Commonly Used Testing Strategy

Urine specimen

Immunoassay Drug Screen
(POC or lab test)


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Quantitation of these drugs, if prescribed (regardless of screen result):


Opiates & oxycodone
panel

Benzodiazepines
panel


Drug prescribed or expected but not included
in the screen (e.g., buprenorphine)

 Review
Result Positive
Negative

Result of a Screen - Positive

General principle: If a screen shows the presence of an unexpected drug, this should stimulate investigation of the test, the drug, the specimen, or the patient. For details, see our whitepaper. If indicated, a confirmation test specific to the drug is performed.


Drugs that always require quantitation for interpretation. Quantitation is essential to verify whether more than one drug within a drug class was used or to distinguish drugs and drug metabolites from pharmaceutical contaminants. If patient is expected to be taking the following drug classes, quantitative tests for each should be performed regardless of the screen result:


Positive screens that do not usually require confirmation. A positive screen for the following drug classes need not be confirmed unless indicated. False positivity is <5 percent, except for amphetamine, which generally has a higher false-positivity rate.

  • Amphetamine without methamphetamine, if Adderall (or equivalent) is prescribed (applies to ARUP Drug Screen Cup)
  • Barbiturates, if prescribed
  • Cocaine, as indicated by its metabolite
  • Marijuana/THC, as indicated by its metabolite
  • Methadone, if prescribed
  • Methamphetamine and amphetamine, if both are positive (applies to ARUP Drug Screen Cup)
  • Phencyclidine (PCP)
  • Propoxyphene, if prescribed
  • Tricyclic antidepressants, if prescribed

Result of a Screen - Negative

General principle: If a screen shows the absence of an expected drug, this should stimulate investigation of the test, the drug, the specimen, or the patient. For details, see our whitepaper. If indicated, a confirmation test specific to the drug is performed.


Drugs that always require quantitation for interpretation. If the patient is expected to be taking opiates, oxycodone, or benzodiazepines, a negative result may mean that the screen was not sensitive enough for that particular drug. Sensitive and specific quantitation of these drugs is essential.


Negative screens usually need not be confirmed, unless a positive result was expected.