Identifying excessive chronic alcohol use with phosphatidylethanol in patients with suspected severe injury-results from the IDART study.

INTRODUCTION: Acute and chronic alcohol use are well-known risk factors for accidents and injuries, and concurrent psychoactive drug use can increase injury risk further. Phosphatidylethanol (PEth) 16:0/18:1 is a biomarker used to determine alcohol consumption the previous 3-4 weeks. The aim was to investigate the prevalence of chronic alcohol use in trauma patients, as determined by PEth 16:0/18:1 concentrations, and how excessive chronic alcohol use relate to demographic variables, injury mechanisms and drug use. SETTING: Patients received at Norwegian trauma hospitals from March 2019 to February 2020. The study is part of the Impairing Drugs and Alcohol as Risk factors for Traumatic Injuries study. METHODS: All patients aged ≥ 16 years received with trauma team were included in the study. Data on injury date and mechanism, gender and age was registered. Blood samples were analyzed for 22 psychoactive medicinal and illicit drugs, ethanol and phosphatidylethanol 16:0/18:1. Regression analyses were conducted to assess associations between alcohol use and gender, age, injury mechanism and drug use. RESULTS AND CONCLUSION: Of the 4845 patients included in the study, 10% had PEth 16:0/18:1 concentration ≥ 600 nM (~430 ng/mL), indicative of excessive chronic alcohol use. Being male, between 44-61 years old, involved in violence, and testing positive for medicinal drugs was associated with excessive chronic alcohol use.Excessive chronic alcohol use was common among males, middle-aged, patients with violence as injury mechanism and those with medicinal drug use. These findings emphasize the need to detect and treat excessive chronic alcohol use among trauma patients.

Is alcohol and psychoactive medication use associated with excess hospital length-of-stay and admission frequency? A cross-sectional, observational study.

BACKGROUND: Hospital length-of-stay and admission frequency are commonly used indicators of disease burden and health resource expenditures. However, the impact of psychoactive prescription medication use and harmful alcohol consumption on both the duration and frequency of hospital admissions is under-explored. METHODS: We conducted an analysis of data gathered from 2872 patients admitted to the Emergency Department at Lovisenberg Diaconal Hospital in Oslo, Norway. Psychoactive medicines (benzodiazepines, opioids, and z-hypnotics) were detected via liquid chromatography-mass spectrometry analysis of whole blood, while alcohol consumption was self-reported through the Alcohol Use Disorder Identification Test-4 (AUDIT-4). Using logistic regression, we examined associations with our primary outcomes, which were excess length-of-stay and admission frequency, defined as exceeding the sample median of 3.0 days and 0.2 admissions per year, respectively. RESULTS: Compared to the absence of psychoactive medication, and after adjusting for age, gender, malignant disease, pre-existing substance use disorder and admission due to intoxication, the detection of two or more psychoactive medicines was associated with both excess length-of-stay (odds ratio [OR], 1.60; 95% confidence interval [CI], 1.20 to 2.14) and yearly hospitalization rate (OR, 3.72; 95% CI, 2.64 to 5.23). This association persisted when increasing the definition for excess length-of-stay to 4 and 5 days and to 1.0 and 1.5 admissions per year for admission frequency. Harmful alcohol consumption (AUDIT-4 scores of 9 to 16) was not associated with excess length-of-stay, but with excess admission frequency when defined as more than 1.0 admission per year when compared to scores of 4 to 6 (OR, 2.68; 95% CI, 1.58 to 4.57). CONCLUSIONS: Psychoactive medication use is associated with both excess length-of-stay and increased antecedent admission frequency, while harmful alcohol consumption may be associated with the latter. The utility of our findings as a causal factor should be explored through intervention-based study designs.

The Association between the Alcohol Biomarker Phosphatidylethanol (PEth) and Self-Reported Alcohol Consumption among Russian and Norwegian Medical Patients.

AIMS: Valid measures to identify harmful alcohol use are important. Alcohol Use Disorders Identification Test (AUDIT) is a validated questionnaire used to self-report harmful drinking in several cultures and settings. Phosphatidylethanol 16:0/18:1 (PEth) is a direct alcohol biomarker measuring alcohol consumption levels. The aim of this study was to investigate how PEth levels correlate with AUDIT-QF and weekly grams of alcohol consumed among patients in two urban hospitals. In addition, we wanted to investigate the predictive value of PEth in identifying harmful alcohol use as defined by AUDIT-QF and weekly grams of alcohol cutoffs. METHODS: A cross-sectional study comprising acute medically ill patients with measurable PEth levels (≥0.030 µM) admitted to two urban hospitals in Oslo, Norway (N = 931) and Moscow, Russia (N = 953) was conducted using PEth concentrations in whole blood, sociodemographic data and AUDIT-QF questionnaires. RESULTS: PEth levels from patients with measurable PEth were found to be positively correlated with AUDIT-QF scores, with PEth cutpoints of 0.128 µM (Oslo) and 0.270 µM (Moscow) providing optimal discrimination for harmful alcohol use defined by AUDIT-QF (the difference between cities probably reflecting different national drinking patterns in QF). When converting AUDIT-QF into weekly grams of alcohol consumed, the predictive value of PEth improved, with optimal PEth cutpoints of 0.327 (Oslo) and 0.396 (Moscow) µM discriminating between harmful and non-harmful alcohol use as defined in grams (≥350 grams/week). CONCLUSIONS: By using PEth levels and converting AUDIT-QF into weekly grams of alcohol it was possible to get an improved rapid and sensitive determination of harmful alcohol use among hospitalized patients.

Prevalence and Correlates of Illicit Drug Use among Norwegian Nightlife Patrons.

BACKGROUND: Nightclubs and bars are recreational settings with extensive availability and consumption of alcohol and recreational drugs. OBJECTIVES: This study aims to determine the proportion of nightclub patrons in Norway that tested positive for illicit drugs, moreover, we examined the correlation between positive test results and demographic and substance use characteristics. METHODS: Patrons were recruited outside nightclubs on Friday and Saturday nights between 10:00 pm and 04:00 am. Substance use was determined by breath testing and oral fluid testing for alcohol and drugs, respectively, using accurate and specific analytical methods. Questionnaires recorded demographic and substance use characteristics. RESULTS: Of the 1988 included nightclub patrons, 90% tested positive for alcohol, 14% for illicit drug use, and 3% for two or more illicit drugs. The proportion of patrons who tested positive for illicit drugs was highest in the early hours of the morning. Nine out of ten who tested positive for illicit drugs also consumed alcohol. Testing positive for one or more illicit drugs was most strongly correlated with being male and unemployed, using tobacco or other nicotine products, and early on-set illicit drug use; further the correlations were strongest among those who tested positive for two or more illicit drugs.Conclusions/Importance: Patrons who used illicit drugs before or during nightclub visits most often combined drug use with alcohol consumption. Substituting alcohol with cannabis or other drugs was not common in this cohort. The study results provide evidence to introduce harm-reduction prevention programs to address illicit drug and excessive alcohol consumption.

Determination of phosphatidylethanol 16:0/18:1 in whole blood by 96-well supported liquid extraction and UHPLC-MS/MS.

BACKGROUND: Phosphatidylethanols (PEths) are specific, direct alcohol biomarkers that can be determined in human blood to distinguish between heavy and social drinking. PEth 16:0/18:1 is among the most predominant PEth homologues in human blood. The aim of the study was to develop a high throughput and sensitive UHPLC-MS/MS method for the determination of PEth 16:0/18:1 in whole blood. METHODS: Whole blood samples were prepared by 96-well supported liquid extraction (SLE). Extracted samples were analyzed for PEth 16:0/18:1 by reversed phase UHPLC-MS/MS. RESULTS: The developed UHPLC-MS/MS method was fully validated in whole blood with PEth 16:0/18:1-D5 as internal standard. Intermediate precision and intermediate accuracy were within ≤± 12% and ≤± 17%, respectively, at PEth 16:0/18:1 concentrations of 1.4-2112 ng/mL (2.0-3004 nmol/L). Limit of quantification (LOQ) was 1.7 ng/mL (2.4 nmol/L). CONCLUSION: For the first time, 96-well SLE was used for preparation of a PEth homologue in biological samples. A mixture of tert-butyl methyl ether and 2-propanol (5:1, v:v) was chosen as organic eluent based on an evaluation of extraction recovery, purity of extracts, and evaporation time. The developed UHPLC-MS/MS method can be used for high throughput analyses and sensitive determinations of PEth 16:0/18:1 in whole blood.

Longitudinal plasma metabolic profiles, infant feeding, and islet autoimmunity in the MIDIA study.

AIMS: The aim of this study was to investigate the longitudinal plasma metabolic profiles in healthy infants and the potential association with breastfeeding duration and islet autoantibodies predictive of type 1 diabetes. METHOD: Up to four longitudinal plasma samples from age 3 months from case children who developed islet autoimmunity (n = 29) and autoantibody-negative control children (n = 29) with the HLA DR4-DQ8/DR3-DQ2 genotype were analyzed using two-dimensional gas chromatography coupled to a time-of-flight mass spectrometer for detection of small polar metabolites. RESULTS: Plasma metabolite levels were found to depend strongly on age, with fold changes varying up to 50% from age 3 to 24 months (p < 0.001 after correction for multiple testing). Tyrosine levels tended to be lower in case children, but this was not significant after correction for multiple testing. Ornithine levels were lower in case children compared with the controls at the time of seroconversion, but the difference was not statistically significant after correcting for multiple testing. Breastfeeding for at least 3 months as compared with shorter duration was associated with higher plasma levels of isoleucine, and lower levels of methionine and 3,4-dihydroxybutyric acid at 3 months of age. CONCLUSIONS: Plasma levels of several small, polar metabolites changed with age during early childhood, independent of later islet autoimmunity status and sex. Breastfeeding was associated with higher levels of branched-chain amino acids, and lower levels of methionine and 3,4-dihydroxybutyric acid.

Buffer-free high pH mobile phase LC-MS/MS for determination of the alcohol biomarker phosphatidylethanol 16:0/18:1 and 20 drugs and metabolites in whole blood.

BACKGROUND: Acidic mobile phases are commonly used in reversed phase liquid chromatography tandem mass spectrometry (LC-MS/MS) bioanalysis. However, increased sensitivity, improved peak symmetry, and increased retention, especially for basic hydrophilic drugs have been observed using basic mobile phases. In our previous acidic mobile phase LC-MS/MS method we needed two injections (0.4 and 2.0 µL) of each sample for this task, which is inefficient. The aim of this study was to investigate if basic mobile phase LC-MS/MS could be used to determine phosphatidylethanol 16:0/18:1 and 20 other drugs and metabolites with satisfactory sensitivity in one single run. METHODS: Whole blood was prepared by 96-well supported-liquid extraction using heptane/ethyl acetate/2-propanol (16:64:20, v:v:v). Chromatographic separation was achieved on an Acquity BEH C18 column (50 × 2.1 mm I.D.), using a mobile phase with 0.025 % ammonia, pH 10.7 (Solvent A) and methanol (Solvent B). All compounds had isotope-labelled internal standards. RESULTS: The method was fully validated. Recovery was between 63 and 91 % for 20 compounds and 10 % for benzoylecgonine. Matrix effects were low, except for ion enhancement of buprenorphine and ion suppression for THC. However, internal standards compensated for these effects. Inter-assay precision and accuracy were < ± 20 % for all compounds at five tested concentrations, except for methamphetamine at the highest concentration. CONCLUSION: An LC-MS/MS method for simultaneous determination of PEth 16:0/18:1 and 20 drugs and metabolites in whole blood were for the first time developed and validated. Retention of PEth 16:0/18:1 was, in contrast to the other 20 compounds, largely affected by mobile phase buffer concentration. The buffer free basic mobile phase ensured that phosphatidylethanol 16:0/18:1 eluted before most of the unwanted phospholipids.

Prevalence of use and impairment from drugs and alcohol among trauma patients: A national prospective observational study.

BACKGROUND: Being under the influence of psychoactive substances increases the risk of involvement in and dying from a traumatic event. The study is a prospective population-based observational study that aims to determine the prevalence of use and likely impairment from psychoactive substances among patients with suspected severe traumatic injury. METHOD: This study was conducted at 35 of 38 Norwegian trauma hospitals from 1 March 2019 to 29 February 2020. All trauma admissions for patients aged ≥ 16 years admitted via trauma team activation during the study period were eligible for inclusion. Blood samples collected on admission were analysed for alcohol, benzodiazepines, benzodiazepine-like hypnotics (Z-drugs), opioids, stimulants, and cannabis (tetrahydrocannabinol). RESULTS: Of the 4878 trauma admissions included, psychoactive substances were detected in 1714 (35 %) and in 771 (45 %) of these, a combination of two or more psychoactive substances was detected. Regarding the level of impairment, 1373 (28 %) admissions revealed a concentration of one or more psychoactive substances indicating likely impairment, and 1052 (22 %) highly impairment. Alcohol was found in 1009 (21 %) admissions, benzodiazepines and Z-drugs in 613 (13 %), opioids in 467 (10 %), cannabis in 352 (7 %), and stimulants in 371 (8 %). Men aged 27-43 years and patients with violence-related trauma had the highest prevalence of psychoactive substance use with respectively 424 (50 %) and 275 (80 %) testing positive for one or more compounds. CONCLUSION: The results revealed psychoactive substances in 35 % of trauma admissions, 80 % of which were likely impaired at the time of traumatic injury. A combination of several psychoactive substances was common, and younger males and patients with violence-related injuries were most often impaired. Injury prevention strategies should focus on high-risk groups and involve the prescription of controlled substances. We should consider toxicological screening in trauma admissions and incorporation of toxicological data into trauma registries.

Determination of eight phosphatidylethanol homologues in blood by reversed phase liquid chromatography-tandem mass spectrometry - How to avoid co-elution of phosphatidylethanols and unwanted phospholipids.

Phosphatidylethanols (PEths) are specific, direct alcohol biomarkers with a substantially longer half-life than ethanol, and can be used to distinguish between heavy- and social drinking. More than forty PEth homologues have been detected in blood from heavy drinkers, and PEth 16:0/18:1 is the predominant one. Since PEths are phospholipids it can be difficult to isolate them from unwanted phospholipids during sample preparation. To minimize possible matrix effects it is therefore important to separate PEths from other phospholipids during LC-MS/MS analysis. In this study, we have investigated how the retention and chromatographic separation of eight PEth homologues and the phospholipid background are influenced by changes in mobile phase composition using two different LC columns, the Acquity BEH C18 column (50 × 2.1 mm ID, 1.7 µm particles) and the Kinetex biphenyl column (100 × 2.1 mm ID, 1.7 µm particles). Our findings show that the buffer concentration of the aqueous part of the mobile phase had a huge effect on the retention of PEth homologues and separation of PEths from unwanted phospholipids. By using a buffer-free mobile phase consisting of 0.025% ammonia in Type 1 water, pH 10.7, as solvent A and methanol as solvent B, all eight PEth homologues were separated from both the early eluting lyso-phospholipids and the later eluting phospholipids with two fatty chains using the BEH C18 column. The knowledge obtained in this study can be of great importance for those seeking to develop reliable and robust bioanalytical LC-MS/MS methods for determination of PEth homologues.

Determination of the alcohol biomarker phosphatidylethanol 16:0/18:1 and 33 compounds from eight different drug classes in whole blood by LC-MS/MS.

INTRODUCTION: Most bioanalytical LC-MS/MS methods are developed for determination of single drugs or classes of drugs, but a multi-compound LC-MS/MS method that can replace several methods could reduce both analysis time and costs. The aim of this study was to develop a high-throughput LC-MS/MS method for determination of the alcohol biomarker phosphatidylethanol 16:0/18:1 (PEth 16:0/18:1) and 33 other compounds from eight different drug classes in whole blood. METHODS: Whole-blood samples were prepared by 96-well supported liquid extraction (SLE). Chromatographic separations were performed on a biphenyl core shell column with a mobile phase consisting of 10 mM ammonium formate, pH 3.1 and methanol. Each extract was analyzed twice by LC-MS/MS, injecting 0.4 µL and 2 µL, in order to obtain narrow and symmetrical peaks and good sensitivity for all compounds. Stable isotope-labeled internal standards were used for 31 of the 34 compounds. RESULTS: A 96-well SLE reversed phase LC-MS/MS method for determination of PEth 16:0/18:1 and 33 other compounds from eight different drug classes was developed and validated. By using an organic solvent mixture of isopropanol/ methyl tert-butyl ether (1:5, v:v), all compounds, including the polar and ampholytic compounds pregabalin, gabapentin and benzoylecgonine, was extracted by 96-well SLE. DISCUSSION/CONCLUSION: For the first time an LC-MS/MS method for the determination of alcohol biomarker PEth 16:0/18:1 and drugs and metabolites from several different drug classes was developed and validated. The developed LC-MS/MS method can be used for high-throughput analyses and sensitive determinations of the 34 compounds in whole blood.

Multimorbidity, psychoactive substance use and psychological distress among acute medically ill patients: a cross-sectional study.

BACKGROUND: In order to target the complex health needs of patients with multimorbidity using psychoactive substances, knowledge regarding the association between substance use and multimorbidity in an acute setting is needed. AIMS: Examine psychoactive substance use patterns among acute medically ill patients, and determine the association between multimorbidity and substance use, and psychological distress. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: 2874 acute medically ill patients admitted to a medical emergency department in Oslo, Norway. MEASUREMENTS: Primary outcome: multimorbidity recorded by the presence of ≥2 International Classification of Diseases 10th revision-physical and/or mental health conditions per patient, extracted from medical records. Predictor variables: self-reported data on age, sex, occupational status, psychological distress (Hopkins Symptom Check List-5), alcohol use (Alcohol Use Disorder Identification Test-4) and results from blood samples on psychoactive medicinal and illicit drugs. FINDINGS: Of all patients, 57.2% had multimorbidity. Of these, 62.6% reported psychological distress, 85.5% consumed either alcohol, medicinal and/or illicit drugs and 64.4% combined alcohol with psychoactive medicinal drugs. Patients with risky alcohol use were more likely to have multimorbidity compared with patients with low-risk alcohol use (OR 1.53; 95% CI 1.05 to 2.24). Patients using psychoactive medicinal drugs were more likely to have multimorbidity compared with non-users (OR 1.34; 95% CI 1.07 to 1.67). CONCLUSION: Multimorbidity was associated with psychoactive medicinal drug and risky alcohol use, and psychological distress. Substance use was widespread, with alcohol and psychoactive medicinal drugs most frequently combined. Monitoring substance use among multimorbid patients is necessary to develop tailored treatments, and reduce burden on the healthcare system.

Prevalence of psychoactive substance use among acutely hospitalised patients in Oslo and Moscow: a cross-sectional, observational study.

OBJECTIVES: The use of psychoactive prescription medication is increasing in the general population. This is a cause for concern, particularly among the elderly, where physiological changes related to senescence increase the risk for adverse effects. While previous studies regarding psychoactive substance use have generally been population based, we sought to determine the frequency of such use among acutely hospitalised patients. SETTING: Two emergency departments (EDs), one in Oslo and one in Moscow, admitting patients to Departments of Internal Medicine. PARTICIPANTS: 5583 patients aged ≥18 years participated, distributed evenly between genders and study locations. Patients unable to give informed consent were excluded. The study sites did not admit patients with surgical conditions and/or injuries. PRIMARY AND SECONDARY OUTCOMES: The presence of psychoactive substances was determined through blood analysis using liquid chromatography-mass spectrometry. Secondary outcomes comprised demographic data (including age, gender, employment and marital status), degree of psychological distress, concurrent alcohol use, and self-reported alcohol, psychoactive drug and illicit substance use. RESULTS: 32.3% in Oslo and 12% in Moscow were positive for one or more psychoactive medicinal drugs (benzodiazepines, z-hypnotics, opioids or barbiturates). In Oslo, medicinal drug use was associated with being aged 61 to 70 years (OR 2.40, 95% CI 1.61 to 3.58) compared with 18 to 40 years, and psychological distress (OR 2.61, 95% CI 2.06 to 3.30). In Moscow, psychoactive medicinal drug use was also associated with psychological distress (OR 1.68, 95% CI 1.18 to 2.39), and was less common among patients aged 41 to 60 years (OR 0.62, 95% CI 0.43 to 0.88) than among patients aged 18 to 40 years. CONCLUSION: A significant proportion of admitted patients used one or more psychoactive medicinal drugs, in particular benzodiazepines (Oslo and Moscow) and opiates (Oslo). We suggest formalised screening for inappropriate prescription drug use and increased adherence to clinical prescription guidelines.

Association between speeding and use of alcohol and medicinal and illegal drugs and involvement in road traffic crashes among motor vehicle drivers.

OBJECTIVE: The objective of this study was to study the association between self-reported road traffic crashes (RTCs) and recent use of alcohol and medicinal and illicit drug use and self-reported speeding in the previous 2 years. METHODS: During the period from April 2016 to April 2017, drivers of cars, vans, motorcycles, and mopeds were stopped in a Norwegian roadside survey performed in collaboration with the police. Participation was voluntary and anonymous. The drivers were asked to deliver an oral fluid sample (mixed saliva), which was analyzed for alcohol and 39 illicit and medicinal drugs and metabolites. In addition, data on age, sex, and self-reported speeding tickets and RTCs during the previous 2 years were collected. RESULTS: A total of 5,031 participants were included in the study, and 4.9% tested positive for the use of one or more illicit or medicinal drugs or alcohol. We found a significant, positive association between the use of cannabis and RTC involvement (odds ratio [OR] = 1.93; 95% confidence interval [CI], 1.05-3.57; P = 0.035) and also between previous speeding tickets and RTC involvement (OR = 1.39; 95% CI, 1.08-1.80; P = 0.012). In addition, older age groups were found to have a significant, negative association with RTC involvement, with ORs equal to or less than 0.49, when using the age group 16-24 as reference. CONCLUSION: Speeding, as an indicator of risk behavior, and the use of cannabis were associated with previous RTC involvement, whereas increasing age was significantly associated with lower risk. This is consistent with previous studies on RTCs.

The Metabolome in Finnish Carriers of the MYBPC3-Q1061X Mutation for Hypertrophic Cardiomyopathy.

AIMS: Mutations in the cardiac myosin-binding protein C gene (MYBPC3) are the most common genetic cause of hypertrophic cardiomyopathy (HCM) worldwide. The molecular mechanisms leading to HCM are poorly understood. We investigated the metabolic profiles of mutation carriers with the HCM-causing MYBPC3-Q1061X mutation with and without left ventricular hypertrophy (LVH) and non-affected relatives, and the association of the metabolome to the echocardiographic parameters. METHODS AND RESULTS: 34 hypertrophic subjects carrying the MYBPC3-Q1061X mutation, 19 non-hypertrophic mutation carriers and 20 relatives with neither mutation nor hypertrophy were examined using comprehensive echocardiography. Plasma was analyzed for molecular lipids and polar metabolites using two metabolomics platforms. Concentrations of branched chain amino acids, triglycerides and ether phospholipids were increased in mutation carriers with hypertrophy as compared to controls and non-hypertrophic mutation carriers, and correlated with echocardiographic LVH and signs of diastolic and systolic dysfunction in subjects with the MYBPC3-Q1061X mutation. CONCLUSIONS: Our study implicates the potential role of branched chain amino acids, triglycerides and ether phospholipids in HCM, as well as suggests an association of these metabolites with remodeling and dysfunction of the left ventricle.

The influence of sample collection methodology and sample preprocessing on the blood metabolic profile.

AIM: Blood serum and plasma have intrinsic differences in their composition and the preprocessing, such as clotting temperature in serum, and storage at room temperature may have further effect on metabolite concentrations. METHODS: The influence of sampling preprocessing on the metabolic profiles in serum and different types of plasma was investigated using liquid chromatography and comprehensive 2D gas chromatography coupled to a mass spectrometer. RESULTS: The profiles of polar metabolites were significantly dependent on the type of the sample, while lipid profiles were similar in serum and different types of plasma. Extended storage of plasma at room temperature resulted in degradation of lipids already after 1 day. Serum clotting at room temperature generally resulted in higher metabolite concentration compared with serum clotting on ice.

Determination of buprenorphine, fentanyl and LSD in whole blood by UPLC-MS-MS.

A sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method has been developed and validated for the quantification of buprenorphine, fentanyl and lysergic acid diethylamide (LSD) in whole blood. Sample preparation was performed by liquid-liquid extraction (LLE) with methyl tert-butyl ether. UPLC-MS-MS analysis was performed with a mobile phase consisting of ammonium formate (pH 10.2) and methanol. Positive electrospray ionization MS-MS detection was performed with two multiple reaction monitoring transitions for each of the analytes and the deuterium labeled internal standards. Limit of detection values of buprenorphine, fentanyl and LSD were 0.28, 0.044 and 0.0097 ng/mL and limit of quantification values were 0.94, 0.14 and 0.036 ng/mL, respectively. Most phospholipids were removed during LLE. No or only minor matrix effects were observed. The method has been routinely used at the Norwegian Institute of Public Health since September 2011 for qualitative and quantitative detections of buprenorphine, fentanyl and/or LSD in more than 400 whole blood samples with two replicates per sample.