Simultaneous quantification of methadone, cocaine, opiates, and metabolites in human placenta by liquid chromatography-mass spectrometry

An LC-MS/MS method for the simultaneous quantitation of sulfasalazine and sulfapyridine in human placenta

Sulfasalazine has been identified as a candidate molecule to be investigated as an intervention to treat preterm pre-eclampsia during pregnancy. However, placental exposure of sulfasalazine and its systemically absorbed metabolite, sulfapyridine, is unknown. A robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously quantitate these analytes in human placenta with an application to a pilot clinical trial. The placental tissue was homogenised using a water:methanol (1:1, v/v) mixture, followed by sample extraction using both protein precipitation and solid phase extraction. Sulfasalazine-d4 and sulfapyridine-d4 were used as internal standards. An Agilent Poroshell EC-C18 (3.0 ×100 mm, 2.7 µm) column was used for chromatographic separation, with gradient elution employed at a flow rate of 0.450 mL/min over a total run time of seven minutes. The mobile phases consisted of water with 0.1% formic acid (mobile phase A) and acetonitrile:methanol (90:10, v/v) with 0.1% formic acid (mobile phase B). A Shimadzu-8040 mass spectrometer was operated in multiple reaction monitoring (MRM) mode using positive electrospray ionisation (ESI). For both analytes, the assay was validated over the range 30-30,000 ng/mL, or 150-150,000 ng/g. During inter-day validations (n = 18), the average accuracies of quality controls ranged from 101.6% to 112.7% with corresponding precisions of 4.4-6.7% for sulfasalazine, and from 97.4% to 108.4%, with corresponding precisions of 3.7-10.0% for sulfapyridine. No significant matrix effects were observed, and the method proved to be sensitive and specific for both analytes. This study presents the first validated analytical method for quantifying sulfasalazine and sulfapyridine in human placenta as part of a pilot clinical trial to generate preliminary data on its pharmacokinetics and efficacy as in intervention for preterm pre-eclampsia.

Intrauterine and Neonatal Exposure to Opioids: Toxicological, Clinical, and Medico-Legal Issues

Opioids have a rapid transplacental passage (i.e., less than 60 min); furthermore, symptoms characterize the maternal and fetal withdrawal syndrome. Opioid withdrawal significantly impacts the fetus, inducing worse outcomes and a risk of mortality. Moreover, neonatal abstinence syndrome (NAS) follows the delivery, lasts up to 10 weeks, and requires intensive management. Therefore, the prevention and adequate management of NAS are relevant public health issues. This review aims to summarize the most updated evidence in the literature regarding toxicological, clinical, and forensic issues of intrauterine exposure to opioids to provide a multidisciplinary, evidence-based approach for managing such issues. Further research is required to standardize testing and to better understand the distribution of opioid derivatives in each specimen type, as well as the clinically relevant cutoff concentrations in quantitative testing results. A multidisciplinary approach is required, with obstetricians, pediatricians, nurses, forensic doctors and toxicologists, social workers, addiction specialists, and politicians all working together to implement social welfare and social services for the baby when needed. The healthcare system should encourage multidisciplinary activity in this field and direct suspected maternal and neonatal opioid intoxication cases to local referral centers.

Validated single urinary assay designed for exposomic multi-class biomarkers of common environmental exposures

Epidemiological studies often call for analytical methods that use a small biospecimen volume to quantify trace level exposures to environmental chemical mixtures. Currently, as many as 150 polar metabolites of environmental chemicals have been found in urine. Therefore, we developed a multi-class method for quantitation of biomarkers in urine. A single sample preparation followed by three LC injections was optimized in a proof-of-approach for a multi-class method. The assay was validated to quantify 50 biomarkers of exposure in urine, belonging to 7 chemical classes and 16 sub-classes. The classes represent metabolites of 12 personal care and consumer product chemicals (PCPs), 5 polycyclic aromatic hydrocarbons (PAHs), 5 organophosphate flame retardants (OPFRs), 18 pesticides, 5 volatile organic compounds (VOCs), 4 tobacco alkaloids, and 1 drug of abuse. Human urine (0.2 mL) was spiked with isotope-labeled internal standards, enzymatically deconjugated, extracted by solid-phase extraction, and analyzed using high-performance liquid chromatography-tandem mass spectrometry. The methanol eluate from the cleanup was split in half and the first half analyzed for PCPs, PAH, and OPFR on a Betasil C18 column; and pesticides and VOC on a Hypersil Gold AQ column. The second half was analyzed for tobacco smoke metabolites and a drug of abuse on a Synergi Polar RP column. Limits of detection ranged from 0.01 to 1.0 ng/mL of urine, with the majority ≤0.5 ng/mL (42/50). Analytical precision, estimated as relative standard deviation of intra- and inter-batch uncertainty, variabilities, was <20%. Extraction recoveries ranged from 83 to 109%. Results from the optimized multi-class method were qualified in formal international proficiency testing programs. Further method customization options were explored and method expansion was demonstrated by inclusion of up to 101 analytes of endo- and exogenous chemicals. This exposome-scale assay is being used for population studies with savings of assay costs and biospecimens, providing both quantitative results and the discovery of unexpected exposures.

Determination of Prenatal Substance Exposure Using Meconium and Orbitrap Mass Spectrometry

The aim of this study was to develop and to validate a toxicological untargeted screening relying on LC-HRMS in meconium including the detection of the four main classes of drugs of abuse (DoA; amphetamines, cannabinoids, opioids and cocaine). The method was then applied to 29 real samples. Analyses were performed with a liquid chromatography system coupled to a benchtop Orbitrap operating in a data-dependent analysis. The sample amount was 300 mg of meconium extracted twice by solid phase extraction following two distinct procedures. Raw data were processed using the Compound Discoverer 3.2 software (Thermo). The method was evaluated and validated on 15 compounds (6-MAM, morphine, buprenorphine, norbuprenorphine, methadone, EDDP, amphetamine, MDA, MDMA, methamphetamine, cocaine, benzoylecgonine, THC, 11-OH-THC, THC-COOH). Limits of detection were between 0.5 and 5 pg/mg and limits of identification between 5 and 50 pg/mg. Mean matrix effect was between −79 and −19% (n = 6) and mean overall recovery between 18 and 73% (n = 6) at 100 pg/mg. The application allows the detection of 88 substances, including 47 pharmaceuticals and 15 pharmaceutical metabolites, cocaine and its metabolites, THC and its metabolites, and natural (morphine, codeine) and synthetic (methadone, buprenorphine, tramadol, norfentanyl) opioids. This method is now used routinely for toxicological screening in high-risk pregnancies

Testing Unconventional Matrices to Monitor for Prenatal Exposure to Heroin, Cocaine, Amphetamines, Synthetic Cathinones, and Synthetic Opioids

BACKGROUND

The prevalence of drug use during pregnancy continues to increase despite the associated serious adverse obstetrical outcomes, including increased risk of miscarriage, fetal growth restriction, brain development impairment, neonatal abstinence syndrome, preterm delivery, and stillbirths. Monitoring drug use during pregnancy is crucial to limit prenatal exposure and provide suitable obstetrical health care. The authors reviewed published literature reporting the concentrations of common drugs of abuse and new psychoactive substances (NPS), such as synthetic cathinones and synthetic opioids, NPS, and their metabolites using unconventional matrices to identify drug use during pregnancy and improve data interpretation.

METHODS

A literature search was performed from 2010 to July 2019 using PubMed, Scopus, Web of Science scientific databases, and reports from international institutions to review recently published articles on heroin, cocaine, amphetamine, methamphetamine, synthetic cathinone, and synthetic opioid monitoring during pregnancy.

RESULTS

Meconium has been tested for decades to document prenatal exposure to drugs, but data regarding drug concentrations in amniotic fluid, the placenta, the umbilical cord, and neonatal hair are still lacking. Data on prenatal exposure to NPS are limited.

CONCLUSIONS

Maternal hair testing is the most sensitive alternative matrix for identifying drug use during pregnancy, while drug concentrations in the meconium, placenta, and umbilical cord offer the identification of prenatal drug exposure at birth. Adverse developmental outcomes for the infant make it critical to promptly identify maternal drug use to limit fetal exposure or, if determined at birth, to provide resources to the exposed child and family. Alternative matrices offer choices for monitoring and challenge laboratories to deliver highly sensitive and specific analytical methods for detection.

Screening Pregnant Women and Their Neonates for Illicit Drug Use: Consideration of the Integrated Technical, Medical, Ethical, Legal, and Social Issues

North America is currently suffering from one of the worst epidemics of illicit drug use in recent history: the opioid crisis. Pregnant women are not immune to the ravages of substance misuse which affects themselves, their pregnancies, and the wider community. The prevalence of drug misuse in pregnancy is not well quantified due to the lack of good validated tests, cooperation between clinicians and scientists developing tests, and consensus as to who should be tested and how results should be used. A wide range of tissues can be tested for drug use, including maternal blood, urine, and hair; neonatal meconium, urine, and hair; and placenta and umbilical cord tissues. Testing methods range from simple spectrophotometry and clinical chemistry to sophisticated analytical HPLC or mass spectrometry techniques. The drive for ever greater accuracy and sensitivity must be balanced with the necessities of medical practice requiring minimally invasive sampling, rapid turnaround, and techniques that can be realistically utilized in a clinical laboratory. Better screening tests have great potential to improve neonatal and maternal medical outcomes by enhancing the speed and accuracy of diagnosis. They also have great promise for public health monitoring, policy development, and resource allocation. However, women can and have been arrested for positive drug screens with even preliminary results used to remove children from custody, before rigorous confirmatory testing is completed. Balancing the scientific, medical, public health, legal, and ethical aspects of screening tests for drugs in pregnancy is critical for helping to address this crisis at all levels.

Drug exposure during pregnancy: analytical methods and toxicological findings

Drug use during pregnancy constitutes a major preventable worldwide public health issue. Birth defects, growth retardation and neurodevelopmental disorders are associated with tobacco, alcohol or drugs of abuse exposure during pregnancy. Besides these adverse health effects, drug use during pregnancy also raises legal and social concerns. Identification and quantification of drug markers in maternal and newborn biological samples offers objective evidence of exposure and complements maternal questionnaires. We reviewed the most recent analytical methods for quantifying drugs of abuse, tobacco, alcohol and psychotropic drugs in maternal, newborn and maternal-fetal unit biological samples by gas and liquid chromatography coupled to mass spectrometry. In addition, manuscripts comparing the usefulness of different biological samples to detect drug exposure during pregnancy were reviewed.

Precise simultaneous quantification of methadone and cocaine in rat serum and brain tissue samples following their successive i.p. administration

A sensitive high-performance liquid chromatography (HPLC) assay with dual UV detection has been developed and validated for the simultaneous quantification of methadone and cocaine in rat serum and brain tissue samples. Liquid-liquid extraction using hexanes was applied for samples extraction with Levo-Tetrahydropalmatine (L-THP) as the internal standard. Chromatographic separation of the analytes was achieved on a reversed-phase Waters Symmetry^® C₁₈ column (150mm×4.6mm, 5μm). A gradient elution was employed with a mobile phase consisting of 5mM potassium phosphate containing 0.1% triethylamine (pH=6.5) (A) and acetonitrile (B) with a flow rate of 1mL/min. UV detection was employed at 215nm and 235nm for the determination of methadone and cocaine, respectively. The calibration curves were linear over the range of 0.05-10μg/mL for both methadone and cocaine. The assay was validated according to FDA guidelines for bioanalytical method validation and results were satisfactory and met FDA criteria. Inter-day accuracy values of serum and brain samples ranged from 96.97 to 105.59% while intra-day accuracy values ranged from 91.49 to 111.92%. Stability assays showed that both methadone and cocaine were stable during sample storage, preparation, and analytical procedures. The method was successfully used to analyze biological samples obtained from a drug- drug interaction pharmacokinetics (PK) study conducted in rats to investigate the effect of methadone on cocaine PK. Our method not only can be used for bioanalysis of samples obtained from rats but also can potentially be applied to human biological serum samples to monitor compliance to methadone maintenance therapy (MMT) and to detect possible cocaine-methadone co-abuse.

Porous silicon mass spectrometry as an alternative confirmatory assay for compliance testing of methadone

Porous silicon based surface-assisted laser desorption ionization mass spectrometry (pSi SALDI-MS) is an analytical technique well suited for high throughput analysis of low molecular weight compounds from biological samples. A potential application of this technology is the compliance monitoring of opioid addiction programmes, where methadone is used as a pharmacological treatment for drugs such as heroin. Here, we present the detection and quantification of methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) from water and clinical samples (saliva, urine, and plasma) from opioid dependent participants using pSi SALDI-MS. A one-step solvent phase extraction using chloroform was developed for the detection of methadone from clinical samples for analysis by pSi SALDI-MS. Liquid chromatography-mass spectrometry (LC-MS) was used as a comparative technique for the quantification of methadone from clinical saliva and plasma samples. In all cases, we obtained a good correlation of pSi SALDI-MS and LC-MS results, suggesting that pSi SALDI-MS may be an alternative procedure for high-throughput screening and quantification for application in opioid compliance testing. Copyright © 2016 John Wiley & Sons, Ltd.

Assessing cocaine abuse using LC-MS/MS measurements in biological specimens

Cocaine use is still a problem in today's world, and this has several implications on human activities. Indeed, important problems related to cocaine derive from its use in situations where concentration and focus skills are necessary, namely while driving and/or working. The need of analytical methods for drug analysis in specimens of biological origin for proper documentation of human exposure is increasing. While GC-MS-based procedures represented the state-of-the-art of analytical techniques a few years ago, there is a growing trend for their replacement by LC-MS/MS, which can be justified by the increased sensitivity presented by these new technologies. This paper will review recently published papers on the use of LC-MS/MS-based procedures for cocaine measurement in biological specimens.

Multiple stage MS in analysis of plasma, serum, urine and in vitro samples relevant to clinical and forensic toxicology

This paper reviews MS approaches applied to metabolism studies, structure elucidation and qualitative or quantitative screening of drugs (of abuse) and/or their metabolites. Applications in clinical and forensic toxicology were included using blood plasma or serum, urine, in vitro samples, liquids, solids or plant material. Techniques covered are liquid chromatography coupled to low-resolution and high-resolution multiple stage mass analyzers. Only PubMed listed studies published in English between January 2008 and January 2015 were considered. Approaches are discussed focusing on sample preparation and mass spectral settings. Comments on advantages and limitations of these techniques complete the review.

Bioanalysis during pregnancy: recent advances and novel sampling strategies

Consumption of drugs of abuse, tobacco and alcohol throughout pregnancy is a serious public health problem and results in an important economic cost to the health system. Drug and/or metabolites determination in biological matrices from mother and newborn is an objective measure of in utero drug exposure. We reviewed methods published for the determination of in utero drug exposure from 2007 to 2014, with special focus on meconium, placenta, umbilical cord and newborn hair. Accurate bioanalytical procedures are essential to obtain high-quality data to perform interventions and to establish correlations between analytical measures and clinical outcomes. We included a brief overview of clinical implications of in utero drug exposure to better understand the importance of this serious health issue.

Economical synthesis of 13C-labeled opiates, cocaine derivatives and selected urinary metabolites by derivatization of the natural products

The illegal use of opiates and cocaine is a challenge world-wide, but some derivatives are also valuable pharmaceuticals. Reference samples of the active ingredients and their metabolites are needed both for controlling administration in the clinic and to detect drugs of abuse. Especially, ¹³C-labeled compounds are useful for identification and quantification purposes by mass spectroscopic techniques, potentially increasing accuracy by minimizing ion alteration/suppression effects. Thus, the synthesis of [acetyl-¹³C₄]heroin, [acetyl-¹³C₄-methyl-¹³C]heroin, [acetyl-¹³C₂-methyl-¹³C]6-acetylmorphine, [N-methyl-¹³C-O-metyl-¹³C]codeine and phenyl-¹³C₆-labeled derivatives of cocaine, benzoylecgonine, norcocaine and cocaethylene was undertaken to provide such reference materials. The synthetic work has focused on identifying ¹³C atom-efficient routes towards these derivatives. Therefore, the ¹³C-labeled opiates and cocaine derivatives were made from the corresponding natural products.

Effects of addictive substances during pregnancy and infancy and their analysis in biological materials

The use of addictive substances during pregnancy is a serious social problem, not only because of effects on the health of the woman and child, but also because drug or alcohol dependency detracts from child care and enhances the prospect of child neglect and family breakdown. Developing additive substance abuse treatment programs for pregnant women is socially important and can help ensure the health of babies, prevent subsequent developmental and behavioral problems (i.e., from intake of alcohol or other additive substances such as methamphetamine, cocaine,or heroine) and can reduce addiction costs to society. Because women of childbearing age often abuse controlled substances during their pregnancy, it is important to undertake biomonitoring of these substances in biological samples taken from the pregnant or nursing mother (e.g., blood, urine,hair, breast milk, sweat, oral fluids, etc.), from the fetus and newborn (e.g., meconium,cord blood, neonatal hair and urine) and from both the mother and fetus (i.e.,amniotic fluids and placenta). The choice of specimens to be analyzed is determined by many factors; however, the most important is knowledge of the chemical and physical characteristics of a substance and the route of it administration. Maternal and neonatal biological materials reflect exposures that occur over a specific time period, and each of these biological specimens has different advantages and disadvantages,in terms of accuracy, time window of exposure and cost/benefit ratio.Sampling the placenta may be the most important biomonitoring choice for assessing in utero exposure to addictive substances. The use of the placenta in scientific research causes a minimum of ethical problems, partly because its sampling is noninvasive, causes no harm to mother or child, and partly because, in any case,placentas are discarded and incinerated after birth. Such samples, when properly analyzed, may provide key essential information about fetal exposure to toxic substances, and may provide the groundwork for protecting the fetus or newborn and the mother from further damage.Several sensitive and specific bioanalytical methods are commonly utilized to accurately measure for drug biomarkers of in utero drug exposure. Moreover, several immunoassay methods are used to rapidly screen for drugs in many biological specimen types. However, results from immunoassays should be carefully interpreted,and should be confirmed by more specific and sensitive chromatographic methods, such as GC-MS or LC-MS. Although techniques for analysis of addictive substances are still being developed or are being refined, current methods are efficient and sensitive and provide valuable information on human exposures to addictive substances and their metabolites.

Methadone, cocaine, opiates, and metabolite disposition in umbilical cord and correlations to maternal methadone dose and neonatal outcomes

OBJECTIVES

The purpose was to explore methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) umbilical cord disposition, correlate with maternal methadone dose and neonatal outcomes, and evaluate the window of drug detection in umbilical cord of in utero illicit drug exposure.

METHODS

Subjects comprised 19 opioid-dependent pregnant women from 2 clinical studies, one comparing methadone and buprenorphine pharmacotherapy for opioid-dependence treatment and the second examining monetary reinforcement schedules to maintain drug abstinence. Correlations were calculated for methadone and EDDP umbilical cord concentrations and maternal methadone dose, and neonatal outcomes. Cocaine- and opiate-positive umbilical cord concentrations were compared with those in placenta and meconium, and urine specimens collected throughout gestation.

RESULTS

Significant positive correlations were found for umbilical cord methadone concentrations and methadone mean daily dose, mean dose during the third trimester, and methadone cumulative daily dose. Umbilical cord EDDP concentrations and EDDP/methadone concentration ratios were positively correlated to newborn length, peak neonatal abstinence syndrome (NAS) score, and time-to-peak NAS score. Methadone concentrations and EDDP/methadone ratios in umbilical cord and placenta were positively correlated. Meconium identified many more cocaine- and opiate-positive specimens than did umbilical cord.

CONCLUSIONS

Umbilical cord methadone concentrations were correlated to methadone doses. Also, our results indicate that methadone and EDDP concentrations might help to predict the NAS severity. Meconium proved to be more suitable than umbilical cord to detect in utero exposure to cocaine and opiates; however, umbilical cord could be useful when meconium is unavailable due to in utero or delayed expulsion.

Nicotine and metabolites in paired umbilical cord tissue and meconium specimens

Umbilical cord tissue was studied as a means of detecting prenatal exposure to nicotine. This was accomplished by comparing the presence and concentration of nicotine as well as nicotine metabolites in both umbilical cord tissue and paired meconium samples with maternal smoking histories obtained by self-report. Nicotine and metabolites (cotinine, 3-hydroxycotinine, nornicotine, and anabasine) were detected and quantitated using liquid chromatography-tandem mass spectroscopy. Between June and September 2009, 19 women with a tobacco exposure history (either first- or second-hand tobacco smoke exposure during pregnancy) were consented for the study. A questionnaire was completed to document nicotine exposure during each trimester of pregnancy. All infants were delivered at term (38 weeks or greater) and paired umbilical cord tissue (10-cm segment or greater) and meconium were obtained. Nicotine and 3-hydroxycotinine were most prominent in meconium, whereas cotinine and 3-hydroxycotinine were most prominent in the umbilical cord. Concentrations of all three analytes were generally higher in meconium. Nornicotine was detected only in meconium, at very low concentrations, and anabasine was not detected in either specimen. All analyte concentrations were lowest when the mother stated she quit smoking early in pregnancy or had only second-hand exposure, and detection was poor if exposure was limited to the first or second trimesters. Although different nicotine and metabolite patterns exist in meconium versus umbilical cord tissue, this work indicates that either specimen can be used to detect third-trimester fetal nicotine exposure.

Bioanalytical procedures and recent developments in the determination of opiates/opioids in human biological samples

The use and abuse of illegal drugs affects all modern societies, and therefore the assessment of drug exposure is an important task that needs to be accomplished. For this reason, the reliable determination of these drugs and their metabolites in biological specimens is an issue of utmost relevance for both clinical and forensic toxicology laboratories in their fields of expertise, including in utero drug exposure, driving under the influence of drugs and drug use in workplace scenarios. Most of the confirmatory analyses for abused drugs in biological samples are performed by gas chromatographic-mass spectrometric methods, but use of the more recent and sensitive liquid chromatography-(tandem) mass spectrometry technology is increasing dramatically. This article reviews recently published articles that describe procedures for the detection of opiates in the most commonly used human biological matrices, blood and urine, and also in unconventional ones, e.g. oral fluid, hair, and meconium. Special attention will be paid to sample preparation and chromatographic analysis.

Maternal methadone dose, placental methadone concentrations, and neonatal outcomes

BACKGROUND

Few investigations have used placenta as an alternative matrix to detect in utero drug exposure, despite its availability at the time of birth and the large amount of sample. Methadone-maintained opioid-dependent pregnant women provide a unique opportunity to examine the placental disposition of methadone and metabolite [2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP)], to explore their correlations with maternal methadone dose and neonatal outcomes, and to test the ability to detect in utero exposure to illicit drugs.

METHODS

We calculated the correlations of placental methadone and EDDP concentrations and their correlations with maternal methadone doses and neonatal outcomes. Cocaine- and opiate-positive placenta results were compared with the results for meconium samples and for urine samples collected throughout gestation.

RESULTS

Positive correlations were found between placental methadone and EDDP concentrations (r=0.685), and between methadone concentration and methadone dose at delivery (r=0.542), mean daily dose (r=0.554), mean third-trimester dose (r=0.591), and cumulative daily dose (r=0.639). The EDDP/methadone concentration ratio was negatively correlated with cumulative daily dose (r=-0.541) and positively correlated with peak neonatal abstinence syndrome (NAS) score (r=0.513). Placental EDDP concentration was negatively correlated with newborn head circumference (r=-0.579). Cocaine and opiate use was detected in far fewer placenta samples than in thrice-weekly urine and meconium samples, a result suggesting a short detection window for placenta.

CONCLUSIONS

Quantitative methadone and EDDP measurement may predict NAS severity. The placenta reflects in utero drug exposure for a shorter time than meconium but may be useful when meconium is unavailable or if documentation of recent exposure is needed.

Maternal buprenorphine dose, placenta buprenorphine, and metabolite concentrations and neonatal outcomes

Buprenorphine is approved as pharmacotherapy for opioid dependence in nonpregnant patients in multiple countries and is currently under investigation for pregnant women in the United States and Europe. This research evaluates the disposition of buprenorphine, opiates, cocaine, and metabolites in five term placentas from a US cohort. Placenta and matched meconium concentrations were compared, and relationships among maternal buprenorphine dose, placenta concentrations, and neonatal outcomes after controlled administration during gestation were investigated. Buprenorphine and/or metabolites were detected in all placenta specimens and were uniformly distributed across this tissue (coefficient of variation less than 27.5%, four locations), except for buprenorphine in three placentas. In two of these, buprenorphine was not detected in some locations and in the third placenta was totally absent. Median (range) concentrations were 1.6 ng/g buprenorphine (not detected to 3.2), 14.9 ng/g norbuprenorphine (6.2-24.2), 3 ng/g buprenorphine-glucuronide (1.3-5.0), and 14.7 ng/g norbuprenorphine-glucuronide (11.4-25.8). Placenta is a potential alternative matrix for detecting in utero buprenorphine exposure, but at lower concentrations (15- to 70-fold) than in meconium. Statistically significant correlations were observed for mean maternal daily dose from enrollment to delivery and placenta buprenorphine-glucuronide concentration and for norbuprenorphine-glucuronide concentrations and time to neonatal abstinence syndrome onset and duration, for norbuprenorphine/norbuprenorphine-glucuronide ratio and maximum neonatal abstinence syndrome score, and newborn length. Analysis of buprenorphine and metabolites in this alternative matrix, an abundant waste product available at the time of delivery, may be valuable for prediction of neonatal outcomes for clinicians treating newborns of buprenorphine-exposed women.