Examining naltrexone and alcohol effects in a minority population: results from an initial human laboratory study

Pharmacological Treatment of Alcohol use Disorder in Patients with Psychotic Disorders: A Systematic Review

BACKGROUND

Patients with psychotic disorders (PD) often have comorbid alcohol use disorder (AUD), which is typically treated pharmacologically. Up till now, no systematic review has examined the effectiveness and safety of AUD treatment in PD patients.

OBJECTIVES

This study aimed to systematically review the literature on (1) the effects of pharmacological treatments for AUD on drinking outcomes, (2) the side effects of the drugs, and (3) the effects of polypharmacy in patients with comorbid AUD and PD.

METHODS

Bibliographic searches were conducted in MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and PsycINFO. At least two reviewers extracted the data, assessed the risk of bias, and performed the qualitative synthesis of the collected evidence.

RESULTS

Twelve eligible studies were identified, half being randomized controlled trials (RCTs). Three studies examined disulfiram, nine naltrexone, two acamprosate, and one nalmefene by comparing the effects of treatment to placebo, baseline, or pharmacological agents. Disulfiram and naltrexone were shown to reduce alcohol intake. Regarding acamprosate, the findings were mixed. Nalmefene decreased alcohol intake. All pharmacological agents appeared safe to use as AUD monotherapy, but cardiac events were reported when combining naltrexone and disulfiram. Nine studies had a high risk of bias, and three had some other concerns.

CONCLUSION

The studies provide tentative support for the use of naltrexone and disulfiram in this population, although combinations of pharmacological AUD treatments and other polypharmacy remain unexplored. The studies had high adherence rates that are hardly replicable in real-world settings. Thus, the findings should be confirmed in larger high quality efficacy and effectiveness RCTs with longer follow-ups.

Intravenous ketamine for severe alcohol use disorder at Moi Teaching & Referral Hospital, Kenya: a case report

BACKGROUND

Alcohol use disorder is prevalent globally and in Kenya, and is associated with significant health and socio-economic consequences. Despite this, available pharmacological treatment options are limited. Recent evidence indicates that intravenous (IV) ketamine can be beneficial for the treatment of alcohol use disorder, but is yet to be approved for this indication. Further, little has been done to describe the use of IV ketamine for alcohol use disorder in Africa. The goal of this paper, is to: 1) describe the steps we took to obtain approval and prepare for off-label use of IV ketamine for patients with alcohol use disorder at the second largest hospital in Kenya, and 2) describe the presentation and outcomes of the first patient who received IV ketamine for severe alcohol use disorder at the hospital.

CASE PRESENTATION

In preparing for the off-label use of ketamine for alcohol use disorder, we brought together a multi-disciplinary team of clinicians including psychiatrists, pharmacists, ethicists, anesthetists, and members of the drug and therapeutics committee, to spearhead the process. The team developed a protocol for administering IV ketamine for alcohol use disorder that took into account ethical and safety issues. The national drug regulatory authority, the Pharmacy and Poison's Board, reviewed and approved the protocol. Our first patient was a 39-year-old African male with severe alcohol use disorder and comorbid tobacco use disorder and bipolar disorder. The patient had attended in-patient treatment for alcohol use disorder six times and each time had relapsed between one to four months after discharge. On two occasions, the patient had relapsed while on optimal doses of oral and implant naltrexone. The patient received IV ketamine infusion at a dose of 0.71 mg/kg. The patient relapsed within one week of receiving IV ketamine while on naltrexone, mood stabilizers, and nicotine replacement therapy.

DISCUSSION & CONCLUSIONS

This case report describes for the first time the use of IV ketamine for alcohol use disorder in Africa. Findings will be useful in informing future research and in guiding other clinicians interested in administering IV ketamine for patients with alcohol use disorder.

Individual and county-level variation in outcomes following non-fatal opioid-involved overdose

BACKGROUND

A lack of large-scale, individually linked data often has impeded efforts to disentangle individual-level variability in outcomes from area-level variability in studies of many diseases and conditions. This study investigated individual and county-level variability in outcomes following non-fatal overdose in a state-wide cohort of opioid overdose patients.

METHODS

Participants were 24 031 patients treated by emergency medical services or an emergency department for opioid-involved overdose in Indiana between 2014 and 2017. Outcomes included repeat non-fatal overdose, fatal overdose and death. County-level predictors included sociodemographic, socioeconomic and treatment availability indicators. Individual-level predictors included age, race, sex and repeat non-fatal opioid-involved overdose. Multilevel models examined outcomes following non-fatal overdose as a function of patient and county characteristics.

RESULTS

10.9% (n=2612) of patients had a repeat non-fatal overdose, 2.4% (n=580) died of drug overdose and 9.2% (n=2217) died overall. Patients with a repeat overdose were over three times more likely to die of drug-related causes (OR=3.68, 99.9% CI 2.62 to 5.17, p<0.001). County-level effects were limited primarily to treatment availability indicators. Higher rates of buprenorphine treatment providers were associated with lower rates of mortality (OR=0.82, 95% CI 0.68 to 0.97, p=0.024), but the opposite trend was found for naltrexone treatment providers (OR=1.20, 95% CI 1.03 to 1.39, p=0.021). Cross-level interactions showed higher rates of Black deaths relative to White deaths in counties with high rates of naltrexone providers (OR=1.73, 95% CI 1.09 to 2.73, p=0.019).

CONCLUSION

Although patient-level differences account for most variability in opioid-related outcomes, treatment availability may contribute to county-level differences, necessitating multifaceted approaches for the treatment and prevention of opioid abuse.

The Human Laboratory and Drug Development in Alcohol Use Disorder: Recent Updates

Despite a number of approved medications for alcohol use disorder (AUD), this chronic relapsing disease still produces a considerable global burden, with both health-related and financial consequences. While clinical trials are a critical step in drug development, human laboratory studies provide the field with means of screening pharmacotherapy for more nuanced aspects of AUD. Specifically, studies employing alcohol administration techniques (e.g., alcohol challenge and self-administration) are able to investigate potential drugs with respect to their ability to alter various responses to alcohol administration or alter alcohol consumption in laboratory settings. This chapter reviews methodological designs and provides updates from alcohol administration studies used to screen for potential AUD pharmacotherapy over the past decade. These recent studies have supported the efficacy of approved drugs, identified some promising novel drugs, and investigated other drugs that appear ineffective in AUD treatment. Yet, few drugs are explored using the different variants of alcohol administration methods, and using the different methods has provided inconsistent results for the same drug. Future research would aid advancement in the field by testing medication with various methodologies and refining recently developed techniques.

Naltrexone effects on subjective responses to alcohol in the human laboratory: A systematic review and meta-analysis

Naltrexone (NTX) has been widely studied for the treatment of alcohol use disorder with overall support for its efficacy. The mechanisms of action of naltrexone are thought to involve attenuation of the hedonic effects of alcohol and potentiation of its aversive effects. In order to provide a quantitative estimate of the effects of naltrexone on subjective response to alcohol, the aims of this meta-analytic review are to examine the effects of naltrexone across four domains of subjective response. Meta-analyses of naltrexone effects on alcohol craving (k = 16, N = 686), stimulation (k = 15, N = 675), sedation (k = 18, N = 777), and negative mood (k = 9, N = 281) suggested that under laboratory conditions and compared with placebo, naltrexone reduces craving (Hedges g = -0.252; SE = 0.054; 95% CI, -0.375 to -0.130; P < 0.01), reduces stimulation (g = -0.223; SE = 0.067; 95% CI, -0.372 to -0.074; P < 0.01), increases sedation (g = 0.251; SE = 0.064; 95% CI, 0.112-0.389; P < 0.01), and increases negative mood (g = 0.227; SE = 0.047; 95% CI, 0.100-0.354; P < 0.01). Results were robust when drinks per month and alcohol dose were added to the models as covariates. The effects of naltrexone varied by severity of alcohol use with medication effects on craving and stimulation being observed in sample of both heavy drinkers and AUD individuals. These results are consistent with the hypothesized mechanisms of action of NTX, although the effects are of small magnitude. This meta-analysis aggregates across multiple human laboratory studies of NTX's effects on subjective response to alcohol, providing a comprehensive summary of a key mechanism of NTX efficacy, namely, alteration of the subjective experience of alcohol.

Naltrexone efficacy in treating alcohol-use disorder in individuals with comorbid psychosis: a systematic review

BACKGROUND

Psychotic illnesses, such as schizophrenia, are typically enduring and disabling conditions, impacting individual, family, and societal outcomes. Individuals with these face greater vulnerabilities in developing alcohol-use disorder (AUD). Furthermore, the nature of psychoses, often manifesting with paranoia, cognitive impairment, a lack of insight, sub-optimal treatment adherence, and stigma from others, means that they can pose unique treatment challenges when these two conditions comorbidly occur. These challenges mean that the standard literature on the effectiveness of the opioid antagonist naltrexone in AUD does not necessarily translate to this vulnerable population.

METHODS

Following PRISMA guidelines, we herein systematically reviewed the evidence for naltrexone in individuals with both psychosis and AUD. Overall, there is a paucity of research in this important area, with only nine reports meeting search criteria, only four of which were randomized control trials. Studies compared naltrexone with: placebo, another pharmaceutical agent, or upon changes to baseline drinking behaviour. One study evaluated the long-acting injectable formulation of this drug.

RESULTS

Most studies, including the methodologically more robust ones, supported naltrexone's effectiveness over placebo in terms of reduction in drinking days and numbers of drinks consumed on such days in this cohort. Work comparing naltrexone to other pharmaceutical interventions showed approximate equivalence with disulfiram, and modest superiority over acamprosate.

CONCLUSIONS

On this limited evidence base, this review endorses the use of naltrexone as both safe and effective in those with both psychotic illnesses and AUD. Several key issues remain to be elucidated. Critically, study designs meant that they were limited to individuals with good engagement with services, and levels of adherence were attained that are unlikely to be replicated in this cohort in real-world settings. Finally, effects of specific psychosis symptomatology, not least paranoia and insight, upon naltrexone use, and the reverse directional potential of 'double dysphoria' from an opioid antagonist remain largely unexplored.

Medications development for the treatment of alcohol use disorder: insights into the predictive value of animal and human laboratory models

Development of effective treatments for alcohol use disorder (AUD) represents an important public health goal. This review provides a summary of completed preclinical and clinical studies testing pharmacotherapies for the treatment of AUD. We discuss opportunities for improving the translation from preclinical findings to clinical trial outcomes, focusing on the validity and predictive value of animal and human laboratory models of AUD. Specifically, while preclinical studies of medications development have offered important insights into the neurobiology of the disorder and alcohol's molecular targets, limitations include the lack of standardized methods and streamlined processes whereby animal studies can readily inform human studies. Behavioral pharmacology studies provide a less expensive and valuable opportunity to assess the feasibility of a pharmacotherapy prior to initiating larger scale clinical trials by providing insights into the mechanism of the drug, which can then inform recruitment, analyses, and assessments. Summary tables are provided to illustrate the wide range of preclinical, human laboratory, and clinical studies of medications development for alcoholism. Taken together, this review highlights the challenges associated with animal paradigms, human laboratory studies, and clinical trials with the overarching goal of advancing treatment development and highlighting opportunities to bridge the gap between preclinical and clinical research.

Review: Pharmacogenetics of alcoholism treatment: Implications of ethnic diversity

BACKGROUND AND OBJECTIVES

Pharmacogenetic studies of alcohol use disorder (AUD) have suggested that the efficacy of treatments for AUD is, in part, influenced by the genetic background of an individual. Since the frequency of alleles associated with pharmacotherapy for AUD varies by ancestral background, the effectiveness of medications used to treat AUD may vary among different populations. The purpose of this review is to summarize the existing pharmacogenetic studies of treatments for AUD in individuals of European, East Asian, African, and American Indian/Alaska Native ancestry.

METHODS

Electronic databases were searched for pharmacogenetic studies of AUD treatment that included individuals of diverse ancestral backgrounds.

RESULTS

Pharmacogenetic studies of AUD reviewed here have primarily investigated genetic variation thought to play a role in the response to naltrexone, ondansetron, and topiramate. There is support that the A118G polymorphism should be further investigated in individuals of East Asian ancestry.

DISCUSSION AND CONCLUSIONS

Given the lack of pharmacogenetic research on response to AUD medication in ethnic minority populations and the mixed results, there is a critical need for future studies among individuals of different ancestries. More efforts should be devoted to standardizing procedures such that results can be more readily integrated into a body of literature that can directly inform clinical practice.

SCIENTIFIC SIGNIFICANCE

This review highlights the importance for future research to aim for inclusiveness in pharmacogenetic studies of AUD and increase diversity of clinical trials in order to provide the best treatment outcomes for individuals across different racial and ethnic groups. (Am J Addict 2017;26:516-525).

Advances in Substance Abuse Prevention and Treatment Interventions Among Racial, Ethnic, and Sexual Minority Populations

Substance abuse research among racial, ethnic, and sexual minority populations historically has lagged behind that conducted with majority samples. However, interesting and potentially important advances in prevention, brief interventions, and treatment have been made in the last few years, at least among some minority populations, such as American Indian youth. New prevention efforts have focused on point-of-sale interventions for alcohol, as well as on family-unit interventions designed with subpopulation cultural values in mind. In addition, previously established evidence-based and culturally relevant interventions are being combined with computer technology. Empirical data support using brief interventions with patients of color in medical settings, capitalizing on teachable and reachable moments during a physical trauma or other health crisis. Finally, use of empirically supported treatment may be helpful, with a caveat that these interventions must appropriately match cultural traditions and respect the values of the clients. More research clearly is needed, especially among certain minority populations in the United States. A greater emphasis should be placed on developing novel, culturally grounded interventions in partnership with communities, in addition to adapting existing mainstream interventions for use by other cultures.

Differences in subjective response to alcohol by gender, family history, heavy episodic drinking, and cigarette use: refining and broadening the scope of measurement

OBJECTIVE

Subjective response to alcohol (SR) has been shown to differ by gender, family history of alcoholism, drinking status, and cigarette smoking status. However, the requisite statistical basis for making mean-level comparisons (scalar measurement invariance; MI) has not been established for any SR measure, making it impossible to determine whether observed differences reflect true differences or measurement bias. Secondary data analyses were conducted to evaluate (a) MI of the Subjective Effects of Alcohol Scale (SEAS) by gender, family history, heavy drinking status, and cigarette smoking status using multigroup confirmatory factor analysis; and (b) the impact of these group-level variables on SR using multivariate general linear modeling. A central strength, the SEAS assesses novel high arousal negative (HIGH-; e.g., aggressive) and low arousal positive effects (LOW+; e.g., relaxed) in addition to commonly assessed high arousal positive [HIGH+; e.g., sociable] and low arousal negative effects [LOW-; e.g., woozy]).

METHOD

A total of 215 young adults reported on SR during a placebo-controlled alcohol administration study in a simulated bar setting (target blood alcohol concentration = .08%).

RESULTS

Scalar MI was achieved for each group. After consuming alcohol, family history-positive individuals reported stronger HIGH- effects and female smokers reported weaker LOW+ effects than their counterparts. Heavy episodic drinkers and family history-positive females reported weaker LOW- effects than their counterparts.

CONCLUSIONS

The SEAS permits meaningful SR comparisons within several important groups. SR differences largely were observed on the novel SEAS subscales, highlighting the importance of assessing a full range of SR.

Less drinking, yet more problems: understanding African American drinking and related problems

Researchers have found that, compared to European Americans, African Americans report later initiation of drinking, lower rates of use, and lower levels of use across almost all age groups. Nevertheless, African Americans also have higher levels of alcohol problems than European Americans. After reviewing current data regarding these trends, we provide a theory to understand this apparent paradox as well as to understand variability in risk among African Americans. Certain factors appear to operate as both protective factors against heavy use and risk factors for negative consequences from use. For example, African American culture is characterized by norms against heavy alcohol use or intoxication, which protects against heavy use but also provides within-group social disapproval when use does occur. African Americans are more likely to encounter legal problems from drinking than European Americans, even at the same levels of consumption, perhaps thus resulting in reduced consumption but more problems from consumption. There appears to be one particular group of African Americans, low-income African American men, who are at the highest risk for alcoholism and related problems. We theorize that this effect is due to the complex interaction of residential discrimination, racism, age of drinking, and lack of available standard life reinforcers (e.g., stable employment and financial stability). Further empirical research will be needed to test our theories and otherwise move this important field forward. A focus on within-group variation in drinking patterns and problems is necessary. We suggest several new avenues of inquiry.

Endogenous opiates and behavior: 2011

This paper is the thirty-fourth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2011 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration (Section 16); and immunological responses (Section 17).

Human laboratory paradigms in alcohol research

BACKGROUND

Human laboratory studies have a long and rich history in the field of alcoholism. Human laboratory studies have allowed for advances in alcohol research in a variety of ways, including elucidating neurobehavioral mechanisms of risk, identifying phenotypically distinct subtypes of alcohol users, investigating the candidate genes underlying experimental phenotypes for alcoholism, and testing mechanisms of action of alcoholism pharmacotherapies on clinically relevant translational phenotypes, such as persons exhibiting positive-like alcohol effects or alcohol craving. Importantly, the field of human laboratory studies in addiction has progressed rapidly over the past decade and has built upon earlier findings of alcohol's neuropharmacological effects to advancing translational research on alcoholism etiology and treatment.

METHODS AND RESULTS

To that end, the new generation of human laboratory studies has focused on applying new methodologies, further refining alcoholism phenotypes, and translating these findings to studies of alcoholism genetics, medication development, and pharmacogenetics. The combination of experimental laboratory approaches with the recent developments in neuroscience and pharmacology has been particularly fruitful in furthering our understanding of the impact of individual differences in alcoholism risk and in treatment response.

CONCLUSIONS

This review of the literature focuses on human laboratory studies of subjective intoxication, alcohol craving, anxiety, and behavioral economics. Each section discusses opportunities for phenotype refinement under laboratory conditions, as well as its application to translational science of alcoholism. A summary and recommendations for future research are also provided.