Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (635 page)

   Opioids—fentanyl, buprenorphine, methadone, tramadol, oxycodone, oxymorphone, hydrocodone, hydromorphone, meperidine, tapentadol

   Benzodiazepines

   Muscle relaxants—carisoprodol

   Cannabinoids

   Cocaine (mtb)

   Amphetamine/methamphetamine/MDMA

   Barbiturates—phenobarbital, butalbital

   Phencyclidine

   Confirmation Methods and Limitations

   The decision-making process of whether to order confirmation testing should include the following:

   Are the screen results inconsistent with clinical expectations?

   Does the screening test detect the drug(s) of interest?

   Are quantitative results required?

   Drug levels in urine cannot be used to estimate dose.