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By: Paul L. Cary Toxicology Laboratory University of Missouri

THE MARIJUANA DETECTION WINDOW: DETERMINING THE LENGTH OF TIME CANNABINOIDS WILL REMAIN DETECTABLE IN URINE FOLLOWING SMOKING. By: Paul L. Cary Toxicology Laboratory University of Missouri. Introductory Comments:. urinary cannabinoid detection window (CDW) is not settled science

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By: Paul L. Cary Toxicology Laboratory University of Missouri

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  1. THE MARIJUANA DETECTION WINDOW:DETERMINING THE LENGTH OF TIME CANNABINOIDS WILL REMAINDETECTABLE IN URINE FOLLOWING SMOKING By: Paul L. Cary Toxicology Laboratory University of Missouri

  2. Introductory Comments: • urinary cannabinoid detection window (CDW) is not settled science • The law is not black & white – neither is science • elimination of cannabinoids is complex • formualting a CDW invites controversy • should not preclude the court from development of a reasonable & pragmatic CDW for the vast majority case adjudications

  3. Cannabinoid Detection in Urine • Conventional wisdom has led to the common assumption that cannabinoids will remain detectable in urine for 30 days or longer following the use of marijuana. • RESULT: • delay of therapeutic intervention • hindered timely use of judicial sanctioning • fostered denial of marijuana usage by clients

  4. CDW Discussion: • general drug detection window issues • necessity for establishing detection window • cannabinoid elimination research • what perpetuates the 30+ day elimination assumption • guidance for establishing a cannbinoid detection window • effective use of the CDW benchmark

  5. The Drug Detection Window

  6. Defining the detection window: • the length of time in days following the last substance usage that urine samples will continue to produce positive drug test results • the number of days until last positive • NOT - how long drugs will remain in a client’s “system” • reasonable estimate based upon many factors – drug use, biological and testing issues

  7. Factors Influencing Detection Window: • drug dose • route of entry into body • duration & frequency of use • rate of metabolism • testing sensitivity • specificity of testing method

  8. Relative Detection Times –by Specimen

  9. Drug Detection Times - by Drug • amphetamines: 1-4 days • cocaine: up to 72 hours • opiates: 1-4 days • PCP: up to 6 days • barbiturates: up to a week • benzodiazepines: up to a week • . . then there’s alcohol & cannabinoids

  10. Why is establishing a CDW important? How many days is it likely to take for a chronic marijuana user to reach a negative urine drug test result? How long can cannabinoids be excreted and detected in urine after a single exposure to marijuana? How many days of positive urine drug tests for cannabinoids constitutes continued marijuana usage?

  11. Why is establishing a CDW important? How often should a client’s urine be tested to monitor for continued abstinence from marijuana? How many days should the court wait before retesting a client after a positive urine drug test for cannabinoids has been obtained? How should the court interpret a positive urine drug test for cannabinoids after a client has completed an initial 30-day detoxification period designed to “clean out” their system?

  12. Cannabinoid Elimination Research

  13. Conflicting Research? • In a recent forensic publication, Dr. Marilyn Huestis: “Monitoring acute cannabis usage with a commercial cannabinoid immunoassay with a 50-ng/mL cutoff concentration provides only a narrow window of detection of 1–2 days,” (2002). • In a 1985 article by Ellis et. al.; “that under very strictly supervised abstinence, chronic users can have positive results for cannabinoids in urine at 20 ng/mL or above for as many as 46 consecutive days from admission”

  14. Many of the early cannabinoid studies often cited as proof of 30+ day detection periods suffered from . . . • unable to ensure abstinence during the study • detection cutoffs used very low • used testing methods no longer available - poor specificity

  15. Despite these problems . . . . • Smith-Kielland, et. al. – average time to the first negative sample (cannabinoid cutoff of 20 ng/mL) • 3.8 days for infrequent users • 11.3 days for frequent users • Swatek study– 8 of 10 chronic subjects tested below the 50 ng/mL cutoff after an average of 13 days • Johansson et. al. identified only one subject that tested positive for longer than 14 days with all thirteen subjects having an average last day with detectable levels (using a 20 ng/mL cutoff) of 9.8 days • despite potential factors restricting interpretation, study subjects with exceptionally long CDW (30-plus days) were just that—exceptional

  16. Recent Research - Acute Use • 1995 (Huestis, et. al.) six health males - locked medical ward - 20 ng/mL cutoff • CDW 3-6 days following high dose cigarette • 1996 (Huestis, et. al.) six health males - locked medical ward - 15 ng/mL GC/MS cutoff • CDW 122 hours following high dose cigarette • 2001 (Niedbala, et. al.) 18 health males - locked medical ward - 50 ng/mL cutoff • CDW averaged 42 hours after high dose cigarette

  17. Recent Research - Acute Use • acute marijuana elimination studies conclude that after single usage events cannabinoids are detected in urine for no more than a few days

  18. Recent Research - Chronic Studies • 2001 (Reiter, et. al.) 52 volunteer chronic users on detox ward - using 20 ng/mL cutoff • used daily testing to control covert THC use • maximum cannabinoid elimination time – 433.5 hours or 18.1 days • mean elimination 117.5 or 4.9 days

  19. Recent Research - Chronic Studies • 1999 (Kouri, et. al.) 17 chronic users - documented 5000 separate “episodes” marijuana use (one joint per day for 13.7 years) - 20 ng/mL cutoff • 5/17 tested negative at one week • by the second week - 9/17 were negative • by week 3 - 11/17 tested negative • study ended at day 28 with six still testing positive

  20. Recent Research - Chronic Studies • even under extraordinary exposure criteria, the average CDW is approximately 14 days, with significant majority of chronic marijuana users testing negative prior to 30 days

  21. Perpetuating the Myth

  22. Perpetuating 30-Plus Day Assumption • Substance abuse treatment literature that proclaims, “some parts of the body still retain THC even after a couple of months”. • Drug abuse information targeted toward teens “Traces of THC can be detected by standard urine and blood tests for about 2 days up to 11 weeks”. • Health information websites that provide the following guidance; “At the confirmation level of 15 ng/ml, the frequent user will be positive for perhaps as long as 15 weeks.” • And, last but not least Dr. Drew Pinsky (a.k.a. Dr. Drew) who has been the co-host on the popular call-in radio show "Loveline" for 17 years who states; “Pot stays in your body, stored in fat tissues, potentially your whole life.”

  23. Establishing a Cannbinoid Detection Window

  24. CDW – Preface Comments • 30+ day detection window often exaggerates duration of detection window • established need reasonable & pragmatic court guidance • detection window based upon screening test cutoff as benchmark (50 & 20 ng/mL) • based upon current screening methods • no studies of cannabinoid elimination using on-site testing devices (i.e. “instant” tests) • confirmation (GC/MS) cutoff irrelevant

  25. GC/MS Cutoff Irrelevent • initial screen (–); sample not sent for confirmation • initial screen (+) & confirmation (+); confirmation merely validating screen • initial screen (+); sample fails to confirm (–); CDW shorter than guidance - not prejudicial to client

  26. Cannabinoid Detection Window • detection time: at 50 ng/mL cutoff • 1 - 3 days for single event/occasional use • up to 10 days for heavy chronic use • detection time: at 20 ng/mL cutoff • 5-7 days for single event/occasional use • up to 21 days for heavy chronic use

  27. Marijuana Usage Issues • Chronic Use - do drug court practitioners need to be concerned about the potential of extended cannabinoid detection times impacting court decisions (i.e., sanctions)? • client entry into court program • detox or “clean out” phase • following initial detox - past chronic usage will not effect CDW

  28. Detox Stage or “Clean-Out” Phase • 30-day period commonplace • regardless of origin - represents a reasonable time period • it is unlikely (utilizing reasonable physiological or technology criteria) that a drug court client would continue to remain cannabinoid positive at the end of this designated abstinence period

  29. Establishing an Abstinence Baseline • “actual” baseline – client has demonstrated abstinence via repeated negative drug tests • “science-based” baseline – court-established time limit after which a client should not test positive if that client has abstained from drug use • primarily applies to marijuana • individuals who continue to produce positive drug test results beyond the established baseline maximums are subject to sanction • AB – not a secret! Inform clients

  30. Testing Following Positive Results Due to cannabinoids prolonged elimination - Why continue drug testing? • testing includes drug other than cannabinoids • suspension of scheduled client drug testing sends the wrong therapeutic message • curtailingtesting extends unnecessarily the period of uncertainty about a client’s recent behavior and may delay appropriate therapeutic strategies or sanction decisions

  31. Recent Cannabinoid Use versus Non-recent use (double sanction issue): • How do drug courts discriminate between new drug exposure and continued elimination from previous (chronic) use ? • an issue only in first phase of program • only drug that poses concern is cannabinoids • “two negative test” rule – two back-to-back negative drug tests post clean out

  32. Drug Court’s Competing Imperatives • the need for rapid therapeutic intervention (sanctioning designed to produce behavioral change) • the need to ensure that the evidentiary standards, crafted to protect client rights, are maintained

  33. Addressing Imperatives for Cannabinoids • acknowledge research reporting prolonged THC elimination • establish a reasonable and pragmatic detection window guidance for the vast majority of case adjudications • sound judicial practice requires that court decisions be based upon case-specific information • in unconventional situations that confound the court, qualified toxicological assistance should be sought

  34. SUMMARY • One of the most important prerogatives of drug court is to clearly define the behavioral expectations for clients by establishing compliance boundaries required for continued program participation. • Establishing a detection window allows the application court intervention strategies in an equitable and consistent manner. • Establish the cannabinoid detection window based upon drug testing cutoff. • Clients need to understand abstinence benchmarks.

  35. SUMMARY (continued) • The goal is to establish a given time period (detection window limit) after which a client should not test positive for cannabinoids as a result of continued excretion from prior usage. • “Drug-Free” is not an attainable measurement. • While detection window benchmarks should guide the sanctioning process for violations of abstinent behavior, courts are urged to judge a client’s level of compliance on a case-by-case basis using all of the behavioral data available to the court in conjunction with drug testing results.

  36. Full Text of:The Marijuana Detection Window: Determining the Length of Time Cannabinoids Will Remain Detectable in Urine following Smoking: A Critical Review of Relevant Research and Cannabinoid Detection Guidance for Drug Courts, Drug Court Review (publication of the National Drug Court Institute, Arlington VirginiaVolume V, Issue 1, Spring 2006, pages 23-58.

  37. email address: • carypl@health.missouri.edu

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