Effects of Alcohol Cue Reactivity on Subsequent Treatment Outcomes Among Treatment-Seeking Individuals with Alcohol Use Disorder: A Multisite Randomized, Double-Blind, Placebo-Controlled Clinical Trial of Varenicline

BACKGROUND

The alcohol cue reactivity paradigm is increasingly used to screen medications for the treatment of alcohol use disorder (AUD) and other substance use disorders. Yet, its prospective association with craving and naturalistic drinking outcomes in clinical trials remains unknown. This study embedded repeated human laboratory assessments of alcohol cue reactivity within the context of a randomized controlled trial to examine the effects of varenicline tartrate (Chantix^® ), a partial agonist of α4β2 nicotinic acetylcholine receptors, on alcohol craving among treatment-seeking heavy drinkers with AUD. Our main objectives were to test whether varenicline, as compared to placebo, blunts alcohol cue-elicited craving and test whether alcohol cue reactivity observed in the human laboratory predicts subsequent alcohol craving and use during the remainder of the trial.

DESIGN AND METHODS

This double-blind, randomized, 2-site study compared the effects of varenicline (up to 2 mg/d) and placebo on responses to in vivo alcohol cue and affective picture cue exposure in the human laboratory. Forty-seven volunteers (18 females, 29 males), ages 23 to 67 years (M = 43.7, SD = 11.5), were recruited from the community via advertisements to participate in a clinical trial designed to study the effects of varenicline on alcohol use. Participants were randomized to either varenicline or placebo for 6 weeks.

RESULTS

Varenicline did not attenuate cue-induced alcohol craving relative to placebo, but craving captured during the cue reactivity paradigm significantly predicted subsequent alcohol use in real-world settings during the clinical trial. Higher craving predicted heavier alcohol use.

CONCLUSIONS

Our results are among the first to show alcohol cue-induced craving captured during a human laboratory paradigm predicts drinking outcomes in the context of a clinical trial.

Gabapentin Enacarbil Extended-Release for Alcohol Use Disorder: A Randomized, Double-Blind, Placebo-Controlled, Multisite Trial Assessing Efficacy and Safety

BACKGROUND

Several single-site alcohol treatment clinical trials have demonstrated efficacy for immediate-release (IR) gabapentin in reducing drinking outcomes among individuals with alcohol dependence. The purpose of this study was to conduct a large, multisite clinical trial of gabapentin enacarbil extended-release (GE-XR) (HORIZANT^® ), a gabapentin prodrug formulation, to determine its safety and efficacy in treating alcohol use disorder (AUD).

METHODS

Men and women (n = 346) who met DSM-5 criteria for at least moderate AUD were recruited across 10 U.S. clinical sites. Participants received double-blind GE-XR (600 mg twice a day) or placebo and a computerized behavioral intervention (Take Control) for 6 months. Efficacy analyses were prespecified for the last 4 weeks of the treatment period.

RESULTS

The GE-XR and placebo groups did not differ significantly on the primary outcome measure, percentage of subjects with no heavy drinking days (28.3 vs. 21.5, respectively, p = 0.157). Similarly, no clinical benefit was found for other drinking measures (percent subjects abstinent, percent days abstinent, percent heavy drinking days, drinks per week, drinks per drinking day), alcohol craving, alcohol-related consequences, sleep problems, smoking, and depression/anxiety symptoms. Common side-effects were fatigue, dizziness, and somnolence. A population pharmacokinetics analysis revealed that patients had lower gabapentin exposure levels compared with those in other studies using a similar dose but for other indications.

CONCLUSIONS

Overall, GE-XR at 600 mg twice a day did not reduce alcohol consumption or craving in individuals with AUD. It is possible that, unlike the IR formulation of gabapentin, which showed efficacy in smaller Phase 2 trials at a higher dose, GE-XR is not effective in treating AUD, at least not at doses approved by the U.S. Food and Drug Administration for treating other medical conditions.

An exploratory evaluation of Take Control: A novel computer-delivered behavioral platform for placebo-controlled pharmacotherapy trials for alcohol use disorder

Placebo-controlled pharmacotherapy trials for alcohol use disorder (AUD) require an active behavioral platform to avoid putting participants at risk for untreated AUD and to better assess the effectiveness of the medication. Therapist-delivered platforms (TDP) can be costly and present a risk to study design because of the variability in therapist fidelity. Take Control is a novel computer-delivered behavioral platform developed for use in pharmacotherapy trials sponsored by the National Institute on Alcohol Abuse and Alcoholism Clinical Investigations Group (NCIG). This behavioral platform was developed with the goal of reducing trial implementation costs and limiting potential bias introduced by therapists providing TDP. This exploratory study is the first to compare Take Control with TDP on measures related to placebo response rate, medication adherence, and participant retention. Data were drawn from the placebo arms of four multisite, double-blind, randomized controlled trials (RCT) for AUD conducted by NCIG from 2007 to 2015. Data were compared from subjects receiving TDP (n=156) in two RCTs and Take Control (n=155) in another two RCTs. Placebo response rate, as represented by weekly percentage of heavy drinking days, was similar between groups. Subjects who received Take Control had a higher rate of medication adherence than those who received TDP. Subject retention was not significantly different between groups. The findings suggest that Take Control is comparable to TDP on measures of retention, medication adherence, and placebo response. Additional research is needed to evaluate Take Control directly against TDPs in a randomized trial.

Discovery, Development, and Adoption of Medications to Treat Alcohol Use Disorder: Goals for the Phases of Medications Development

For more than 25 years, advances have been made in developing medications to treat alcohol use disorder (AUD), highlighted by the U.S. Food and Drug Administration's approval of naltrexone (oral and long-acting) and acamprosate. Despite this progress, more work remains to be done in this area because these medications, although effective for some people, do not work for everyone. A high priority for the National Institute on Alcohol Abuse and Alcohol is to put into place a solid infrastructure to aid in the development of medications that are more effective than those currently available and with few side effects. Medication development, especially for a disorder as complex as AUD, is challenging and involves multiple phases, including discovery of "druggable" targets, preclinical studies, human clinical trials, and the adoption and implementation of the new medication into mainstream medicine. A successful medications development program requires clearly established goals for each phase to ensure that a candidate compound is not trapped in one particular phase, a condition known as "the valley of death." In this article, the phases of medication development are described as they apply to AUD, and specific goals of each phase are identified for the next decade. In addition, several important crosscutting themes are outlined for each phase, all of which are essential for advancing medications development. These include identifying and validating screening models and druggable targets, making use of precision medicine, and establishing partnerships among key stakeholders. Our goal in writing this article is to provide a guide on medications development that will aid the alcohol research community in planning, testing, and developing medications for AUD.

Medications development to treat alcohol dependence: a vision for the next decade

More than 76 million people world-wide are estimated to have diagnosable alcohol use disorders (AUDs) (alcohol abuse or dependence), making these disorders a major global health problem. Pharmacotherapy offers promising means for treating AUDs, and significant progress has been made in the past 20 years. The US Food and Drug Administration approved three of the four medications for alcoholism in the last two decades. Unfortunately, these medications do not work for everyone, prompting the need for a personalized approach to optimize clinical benefit or more efficacious medications that can treat a wider range of patients, or both. To promote global health, the potential reorganization of the National Institutes of Health (NIH) must continue to support the National Institute on Alcohol Abuse and Alcoholism's (NIAAA's) vision of ensuring the development and delivery of new and more efficacious medications to treat AUDs in the coming decade. To achieve this objective, the NIAAA Medications Development Team has identified three fundamental long-range goals: (1) to make the drug development process more efficient; (2) to identify more efficacious medications, personalize treatment approaches, or both; and (3) to facilitate the implementation and adaptation of medications in real-world treatment settings. These goals will be carried out through seven key objectives. This paper describes those objectives in terms of rationale and strategy. Successful implementation of these objectives will result in the development of more efficacious and safe medications, provide a greater selection of therapy options and ultimately lessen the impact of this devastating disorder.

A double-blind, placebo-controlled trial assessing the efficacy of levetiracetam extended-release in very heavy drinking alcohol-dependent patients

BACKGROUND

Despite advances in the development of medications to treat alcohol dependence, few medications have been approved by the U.S. Food and Drug Administration. The use of certain anticonvulsant medications has demonstrated potential efficacy in treating alcohol dependence. Previous research suggests that the anticonvulsant levetiracetam may be beneficial in an alcohol-dependent population of very heavy drinkers.

METHODS

In this double-blind, randomized, placebo-controlled clinical trial, 130 alcohol-dependent patients who reported very heavy drinking were recruited across 5 clinical sites. Patients received either levetiracetam extended-release (XR) or placebo and a Brief Behavioral Compliance Enhancement Treatment intervention. Levetiracetam XR was titrated during the first 4 weeks to 2,000 mg/d. This target dose was maintained during weeks 5 through 14 and was tapered during weeks 15 and 16.

RESULTS

No significant differences were detected between the levetiracetam XR and placebo groups in either the primary outcomes (percent heavy drinking days and percent subjects with no heavy drinking days) or in other secondary drinking outcomes. Treatment groups did not differ on a number of nondrinking outcomes, including depression, anxiety, mood, and quality of life. The only difference observed was in alcohol-related consequences. The levetiracetam XR treatment group showed significantly fewer consequences than did the placebo group during the maintenance period (p = 0.02). Levetiracetam XR was well tolerated, with fatigue being the only significantly elevated adverse event, compared with placebo (53% vs. 24%, respectively; p = 0.001).

CONCLUSIONS

This multisite clinical trial showed no efficacy for levetiracetam XR compared with placebo in reducing alcohol consumption in heavy drinking alcohol-dependent patients.

A double-blind, placebo-controlled trial to assess the efficacy of quetiapine fumarate XR in very heavy-drinking alcohol-dependent patients

BACKGROUND

Despite advances in developing medications to treat alcohol dependence, few such medications have been approved by the Food and Drug Administration. Identified molecular targets are encouraging and can lead to the development and testing of new compounds. Atypical antipsychotic medications have been explored with varying results. Prior research suggests that the antipsychotic quetiapine may be beneficial in an alcohol-dependent population of very heavy drinkers.

METHODS

In this double-blind, placebo-controlled trial, 224 alcohol-dependent patients who reported very heavy drinking were recruited across 5 clinical sites. Patients received either quetiapine or placebo and Medical Management behavioral intervention. Patients were stratified on gender, clinical site, and reduction in drinking prior to randomization.

RESULTS

No differences between the quetiapine and placebo groups were detected in the primary outcome, percentage heavy-drinking days, or other drinking outcomes. Quetiapine significantly reduced depressive symptoms and improved sleep but had no effect on other nondrinking outcomes. Results from a subgroup analysis suggest that patients who reduced their drinking prior to randomization had significantly better drinking outcomes during the maintenance phase (p < 0.0001). No significant interactions, however, were observed between reducer status and treatment group. Finally, quetiapine was generally well tolerated. Statistically significant adverse events that were more common with quetiapine versus placebo include dizziness (14 vs. 4%), dry mouth (32 vs. 9%), dyspepsia (13 vs. 2%), increased appetite (11 vs. 1%), sedation (15 vs. 3%), and somnolence (34 vs. 9%).

CONCLUSIONS

This multisite clinical trial showed no efficacy for quetiapine compared with placebo at reducing alcohol consumption in heavy-drinking alcohol-dependent patients.

Carbohydrate-deficient transferrin: an aid to early recognition of alcohol relapse

Although the primary use of biochemical markers of heavy drinking is to assist in screening for alcohol problems, laboratory tests may also aid in early identification of relapse. This report reviews research findings on a new marker, carbohydrate deficient transferrin (CDT), in alcoholics receiving treatment or in follow-up. It also offers recommendations on how CDT may be employed by clinicians monitoring drinking status.

Carbohydrate-deficient transferrin, gamma-glutamyltransferase, and macrocytic volume as biomarkers of alcohol problems in women

BACKGROUND

Early identification of alcohol problems in women is important. Differences in patterns of drinking and in biological function between genders, however, may present unique difficulties in biochemical screening.

METHODS

Published alcohol-screening studies with female samples and use as biomarkers of carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), and macrocytic volume were reviewed.

RESULTS

A wide range of sensitivities and specificities of GGT and CDT have been reported, although, in general, the two markers seem approximately equal in accuracy. As in the case of males, use of them in combination substantially enhances sensitivity and little reduces specificity. Use of macrocytic volume improves the sensitivity of both GGT and CDT as alcohol-screening markers.

CONCLUSIONS

GGT and CDT have moderate sensitivity in screening for alcohol problems in women. Use of them in concert offers further advantage.

Screening for alcohol problems in the military: recommended tests

This article suggests two new techniques for identifying alcohol problems in a military setting. The Alcohol Use Disorders Identification Test is a well validated self-report procedure and requires approximately 2 minutes for administration. Measurement of carbohydrate-deficient transferrin provides a useful biochemical index of recent heavy alcohol consumption. Employment of these tests could improve selection of individuals seeking entry to the military, aid recognition of current personnel in need of treatment, and assist in evaluating progress of patients in treatment.

A review of research on the Alcohol Use Disorders Identification Test (AUDIT)

Research on the core version of the Alcohol Use Disorders Identification Test (AUDIT) is reviewed. Sensitivities and specificities of the AUDIT or criteria of current hazardous use and, to a slightly lesser extent, lifetime alcohol dependence are high. In general, AUDIT scores are at least moderately related to other self-report alcohol screening tests. Several studies also show them as correlated with biochemical measures of drinking. Results of the AUDIT have also been associated with more distal indicators of problematic drinking. Indices of internal consistency, including Cronbach's alpha and item-total correlations, are generally in the 0.80's. Future directions for research on the AUDIT are suggested.

Proposed recommendations for research on biochemical markers for problematic drinking

Biochemical markers can serve as valuable tools in screening for problematic drinking, determining whether a health problem is likely alcohol related, and monitoring alcoholics for relapse during and after treatment. Furthermore, biochemical markers can assist in forensic investigations; in identification of public health, safety, and transportation workers who may drink excessively and who, as a result, may put others at risk; in evaluation of efficacy of treatments for alcohol abuse; and in recognition of early phase alcohol-related tissue damage. Within all of these contexts, a biochemical marker or set of markers may corroborate verbal reports or may provide valuable independent information on alcohol use when an individual is unable or unwilling to offer valid data about alcohol consumption.

Health behavior correlates of hazardous drinking by Army personnel

The current investigation determined that military personnel who drink heavily differ from those who drink moderately in the practice of nine behaviors often associated with unhealthy lifestyle. In particular, excessive drinkers were found to smoke more, drive dangerously more frequently, and consume saturated fats more often. The project further found that the relationship of excessive drinking to these activities is mediated by age, marital status, and race, although not by gender or rank. Implications of the findings for prevention and treatment are suggested.

Gamma-glutamyltranspeptidase and carbohydrate deficient transferrin: alternative measures of excessive alcohol consumption

Both gamma-glutamyltranspeptidase and carbohydrate-deficient transferrin have been extensively researched as biological markers of heavy alcohol consumption. The current study briefly describes each test, identifies subject variables that influence their relative sensitivities and specificities, and examines issues surrounding use of the two markers in combination. In addition, this study suggests five design features that should characterize projects evaluating the validity of biochemical markers.

Personality-based subtypes of chemically dependent patients

Jackson's Personality Research Form E (PRF) was administered to a large, heterogeneous group of adult inpatients with diagnoses of alcohol and/or drug dependence. Cluster analysis of PRF factor scores yielded five distinct patient subtypes: hostile-dependent, cooperative-nonreflective, socially uninvolved, impulsive-unsociable, and hostile-overcontrolled. The subtypes differed on two MMPI canonical variables and on self-reported high risk factors for substance usage. Implications of the findings for more appropriate matching of patients to chemical dependency interventions are offered.

Psychometric analyses of the Alcohol Dependence Scale among United States and Russian clinical samples

This project explores the cross-national construct validity of the Alcohol Dependence Syndrome. The investigation also examines basic psychometric properties of the Alcohol Dependence Scale (ADS), an instrument commonly employed to measure dependence. Subjects consisted of inpatients and outpatients in American and Russian alcoholism treatment programs. Despite some variations, an orthogonal four factor structure of the ADS appears similar across the two cultural samples, thus lending support to the alcohol dependence construct. Analyses of psychometric properties of the Scale generally support its value in future cross-cultural research on alcohol dependence.

CAGE as a predictor of hazardous alcohol consumption in U.S. Army personnel

Sensitivities, specificities, and odds ratios for hazardous drinking for various cut scores on the CAGE are computed for a large sample active duty Army personnel. Contrasts on these properties are made between the standard CAGE and a "modified CAGE" consisting of standard CAGE items and two other items dealing with problematic drinking. The role of demographic variables--gender, ethnicity, marital status, rank category, and age in mediating relationships of both versions of the screening test to hazardous drinking--is also explored. At a cutoff score of one endorsed item, odds ratios were highest for female personnel and commissioned officers.

Structure and correlates of alcohol dependence in clinical samples in the United States and Russia

Using items from the Composite International Diagnostic Interview, dimensionality of the alcohol dependence syndrome was assessed in clinical samples in the United States and Russia. In both groups, a single-factor model provided a high degree of goodness of fit thus demonstrating cross-cultural coherence of the construct. The item dealing with narrowing of the drinking repertoire is most disparate in each sample. Severity of alcohol consequences was moderately related to alcohol dependence in both samples. Demographic variables, however, correlated less with severity of consequences. After the effects of severity of dependence and demographics were removed, quantity/frequency of recent alcohol consumption did not contribute to severity of consequences. Country, however, remained a significant, but small, predictor of severity of alcohol consequences.

Neuroendocrine, physiologic, and behavioral responses following intravenous nicotine in nonsmoking healthy volunteers and in patients with Alzheimer's disease

In separate studies, nonsmoking nicotine-naive subjects (11 young and middle-aged normal volunteers and 11 nonsmoking patients with Alzheimer's disease) received up to three doses of intravenous nicotine bitartrate (0.125, 0.25, and 0.5 micrograms/kg/min) and placebo for 60 min. Measurement of plasma ACTH, cortisol, and prolactin showed that nicotine produced in both groups a dose-dependent increase in cortisol, with ACTH in both groups and prolactin in the Alzheimer's group significantly elevated only by the 0.5 micrograms dose. Physiologic measures showed dose-dependent increases that were consistent with previous reports of nicotinic cholinergic stimulation. Behavioral effects included increases in anxiety and decreases in mood, especially following the 0.5 micrograms dose. Physical side effects were modest. The results indicate that nicotinic cholinergic stimulation can activate pituitary hormonal secretion in the human and suggest that nicotinic cholinergic stimulation may constitute an important part of cholinesterase inhibitor-induced endocrine stimulation and behavioral activation.

The effects of acute exercise on subsequent cigarette smoking

The present study was conducted to examine the effects of acute aerobic exercise on smoking behavior. On alternate days, 10 healthy young smokers were subjected to half an hour of sustained high exercise (about 56% of maximum work capacity) or of low exercise (about 28% of maximum, simulating normal daytime activity). During the high-exercise condition, there were pronounced increases in physiological markers of physical activity such as mean work, heart rate, and lactic acid as well as elevations in circulating hormones (norepinephrine, epinephrine, and immunoreactive beta-endorphin and cortisol) known to be affected by vigorous exercise. Despite a trend toward decreased desire for cigarettes after the high exercise condition, there were no differences in plasma nicotine levels following the smoking of a usual-brand cigarette 35 min later. The sustained effects of the two exercise conditions were also similar: plasma cotinine levels 24 hr later (reflecting nicotine intake over the entire exercise day) revealed no significant differences between high and low exercise.

Nicotine-produced antinociception in minimally deprived smokers and ex-smokers

The antinociceptive effects of two different modes of nicotine administration were investigated using a within-subject design. Ten minimally-deprived, habitual smokers and fifteen ex-smokers were studied in separate experiments. Nicotine was delivered in research cigarettes and tobacco snuff. Pain was induced using the cold pressor test. Subjects in both experiments exhibited pain reduction after nicotine administration without changes in nicotine withdrawal. The results suggest that nicotine can produce physiological and psychological changes that are relevant to the reinforcement of smoking but are independent of the state of nicotine withdrawal.

Pituitary hormone response to cigarette smoking

Nausea was induced by having subjects smoke two high nicotine cigarettes in quick succession. Plasma levels of prolactin, adrenocorticotropic hormone, beta-endorphin/beta-lipotropin, growth hormone, arginine vasopressin, and neurophysin I increased without changes in thyroid stimulating hormone, luteinizing hormone, or follicle stimulating hormone. Nausea and pituitary hormone release correlated with high nicotine intake (smoking 2.87 mg nicotine cigarettes) but did not occur during lower nicotine intake (smoking 0.48 mg nicotine cigarettes). Individual differences in nausea and related hormonal responses may provide an objective method for predicting receptivity to smoking.

Scaling of antipyrine intrinsic clearance of unbound drug in 15 mammalian species

The intrinsic clearance of unbound drug (CLuint) for antipyrine in 15 mammalian species was characterized by an equation of the form, CLuint = theta 1 (body weight) theta 2 (brain weight) theta 3, where thetas are constants. Maximum lifespan potential in mammals can also be characterized by an equation of this form. It is suggested that the set of genetic mechanisms regulating longevity and other constitutional characteristics in species is also linked to rates of drug metabolism. The ability to scale interspecies data in pharmacokinetics is taken as an expression of this design principle.

The effects of cigarette smoking on pain and anxiety

The antinociceptive and anxiolytic consequences of smoking a nicotine-containing cigarette or a zero-nicotine cigarette were investigated in minimally deprived habitual smokers, using a within-subject design. Five subjects were studied in each of two experiments. In one, pain was induced using the cold pressor test; in the other, anxiety, using unsolvable anagrams. All subjects exhibited pain- and anxiety-reduction after smoking a nicotine-containing cigarette. The results support the hypothesis that nicotine from smoking can produce psychological changes that are independent of the state of nicotine withdrawal.

Nicotine dependence in cigarette smoking: an empirically-based, multivariate model

Nicotine dependence implies a pattern of heavy smoking which is resistant to change, as well as nicotine tolerance, withdrawal, and regulation. The present study attempted to develop a coherent model of cigarette smoking by examining responses on several different measures of nicotine dependence. Twenty-seven habitual smokers filled out questionnaires before and after smoking research cigarettes differing in nicotine content in the laboratory. Plasma cotinine was used to estimate nicotine intake from usual brand cigarettes outside the laboratory. Subjects in the high cotinine quartile (heavy smokers) were found to be consistently more nicotine-dependent than subjects in the low cotinine quartile (light smokers). Taking all subjects into account, the six measures of nicotine dependence which exhibited significant correlations with plasma cotinine accounted for about half of the cotinine variance in a multivariate, linear-regression model. Multivariate approaches provide additional tools for assessing biobehavioral mechanisms in substance abuse and may lead to the development of more-comprehensive and sufficient explanations of smoking than are currently available.

Neuroendocrine reactivity to nicotine in smokers

The present study explored neuropeptide responses to nicotine from smoking. Habitual smokers smoked research cigarettes of known strength under controlled laboratory conditions while blood samples were withdrawn unobtrusively for subsequent biochemical analysis. To provide a metric that reflected total nicotine intake and total neurohormonal output, data were integrated over time. Subjects were relatively unresponsive in the low-nicotine (0.48 mg) condition. In the high-nicotine (2.87 mg) condition, there were significant positive correlations between integrated plasma nicotine and plasma arginine vasopressin (r = +0.985), its carrier protein neurophysin I (r = +0.944), and beta-endorphin-beta-lipotropin (r = +0.977), but not adrenocorticotropic hormone. Data from an experiment that used an extraction step to remove beta-lipotropin corroborated the functional relationship between plasma nicotine and beta-endorphin implied by the original findings. Taking into account recent research on the role of neuropeptides in the modulation of affective states and cognitive function as well as of other CNS activity, the present findings were interpreted as strengthening the hypothesis that nicotine-stimulated neuropeptide release provides positive reinforcement for smoking.