Alcohol Use Disorder and Chronic Pain: An Overlooked Epidemic

Alcohol use disorder (AUD) and chronic pain disorders are pervasive, multifaceted medical conditions that often co-occur. However, their comorbidity is often overlooked, despite its prevalence and clinical relevance. Individuals with AUD are more likely to experience chronic pain than the general population. Conversely, individuals with chronic pain commonly alleviate their pain with alcohol, which may escalate into AUD. This narrative review discusses the intricate relationship between AUD and chronic pain. Based on the literature available, the authors present a theoretical model explaining the reciprocal relationship between AUD and chronic pain across alcohol intoxication and withdrawal. They propose that the use of alcohol for analgesia rapidly gives way to acute tolerance, triggering the need for higher levels of alcohol consumption. Attempts at abstinence lead to alcohol withdrawal syndrome and hyperalgesia, increasing the risk of relapse. Chronic neurobiological changes lead to preoccupation with pain and cravings for alcohol, further entrenching both conditions. To stimulate research in this area, the authors review methodologies to improve the assessment of pain in AUD studies, including self-report and psychophysical methods. Further, they discuss pharmacotherapies and psychotherapies that may target both conditions, potentially improving both AUD and chronic pain outcomes simultaneously. Finally, the authors emphasize the need to manage both conditions concurrently, and encourage both the scientific community and clinicians to ensure that these intertwined conditions are not overlooked given their clinical significance.

Neutrophil-lymphocyte ratio as a predictor of delirium tremens in hospitalized patients with alcohol withdrawal

Delirium Tremens (DT) is a severe form of alcohol withdrawal that can be fatal if not recognized early and treated appropriately. In our study, we aimed to determine the role of Neutrophil-Lymphocyte ratio (NLR), a marker of systemic inflammation, in predicting the development of DT. This retrospective study was conducted in an alcohol and drug treatment center between March 2017 and March 2020. A total of 212 patients with a diagnosis of alcohol use disorder who were admitted to a special care unit after alcohol withdrawal were included. Blood tests were collected within 24 hours of the patients' admission. Comparisons were made according to whether the patients developed DT during the hospitalization. DT was diagnosed in 24.1% of the patients. It was determined that higher NLR level (odds ratio [OR]: 4.38, 95%CI: 2.58-7.43) and history of DT (OR: 1.33, 95%CI: 1.23-11.73) are independent risk factors for the development of DT in the logistic regression analysis. The optimal cut-off value of NLR in predicting DT was 2.67 (sensitivity: 82.4%, specificity: 88.8%). The ROC curve of NLR showed a larger area under the curve (AUC) than the curves of other systemic inflammation markers. NLR is a simple, practical and inexpensive marker that can predict the development of DT in patients with alcohol withdrawal syndrome.

Transient Elastography Accurately Screens for Compensated Advanced Chronic Liver Disease in Patients With Ongoing or Recent Alcohol Withdrawal

BACKGROUND & AIMS

Liver stiffness measurement by transient elastography (TE) is a promising method for staging fibrosis in alcohol-related liver disease, but uncertainties remain regarding the influence of alcohol consumption and thus the ideal timing for TE performance. We evaluated the performance of TE compared with liver biopsy to exclude compensated advanced chronic liver disease (cACLD) in patients hospitalized for alcohol detoxification.

METHODS

Patients were recruited prospectively at 6 in-patient addiction centers in France. Eligible patients had increased aspartate aminotransferase levels, and no history or signs of overt cirrhosis. TE, histology, and biochemistry measurements were obtained within a median of 6 days after alcohol withdrawal. TE and biochemistry were repeated 1 and 2 months later.

RESULTS

The study included 259 patients for per-protocol analysis, of whom 45 (17%) had cACLD. TE identified patients with high accuracy at inclusion and at the 1- and 2-month follow-up evaluation, with area under the curve values of 0.96 (95% CIs, 0.94-0.99), 0.96 (95% CIs, 0.92-0.99), and 0.93 (95% CIs, 0.85-1.00), respectively. In 84% of patients, cACLD was ruled out when liver stiffness was less than 10 kPa (negative predictive value, 99% (95% CIs, 98%-100%)) or ruled in when greater than 25 kPa (positive predictive value, 93% (95% CI, 83%-102%)). Algorithms based on aminotransferase levels and/or bilirubin did not add to the diagnostic performance of TE in this period. Among patients with initial liver stiffness of 10 to 25 kPa, more than half of those with no cACLD showed liver stiffness of less than 10 at 1- and 2-month follow-up testing.

CONCLUSIONS

TE performed during the first 2 months after alcohol cessation is an excellent method for excluding alcohol-related cACLD.

CLINICAL TRIAL NUMBER

NCT01789008.

Risk Locus Identification Ties Alcohol Withdrawal Symptoms to SORCS2

BACKGROUND

Efforts to promote the cessation of harmful alcohol use are hindered by the affective and physiological components of alcohol withdrawal (AW), which can include life-threatening seizures. Although previous studies of AW and relapse have highlighted the detrimental role of stress, little is known about genetic risk factors.

METHODS

We conducted a genome-wide association study of AW symptom count in uniformly assessed subjects with histories of serious AW, followed by additional genotyping in independent AW subjects.

RESULTS

The top association signal for AW severity was in sortilin family neurotrophin receptor gene SORCS2 on chromosome 4 (European American meta-analysis n = 1,478, p = 4.3 × 10-9 ). There were no genome-wide significant findings in African Americans (n = 1,231). Bioinformatic analyses were conducted using publicly available high-throughput transcriptomic and epigenomic data sets, showing that in humans SORCS2 is most highly expressed in the nervous system. The identified SORCS2 risk haplotype is predicted to disrupt a stress hormone-modulated regulatory element that has tissue-specific activity in human hippocampus. We used human neural lineage cells to demonstrate in vitro a causal relationship between stress hormone levels and SORCS2 expression, and show that SORCS2 levels in culture are increased upon ethanol exposure and withdrawal.

CONCLUSIONS

Taken together, these findings indicate that the pathophysiology of withdrawal may involve the effects of stress hormones on neurotrophic factor signaling. Further investigation of these pathways could produce new approaches to managing the aversive consequences of abrupt alcohol cessation.

Effective Reduction of Acute Ethanol Withdrawal by the Tetracycline Derivative, Tigecycline, in Female and Male DBA/2J Mice

BACKGROUND

Alcohol use disorder (AUD) is a spectrum disorder characterized by mild to severe symptoms, including potential withdrawal signs upon cessation of consumption. Approximately five hundred thousand patients with AUD undergo clinically relevant episodes of withdrawal annually (New Engl J Med, 2003, 348, 1786). Recent evidence indicates potential for drugs that alter neuroimmune pathways as new AUD therapies. We have previously shown the immunomodulatory drugs, minocycline and tigecycline, were effective in reducing ethanol (EtOH) consumption in both the 2-bottle choice and drinking-in-the-dark paradigms. Here, we test the hypothesis that tigecycline, a tetracycline derivative, will reduce the severity of EtOH withdrawal symptoms in a common acute model of alcohol withdrawal (AWD) using a single anesthetic dose of EtOH in seizure sensitive DBA/2J (DBA) mice.

METHODS

Naïve adult female and male DBA mice were given separate injections of 4 g/kg i.p. EtOH with vehicle or tigecycline (0, 20, 40, or 80 mg/kg i.p.). The 80 mg/kg dose was tested at 3 time points (0, 4, and 7 hours) post EtOH treatment. Handling-induced convulsions (HICs) were measured before and then over 12 hours following EtOH injection. HIC scores and areas under the curve were tabulated. In separate mice, blood EtOH concentrations (BECs) were measured at 2, 4, and 7 hours postinjection of 4 g/kg i.p. EtOH in mice treated with 0 and 80 mg/kg i.p. tigecycline.

RESULTS

AWD symptom onset, peak magnitude, and overall HIC severity were reduced by tigecycline drug treatment compared to controls. Tigecycline treatment was effective regardless of timing throughout AWD, with earlier treatment showing greater efficacy. Tigecycline showed a dose-responsive reduction in acute AWD convulsions, with no sex differences in efficacy. Importantly, tigecycline did not affect BECs over a time course of elimination.

CONCLUSIONS

Tigecycline effectively reduced AWD symptoms in DBA mice at all times and dosages tested, making it a promising lead compound for development of a novel pharmacotherapy for AWD. Further studies are needed to determine the mechanism of tigecycline action.

Assessment of Withdrawal and Hangover is Confounded in the Alcohol Use Disorder and Associated Disabilities Interview Schedule: Withdrawal Prevalence is Likely Inflated

BACKGROUND

The Alcohol Use Disorder and Associated Disabilities Interview Schedule-IV (AUDADIS-IV) and AUDADIS-5 are diagnostic interviews used in major epidemiological and other studies of alcohol use disorder (AUD). Much of what we know regarding the prevalence of AUD in the United States is based upon this interview. However, past research and meta-analytic evidence suggest that differential operationalization of the AUD criteria across instruments can lead to differential endorsement of symptoms and resulting AUD diagnosis rates. In particular, studies employing the AUDADIS are observed to have markedly higher endorsement rates of withdrawal than other large epidemiological studies. One explanation for this is that when assessing withdrawal, the AUDADIS combines effects from the morning after drinking with those from the days following, thereby conflating hangover and withdrawal.

METHODS

This study addresses whether this operationalization confounds rates of endorsement when compared to simpler, less ambiguous hangover or withdrawal stems. To this aim, 497 college student drinkers were randomized into 1 of 3 stem conditions: (i) hangover (n = 164), (ii) withdrawal (n = 167), or (iii) combined AUDADIS-IV (n = 166).

RESULTS

Across conditions, participants were more likely to report the occurrence of each withdrawal symptom in the combined stem condition than in the explicit withdrawal stem condition, but not in the explicit hangover stem condition. Within the combined stem condition, probed symptoms were more likely to be reported as a result of a hangover.

CONCLUSIONS

The AUDADIS potentially results in false positives for withdrawal, arguably a pathognomonic symptom of alcoholism and, in turn, likely affects rates of the diagnosis of AUD.

Genetic Variation in the Vesicular Monoamine Transporter 1 (VMAT1/SLC18A1) Gene and Alcohol Withdrawal Severity

BACKGROUND

Alcohol withdrawal (AW) can be a serious consequence of alcohol dependence and consists of various neurochemical adaptations in the brain. One such neuroadaptation occurs in the monoamine neurotransmitter system. Recently, a functional variant in the presynaptic vesicular monoamine transporter gene (VMAT1/SLC18A1-Thr136Ile-rs1390938) was found to significantly increase transport of monoamines into synaptic vesicles in vitro. We hypothesize that the alteration of magnitude of monoamine release contributes to severity of AW symptoms.

METHODS

Alcohol-dependent individuals (n = 609; European American n = 340; African American n = 216; other n = 53) were administered the Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised (CIWA-Ar) questionnaire at the time of inpatient admission. Patients were subsequently genotyped for 12 single nucleotide polymorphism (SNP) markers in VMAT1. Association analyses were conducted on the combined sample and separated by ethnicity.

RESULTS

Single marker association tests revealed a significant association between 3 VMAT1 markers and CIWA-Ar scores in the EA sample. The minor alleles of rs1390938 (A) and rs952859 (C) were significantly associated with lower CIWA-Ar scores (p = 0.0006; p = 0.0007), whereas the minor allele of rs3779672 (G) was significantly associated with higher scores (p = 0.006). Additionally, these 3 SNPs were found in a haplotype block that was significantly associated with lower CIWA-Ar scores after haplotype analyses were run (p = 0.009).

CONCLUSIONS

This study shows that genetic variants in VMAT1, including the functional SNP rs1390938, contribute to the severity of AW in patients of European descent. Our data show for the first time a role of presynaptic neurotransmitter release in AW severity. This finding could contribute to identifying patients at risk for severe AW and shed light into the pathophysiology of AW and its treatment.

How Imaging Glutamate, γ-Aminobutyric Acid, and Dopamine Can Inform the Clinical Treatment of Alcohol Dependence and Withdrawal

Neuroimaging studies have dramatically advanced our understanding of the neurochemical basis of alcohol dependence, a major public health issue. In this paper, we review the research generated from neurochemical specific imaging modalities including magnetic resonance spectroscopy, positron emission tomography, and single-photon emission computed tomography in studies of alcohol dependence and withdrawal. We focus on studies interrogating γ-aminobutyric acid (GABA), glutamate, and dopamine, as these are prominent neurotransmitter systems implicated in alcohol dependence. Highlighted findings include diminished dopaminergic functioning and modulation of the GABA system by tobacco smoking during alcohol withdrawal. Then, we consider how these findings impact the clinical treatment of alcohol dependence and discuss directions for future experiments to address existing gaps in the literature, for example, sex differences and smoking comorbidity. These and other considerations provide opportunities to build upon the current neurochemistry imaging literature of alcohol dependence and withdrawal, which may usher in improved therapeutic and relapse prevention strategies.

Healthcare utilization in medical intensive care unit survivors with alcohol withdrawal

BACKGROUND

Rehospitalization is an important and costly outcome that occurs commonly in several diseases encountered in the medical intensive care unit (ICU). Although alcohol use disorders are present in 40% of ICU survivors and alcohol withdrawal is the most common alcohol-related reason for admission to an ICU, rates and predictors of rehospitalization have not been previously reported in this population.

METHODS

We conducted a retrospective cohort study of medical ICU survivors with a primary or secondary discharge diagnosis of alcohol withdrawal using 2 administrative databases. The primary outcome was time to rehospitalization or death. Secondary outcomes included time to first emergency department or urgent care clinic visit in the subset of ICU survivors who were not rehospitalized. Cox proportional hazard models were adjusted for age, gender, race, homelessness, smoking, and payer source.

RESULTS

Of 1,178 patients discharged from the medical ICU over the study period, 468 (40%) were readmitted to the hospital and 54 (4%) died within 1 year. Schizophrenia (hazard ratio 2.23, 95% CI 1.57, 3.34, p < 0.001), anxiety disorder (hazard ratio 2.04, 95% CI 1.30, 3.32, p < 0.01), depression (hazard ratio 1.62, 95% CI 1.05, 2.40, p = 0.03), and Deyo comorbidity score ≥3 (hazard ratio 1.43, 95% CI 1.09, 1.89, p = 0.01) were significant predictors of time to death or first rehospitalization. Bipolar disorder was associated with time to first emergency department or urgent care clinic visit (hazard ratio 2.03, 95% CI 1.24, 3.62, p < 0.01) in the 656 patients who were alive and not rehospitalized within 1 year.

CONCLUSIONS

The presence of a psychiatric comorbidity is a significant predictor of multiple measures of unplanned healthcare utilization in medical ICU survivors with a primary or secondary discharge diagnosis of alcohol withdrawal. This finding highlights the potential importance of targeting longitudinal multidisciplinary care to patients with a dual diagnosis.

Takotsubo cardiomyopathy in the setting of acute alcohol withdrawal

Takotsubo Cardiomyopathy (TCM), also known as stress-induced cardiomyopathy, is a cardiomyopathy characterized by acute reversible apical ventricular dysfunction and apical akinesis in the absence of obstructive coronary artery disease. Although the disease may be precipitated by an acute emotional or physical stressor, the pathophysiology, postulated to involve excess catecholamine release, remains unproven. In contrast, the role of catecholamine excess and hyperadrenergic physiology in acute alcohol withdrawal (AAW) is more established. TCM in the context of acute alcohol withdrawal has been only rarely described. The authors present a new case of TCM in the setting of AAW, along with a review of other reported cases. Current theories on the etiology of TCM and a possible pathophysiologic linkage between TCM and AAW are discussed.