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Knowledge Exchange > Primary Care > Toolkits > Addiction Toolkit > Opioid misuse and addiction > Opioid FAQ: Should I be doing urine drug screening?

PRIMARY CARE
Addiction TOOLKIT
Opioid misuse and addiction
Should I be doing urine drug screening?

© 2011 CAMH and St. Joseph’s Health Centre, Toronto

  • Consider regular urine drug screening (UDS) for patients at high risk of opioid addiction, and for patients showing aberrant behaviours. Urine drug screens can provide important clinical information. For example, the absence of a prescribed drug on a UDS could indicate diversion or non-compliance, and the presence of an illegal drug could indicate addiction. The presence of a non-prescribed opioid could indicate double-doctoring or street use.
  • Remember that UDS is just a lab test. Diagnoses and treatment decisions must be based a careful assessment of the patient; you can be misled if you rely on a single UDS result. For example, the absence of a prescribed opioid does not necessarily mean that the patient is diverting the opioid. The result could be a false negative, the patient may have run out of the medication a few days before the test, or the patient may not always take it as prescribed.
  • Prior to the UDS, patients should provide a detailed history of their medication use over the preceding several hours and days (e.g., did they take their opioid medication that morning?). Always inform patients that they are providing urine for UDS and obtain consent. UDS should be a part of a treatment agreement. 
  • The two primary types of UDS test are enzyme immunoassay and chromatography. The tables below compare the two methods.  

Immunoassay versus chromatography for detection of opioid use
Immunoassay Chromatography
Does not differentiate between various opioids. Differentiates: codeine, morphine, oxycodone, hydrocodone, hydromorphone, heroin (monoacetylmorphine)
Will show false positives: Poppy seeds, quinolone antibiotics Does not react to poppy seeds
Often misses semi-synthetic and synthetic opioids, e.g., oxycodone, methadone, fentanyl More accurate for semi-synthetic and synthetic opioids
This table is reproduced with permission from the Canadian Guideline for Safe and Effective Use of Opioids for Chronic Non-Cancer Pain [link: ] © 2010 National Opioid Use Guideline Group (NOUGG)

Detection times for immunoassay and chromatography
Drug Number of days drug is detectable 
Immunoassay Chromatography  
Benzodiazepines (regular use) 

20+ days for regular diazepam use

Immunoassay does not distinguish different benzodiazepines

Intermediate-acting benzodiazepines such as clonazepam are often undetected 

Not usually used for benzodiazepines 
Cannabis  20+  Not used for cannabis 
Cocaine + metabolite 3–7 1–2
Codeine 2–5 1–2 (codeine metabolized to morphine)
Hydrocodone 2–5 1–2
Hydromorphone 2–5 1–2
Meperidine 1 (often missed) 1
Morphine 2–5 1–2: Morphine can be metabolized to hydromorphone
Oxycodone Often missed 1–2
Source: Adapted from Brands, 1998
This table is reproduced with permission from the Canadian Guideline for Safe and Effective Use of Opioids for Chronic Non-Cancer Pain 
© 2010 National Opioid Use Guideline Group (NOUGG).

  

 

Contents of Opioid misuse and addiction

Introduction

Methadone

Buprenorphine-naloxone

Naltrexone

Resources

Patient information

References

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