An automated and fully validated LC‐MS/MS procedure for the simultaneous determination of 11 opioids used in palliative care, with 5 of their metabolites

Abstract

A fully validated liquid chromatographic procedure coupled with electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) is presented for quantitative determination of the opioids buprenorphine, codeine, fentanyl, hydromorphone, methadone, morphine, oxycodone, oxymorphone, piritramide, tilidine, and tramadol together with their metabolites bisnortilidine, morphine-glucuronides, norfentanyl, and nortilidine in blood plasma after an automatically performed solid-phase extraction (SPE). Separation was achieved in 35 min on a Phenomenex C12 MAX-RP column (4 microm, 150 x 2 mm) using a gradient of ammonium formiate buffer (pH 3.5) and acetonitrile. The validation data were within the required limits. The assay was successfully applied to authentic plasma samples, allowing confirmation of the diagnosis of overdose situations as well as monitoring of patients' compliance, especially in patients under palliative care.

Quantification of midazolam, morphine and metabolites in plasma using 96‐well solid‐phase extraction and ultra‐performance liquid chromatography–tandem mass spectrometry

“…The combined analysis of multiple drugs in itself reduces the required sample volume as well, especially in combination with a micro-SPE manifold that allows samples of 50 μL or less with minimal elution volumes. Most published analytical methods for these analytes require more sample, varying from 200 μL to quantify MDZ and OHM (Link et al, 2007) up to 700 μL or more for MOR, M3G and M6G (Musshoff et al, 2006). Recently, a LC-MS method has been published using 100 μL, but without quantifi cation of all analytes (Bengtsson et al, 2005).…”

Issues Affecting Interpretation: Stability and Artefacts

“…Total morphine and codeine concentrations slightly decreased in authentic urine samples from heroin users when stored in the freezer and refrigerator, while that of the respective free compounds showed a moderate increase. The per cent losses after a storage period of 11 months was similar for buprenorphine, codeine, fentanyl, methadone, oxycodone, tilidine and tramadol including major metabolites appear to be reasonably stable when stored at -20°C or subjected to freezethaw cycles (Rook et al 2005;Musshoff et al 2006). When stored at -25°C, buprenorphine is stable in spiked blood for approximately 3-4 months (Hadidi and Oliver 1998), and up to 24 or 125 days when stored at room temperature or at 4°C, respectively (Moody et al 1997).…”

Relationship between plasma concentrations of morphine and its metabolites and pain in cancer patients

“…However, many reports describe the need for multiple extractions and complex chromatographic systems to ensure reproducibility and resolution [19][20][21][22][23][24][25]. Recently, a method employing HPLC combined with electro spray ionization-tandem mass spectrometry (HPLC-ESI-MS-MS) for low level quantitation of MOR, M3G and M6G has been described [26]. The novel methods are exceptionally robust and sensitive, however access to the necessary instrumentation is often limited and such methods commonly include a derivatization process, multiple extraction steps, solvent evaporation and expensive equipment.…”