Genetic basis for predicting response to naltrexone in the treatment of alcohol dependence

Pharmacotherapies and personalized medicine for alcohol use disorder: a review

Alcohol use disorder (AUD) is highly prevalent and among the leading causes of morbidity and mortality in the United States. Pharmacotherapies for AUD are limited, thus making identification of patient subgroups that are most likely to respond favorably crucial. In this article, pharmacogenetic research on US FDA-approved and commonly prescribed off-label medications for the treatment of AUD is comprehensively reviewed. While the field has advanced in understanding pharmacotherapies for AUD and potential genetic moderators of treatment responses, the pharmacogenetic data to guide the prescribing clinician are limited and should be interpreted with caution. Precision medicine for AUD with more beneficial treatment responses and minimal side effects remains a high priority for further research.

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.

Guidelines for biological treatment of substance use and related disorders, part 1: Alcoholism, first revision

These practice guidelines for the biological treatment of alcohol use disorders are an update of the first edition, published in 2008, which was developed by an international Task Force of the World Federation of Societies of Biological Psychiatry (WFSBP). For this 2016 revision, we performed a systematic review (MEDLINE/PUBMED database, Cochrane Library) of all available publications pertaining to the biological treatment of alcoholism and extracted data from national guidelines. The Task Force evaluated the identified literature with respect to the strength of evidence for the efficacy of each medication and subsequently categorised it into six levels of evidence (A-F) and five levels of recommendation (1-5). Thus, the current guidelines provide a clinically and scientifically relevant, evidence-based update of our earlier recommendations. These guidelines are intended for use by clinicians and practitioners who evaluate and treat people with alcohol use disorders and are primarily concerned with the biological treatment of adults with such disorders.

Continuous Abstinence During Early Alcohol Treatment is Significantly Associated with Positive Treatment Outcomes, Independent of Duration of Abstinence

AIMS

Neither the predictive value of early continuous abstinence in alcohol use disorder (AUD) or the point at which this effect may emerge has been evaluated. This analysis of the Combined Pharmacotherapies and Behavioral Interventions (COMBINE) clinical trial evaluated whether abstinence early in treatment was a predictor of longer term abstinence.

METHODS

Participants who stated a goal of total abstinence (N = 954) were dichotomized into Early Abstainer vs. Nonabstainers and were compared on a variety of drinking outcome measures that are frequently used in clinical trial evaluations of alcohol treatment strategies, as a function of duration of early continuous abstinence.

RESULTS

Significant differences existed for every outcome. Early Abstinence was significantly associated with fewer drinks per drinking day, number of drinking and number of heavy drinking days, and longer time to first drinking and first heavy drinking day. Effects were evident within the first week. The magnitude of all effects increased as the duration of early abstinence (1-4 weeks) increased, though the size of increase varied across the outcomes.

CONCLUSIONS

These data provide evidence that drinking at the beginning of alcohol treatment is significantly and robustly associated with drinking throughout and at the end of a clinical trial treatment for AUD. Early drinking may be a useful early index to identify whether patients are responding positively to a treatment strategy, and provides a useful method for tailoring treatment to patients that is consistent with a personalized medicine approach.

Pharmacogenetics of alcohol use disorders and comorbid psychiatric disorders

Alcohol use disorders (AUDs) represent a significant health burden worldwide. Currently, there are three medications approved by the U.S. Food and Drug Administration for the treatment of AUDs, and other drugs are being prescribed off-label for this purpose. However, response rates for pharmacologic treatment are low, and extant research suggests that treatment effects may partially depend on genetic factors. Personalized medicine, or using a patient's genetics and/or personal history to determine efficacy of treatment prior to prescription, is an emerging tool that will help clinicians treat their patients more effectively and safely. This review systematically discusses current findings from AUD pharmacotherapy trials examining disulfiram, acamprosate, naltrexone, the injectable naltrexone, and topiramate. Furthermore, it presents pharmacogenetics findings associated with these medications in an attempt to further the field of personalized medicine. Research from trials examining AUDs and comorbid major depressive disorder and anxiety disorders is also presented, and pharmacogenetic findings for these treatments are discussed. Lastly, the authors comment on the present and future states of the field of personalized medicine for AUD.

Improving clinical outcomes for naltrexone as a management of problem alcohol use

Despite being a relatively effective and safe treatment, the clinical management of alcohol abuse/dependence by oral naltrexone can be compromised due to the patient's non-compliance with daily use of this medication. Over the past decade an increasing body of research has suggested that the use of sustained release depot naltrexone preparations can overcome this issue and deliver improved clinical outcomes. However, at the same time, research findings from diverse areas of pharmacogenetics, neurobiology and behavioural psychology have also been converging to identify variables including genetic markers, patient psychosocial characteristics and drug use history differences, or clusters of these variables that play a major role in mediating the response of alcohol abuse/dependent persons to treatment by naltrexone. While this article does not attempt to review all available data pertaining to an individual alcohol dependent patient's response to treatment by naltrexone, it does identify relevant research areas and highlights the importance of data arising from them. The characterization of clinical markers, to identify those patients who are most likely to benefit from naltrexone and to tailor a more individual naltrexone treatment, will ultimately provide significant benefit to both patients and clinicians by optimizing treatment outcome.

Current progress in pharmacologic treatment strategies for alcohol dependence

Alcoholism is a progressive neurological disorder that represents one of the leading preventable causes of morbidity and mortality in the USA. Individuals with alcohol dependence may exhibit differences in their sensitivity to intoxication, the age at which they begin heavy drinking or the presentation of comorbid psychiatric illness. The heterogeneous nature of the disorder has complicated efforts to predict treatment outcomes, indicating a need for improved diagnostic and therapeutic approaches. Pharmaceutical development has focused on treating the symptoms of alcohol withdrawal, reducing consumption of and craving for alcohol, preventing relapse and treating associated psychiatric problems. Current therapies may be optimized by combining psychosocial and pharmacologic approaches to treat alcoholic patients with the most appropriate regimen to achieve the desired therapeutic outcome. This article will describe the neurobiological mechanisms of dependence on alcohol in brief and review major medications approved for the treatment of alcoholism with regard to recent clinical evidence for the therapeutic efficacy of each agent. Investigations on the use of drugs with other indications (e.g., antidepressants and anticonvulsants) to target alcohol-dependent subtypes will also be discussed.

Pharmacotherapy of alcohol use disorders and concurrent psychiatric disorders: a review

Alcohol use disorders (AUDs) are among the most prevalent psychiatric disorders. Epidemiologic studies have shown a high prevalence of concurrent psychiatric disorders among people with AUDs as well as a higher prevalence of AUDs in people with psychiatric disorders than in the general population. Though psychiatric patients with concurrent AUDs are at increased risk for morbidity and mortality, they are commonly undertreated for their alcohol-related disorders. The efficacy of pharmacotherapy for AUDs is well documented. Our paper reviews the common pharmacotherapies available for AUDs and focuses on the available research regarding treatment of AUDs among psychiatric populations with mood, anxiety, and psychotic disorders. Despite the high prevalence of concurrent AUDs and psychiatric disorders, very limited information has been collected using a randomized controlled trial design targeting those concurrent conditions. Several prevalent psychiatric disorders have not been studied when co-occurring with AUDs. Further research of pharmacological treatments for concurrent AUDs and psychiatric diagnoses is urgently needed.

Gabapentin combined with naltrexone for the treatment of alcohol dependence

OBJECTIVE

Naltrexone, an efficacious medication for alcohol dependence, does not work for everyone. Symptoms such as insomnia and mood instability that are most evident during early abstinence might respond better to a different pharmacotherapy. Gabapentin may reduce these symptoms and help prevent early relapse. This clinical trial evaluated whether the combination of naltrexone and gabapentin was better than naltrexone alone and/or placebo during the early drinking cessation phase (first 6 weeks), and if so, whether this effect persisted.

METHOD

A total of 150 alcohol-dependent individuals were randomly assigned to a 16-week course of naltrexone alone (50 mg/day [N=50]), naltrexone (50 mg/day) with gabapentin (up to 1,200 mg/day [N=50]) added for the first 6 weeks, or double placebo (N=50). All participants received medical management.

RESULTS

During the first 6 weeks, the naltrexone-gabapentin group had a longer interval to heavy drinking than the naltrexone-alone group, which had an interval similar to that of the placebo group; had fewer heavy drinking days than the naltrexone-alone group, which in turn had more than the placebo group; and had fewer drinks per drinking day than the naltrexone-alone group and the placebo group. These differences faded over the remaining weeks of the study. Poor sleep was associated with more drinking in the naltrexone-alone group but not in the naltrexone-gabapentin group, while a history of alcohol withdrawal was associated with better response in the naltrexone-gabapentin group.

CONCLUSIONS

The addition of gabapentin to naltrexone improved drinking outcomes over naltrexone alone during the first 6 weeks after cessation of drinking. This effect did not endure after gabapentin was discontinued.

Commentary: physician-scientist's frustrations fester

A growing problem of major proportions had been confronting biomedical scientists for many decades. Until solved, this long-neglected problem, the abject failure of the American health care system, presents a gigantic obstacle to the application of the discoveries flowing from neuropsychopharmacological research into deliverable medications utilized by medical practitioners. Although it is recognized that such advances could benefit all of society, both in the United States and globally, progress toward this important goal has not happened. As I noted 5 years ago, 'Unless steps are taken soon to undertake a comprehensive restoration of our system, the profound advances in bio-medical research so rapidly accruing today may never be effectively transformed into meaningful advances in health care for society.' I remain perplexed and frustrated by the reluctance of scientific research societies such as our ACNP to engage their energies and intellect into this most serious issue.