UDT

Urine Drug Testing (UDT)

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Frequency

• SAMHSA TIP 63 (2018): “Periodic random testing” frequency is clinically determined.

• At least at time of initial evaluation and initiation of medication then weekly → monthly.
• Regulation and reimbursement vary among states and insurers.
• Urine is the preferred medium for testing due to:
• Ease of obtaining sample, lowest cost
• Ideal detection time (2-3 days)
• Presence and persistence of metabolites
• Availability of office-based testing tools

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Implementation

• Discuss with a patient:​
• "This is for safety, and this is the standard of care." ​
• Know the scope and limits of tests and lab:​
• Beware of false negatives and positives.​
• Consider random versus scheduled testing.​
• Incorporate quality control procedures (temperature strip).​
• Consider establishing consult lab linkage:​
• GCMS/LCMS confirmatory testing​
• Expert consultation on test interpretation

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Immunoassays

Cons

Pros

• Point of care or lab-based
• Fast
• Inexpensive
• Specific tests available for many drugs
• Oxycodone
• Buprenorphine
• Fentanyl
• Can be used as screening with option for confirmation

• Qualitative tests
• Cutoff ng/ml
• Opiates: 300
• Cocaine metabolite: 300
• False positives

• Cross-reactivity
• Contamination
• False negatives
• Below the cutoff

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Immunoassay Detection Windows in Urine​

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GCMS/LCMS

• Gas or liquid chromatography, mass spectrometry
• Quantitative
• Limitations
• More costly​
• Requires specialized lab​
• Levels do not indicate amount of medication taken!​
• Variables: ​
• Time of dosing​
• Metabolism​
• GFR​
• Hydration​