Toxicology Screening

1. Protocol: Assess validity of real urine sample
   1. Urine temperature (within 4 minutes of voiding): 90 F (32.2 C) to 100 F (37.7 C)
   2. Urine pH: 4.5 to 8.5 (some facilities use pH 3.0-11.0)
   3. Urine Creatinine: 20 mg/dl or greater (otherwise artificially diluted)
   4. Nitrite concentration <500 mg/dl (<4.2 mmol/L)
   5. Sample size 30 ml or more
2. Protocol: Prevent urine sample tampering
   1. Remove outer clothing (jackets, sweatshirts, hat)
   2. Remove any items in urine collection area that could be used to tamper with sample (bleach, vinegar, soap, ammonia, salt)
   3. Remove any items from pockets
   4. Do not allow briefcases, backpacks, purses and other similar items in collection area
   5. Patient should wash and dry hands with liquid soap under observation
   6. Add bluing agent to toilet and turn off water to the testing area
   7. Observe the actual collection and use chain of custody forms to accompany the sample
   8. Consider split sample collections with tamper resistant containers
3. Preparations: Sedatives and Hypnotics
   1. Alcohol (Ethanol)
      1. Positive: 3 to 10 hours
   2. Barbiturates
      1. Positive: 2 to 6 weeks
   3. Benzodiazepines
      1. Short-acting agents (e.g. Lorazepam, Alprazolam): 3-5 days
      2. Long acting agents (Clonazepam, Diazepam): 30 days
4. Preparations: Stimulants
   1. Cocaine
      1. Direct: 5 hours
      2. Metabolite (Benzoylecgonine): 2-4 days (may persist as long as 8 days with heavy use)
   2. Amphetamine or Methamphetamine
      1. Positive: 1 to 3 days
      2. May also detect MDMA
5. Preparations: Opioids
   1. General
      1. Enzyme linked assays:
         1. Reliably detects morphine and codeine
         2. Misses hydrocodone, Oxycodone, hydromorphone, oxymorphone, Fentanyl, Methadone, Buprenorphine
      2. Gas chromatography: Detects all Opioids
   2. Codeine
      1. Positive: 1 to 2 days
      2. May be detected as Morphine (metabolite)
   3. Heroin (detected as Morphine on less specific testing)
      1. Positive: 1 to 2 days
   4. Hydromorphone (Dilaudid)
      1. Positive: 1 to 2 days
   5. Methadone (Dolophine)
      1. Positive: 2 to 3 days
   6. Propoxyphene (Darvon)
      1. Direct: 6 hours
      2. Metabolites: 6 to 48 hours
   7. Hydrocodone (e.g. Vicodin)
      1. May be detected as hydromorphone (metabolite)
   8. Morphine
      1. Positive: 1 to 2 days
6. Preparations: Miscellaneous Agents
   1. Methaqualone (Quaalude)
      1. Positive: 2 weeks
   2. PCP (Phencyclidine)
      1. Positive: 2 to 8 days (may persist as long as 14 days in some cases)
   3. Marijuana (THC metabolite)
      1. General
         1. Second hand Marijuana smoke does not cause a positive result (50 ng/ml or more)
      2. Positive Urine
         1. Use of one joint: 2-3 days for use of 1 joint
         2. Use 3-4 times per week: 5-7 days (may persist for 14 days)
         3. Used Daily: 10-15 days (may persist 3 to 6 weeks with heavy use)
      3. Positive Blood: 8 hours
   4. Rohypnol
      1. Positive: 72 hours
   5. GHB
      1. Positive: 6-12 hours
   6. Soma
      1. Detected as Meprobamate (metabolite)
7. Efficacy: False positives
   1. Amphetamines or Methamphetamines
      1. Amantadine
      2. Bupropion (Wellbutrin)
      3. Chlorpromazine
      4. Desipramine
      5. Fluoxetine (Prozac)
      6. Labetalol
      7. Methylphenidate (Ritalin)
      8. Phentermine
      9. Phenylephrine
      10. Phenylpropanolamine
      11. Promethazine (Phenergan)
      12. Pseudoephedrine
      13. Ranitidine (Zantac)
      14. Thioridazine
      15. Trazodone
   2. Benzodiazepines
      1. Oxaprozin (Daypro)
      2. Sertraline (Zoloft)
   3. Opioids
      1. Dextromethorphan
      2. Diphenhydramine
      3. Fluoroquinolones
      4. Poppy seeds (requires high concentration)
      5. Quinine
      6. Rifampin
      7. Levofloxacin
      8. Verapamil
   4. Phencyclidine (PCP)
      1. Dextromethorphan
      2. Diphenhydramine
      3. Ibuprofen
      4. Imipramine
      5. Ketamine
      6. Meperidine
      7. Thioridazine
      8. Tramadol
      9. Venlafaxine
   5. Marijuana (THC, Tetrahydrocannabinol)
      1. Dronabinol (Marinol)
      2. NSAIDS (especially Ibuprofen, Naproxen, sulindac)
      3. Pantoprazole
8. Efficacy: False Negatives
   1. Oxycodone
   2. Methadone
   3. Fentanyl
9. References
   1. Jaffee (2007) J Subst Abuse Treat 33(1): 33-42
   2. Moeller (2008) Mayo Clin Proc 83(1): 66-76
   3. Standridge (2010) Am Fam Physician 81(5): 635-40