Simultaneous liquid chromatography-mass spectrometry quantification of urinary opiates, cocaine, and metabolites in opiate-dependent pregnant women in methadone-maintenance treatment

Abstract

Opiates, cocaine, and metabolites were quantified by liquid chromatography-mass spectrometry (LC-MS) in 284 urine specimens, collected thrice weekly, to monitor possible drug relapse in 15 pregnant heroin-dependent women. Opiates were detected in 149 urine specimens (52%) with limits of quantification (LOQ) of 10-50 microg/L. Morphine, morphine-3-glucuronide, and/or morphine-6-glucuronide were positive in 121 specimens; 6-acetylmorphine, a biomarker of heroin ingestion, was quantifiable in only 7. No heroin, 6-acetylcodeine, papaverine, or noscapine were detected. One hundred and sixty-five urine specimens (58%) from all 15 participants were positive for one or more cocaine analytes (LOQ 10-100 microg/L). Ecgonine methylester (EME) and/or benzoylecgonine were the major cocaine biomarkers in 142. Anhydroecgonine methylester, a biomarker of smoked cocaine, was positive in six; cocaethylene and/or ecgonine ethylester, biomarkers of cocaine and ethanol co-ingestion, were found in 25. At the current Substance Abuse Mental Health Services Administration cutoffs for total morphine (2000 microg/L), codeine (2000 microg/L), 6-acetylmorphine (10 microg/L), and benzoylecgonine (100 microg/L), 16 opiate- and 29 cocaine-positive specimens were identified. Considering 100 microg/L EME as an additional urinary cocaine biomarker would identify 51 more positive cocaine specimens. Of interest is the differential pattern of opiate and cocaine biomarkers observed after LC-MS as compared to gas chromatography-mass spectrometry analysis.

Figure 1

Schematic flow diagram of heroin and codeine metabolism [6-acetylmorphine, morphine, normorphine, morphine-3-glucuronide (M3G), morphine-6-glucuronide (M6G), norcodeine, 6-acetylcodeine, and codeine-6-glucuronide (C6G)].

Figure 2

Schematic flow diagram of cocaine metabolism [hydroxycocaine (OHCOC), anhydroecgonine methyl ester (AEME), anhydroecgonine (AE), cocaethylene (CE), norcocaethylene (NCE), ecgonine ethyl ester (EEE), ecgonine methyl ester (EME), benzoylecgonine (BE), norcocaine (NCOC), benzoylnorecgonine (BNE), hydroxybenzoylecgonine (OHBE), and ecgonine (E)].

Figure 3

Distribution of opiate analytes (M3G, M6G, and normorphine) in serial urine specimens collected from opiate-dependent pregnant women in methadone-maintenance treatment. Abbreviations: M3G, morphine-3-glucuronide; M6G, morphine-6-glucuronide; and NMOR, normorphine.

Figure 4

Opiate concentrations in urine specimens collected throughout pregnancy from a heroin-dependent pregnant woman enrolled in methadone-maintenance treatment demonstrating heroin relapse throughout the study. Abbreviations: M3G, morphine-3-glucuronide; M6G, morphine-6-glucuronide; and NMOR, normorphine.

Figure 5

Distribution of benzoylecgonine, ecgonine methyl ester, and benzoylnorecgonine in cocaine-positive urine specimens from opiate-dependent pregnant women in methadone-maintenance treatment. Abbreviations: BE, benzoylecgonine; EME, ecgonine methyl ester; and BNE, benzoylnorecgonine.

Figure 6

Concentrations of cocaine analytes in urine specimens collected over time from heroin-dependent pregnant women enrolled in methadone-maintenance treatment. Abbreviations: EME, ecgonine methyl ester and BE, benzoylecgonine.