Drug Screening – Serum or Urine?

Overview and Clinical Utility:

When screening for Drugs of Abuse (DOA), or when monitoring patients taking prescription pain medications, the specimen of choice is urine as opposed to serum or plasma.  Why Urine?  Urine is considered the gold standard; it is non-invasive and fast.  Samples are easy to collect and test and there is generally a longer window of detection than blood.  Drugs of abuse can be detected in urine for days to weeks after exposure, in contrast to blood detection which is generally in hours. For example, heroin has a half-life of 6 to 15 minutes in blood, but opiate metabolites may be detected in urine for 2 to 3 days.

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