactly how much oral fluid was actually collected, so there is a potential for erroneous results, most likely false negatives based on insufficient sample volume.  Cut-off concentrations based on such a device are not relevant or applicable to other types of collectors.

Other devices (e.g. Quantisal™) have a blue volume indicator on the collector showing when 1 mL has been collected.  This is an improvement over the Intercept™ collection system, however, both of these devices are then placed into a buffer for transportation, and it is difficult to determine precisely how much drug is eluted from the pad into the buffer.

Some manufacturers are now requiring donors to “spit in a cup” which is often not too pretty to observe!

  1. Specimen Volume

A problem related to the type of device is the collection of adequate volume for screening and confirmation, particularly if more than one drug confirmation is required. 
Generally, a much lower volume of saliva than urine is provided by a donor.  This brings up the issues of re-testing of the specimen (in the event of a batch failure) and “split-sample” testing (when another laboratory is required to confirm the first result).  An adequate volume of specimen is critical for a valid test.  In some collection devices, drugs may absorb onto the collection pad, and it is not clear how much drug is removed from the pad by the buffer.

Some “on-site” screening tests require the collection of an additional specimen to be sent to the laboratory for confirmation, but the same issues regarding collection device are valid.

  1. Federal Workplace Testing

The Division of Workplace Programs, within the Substance Abuse and Mental Health Service Administration (SAMHSA), has yet to approve any alternative specimens for federal workplace testing, but saliva, hair and sweat are currently under consideration for approval in workplace programs.  Guidelines have been drafted and are in the process of implementation. 

However, certified laboratories are currently offering oral fluid testing and carrying out its analysis under good laboratory practice conditions, including chain-of-custody, quality control, batch review and formal reporting requirements.  There are accrediting agencies specifically inspecting oral fluid procedures, so that the quality of the result is ensured.

Summary

Oral fluid offers a simple, dignified, observed collection.  It provides a relatively short history of drug use, therefore is an excellent specimen choice for “reasonable suspicion”, “post-accident” or “for cause” testing, where identification of the parent drug shows that the donor was “under the influence” of the drug at the time the sample was taken.  It is particularly useful for the identification of heroin users, and those under the influence of marijuana. 

As oral fluid testing becomes more popular, the costs associated with its analysis are approaching those of urine, providing an excellent opportunity for drug testing programs to benefit from the analysis of alternate specimens.

Matrix

Advantages

Disadvantages

 

URINE

  1. Most widely tested specimen
  2. Drugs are generally in high concentration
  3. Adequate volume for testing and re-testing by a second laboratory
  4. Federal standard cut-offs, testing protocols and laboratory procedures exist
  • Easy to adulterate
  • Collection not observed
  • More costly for shipping and storage
  • No relationship between drug concentration and impairment

 

SALIVA

  1. Easy to collect
  2. Difficult to adulterate since collection is observed
  3. Presence of parent drug shows “under the influence”
  4. Useful for the detection of recent drug use
  5. Useful for the identification of heroin users
  1. Short drug history
  2. Marijuana levels are low, and likely due to THC in the mouth following smoking
  3. Specimen volume may be device dependent and is generally low
  4. No standard cut-offs, testing or collection protocols, or laboratory procedures (yet !)

Standard Drug Confirmation Panel

Urine Profile

Oral Fluid Profile

Cocaine: Benzoylecgonine

Cocaine: Cocaine and benzoylecgonine

Opiates:

  • codeine
  • morphine

(Note: Over 2000 ng/ml morphine then requires further testing for 6-acetylmorphine)

Opiates:

  • codeine
  • morphine
  • 6-acetylmorphine (heroin metabolite)
  • hydrocodone
  • hydromorphone
  • oxycodone

Amphetamines:

  • methamphetamine
  • amphetamine

Amphetamines:

  • methamphetamine
  • amphetamine
  • MDMA (Ecstasy)
  • MDA

Marijuana: Carboxy-THC

Marijuana: THC

Phencyclidine

Phencyclidine

Screening Assays

Oral Fluid
Sample Preparation

The oral fluid specimens were collected using a Quantisal™ collection device (Immunalysis, Pomona CA). When the absorbent collection pad had absorbed 1 mL of neat oral fluid (+-10%), a blue dye was visible in the indicator window on the plastic stem of the collection pad.  The pad was placed in a polypropylene transport tube containing 3 mL of extraction buffer solution, capped and sent to the laboratory.

The sample volume of oral fluid used for screening was analyte dependent. The desired concentration range is shown below. An aliquot of the oral fluid + buffer was added to the micro-plate wells for analysis according to the manufacturer’s instructions in the package insert (representative insert included).   A specimen was considered to be presumptively positive if it screened higher than the cut-off concentrations.

 Blood
Sample Preparation

The blood specimens were collected into gray top tubes and transported to the laboratory.  Upon receipt the specimens were diluted 1:10 with bovine serum albumin.

The sample volume of diluted blood used for screening was analyte dependent. The desired concentration range is shown below. An aliquot of the diluted blood was added to the micro-plate wells for analysis according to the manufacturer’s instructions in the package insert (representative insert included).   A specimen was considered to be presumptively positive if it screened higher than the cut-off concentrations.

DOSE RESPONSE IN CONCENTRATION PER MICRO-WELL FOR ELISA

KIT

Picograms / well

Analyte

Amphetamine 209

50-150

d-amphetamine

Barbiturates 210

40-80

Secobarbital

Carisoprodol 231

5000

Carisoprodol

Benzodiazepines 214

40-80

Oxazepam

Benzoylecgonine 206

150-300

Benzoylecgonine

Cocaine/benzoylecgonine 212

200-300

Benzoylecgonine

Methamphetamine 211

50-150

d-methamphetamine

Morphine Specific 213

80-120

Morphine

Oxycodone 221B

150-250

Oxycodone

PCP 208

7.5-15

 PCP

Cannabinoids 224

40 - 60

Carboxy-THC (l)

Cannabinoids 205

40-60

Carboxy-THC (l)

Methadone 232

100-200

Methadone (d,l)

Fluoxetine 234

750-1200

Fluoxetine

Sertraline 235

500 -1000

Sertraline

Tramadol 225

700-1200

Tramadol

Zolpidem 233

40-60

 Zolpidem

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