Hydrophilic interaction LC-MS/MS analysis of opioids in urine: significance of glucuronide metabolites.

In clinical laboratories, a large proportion of the toxicology workload is drug confirmations. Our GC-MS method for opioid confirmation detects total codeine, morphine, hydrocodone, hydromorphone, oxycodone and oxymorphone. The objective of this study was to develop a LC-MS/MS assay measuring the above drugs and glucuronide metabolites. In addition, to determine if measuring free drug only would lead to false negative results. In 85 patient urines, 43% were positive for morphine glucuronide, but not morphine, 48% were positive for hydromorphone glucuronide, but not hydromorphone, 33% were positive for codeine glucuronide, but not codeine, and 44% were positive for oxymorphone glucuronide, but not oxymorphone. We developed an LC-MS/MS assay capable of detecting codeine, morphine, hydrocodone, hydromorphone, oxycodone, oxymorphone and glucuronide metabolites. Detection of free drug only led to false negative confirmations.