Sorted By Test Name - Mayo Medical Laboratories

OPRM1
89612
Interpretation: This procedure reports the total urine concentration; this is the sum of the
unconjugated and conjugated forms of the parent drug. Heroin (diacetylmorphine) is rarely detectable in
body fluids. It has a half-life of a few minutes. Heroin undergoes rapid deacetylation to
6-monoacetylmorphine (6-MAM), which is about 6 times more potent than morphine. 6-MAM is further
deacetylated to morphine; the effects of heroin are attributed to the combined effect of heroin, 6-MAM,
and morphine. The presence of 6-MAM is conclusive evidence of prior heroin use. However, due to its
short half-life, it is only detectable in urine for about 8 hours after administration.(2) Codeine is also
metabolized to morphine. The presence of morphine in urine can indicate exposure to morphine, heroin,
or codeine within 2 to 3 days.(2) Illicit heroin often contains small amounts of codeine. The presence of
both codeine and morphine in urine does not rule out the use of heroin; however, the ratio of morphine to
codeine can be helpful in discriminating between heroin and codeine use.(2) Ingestion of bakery products
containing poppy seeds can also cause morphine to be excreted in urine. If excessively large amounts are
consumed, this can result in urine morphine concentrations up to 2,000 ng/mL for a period of 6 to 12
hours after ingestion. The presence of hydrocodone >lower limit of quantitation (LOQ) indicates exposure
within 2 to 3 days prior to specimen collection.(2) The presence of hydromorphone >LOQ indicates
exposure within 2 to 3 days prior to specimen collection. Hydromorphone is also a metabolite of
hydrocodone, therefore the presence of hydromorphone could also indicate exposure to hydrocodone.(2)
The presence of oxycodone >LOQ indicates exposure to oxycodone within 2 to 3 days prior to specimen
collection.(2)
Reference Values:
Negative
Positives are reported with a quantitative GC-MS result.
Cutoff concentrations
Immunoassay screen: