An overview of alcohol testing and interpretation in the 21st century

Blood alcohol concentration and road accidents: Underestimation due to time of the arrival to the emergency department (ED) or delay in blood sampling. A 4-Year Retrospective Study in Rome

Alcohol is a significant public health issue, according to the World Health Organization. Our study aims to analyze the correlation between blood alcohol concentrations (BACs) of drivers, their demographic features, and the possible underestimation of BACs due to the time elapsed between hospital admission and blood sampling. Methods: This study includes patients evaluated for BAC levels in the emergency department (ED) of Fondazione Policlinico Universitario A. Gemelli IRCCS from January 2013 to December 2016. BAC levels were compared in patients involved in road crashes according to age group, sex, and time of the accident. The delays in blood sampling and BAC measurement in the ED were recorded for each patient. The time between the accident and access to the hospital in most cases was unknown. Results: A total of 398 patients were included in the analysis, 107 of them had BACs more than 0.05 g/L., and 86 of these individuals had BAC levels more than 0.5 g/L. Road accident patients had higher rates of positive BAC readings at night and on weekends. A significant delay in blood sampling for BAC determination was observed. Discussion: This study demonstrates a critical bias due to the arrival time at the ED and the delay in blood sampling that inevitably influences and underestimates the BAC, resulting in possible false negative results (BAC values below the cutoff). Zero tolerance or a retrospective BAC calculation could mitigate this bias. It is necessary to implement preventive strategies to reduce instances of driving under the influence (DUI) of alcohol.

Characterization of alcohol levels in autopsies carried out by Forensic Medicine (Honduras) during December 2022 and January 2023

To determine the existing relationship between ethanol levels in biological fluids, such as blood and urine, and their correlation with causes of death in corpses admitted to the forensic medicine autopsy service in Honduras. The gas chromatography method was employed to determine the concentration of ethyl alcohol. After a statistical analysis using measures of central tendency, it was found that the urine sample presented a median of 227.30mg/dL, while in the blood, it was 276.86mg/dL. After some distribution tests and correlation, it was determined that higher alcohol concentrations influence the "ACCIDENTAL" cause of death, with values of median alcohol concentration of 228.56mg/dL in blood and 277.44 mg/dL in urine. Still, the most frequent cause of death was "HOMICIDE", which differs in the age of the subjects and their ethanol concentration, with values of median alcohol concentration of 227.20mg/dL in blood and 276.86mg/dL in urine; similarities of median indicates that both samples are related or share a standard feature. Subsequent statistical tests showed that blood concentration values are more representative than urine values since the latter represents the final metabolic stage of alcohol in the body and exhibits more excellent dispersion. The average age of the individuals analyzed was 33 years old. However, it should be noted that individuals involved in "ACCIDENTAL" causes of death were in the lower age range corresponding to the so-called young adults. Keywords: Forensic sciences; blood alcohol concentration; autopsy; alcohol in urine

Neurocognitive effects of binge drinking on verbal episodic memory. An ERP study in university students

Background: Verbal memory may be affected by engagement in alcohol binge drinking during youth, according to the findings of neuropsychological studies. However, little is known about the dynamics of the neural activity underlying this cognitive process in young, heavy drinkers. Aims: To investigate brain event-related potentials associated with cued recall from episodic memory in binge drinkers and controls. Methods: Seventy first-year university students were classified as binge drinkers (32: 17 female) or controls (38: 18 female). The participants completed a verbal paired associates learning task during electroencephalogram (EEG) recording. ERPs elicited by old and new word pairs were extracted from the cued-recall phase of the task by using Principal Component Analysis. Subjects also performed a standardized neuropsychological verbal learning test. Results: Two of the three event-related potentials components indicating old/new memory effects provided evidence for anomalies associated with binge drinking. The old/new effects were absent in the binge drinkers in the two subsequent posterior components, identified with the late parietal component and the late posterior negativity The late frontal component revealed similar old/new effects in both groups. Binge drinkers showed similar behavioural performance to controls in the verbal paired associates task, but performed poorly in the more demanding short-term cued-recall trial of a neuropsychological standardized test. Conclusion: Event-related potentials elicited during a verbal cued-recall task revealed differences in brain functioning between young binge drinkers and controls that may underlie emergent deficits in episodic memory linked to alcohol abuse. The brain activity of binge drinkers suggests alterations in the hippocampal - posterior parietal cortex circuitry subserving recognition and recollection of the cue context and generation of the solution, in relation to verbal information shallowly memorised.

Simultaneous Alcohol/Cannabis Use and Driving Under the Influence in the U.S

INTRODUCTION

Alcohol and cannabis are commonly involved in motor vehicle crashes and fatalities. This study examines whether simultaneous use of alcohol/cannabis is associated with higher odds of reporting driving under the influence of alcohol and cannabis in the U.S.

METHODS

Drivers aged ≥16 years with any past-year alcohol and cannabis use in the 2016-2019 National Survey on Drug Use and Health (N=34,514) reported any past-year driving under the influence of alcohol-only, cannabis-only, both alcohol/cannabis, or not driving under the influence. Survey-weighted associations between simultaneous alcohol/cannabis use and each of the driving under the influence outcomes were computed adjusting for sociodemographics and daily alcohol/cannabis use. Analyses were conducted from November 2020 to September 2021.

RESULTS

In 2016-2019, 42% of drivers with past-year alcohol and cannabis use reported driving under the influence (8% alcohol-only, 20% cannabis-only, 14% alcohol/cannabis). Simultaneous alcohol/cannabis use was associated with 2.88-times higher adjusted odds of driving under the influence of cannabis-only (95% CI=2.59, 3.19) and 3.51-times higher adjusted odds of driving under the influence of both alcohol/cannabis (95% CI=3.05, 4.05), compared to not driving under the influence. Associations with driving under the influence of alcohol-only were unexpectedly in the opposite direction (adjusted conditional odds ratio=0.59, 95% CI=0.45, 0.79).

CONCLUSIONS

Overall, 2 in 5 drivers who used alcohol and cannabis reported driving under the influence of alcohol and/or cannabis. People reporting simultaneous alcohol/cannabis use were more likely to report cannabis-related driving under the influence. Prevention strategies should target individuals reporting simultaneous alcohol/cannabis use to reduce the occurrence of driving under the influence.

Development and Validation of an Analytical Method for Volatiles with Endogenous Production in Putrefaction and Submersion Situations

A group of 16 volatile substances (ethyl acetate, 2-propanol, 1-propanol, methanol, acetone, ethanol, acetaldehyde, diethyl ether, methyl ethyl ketone, 1-butanol, 2-butanol, t-butanol, isobutanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 1-pentanol) were qualitatively and quantitatively analyzed through a method developed for volatiles with endogenous production in putrefaction and submersion situations. The method was validated for blood, urine and vitreous humor, using a gas chromatograph (Varian 450-GC) with a flame ionization detector coupled to a headspace injector (HS-GC-FID). The vials were prepared by diluting 100 µL of the sample of interest in 1 mL of internal standard (acetonitrile 100 mg/L), using two capillary columns (VF-624ms and VF-5ms) with different polarities to ensure that all test compounds would be properly identified and undoubtedly distinguished from the rest. All volatiles were studied in a range of 50 to 2,000 mg/L in terms of selectivity/specificity, detection and quantification limits, linearity and calibration model, precision, accuracy, bias, robustness and stability according to the Scientific Working Group for Forensic Toxicology. Detection and quantification limits were between 1 to 8 mg/L and 4 to 24 mg/L, respectively, with coefficient of variation values under 10% in bias studies and in intermediate precision studies for most substances. The developed method was applied to real cases to test the method.

Evaluation of the Compatibility of Ethyl Glucuronide and Ethyl Sulphate Levels to Assess Alcohol Consumption in Decomposed and Diabetic Postmortem Cases

The aim of the study is to evaluate the contribution of ethanol metabolite detection in postmortem cases by showing the connection between the presence of ethanol metabolites, which are indicators of alcohol consumption, and the detection of potential postmortem ethanol formation in decomposed and diabetic cases. Determination of ethanol consumption before death is often one of the most important questions in death investigations. Postmortem ethanol formation or degradation products in the blood make it difficult to distinguish antemortem consumption or postmortem formation of ethanol and eventually may lead to misinterpretation. Decomposed bodies and diabetic cases are vulnerable to postmortem ethanol formation due to putrefaction, fermentation or other degradations. Ethyl glucuronide (EtG) and ethyl sulphate (EtS) are two metabolites of ethanol produced only in the antemortem time interval. In this study, EtG and EtS levels in urine and vitreous humor samples of 27 postmortem cases, including diabetic and degraded bodies were compared to ethanol results of their blood, urine, and vitreous humor samples. EtG and EtS in urine and vitreous humor were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS-MS) and ethanol was assayed by routine headspace gas chromatography-flame ionization detector (GC-FID). These cases were devoid of other influences from forensically relevant drugs, so ethanol and/or glucose were among the only positive findings in these cases. The results of this pilot study indicate the postmortem ethanol concentrations do not correlate with the measured EtG and EtS values but are beneficial in rulings of accidental or natural deaths. This preliminary study gives additional data to help distinguish between antemortem ethanol intake and postmortem formation. EtG and EtS were well correlated positively with antemortem ethanol use instead of forming spontaneously in samples from decedents who are decomposing or have a history of diabetic hyperglycemia.

Cross-country differences in age trends in alcohol consumption among older adults: a cross-sectional study of individuals aged 50 years and older in 22 countries

BACKGROUND AND AIMS

Age-related changes in physiological, metabolic and medication profiles make alcohol consumption likely to be more harmful among older than younger adults. This study aimed to estimate cross-national variation in the quantity and patterns of drinking throughout older age, and to investigate country-level variables explaining cross-national variation in consumption for individuals aged 50 years and older.

DESIGN

Cross-sectional observational study using previously harmonized survey data.

SETTING

Twenty-two countries surveyed in 2010 or the closest available year.

PARTICIPANTS

A total of 106 180 adults aged 50 years and over.

MEASUREMENTS

Cross-national variation in age trends were estimated for two outcomes: weekly number of standard drink units (SDUs) and patterns of alcohol consumption (never, ever, occasional, moderate and heavy drinking). Human Development Index and average prices of vodka were used as country-level variables moderating age-related declines in drinking.

FINDINGS

Alcohol consumption was negatively associated with age (risk ratio = 0.98; 95% confidence interval = 0.97, 0.99; P-value < 0.001), but there was substantial cross-country variation in the age-related differences in alcohol consumption [likelihood ratio (LR) test P-value < 0.001], even after adjusting for the composition of populations. Countries' development level and alcohol prices explained 31% of cross-country variability in SDUs (LR test P-value < 0.001) but did not explain cross-country variability in the prevalence of heavy drinkers.

CONCLUSIONS

Use and harmful use of alcohol among older adults appears to vary widely across age and countries. This variation can be partly explained both by the country-specific composition of populations and country-level contextual factors such as development level and alcohol prices.

Variability in antemortem and postmortem blood alcohol concentration levels among fatally injured adults

Background: Excessive alcohol use is a risk factor for injury-related deaths. Postmortem blood samples are commonly used to approximate antemortem blood alcohol concentration (BAC) levels.Objectives: To assess differences between antemortem and postmortem BACs among fatally injured adults admitted to one shock trauma center (STC).Method: Fifty-two adult decedents (45 male, 7 female) admitted to a STC in Baltimore, Maryland during 2006-2016 were included. STC records were matched with records from Maryland's Office of the Chief Medical Examiner (OCME). The antemortem and postmortem BAC distributions were compared. After stratifying by antemortem BACs <0.10 versus ≥0.10 g/dL, differences in postmortem and antemortem BACs were plotted as a function of length of hospital stay.Results: Among the 52 decedents, 22 died from transportation-related injuries, 20 died by homicide or intentional assault, and 10 died from other injuries. The median BAC antemortem was 0.10 g/dL and postmortem was 0.06 g/dL. Thirty-one (59.6%) decedents had antemortem BACs ≥0.08 g/dL versus 22 (42.3%) decedents using postmortem BACs. Postmortem BACs were lower than the antemortem BACs for 42 decedents, by an average of 0.07 g/dL. Postmortem BACs were higher than the antemortem BACs for 10 decedents, by an average of 0.06 g/dL.Conclusion: Postmortem BACs were generally lower than antemortem BACs for the fatally injured decedents in this study, though not consistently. More routine antemortem BAC testing, when possible, would improve the surveillance of alcohol involvement in injuries. The findings emphasize the usefulness of routine testing and recording of BACs in acute care facilities.

Cross-country and historical variation in alcohol consumption among older men and women: Leveraging recently harmonized survey data in 21 countries

BACKGROUND

Alcohol consumption causes greater harm in older than younger adults. As the population ages, understanding cross-country and time-varying drinking patterns of older adults is of critical importance. Available evidence relies primarily on ecological data.

METHODS

We harmonized survey data for 179,881 adults age 50+ observed repeatedly between 1998 and 2016 in 21 countries. Next, we estimated historical variation in consumption across countries (overall and stratified by gender and age group 50-64/65+).

RESULTS

On average, 51.95 % of older adults consumed any alcohol over the observed period. For 13 countries, the proportion of older adults who drink increased (mean annual increase: 0.76 percent points). Heavy drinking (men drinks/day>3 or binge>5, women drinks/day>2 or binge>4) peaked at 23.54 % for England in 2010 and lifetime abstainers at 69.65 % for China in 2011. Across countries and among drinkers, consumption frequency was 2.57 days/week, the number of standard drink units when drinking was 2.57, and the average number of drinks/day over a week was 1.12. Consumption patterns varied substantially across countries and historical time. Overall probability and frequency of consumption were higher in men than women, with the largest gaps observed in 2011 for China, but gender gaps decreased (even reversed) in the young old and varied across country and time.

CONCLUSIONS

Wide variation in older adults' alcohol consumption across countries and time suggests that broad scale prevention and intervention efforts can be harnessed for potential population-level health benefits. Further variation by gender and age reflect physiological and social factors simultaneously shaping alcohol consumption.

Distributions of alcohol use biomarkers including ethanol, phosphatidylethanol, ethyl glucuronide and ethyl sulfate in clinical and forensic testing

Laboratory tests vary widely in their utility and each test has unique advantages and disadvantages. For the detection of ethanol use and abuse, a variety of direct and indirect markers are available. Alcohol biomarkers provide objective measures for numerous areas of testing including clinical trials, alcohol abuse, postmortem assessment, and drugs of abuse screening. Because the utility of alcohol biomarkers vary depending on the context in which the results will be used, knowing the analogous distribution of results is of value. Herein we report distributions of ethanol in blood, phosphatidylethanol in blood, ethyl glucuronide in urine, and ethyl sulfate in urine for results reported in the last twelve months by our laboratory. Positivity rates were higher for directed analyses when compared to broad screening or panel tests with the highest overall positivity for ethyl glucuronide and ethyl sulfate. The distribution of results for ethyl glucuronide and ethyl sulfate were higher in clinical testing scenarios compared to forensic and a significant correlation between ethyl glucuronide and ethyl sulfate was found consistent with previous reports. Phosphatidylethanol was rarely ordered for forensic use while distributions between routine clinical and clinical trial use were similar. Approximately 21% of all phosphatidylethanol results were in the moderate to chronic alcohol use category. These results provide a summary of four commonly used direct markers for alcohol use with positivity rates and overall quantitative distributions. These data supply insights broken out by various disciplines where applicable providing a concise comparison of results for these markers.

AWARE: A Wearable Awareness with Real-time Exposure, for monitoring alcohol consumption impact through ethyl glucuronide detection

Here we demonstrate for the first time a dynamic monitoring of the ethanol metabolite ethyl glucuronide (EtG) for a more robust evaluation of alcohol consumption, compared to conventional methods. A wearable biosensor device capable of reporting EtG levels in sweat continuously via low power impedance spectroscopy is reported. The custom hardware was compared against a conventional benchtop potentiostat, and demonstrated comparable results in the application of EtG detection in low volume sweat. The device successfully differentiated three distinct EtG concentrations correlating to simulated drinking scenarios estimated to be 1, 2, and 3 standard U.S. drinks consumed over a duration of 60 min, with p < 0.0001. This device has the potential to enable moderate drinkers to engage in guided decision-making, based on objective data, to address the needs of alcohol-sensitive populations. The device also will serve as a tool for researchers to better understand and characterize the relationship between sweat EtG and consumed alcohol.

Alcohol consumption predicts incidence of depressive episodes across 10 years among older adults in 19 countries

Alcohol consumption is increasing in many countries, and excessive alcohol consumption is particularly increasing among older adults. Excessive alcohol consumption causes morbidity and mortality, especially among older adults, including an increased risk of depressive episodes. We review the mechanisms through which alcohol consumption may affect depression, and argue that the effects of alcohol consumption on depressive episodes among older adults are understudied. We harmonized data among older adults (≥50 years) on alcohol consumption, depressive episodes, and an array of risk factors across 10 years and 19 countries (N=57,276). Alcohol consumption was categorized as current or long-term abstainer, occasional, moderate and heavy drinking at an average of 2.3 follow-up time points. Depressive episodes were measured through the CES-D or EURO-D. Multi-level Cox proportional frailty models in which the random effect has a multiplicative relationship to hazard were estimated with controls for co-occurring medical conditions, health behaviors, and demographics. Long-term alcohol abstainers had a higher hazard of depressive episodes (HR=1.14, 95% C.I. 1.08-1.21), as did those reporting occasional (HR=1.16, 95% C.I. 1.10-1.21) and heavy drinking (HR=1.22, 95% C.I. 1.13-1.30), compared with moderate drinking. Hazard ratios were attenuated in frailty models; heavy drinking, however, remained robustly associated in a random-effects model with a frailty component (HR=1.16, 95% C.I. 1.11-1.21). Interactions were observed by gender and smoking status: long-term abstainers, women's, and smokers' (HR for interaction, 1.04, 95% C.I. 1.00-1.07) hazards of depressive episodes increased more than what would be expected based on their multiplicative effects, when compared to moderate drinking, non-smoking men. Excessive alcohol consumption among older adults is a concern not only for physical, but also for mental health. Physician efforts to screen older adults for excessive alcohol use is critical for mental health to remain strong in aging populations.

Simultaneous determination of ethanol's four types of non-oxidative metabolites in human whole blood by liquid chromatography tandem mass spectrometry

The importance of ethanol non-oxidative metabolites as the specific biomarkers of alcohol consumption in clinical and forensic settings is increasingly acknowledged. Simultaneous determination of these metabolites can provide a wealth of information like drinking habit and history, but it was difficult to achieve because of their wide range of polarity. This work describes development and validation of a simple liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for 4 types of ethanol non-oxidative metabolites (ethyl glucuronide, ethyl sulfate, fatty acid ethyl esters and phosphatidylethanols) in 50 μL of human whole blood. Pretreatment method, column and MS conditions were optimized. For the first time, the four types of ethanol non-oxidative metabolites with enormous discrepancies of property were simultaneously extracted and analyzed in one run within 40 min. The limits of detections (LODs) were among 0.1-10 ng/mL, and good linearity was obtained. Deviations in precision and accuracy were all lower than 15% at three QC levels. This method was then applied to two forensic samples, resulting in information on drinking habits and drinking time which were very useful for the interpretation of the blood alcohol results.

Best-practices approach to determination of blood alcohol concentration (BAC) at specific time points: Combination of ante-mortem alcohol pharmacokinetic modeling and post-mortem alcohol generation and transport considerations

Alcohol concentrations in biological matrices offer information regarding an individual's intoxication level at a given time. In forensic cases, the alcohol concentration in the blood (BAC) at the time of death is sometimes used interchangeably with the BAC measured post-mortem, without consideration for alcohol concentration changes in the body after death. However, post-mortem factors must be taken into account for accurate forensic determination of BAC prior to death to avoid incorrect conclusions. The main objective of this work was to describe best practices for relating ante-mortem and post-mortem alcohol concentrations, using a combination of modeling, empirical data and other qualitative considerations. The Widmark modeling approach is a best practices method for superimposing multiple alcohol doses ingested at various times with alcohol elimination rate adjustments based on individual body factors. We combined the selected ante-mortem model with a suggestion for an approach used to roughly estimate changes in BAC post-mortem, and then analyzed the available data on post-mortem alcohol production in human bodies and potential markers for alcohol production through decomposition and putrefaction. Hypothetical cases provide best practice approaches as an example for determining alcohol concentration in biological matrices ante-mortem, as well as potential issues encountered with quantitative post-mortem approaches. This study provides information for standardizing BAC determination in forensic toxicology, while minimizing real world case uncertainties.

Comparative analysis of hospital and forensic laboratory ethanol concentrations: A 15 month investigation of antemortem specimens

Quantitative serum alcohol concentrations from regional hospitals (from specimens collected at time of hospital admission) were compared to results from whole blood (from specimens collected at the time of hospital admission) concentrations measured at the San Diego County Medical Examiner's Office (SDCMEO). Over a 15 month period (January 2012 to March 2013), the postmortem forensic toxicology laboratory analyzed a total of 2,321 cases. Of these, 280 were hospital cases (antemortem) representing 12% of the overall Medical Examiner toxicology casework. 59 of the 280 hospital cases (or 21%) screened positive for alcohol (ethanol). 39 of these 59 cases were included in the study based on available specimens for quantitative analyses. This investigation indicated that serum hospital ethanol concentrations correlated well (R(2) = 0.942) with ethanol values determined at SDCMEO (generally measured in whole blood). There was an observed negative bias with an average of -14.1%. A paired t-test was applied to the data and it was shown that this observed bias is statistically significant. These differences in ethanol concentrations could result from differences in specimen, analytical techniques, and/or calibration. The potential for specimen contamination is also discussed.

The usefulness of biomarkers of alcohol abuse in hair and serum carbohydrate-deficient transferrin: a case report

The detection of carbohydrate-deficient transferrin (CDT) in serum is widely accepted to identify chronic alcohol consumption over the previous two weeks, but minor ethanol metabolites detected in hair often complete the information obtained. In particular, ethylglucuronide and cocaethylene (a marker of simultaneous intake of cocaine and alcohol) allow correct interpretation of data obtained in forensic cases. We refer to a negative CDT value obtained from a serum sample collected during hospitalization of a man admitted for cardiac arrest who died about 14 h later. Clinical analysis performed on admission showed a high ethanol level and a positive urinary screening for cocaine. The toxicological analyses of post-mortem samples found cocaine metabolites in his urine and blood. The negative CDT level suggested the ethanol concentration at admission to be an acute episode. Cocaine and cocaethylene well above the cut-off suggested by the literature were found in hair analyzed for the entire length (about 1 cm). Ethylglucuronide detected on the same hair sample confirmed chronic abuse of ethanol in the previous month, at least. The present report suggests caution in the interpretation of biomarkers of alcohol abuse, encouraging the detection of more than one marker to avoid misinterpretation.

Alcohol: Pharmacology and Disposition

Alcohol is the most common drug detected in forensic cases, is often associated with increased aggression and other disinhibitory behaviors in criminal matters, and frequently contributes to the cause of death in medical examiner cases. Significant adverse effects of alcohol generally manifest at blood alcohol concentrations above 100 mg/dL. In postmortem cases, a number of factors can affect the accuracy of the blood measurement, including site of sampling and putrefactive formation. This paper provides an overview of the pharmacology, pharmacokinetics, and interpretation of alcohol and its concentrations in key specimens, with application to forensic medical cases.

Ethanol Analysis in Postmortem and Human Performance Forensic Toxicology Cases

Ethanol analysis is probably the most common procedure performed in forensic and analytical toxicology laboratories worldwide. Ethanol poisoning is very important in both clinical and forensic investigations. In clinical evaluations, measuring the ethanol concentration is necessary for the timely and appropriate delivery of care to patients who may experience discomfort or life threatening ethanolic overdose or mixed ethanol-drug intoxication. In forensic toxicology investigations, ethanol is routinely measured in both human performance forensic toxicology cases such as drug-facilitated crimes and driving-under-the-influence cases, as well as in postmortem forensic toxicology cases. This review presents information regarding the most commonly analyzed biological specimens used in alcohol analysis including, among others, blood, breath, urine, oral fluid, and vitreous humor. Additionally, it presents the various chemical, biochemical, gas chromatographic, and breath testing techniques commonly employed in ethanol analysis and considers the main advantages and disadvantages of each. Finally, a brief discussion of quality assurance in alcohol analysis is presented.

Risks, management, and monitoring of combination opioid, benzodiazepines, and/or alcohol use

The concurrent use of opioids, benzodiazepines (BZDs), and/or alcohol poses a formidable challenge for clinicians who manage chronic pain. While the escalating use of opioid analgesics for the treatment of chronic pain and the concomitant rise in opioid-related abuse and misuse are widely recognized trends, the contribution of combination use of BZDs, alcohol, and/or other sedative agents to opioid-related morbidity and mortality is underappreciated, even when these agents are used appropriately. Patients with chronic pain who use opioid analgesics along with BZDs and/or alcohol are at higher risk for fatal/nonfatal overdose and have more aberrant behaviors. Few practice guidelines for BZD treatment are readily available, especially when they are combined clinically with opioid analgesics and other central nervous system-depressant agents. However, coadministration of these agents produces a defined increase in rates of adverse events, overdose, and death, warranting close monitoring and consideration when treating patients with pain. To improve patient outcomes, ongoing screening for aberrant behavior, monitoring of treatment compliance, documentation of medical necessity, and the adjustment of treatment to clinical changes are essential. In this article, we review the prevalence and pharmacologic consequences of BZDs and/or alcohol use among patients with pain on chronic opioid therapy, as well as the importance of urine drug testing, an indispensable tool for therapeutic drug monitoring, which helps to ensure the continued safety of patients. Regardless of risk or known aberrant drug-related behaviors, patients on chronic opioid therapy should periodically undergo urine drug testing to confirm adherence to the treatment plan.