A double blind, placebo-controlled trial that combines disulfiram and naltrexone for treating co-occurring cocaine and alcohol dependence

A randomized clinical trial of disulfiram at higher doses for the treatment of cocaine use disorder among methadone-stabilized patients

PURPOSE/BACKGROUND

Previously, disulfiram less than 250 mg/day increased cocaine use relative to placebo whereas disulfiram at 250 mg/day did not differ from placebo among methadone-stabilized individuals with dual cocaine and opioid dependence, suggesting disulfiram at higher doses needed to be tested. This study determined tolerability and efficacy of disulfiram at higher doses (250-500 mg/day).

METHODS/PROCEDURES

In a 14-wk, double blind, placebo-controlled clinical trial, 53 participants with cocaine and opioid dependence were enrolled, inducted onto methadone (weeks 1-2), randomized to receive placebo or disulfiram (250, 375 or 500 mg/day) during weeks 3-14, and provided weekly 1-h individual cognitive behavior therapy throughout. Thrice-weekly urine samples were tested for the presence of cocaine metabolite. Weekly vital signs and monthly mood assessments were obtained.

RESULTS/FINDINGS

Disulfiram groups generally did not differ on subject characteristics or retention. Cocaine-positive urine samples showed a significant increase over time in the placebo group (p = 0.04), with the placebo slope being significantly greater than horizontal. Cocaine-positive urine samples decreased over time in the disulfiram 250 mg (p = 0.014) and 375 mg (p = 0.015), but not 500 mg (p = 0.11), groups relative to placebo, although slopes of these medication groups did not differ significantly from horizontal (p > 0.15). No clinically significant differences across groups with respect to vital signs or mood ratings occurred.

IMPLICATIONS/CONCLUSIONS

Although preliminary due to the small sample size, disulfiram at 250-375 mg/day may be ineffective in reducing cocaine use and have limited efficacy to prevent increases in cocaine use among methadone-stabilized patients with dual cocaine and opioid dependence.

Combined pharmacological and psychosocial interventions for alcohol use disorder

BACKGROUND

Alcohol use disorder (AUD) is a mental disorder characterised by a strong desire to consume alcohol and impaired control of alcohol use, with devastating consequences. Many people with AUD do not respond to psychosocial or pharmacological interventions when these are provided alone. Combining these interventions may improve the response to treatment, though evidence remains limited.

OBJECTIVES

To assess the effects of combined pharmacological and psychosocial interventions for the treatment of AUD in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, three other databases, and two trials registers in November 2023, without language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing combined pharmacological and psychosocial interventions versus pharmacological or psychosocial interventions alone, or no intervention/treatment as usual (TAU), in adults with AUD. Our primary outcomes were continuous abstinent participants, frequency of use (measured as heavy drinkers, percentages of abstinent days, heavy-drinking days), amount of use (number of drinks per drinking day), adverse events, serious adverse events, dropouts from treatment, and dropouts due to adverse events.

DATA COLLECTION AND ANALYSIS

We assessed risk of bias using Cochrane's RoB 1 tool, performed random-effects meta-analyses, and evaluated the certainty of evidence according to the GRADE approach.

MAIN RESULTS

We included 21 RCTs (4746 participants). The most studied pharmacological and psychosocial interventions were naltrexone (81.0%) and cognitive behavioural therapy (66.7%), respectively. Most participants were men (74%), aged about 44 years, with AUD, without comorbid mental disorders or other substance use disorders; 15 RCTs detoxified participants before treatment. We judged 28.5% of the studies as at low risk of bias for random sequence generation, allocation concealment, performance bias for objective and subjective outcomes, and detection bias for subjective outcomes; all studies were at low risk of detection bias for objective outcomes; 85.7% of studies were at low risk of attrition bias; 14.2% of studies were at low risk of reporting bias. 1) Compared to psychosocial intervention alone, combined pharmacological and psychosocial interventions probably reduce the number of heavy drinkers (above the clinically meaningful threshold (MID) of 2%; absolute difference (AD) -10%, 95% confidence interval (CI) -18% to -2%; risk ratio (RR) 0.86, 95% CI 0.76 to 0.97; 8 studies, 1609 participants; moderate-certainty evidence). They may increase continuous abstinent participants (MID 5%; AD 5%, 95% CI 1% to 11%; RR 1.17, 95% CI 1.02 to 1.34; 6 studies, 1184 participants; low-certainty evidence). They probably have little to no effect on: • the rate of abstinent days (MID 8%; mean difference (MD) 4.16, 95% CI 1.24 to 7.08; 10 studies, 2227 participants); • serious adverse events (MID 1%; AD -2%, 95% CI -3% to 0%; RR 0.20, 95% CI 0.03 to 1.12; 4 studies; 524 participants); • dropouts from treatment (MID 10%; AD -3%, 95% CI -5% to 0%; RR 0.89, 95% CI 0.79 to 1.01; 15 studies, 3021 participants); and • dropouts due to adverse events (MID 5%; AD 2%, 95% CI 0% to 5%; RR 1.91, 95% CI 1.04 to 3.52; 8 studies, 1572 participants) (all moderate-certainty evidence). They may have little to no effect on: • heavy-drinking days (MID 5%; MD -3.49, 95% CI -8.68 to 1.70; 4 studies, 470 participants); • number of drinks per drinking day (MID 1 drink; MD -0.57, 95% CI -1.16 to 0.01; 7 studies, 805 participants); and • adverse events (MID 30%; AD 17%, 95% CI -5% to 46%; RR 1.25, 95% CI 0.93 to 1.68; 4 studies, 508 participants) (all low-certainty evidence). 2) Compared to pharmacological intervention alone, combined pharmacological and psychosocial interventions may have little to no effect on: • the rate of abstinent days (MID 8%; MD -1.18, 95% CI -4.42 to 2.07; 2 studies, 1158 participants); and • dropouts from treatment (MID 10%; AD 1%, 95% CI -10 to 14%; RR 0.98, 95% CI 0.65 to 1.47; 3 studies, 1246 participants) (all low-certainty evidence). We are uncertain about their effect on: • continuous abstinent participants (MID 5%; AD 3%, 95% CI -5% to 18%; RR 1.22, 95% CI 0.62 to 2.40; 1 study, 241 participants); • the number of heavy drinkers (MID 2%; AD 2%, 95% CI -4% to 8%; RR 1.03, 95% CI 0.94 to 1.12; 1 study, 917 participants); • the number of drinks per drinking day (MID 1 drink; MD -2.40, 95% CI -3.98 to -0.82; 1 study, 241 participants); and • dropouts due to adverse events (MID 5%; AD -1%, 95% CI -3% to 6%; RR 0.61, 95% CI 0.14 to 2.72; 2 studies, 1165 participants) (all very low-certainty evidence). 3) We are uncertain about the effect of combined pharmacological and psychosocial interventions, when compared to TAU, on: • the number of heavy drinkers (MID 2%; AD -5%, 95% CI -13% to 2%; RR 0.93, 95% CI 0.83 to 1.03; 1 study, 616 participants); • the rate of abstinent days (MID 8%; MD 3.43, 95% CI -1.32 to 8.18; 1 study, 616 participants); • dropouts from treatment (MID 10%; AD 0%, 95% CI -10% to 15%; RR 0.98, 95% CI 0.58 to 1.65; 2 studies, 696 participants); and • dropouts due to adverse events (MID 5%; AD 3%, 95% CI 0% to 15%; RR 2.97, 95% CI 0.70 to 12.67; 1 study, 616 participants) (all very low-certainty evidence). The certainty of evidence ranged from moderate to very low, downgraded mainly due to risk of bias and imprecision.

AUTHORS' CONCLUSIONS

As implications for practice, our findings indicate that adding pharmacological to psychosocial interventions is safe and helps people with AUD recover. These conclusions are based on low- to moderate-certainty evidence. Given the few studies and very low-certainty evidence, any benefits of adding psychosocial to pharmacological interventions or comparing the combined intervention to TAU are less clear. As implications for research, further studies should investigate the effects of the combined intervention compared to pharmacotherapy or TAU.

Integrative Pharmacology in the Treatment of Substance Use Disorders

The detrimental physical, mental, and socioeconomic effects of substance use disorders (SUDs) have been apparent to the medical community for decades. However, it has become increasingly urgent in recent years to develop novel pharmacotherapies to treat SUDs. Currently, practitioners typically rely on monotherapy. Monotherapy has been shown to be superior to no treatment at all for most substance classes. However, many randomized controlled trials (RCTs) have revealed that monotherapy leads to poorer outcomes when compared with combination treatment in all specialties of medicine. The results of RCTs suggest that monotherapy frequently fails since multiple dysregulated pathways, enzymes, neurotransmitters, and receptors are involved in the pathophysiology of SUDs. As such, research is urgently needed to determine how various neurobiological mechanisms can be targeted by novel combination treatments to create increasingly specific yet exceedingly comprehensive approaches to SUD treatment. This article aims to review the neurobiology that integrates many pathophysiologic mechanisms and discuss integrative pharmacology developments that may ultimately improve clinical outcomes for patients with SUDs. Many neurobiological mechanisms are known to be involved in SUDs including dopaminergic, nicotinic, N-methyl-D-aspartate (NMDA), and kynurenic acid (KYNA) mechanisms. Emerging evidence indicates that KYNA, a tryptophan metabolite, modulates all these major pathophysiologic mechanisms. Therefore, achieving KYNA homeostasis by harmonizing integrative pathophysiology and pharmacology could prove to be a better therapeutic approach for SUDs. We propose KYNA-NMDA-α7nAChRcentric pathophysiology, the "conductor of the orchestra," as a novel approach to treat many SUDs concurrently. KYNA-NMDA-α7nAChR pathophysiology may be the "command center" of neuropsychiatry. To date, extant RCTs have shown equivocal findings across comparison conditions, possibly because investigators targeted single pathophysiologic mechanisms, hit wrong targets in underlying pathophysiologic mechanisms, and tested inadequate monotherapy treatment. We provide examples of potential combination treatments that simultaneously target multiple pathophysiologic mechanisms in addition to KYNA. Kynurenine pathway metabolism demonstrates the greatest potential as a target for neuropsychiatric diseases. The investigational medications with the most evidence include memantine, galantamine, and N-acetylcysteine. Future RCTs are warranted with novel combination treatments for SUDs. Multicenter RCTs with integrative pharmacology offer a promising, potentially fruitful avenue to develop novel therapeutics for the treatment of SUDs.

Disulfiram for the treatment of cocaine dependence

BACKGROUND

Cocaine is a psychostimulant used by approximately 0.4% of the general population worldwide. Cocaine dependence is a chronic mental disorder characterised by the inability to control cocaine use and a host of severe medical and psychosocial complications. There is current no approved pharmacological treatment for cocaine dependence. Some researchers have proposed disulfiram, a medication approved to treat alcohol use disorder. This is an update of a Cochrane review first published in 2010.

OBJECTIVES

To evaluate the efficacy and safety of disulfiram for the treatment of cocaine dependence.

SEARCH METHODS

We updated our searches of the following databases to August 2022: the Cochrane Drugs and Alcohol Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and PsycINFO. We also searched for ongoing and unpublished studies via two trials registries. We handsearched the references of topic-related systematic reviews and included studies. The searches had no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials that evaluated disulfiram alone or associated with psychosocial interventions versus placebo, no intervention, other pharmacological interventions, or any psychosocial intervention for the treatment of cocaine dependence.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

Thirteen studies (1191 participants) met our inclusion criteria. Disulfiram versus placebo or no treatment Disulfiram compared to placebo may increase the number of people who are abstinent at the end of treatment (point abstinence; risk ratio (RR) 1.58, 95% confidence interval (CI) 1.05 to 2.36; 3 datasets, 142 participants; low-certainty evidence). However, compared to placebo or no pharmacological treatment, disulfiram may have little or no effect on frequency of cocaine use (standardised mean difference (SMD) -0.11 standard deviations (SDs), 95% CI -0.39 to 0.17; 13 datasets, 818 participants), amount of cocaine use (SMD -0.00 SDs, 95% CI -0.30 to 0.30; 7 datasets, 376 participants), continuous abstinence (RR 1.23, 95% CI 0.80 to 1.91; 6 datasets, 386 participants), and dropout for any reason (RR 1.20, 95% CI 0.92 to 1.55; 14 datasets, 841 participants). The certainty of the evidence was low for all these outcomes. We are unsure about the effects of disulfiram versus placebo on dropout due to adverse events (RR 12.97, 95% CI 0.77 to 218.37; 1 study, 67 participants) and on the occurrence of adverse events (RR 3.00, 95% CI 0.35 to 25.98), because the certainty of the evidence was very low for these outcomes. Disulfiram versus naltrexone Disulfiram compared with naltrexone may reduce the frequency of cocaine use (mean difference (MD) -1.90 days, 95% CI -3.37 to -0.43; 2 datasets, 123 participants; low-certainty evidence) and may have little or no effect on amount of cocaine use (SMD 0.12 SDs, 95% CI -0.27 to 0.51, 2 datasets, 123 participants; low-certainty evidence). We are unsure about the effect of disulfiram versus naltrexone on dropout for any reason (RR 0.86, 95% CI 0.56 to 1.32, 3 datasets, 131 participants) and dropout due to adverse events (RR 0.50, 95% CI 0.07 to 3.55; 1 dataset, 8 participants), because the certainty of the evidence was very low for these outcomes.

AUTHORS' CONCLUSIONS

Our results show that disulfiram compared to placebo may increase point abstinence. However, disulfiram compared to placebo or no pharmacological treatment may have little or no effect on frequency of cocaine use, amount of cocaine use, continued abstinence, and dropout for any reason. We are unsure if disulfiram has any adverse effects in this population. Caution is required when transferring our results to clinical practice.

Naltrexone-bupropion combinations do not affect cocaine self-administration in humans

The FDA has not yet approved a pharmacotherapy for cocaine use disorder despite nearly four decades of research. This study determined the initial efficacy, safety, and tolerability of naltrexone-bupropion combinations as a putative pharmacotherapy for cocaine use disorder. Thirty-one (31) non-treatment seeking participants with cocaine use disorder completed a mixed-design human laboratory study. Participants were randomly assigned to the naltrexone conditions (i.e., 0, 50 mg/day; between-subject factor) and maintained on escalating doses of bupropion (i.e., 0, 100, 200, 400 mg/day; within-subject factor) for at least four days prior to the conduct of experimental sessions. Cocaine self-administration (IN, 0, 40, 80 mg) was then determined using a modified progressive ratio and relapse procedure. Subjective and cardiovascular effects were also measured. Cocaine produced prototypical dose-related increases in self-administration, subjective outcomes (e.g., "Like Drug"), and cardiovascular indices (e.g., heart rate, blood pressure) during placebo maintenance. Naltrexone and bupropion alone, or in combination, did not significantly decrease self-administration on either procedure. Low doses of bupropion (i.e., 100 mg) blunted the effects of the cocaine on subjective measures of "Like Drug" and "Stimulated". No unexpected adverse effects were observed with naltrexone and bupropion, alone and combined, in conjunction with cocaine. Together, these results do not support the use of these bupropion-naltrexone combinations for the treatment of cocaine use disorder. Future research should determine if novel drug combinations may decrease cocaine self-administration.

Cocaine Use Disorder (CUD): Current Clinical Perspectives

Cocaine use disorder (CUD) is a devastating disorder, impacting both individuals and society. Individuals with CUD face many barriers in accessing treatment for CUD, and most individuals with CUD never receive treatment. In this review, we provide an overview of CUD, including risk factors for CUD, common co-occurring disorders, acute and chronic effects of cocaine use, and currently available pharmacological and behavioral treatments. There are no FDA-approved pharmacological treatments for CUD. Future studies with larger sample sizes and testing treatment combinations are warranted. However, individuals with CUD and co-occurring disorders (eg, a mood or anxiety disorder) may benefit from medication treatments. There are behavioral interventions that have demonstrated efficacy in treating CUD – contingency management (CM) and cognitive-behavioral therapy for substance use disorders (CBT-SUD) in particular – however many barriers remain in delivering these treatments to patients. Following the discussion of current treatments, we highlight some promising emerging treatments, as well as offer a framework that can be used in building a treatment plan for individuals with CUD.

Brain regulation of hunger and motivation: The case for integrating homeostatic and hedonic concepts and its implications for obesity and addiction

Obesity and other eating disorders are marked by dysregulations to brain metabolic, hedonic, motivational, and sensory systems that control food intake. Classic approaches in hunger research have distinguished between hedonic and homeostatic processes, and have mostly treated these systems as independent. Hindbrain structures and a complex network of interconnected hypothalamic nuclei control metabolic processes, energy expenditure, and food intake while mesocorticolimbic structures are though to control hedonic and motivational processes associated with food reward. However, it is becoming increasingly clear that hedonic and homeostatic brain systems do not function in isolation, but rather interact as part of a larger network that regulates food intake. Incentive theories of motivation provide a useful route to explore these interactions. Adapting incentive theories of motivation can enable researchers to better how motivational systems dysfunction during disease. Obesity and addiction are associated with profound alterations to both hedonic and homeostatic brain systems that result in maladaptive patterns of consumption. A subset of individuals with obesity may experience pathological cravings for food due to incentive sensitization of brain systems that generate excessive 'wanting' to eat. Further progress in understanding how the brain regulates hunger and appetite may depend on merging traditional hedonic and homeostatic concepts of food reward and motivation.

Systematische Literaturübersicht der Wirksamkeit von Acamprosat, Naltrexon, Disulfiram und Nalmefen zur Trinkmengenreduktion und Aufrechterhaltung der Abstinenz bei Alkoholabhängigkeit

Das Ziel der vorliegenden Übersichtsarbeit ist die systematische Darstellung der aktuellen Evidenz zur Wirksamkeit von Acamprosat, Naltrexon, Disulfiram und Nalmefen für die Aufrechterhaltung der Abstinenz oder Trinkmengenreduktion bei alkoholabhängigen Patient:innen. Bezogen auf den Zeitraum 2005 bis 2020 wurden insgesamt 27 Studien identifiziert, die alle Einschlusskriterien (u. a. RCT, mind. 8 Wochen Behandlungsdauer) erfüllten. Es wurden überwiegend Hinweise zur Wirksamkeit von Nalmefen gefunden. Acamprosat war nicht (zusätzlich) wirksam. Naltrexon trug in kombinierten Interventionen einen zusätzlichen Nutzen bei, dies galt jedoch nicht für die Mehrzahl der Studien. Disulfiram war nicht wirksam darin, einen zusätzlichen Nutzen zur Erhaltung der Abstinenz beizutragen, im Vergleich zu Topiramat, einem Antikonvulsivum, jedoch effektiver. Die Ergebnisse stehen nicht im Einklang mit dem bisher bekannten Forschungsstand, der Acamprosat, Naltrexon und Nalmefen als überwiegend effektiv und sicher einstuft und Disulfiram als mäßig wirksam. Der pharmakologische Interventionsbedarf sollte bei Bestehen alkoholbezogener Probleme exploriert und ggf. erwogen werden, damit diesbezüglich Vorbehalte abgebaut und ein umfassendes und zugleich individuelles Behandlungsangebot geschaffen wird. Hinsichtlich der Trinkmengenreduktion sollten Aspekte der Schadensminderung als Behandlungsziel berücksichtigt werden.

Advantages and disadvantages of disulfiram coadministered with popular addictive substances

Disulfiram (DSF) is a well-known anti-alcohol agent that inhibits aldehyde dehydrogenase and results in extreme 'hangover' symptoms when consumed with alcohol. This drug, however, has been suggested as useful in other forms of drug addiction due to its beneficial potential in both drug abuse reduction and withdrawal. However, among other drugs used in alcohol dependence, it carries the greatest risk of pharmacological interactions. Concomitant use of DSF and central nervous system stimulants usually leads to harmful, undesirable effects. To date, there is still limited data regarding the detailed safety profile of DSF as a concomitant drug. In this review article, we outline the current state of knowledge about DSF, its broad pharmacological action, as well as therapeutic effects, with a particular emphasis on the molecular understanding of its potential pharmacodynamic interactions with common addictive substances (e.g., alcohol, cocaine, cannabinoids, opioids) supported by relevant examples.

Pharmacotherapeutic strategies for treating cocaine use disorder-what do we have to offer?

BACKGROUND

Cocaine use contines to be a significant public health problem world-wide. However, despite substantial research efforts, no pharmacotherapies are approved for the treatment of cocaine use disorder (CUD).

ARGUMENT

Studies have identified positive signals for a range of medications for treating CUD. These include long-acting amphetamine formulations, modafinil, topiramate, doxazosin and combined topiramate and mixed amphetamine salts extended-release (MAS-ER). However, valid conclusions about a medication's clinical efficacy require nuanced approaches that take into account behavioural phenotypes of the target population (frequency of use, co-abuse of cocaine and other substances, genetic subgroups, psychiatric comorbidity), variables related to the medication (dose, short-/long-acting formulations, titration speed, medication adherence) and other factors that may affect treatment outcomes. Meta-analyses frequently do not account for these co-varying factors, which contributes to a somewhat nihilistic view on pharmacotherapeutic options for CUD. In addition, the predominant focus on abstinence, which is difficult for most patients to achieve, may overshadow more nuanced therapeutic signals.

CONCLUSION

While there is an emphasis on finding new medications with novel mechanisms of action for treating CUD, currently available medications deserve further investigation based on the existing literature. Evaluating refined metrics of treatment success in well-defined subgroups of patients, and further exploring combination therapies and their synergy with behavioural/psychosocial interventions, are promising avenues to establishing effective therapies for CUD.

Treatment of stimulant use disorder: A systematic review of reviews

AIMS

Stimulant use disorder contributes to a substantial worldwide burden of disease, although evidence-based treatment options are limited. This systematic review of reviews aims to: (i) synthesize the available evidence on both psychosocial and pharmacological interventions for the treatment of stimulant use disorder; (ii) identify the most effective therapies to guide clinical practice, and (iii) highlight gaps for future study.

METHODS

A systematic database search was conducted to identify systematic reviews and meta-analyses. Eligible studies were those that followed standard systematic review methodology and assessed randomized controlled trials focused on the efficacy of interventions for stimulant use disorder. Articles were critically appraised using an assessment tool adapted from Palmeteer et al. and categorized for quality as 'core' or 'supplementary' reviews. Evidence from the included reviews were further synthesized according to pharmacological or non-pharmacological management themes.

RESULTS

Of 476 identified records, 29 systematic reviews examining eleven intervention modalities were included. The interventions identified include: contingency management, cognitive behavioural therapy, acupuncture, antidepressants, dopamine agonists, antipsychotics, anticonvulsants, disulfiram, opioid agonists, N-Acetylcysteine, and psychostimulants. There was sufficient evidence to support the efficacy of contingency management programs for treatment of stimulant use disorder. Psychostimulants, n-acetylcysteine, opioid agonist therapy, disulfiram and antidepressant pharmacological interventions were found to have insufficient evidence to support or discount their use. Results of this review do not support the use of all other treatment options.

CONCLUSIONS

The results of this review supports the use of contingency management interventions for the treatment of stimulant use disorder. Although evidence to date is insufficient to support the clinical use of psychostimulants, our results demonstrate potential for future research in this area. Given the urgent need for effective pharmacological treatments for stimulant use disorder, high-quality primary research focused on the role of psychostimulant medications for the treatment of stimulant use disorder is needed.

Mindfulness as a predictor of cognitive-behavioral therapy outcomes in inner-city adults with posttraumatic stress and substance dependence

The co-occurrence of posttraumatic stress disorder (PTSD) and substance use disorders (SUD) is highly prevalent and difficult-to-treat. Mindfulness, defined as nonjudgmental attention to and awareness of present-moment experiences, represents a targetable mechanism with potential to predict and improve treatment outcomes for PTSD/SUD populations. We hypothesized that greater self-reported mindfulness at baseline (pre-treatment) would predict (a) lower end-of-treatment PTSD severity and (b) greater longest sustained abstinence during a 12-week cognitive-behavioral treatment program. Participants included 53 inner-city adults meeting at least four current symptoms of DSM-5 PTSD and current (DSM-IV) substance dependence (51% women; 75.5% African American; Mage = 45.42, SD = 9.99). Hierarchical regression analysis results indicated that higher levels of baseline mindfulness predicted lower end-of-treatment PTSD severity but not longest sustained abstinence from the primary substance of choice. Post hoc exploration of end-of-treatment PTSD symptom clusters indicated that higher baseline mindfulness predicted lower intrusion, negative alterations in cognitions and mood, and arousal and reactivity symptoms but not avoidance symptoms. Clinical and research implications are discussed.

Clinical effects beyond cocaine use of sustained-release dexamphetamine for the treatment of cocaine dependent patients with comorbid opioid dependence: secondary analysis of a double-blind, placebo-controlled randomized trial

BACKGROUND AND AIMS

Sustained-release (SR) formulations of dexamphetamine and mixed amphetamine salts have shown positive effects in the treatment of patients with a cocaine use disorder. We previously demonstrated the efficacy of SR-dexamphetamine for patients with cocaine dependence in terms of cocaine use reductions. In this secondary analysis, we assessed whether SR-dexamphetamine treatment also improves the health status of these patients.

DESIGN

Multi-centre randomized, double-blind placebo-controlled trial.

SETTING

Four supervised heroin-assisted treatment (HAT) out-patient clinics in the Netherlands. In HAT, methadone treatment-refractory opioid-dependent patients can self-administer individually titrated doses of pharmaceutical grade diacetylmorphine, coprescribed with oral methadone.

PARTICIPANTS

Seventy-three cocaine-dependent patients (90% males; average age = 48.7 years), participating in HAT for their treatment-refractory comorbid opioid dependence.

INTERVENTIONS

Twelve weeks pharmacotherapy with once-daily, supervised intake of two tablets of SR-dexamphetamine (2 × 30 mg/day) or two identical placebo tablets.

MEASUREMENTS

Assessment every 4 weeks: cocaine use (time-line follow-back), physical health (Maudsley Addiction Profile-Health Symptoms Scale), mental health (Brief Symptom Inventory) and illegal activities (Addiction Severity Index). Primary outcome was 'overall health', a dichotomous, multi-domain response index based on physical health, mental health and social functioning.

FINDINGS

Compared with placebo, SR-dexamphetamine resulted in larger increases in the number of cocaine abstinent days (P = 0.004) and the proportion of overall health treatment responders (P = 0.045) from the 4 weeks preceding baseline to the final 4 weeks of treatment. While the number of cocaine abstinent days was not associated with overall health in the total study sample, it was positively associated with overall health among patients in poor overall health at the start of SR-dexamphetamine treatment (n = 50), i.e. patients with the potential to improve on this multi-domain response index (odds ratio = 1.076; 95% confidence interval = 1.025-1.130).

CONCLUSIONS

SR-dexamphetamine reduces cocaine use and may improve clinically relevant health-related outcomes in patients with cocaine dependence who are participating in heroin-assisted treatment for their comorbid heroin dependence.

Vibration of effects from diverse inclusion/exclusion criteria and analytical choices: 9216 different ways to perform an indirect comparison meta-analysis

BACKGROUND

Different methodological choices such as inclusion/exclusion criteria and analytical models can yield different results and inferences when meta-analyses are performed. We explored the range of such differences, using several methodological choices for indirect comparison meta-analyses to compare nalmefene and naltrexone in the reduction of alcohol consumption as a case study.

METHODS

All double-blind randomized controlled trials (RCTs) comparing nalmefene to naltrexone or one of these compounds to a placebo in the treatment of alcohol dependence or alcohol use disorders were considered. Two reviewers searched for published and unpublished studies in MEDLINE (August 2017), the Cochrane Library, Embase, and ClinicalTrials.gov and contacted pharmaceutical companies, the European Medicines Agency, and the Food and Drug Administration. The indirect comparison meta-analyses were performed according to different inclusion/exclusion criteria (based on medical condition, abstinence of patients before inclusion, gender, somatic and psychiatric comorbidity, psychological support, treatment administered and dose, treatment duration, outcome reported, publication status, and risk of bias) and different analytical models (fixed and random effects). The primary outcome was the vibration of effects (VoE), i.e. the range of different results of the indirect comparison between nalmefene and naltrexone. The presence of a "Janus effect" was investigated, i.e. whether the 1st and 99th percentiles in the distribution of effect sizes were in opposite directions.

RESULTS

Nine nalmefene and 51 naltrexone RCTs were included. No study provided a direct comparison between the drugs. We performed 9216 meta-analyses for the indirect comparison with a median of 16 RCTs (interquartile range = 12-21) included in each meta-analysis. The standardized effect size was negative at the 1st percentile (- 0.29, favouring nalmefene) and positive at the 99th percentile (0.29, favouring naltrexone). A total of 7.1% (425/5961) of the meta-analyses with a negative effect size and 18.9% (616/3255) of those with a positive effect size were statistically significant (p < 0.05).

CONCLUSIONS

The choice of inclusion/exclusion criteria and analytical models for meta-analysis can result in entirely opposite results. VoE evaluations could be performed when overlapping meta-analyses on the same topic yield contradictory result.

TRIAL REGISTRATION

This study was registered on October 19, 2016, in the Open Science Framework (OSF, protocol available at https://osf.io/7bq4y/ ).

Varenicline and nabilone in tobacco and cannabis co-users: effects on tobacco abstinence, withdrawal and a laboratory model of cannabis relapse

Tobacco and cannabis co-users (T+CUs) have poor cannabis cessation outcomes, but the mechanisms underlying this are not well understood. This laboratory study examined the effects of (1) the partial nicotinic agonist, varenicline, on tobacco cessation among T+CUs, and (2) varenicline, alone, and when combined with the cannabinoid agonist nabilone, on cannabis withdrawal and a laboratory model of cannabis relapse. Non-treatment-seeking T+CUs were randomized to active-varenicline or placebo-varenicline, and completed a 15-day outpatient phase; varenicline was titrated to 1 mg BID during days 1-8, and participants were instructed to abstain from tobacco during days 9-15. Participants then moved inpatient for 16 days, where they continued their outpatient medication and tobacco abstinence. Inpatient testing included two, 8-day medication periods, where active-nabilone and placebo-nabilone were administered in counterbalanced order, and measures of acute cannabis effects (days 1-2), withdrawal (days 4-5) and 'relapse' (days 6-8) were collected. Participants in the active-varenicline group were more likely to achieve cotinine-verified tobacco abstinence during the outpatient period versus placebo-varenicline group (46 percent versus 24 percent, respectively), and also reported less mood disturbance and cigarette craving while inpatient. Active-nabilone attenuated cannabis withdrawal in both groups but did not affect cannabis relapse. Regression analyses revealed that two tobacco-related variables, i.e. age of first cigarette use, and cigarette craving while inpatient, were independent predictors of cannabis relapse outcomes. Thus, varenicline holds promise in this population, as a tool to examine the effects of tobacco abstinence on cannabis use outcomes, and as a component of smoking cessation treatments targeting T+CUs.

What happens to agreement over time? A longitudinal study of self-reported substance use compared to saliva toxicological testing among subsidized housing residents

The agreement between self-reported and toxicologically verified substance use provides important information about the validity of self-reported use. While some studies report aggregate agreement across follow-up points, only a few have examined the agreement at each time point separately. An overall rate of agreement across time may miss changes that occur as people progress through a research study. In this study, a sample of 644 adults (43.8% male, 32.6% White, 57.0% Black, 90.2% ages 36+) residing in subsidized housing was used to determine the agreement between self-reported use and saliva toxicological testing for marijuana, cocaine, PCP, amphetamine, and methamphetamine at three different time points. Agreement between saliva toxicological testing and self-report ranged between 84.2% and 94.3% for different substances over time. Higher rates of agreement were found for cocaine than had been reported by previous studies. Statistically significant differences in the odds ratios of concordance over time (baseline, 6-month, and 12-month follow-up) were found for marijuana and the combined category for PCP, amphetamine, and methamphetamine. Our findings suggest that oral fluid drug tests generally withstand community field assessments and result in relatively high levels of agreement for marijuana, cocaine, PCP, amphetamine, and methamphetamine use, when compared to self-report. Because of the ease of sample collection and low chance of adulteration, we conclude that saliva testing is a viable method for toxicological confirmation of substance use behavior in this setting.

Preoperative Interventions for Alcohol and Other Recreational Substance Use: A Systematic Review and Meta-Analysis

Background: Preoperative alcohol and other recreational substance use (ORSU) may catalyze perioperative complications. Accordingly, interventions aiming to reduce preoperative substance use are warranted. Methods: Studies investigating interventions to reduce alcohol and/or ORSU in elective surgery patients were identified from: Cochrane Library; MEDLINE; PSYCINFO; EMBASE; and CINAHL. In both narrative summaries of results and random effects meta-analyses, effects of interventions on perioperative alcohol/ORSU, complications, mortality and length of stay were assessed. Primary Results: Nine studies (n = 903) were included. Seven used behavioral interventions only, two provided disulfiram in addition. Pooled analyses found small effects on alcohol use (d: 0.34; 0.05-0.64), though two trials using disulfiram (0.71; 0.36-1.07) were superior to two using behavioral interventions (0.45; -0.49-1.39). No significant pooled effects were found for perioperative complications, length of hospital stay or mortality in studies solely targeting alcohol/ORSU. Too few interventions targeting ORSU (n = 1) were located to form conclusions regarding their efficacy. Studies were generally at high risk-of-bias and heterogeneous. Conclusions: Preoperative interventions were beneficial in reducing substance use in some instances, but more high-quality studies targeting alcohol/ORSU specifically are needed. The literature to date does not suggest that such interventions can reduce postoperative morbidity, length of hospital stay or mortality. Limitations in the literature are outlined and recommendations for future studies are suggested.

Enkephalin as a Pivotal Player in Neuroadaptations Related to Psychostimulant Addiction

Enkephalin expression is high in mesocorticolimbic areas associated with psychostimulant-induced behavioral and neurobiological effects, and may also modulate local neurotransmission in this circuit network. Psychostimulant drugs, like amphetamine and cocaine, significantly increase the content of enkephalin in these brain structures, but we do not yet understand the specific significance of this drug-induced adaptation. In this review, we summarize the neurochemical and molecular mechanism of psychostimulant-induced enkephalin activation in mesocorticolimbic brain areas, and the contribution of this opioid peptide in the pivotal neuroadaptations and long-term behavioral changes underlying psychostimulant addiction. There is evidence suggesting that adaptive changes in enkephalin content in the mesocorticolimbic circuit, induced by acute and chronic psychostimulant administration, may represent a key initial step in the long-term behavioral and neuronal plasticity induced by these drugs.

Brief online interventions targeting risk and protective factors for increased and problematic alcohol use among American college students studying abroad

Research documents increased and problematic alcohol use during study abroad experiences for college students yet no research documents effective preventive programs with these students. The present randomized controlled trial was designed to prevent increased and problematic alcohol use abroad by correcting misperceptions of peer drinking norms abroad and by promoting positive and healthy adjustment into the host culture (i.e., sojourner adjustment) through brief online personalized feedback interventions. A sample of 343 study abroad college students was randomly assigned to 1 of 4 conditions including a personalized normative feedback intervention (PNF), a sojourner adjustment feedback intervention (SAF), a combined PNF + SAF intervention, and an assessment-only control condition. Generalized estimated equation analyses accounting for baseline drinking and consequences revealed an intervention effect for PNF that was mitigated by baseline drinking level, such that PNF was best for those with lighter baseline drinking, but heavier baseline drinkers receiving PNF alone or PNF + SAF drank comparatively similar or more heavily abroad to those in the control condition. However, PNF + SAF condition participants with greater baseline levels of consequences reported comparatively less consequences abroad than their control participants. Thus, PNF alone may be helpful for lighter drinkers at predeparture and the addition of SAF to PNF may help prevent consequences abroad for those reporting more consequences prior to departure abroad. This research represents an important first step in designing and implementing efficacious interventions with at-risk study abroad college students, for which no current empirically based programs exist. (PsycINFO Database Record

Treatment-refractory substance use disorder: Focus on alcohol, opioids, and cocaine

Substance use disorders are common, but only a small minority of patients receive adequate treatment. Although psychosocial therapies are effective, relapse is common. This review focusses on novel pharmacological and other treatments for patients with alcohol, opioid, or cocaine use disorders who do not respond to conventional treatments. Disulfiram, acamprosate, and the opioid antagonist naltrexone have been approved for the treatment of alcoholism. A novel, "as needed" approach is the use of the mu-opioid antagonist and partial kappa agonist nalmefene to reduce alcohol consumption. Other novel pharmacological approaches include the GABA-B receptor agonist baclofen, anticonvulsants such as topiramate and gabapentin, the partial nicotine receptor agonist varenicline, and other drugs. For opioid dependence, opioid agonist therapy with methadone or buprenorphine is the first-line treatment option. Other options include oral or depot naltrexone, morphine sulfate, depot or implant formulations, and heroin (diacetylmorphine) in treatment-refractory patients. To date, no pharmacological treatment has been approved for cocaine addiction; however, 3 potential pharmacological treatments are being studied, disulfiram, methylphenidate, and modafinil. Pharmacogenetic approaches may help to optimize treatment response in otherwise treatment-refractory patients and to identify which patients are more likely to respond to treatment, and neuromodulation techniques such as repeated transcranial magnetic stimulation and deep brain stimulation also may play a role in the treatment of substance use disorders. Although no magic bullet is in sight for treatment-refractory patients, some novel medications and brain stimulation techniques have the potential to enrich treatment options at least for some patients.

Impact of prospectively determined A118G polymorphism on treatment response to injectable naltrexone among methamphetamine-dependent patients: an open-label, pilot study

OBJECTIVES

Methamphetamine (MA) addiction has no known effective pharmacotherapy. Small trials showed beneficial effects for oral naltrexone in amphetamine users. Trials in alcohol-dependent subjects showed better response in persons with the A118G single nucleotide polymorphism of the μ-opioid receptor. We conducted a pharmacogenetic trial of sustained release intramuscular naltrexone to examine the role of the A118G single nucleotide polymorphism in MA dependence.

METHOD

All eligible A118G subjects screened were enrolled; an equal number of wild type (A118A) subjects were selected using modified urn randomization, balanced on sex and frequency of recent MA use. Enrolled subjects received a single 380 mg naltrexone injection and weekly psychotherapy for 4 weeks. Self-report of MA use and urine toxicology for MA was assessed twice weekly. Urine samples with less than 1000 ng/mL of MA were considered negative.

RESULTS

Eleven A118G and 11 A118A subjects were enrolled. There were no significant differences between the groups in days of abstinence from MA use (11.5 vs 14.8, respectively, P = 0.51), the number of MA-negative urine samples (1.7 vs 1.8, respectively, P = 0.97), consecutive MA-negative urine samples (1.0 vs 1.5, respectively, P = 0.91), or the number of MA-negative urine samples before first relapse (0.9 vs 1.5, respectively, P = 0.86).

CONCLUSIONS

Although A118G polymorphism has been shown to be associated with improved treatment response to naltrexone among alcoholics, whether this polymorphism impacts naltrexone treatment response among MA users is unclear at this time.

Familial expressed emotion among heroin addicts in methadone maintenance treatment: does it matter?

BACKGROUND

Expressed emotion (EE) is the quality of the atmosphere between a relative and a family member with mental illness. Substantial research has focused on the relationship between the level of EE and the outcomes of mental illness. However, no prior study has explored the role of EE relative to heroin addicts.

AIM

The aims of this study were to investigate the influence of EE on patient outcome in methadone maintenance treatment (MMT) and the relationship between the EE of heroin addicts and other demographic and psychological variables.

METHODS

A total of 117 heroin addicts who entered MMT were enrolled. Each subject underwent a comprehensive interview to record demographic data and drug use history. The Family Emotional Involvement Scale (FEICS), Beck Depression Inventory (BDI), and Beck Anxiety Depression Inventory (BAI) were used at baseline. All subjects were followed for 12 months. The results of monthly urine tests and the treatment retention were recorded for further analysis.

RESULTS

Perceived criticism was correlated with depression (r=0.20, P<0.01). The overall retention rate in 12-month MMT was 54.70%. Lower perceived criticism (OR=1.84, 95% CI=1.20-3.60, P<0.01) and lower depression (OR=1.24, 95% CI=0.65-1.80, P=0.02) predicted longer retention in MMT.

CONCLUSION

EE, especially perceived criticism, has its influences on outcomes among heroin addicts in MMT. This suggested the potential benefits of family therapy among high EE heroin addicts in MMT. Furthermore, the mechanism how EE affects the outcome of MMT needs to be further investigated.

Psychostimulants: Basic and Clinical Pharmacology

Substance use disorder, and particularly psychostimulant use disorder, has considerable socioeconomic burden globally. The psychostimulants include several chemical classes, being derivatives of benzoylecgonine, phenethylamine, phenylpropanolamine, or aminoaryloxazoline. Psychostimulant drugs activate the brain reward pathways of the mesoaccumbal system, and continued use leads to persistent neuroplastic and dysfunctional changes of a variety of structures involved in learning and memory, habit-forming learning, salience attribution, and inhibitory control. There are a variety of neurochemical and neurobehavioral changes in psychostimulant addiction, for example, dopaminergic, glutamatergic, serotonergic (5-HT-ergic), and γ-amino butyric acid (GABA) changes have all noted. In this chapter, we will review pharmacological changes associated with psychostimulant use and abuse in humans and animals, and on the basis of the best characterized and most widely abused psychostimulants (amphetamines, cocaine) discuss why use transitions into abuse and review basic science and clinical strategies that might assist in treating psychostimulant abuse.

Effectiveness of secondary prevention and treatment interventions for crack-cocaine abuse: a comprehensive narrative overview of English-language studies

There are an estimated several million crack-cocaine users globally; use is highest in the Americas. Most crack users are socio-economically marginalized (e.g., homeless), and feature elevated risks for morbidity (e.g., blood-borne viruses), mortality and crime/violence involvement, resulting in extensive burdens. No comprehensive reviews of evidence-based prevention and/or treatment interventions specifically for crack use exist. We conducted a comprehensive narrative overview of English-language studies on the efficacy of secondary prevention and treatment interventions for crack (cocaine) abuse/dependence. Literature searches (1990-2014) using pertinent keywords were conducted in main scientific databases. Titles/abstracts were reviewed for relevance, and full studies were included in the review if involving a primary prevention/treatment intervention study comprising a substantive crack user sample. Intervention outcomes considered included drug use, health risks/status (e.g., HIV or sexual risks) and select social outcome indicators. Targeted (e.g., behavioral/community-based) prevention measures show mixed and short-term effects on crack use/HIV risk outcomes. Material (e.g., safer crack use kit distribution) interventions also document modest efficacy in risk reduction; empirical assessments of environmental (e.g., drug consumption facilities) for crack smokers are not available. Diverse psycho-social treatment (including contingency management) interventions for crack abuse/dependence show some positive but also limited/short-term efficacy, yet likely constitute best currently available treatment options. Ancillary treatments show little effects but are understudied. Despite ample studies, pharmaco-therapeutic/immunotherapy treatment agents have not produced convincing evidence; select agents may hold potential combined with personalized approaches and/or psycho-social strategies. No comprehensively effective 'gold-standard' prevention/treatment interventions for crack abuse exist; concerted research towards improved interventions is urgently needed.

Future pharmacological treatments for substance use disorders

Substance use disorders represent a serious public health and social issue worldwide. Recent advances in our understanding of the neurobiological basis of the addictive processes have led to the development of a growing number of pharmacological agents to treat addictions. Despite this progress, there are no approved pharmacological treatments for cocaine, methamphetamine and cannabis addiction. Moving treatment development to the next stage will require novel ways of approaching substance use disorders. One such novel approach is to target individual vulnerabilities, such as cognitive function, sex differences and psychiatric comorbidities. This review provides a summary of promising pharmacotherapies for alcohol, opiate, stimulant and nicotine addictions. Many medications that target positive and negative reinforcement of drugs, as well as individual vulnerabilities to addiction, are in different phases of development. Clinical trials testing the efficacy of these medications for substance use disorder are warranted.

Effects of naltrexone plus topiramate on ethanol self-administration and tyrosine hydroxylase gene expression changes

The purpose of this study was to evaluate the effects of naltrexone (0.7 mg/kg) and/or topiramate (25 mg/kg) on ethanol consumption and the motivation to drink in an oral-operant conditioning paradigm in C57BL/6 mice. Subsequent real-time polymerase chain reaction (PCR) experiments were performed to analyze gene expression changes in tyrosine hydroxylase (TH) in the ventral tegmental area (VTA). The administration of naltrexone significantly reduced ethanol consumption and the motivation to drink during the different stages of the experiment, whereas the treatment with topiramate resulted in a much lower effect. Interestingly, the administration of naltrexone plus topiramate reduced ethanol consumption markedly compared with single-drug treatment. The water self-administration paradigm was also performed using the same drugs and no differences were found between treatment groups. Real-time PCR analyses revealed that naltrexone significantly normalized the increase of TH gene expression in the VTA induced by ethanol, whereas the administration of topiramate did not produce any significant effect. In the ethanol self-administration procedure, the combination of both drugs further reduced TH gene expression, reaching statistical significance compared with the vehicle, naltrexone or topiramate groups. Taken together, these findings indicate that the administration of naltrexone plus topiramate further reduced ethanol consumption and the motivation to drink in comparison with single-drug treatment. This action may be due, at least in part, to a greater decrease in TH gene expression in the VTA. These results suggest that the combination of both drugs deserves further exploration for the treatment of problems related to alcohol consumption.

Combination pharmacotherapies for stimulant use disorder: a review of clinical findings and recommendations for future research

Despite concerted efforts to identify a pharmacotherapy for managing stimulant use disorders, no widely effective medications have been approved. Innovative strategies are necessary to develop successful pharmacotherapies for stimulant use disorders. This manuscript reviews human laboratory studies and clinical trials to determine whether one such strategy, use of combination pharmacotherapies, holds promise. The extant literature shows that combination pharmacotherapy produced results that were better than placebo treatment, especially with medications shown to have efficacy as monotherapies. However, many studies did not compare individual constituents to the combination treatment, making it impossible to determine whether combination treatment is more effective than monotherapy. Future research should systematically compare combined treatments with individual agents using medications showing some efficacy when tested alone.

A two-phased screening paradigm for evaluating candidate medications for cocaine cessation or relapse prevention: modafinil, levodopa-carbidopa, naltrexone

BACKGROUND

Cocaine pharmacotherapy trials are often confounded by considerable variability in baseline cocaine-use levels, obscuring possible medication efficacy. Testing the feasibility of using a prerandomization, abstinence-induction protocol, we screened three candidate medications to explore treatment response in patients who did, or did not, achieve abstinence during an extended baseline phase.

METHOD

Eligible treatment-seeking, cocaine-dependent subjects entered a 4-week baseline period (Phase I) with high-value abstinence contingent vouchers and two motivational interviewing sessions, followed by a 12-week medication trial (Phase II) with random assignment stratified on Phase I abstinence status to (1) modafinil (400mg/d), (2) levodopa/carbidopa (800/200mg/d), (3) naltrexone (50mg/d), or (4) placebo. Treatment consisted of thrice-weekly clinic visits for urine benzoylecgonine testing and weekly cognitive behavioral therapy with contingency management targeting medication compliance.

RESULTS

Of the 118 subjects enrolled, 81 (80%) completed Phase I, with 33 (41%) achieving abstinence, defined a priori as 6 consecutive cocaine-negative urines. Tests of the interaction of each medication (active versus placebo) by baseline status (abstinent versus nonabstinent) permitted moderator effect analysis. Overall, baseline abstinence predicted better outcome. Cocaine-use outcomes for levodopa and naltrexone treatment differed as a function of Phase I abstinence status, with both medications producing benefit in nonabstinent but not baseline-abstinent subjects. There was no evidence of a moderator effect for modafinil.

CONCLUSIONS

The two-phase screening trial demonstrated that subgrouping of patients with respect to baseline abstinence status is feasible and clinically useful for exploring cocaine cessation and relapse-prevention effects of candidate medications.

Disulfiram efficacy in the treatment of alcohol dependence: a meta-analysis

Background

Despite its success with compliant or supervised patients, disulfiram has been a controversial medication in the treatment of alcoholism. Often, study designs did not recognize a pivotal factor in disulfiram research, the importance of an open-label design. Our objectives are: (1) to analyze the efficacy and safety of disulfiram in RCTs in supporting abstinence and (2) to compare blind versus open-label studies, hypothesizing that blinded studies would show no difference between disulfiram and control groups because the threat would be evenly spread across all groups.

Methods and Findings

We searched PubMed, EMBASE and the Cochrane Central Register for RCTs on disulfiram use with alcoholics in comparison to any alcoholic control group. The primary outcome was defined by the authors of each trial. Additional analyses included: blind vs. open-label, with or without supervision, cocaine study or not, and type of control.

Overall, the 22 included studies showed a higher success rate of disulfiram compared to controls Hedges'g = .58 (95%CI = .35–.82). When comparing blind and open-label RCTs, only open-label trials showed a significant superiority over controls g = .70 (95%CI = .46–.93). RCTs with blind designs showed no efficacy of disulfiram compared to controls. Disulfiram was also more effective than the control condition when compared to naltrexone g = .77, 95%CI = .52–1.02, to acamprosate g = .76, 95%CI = .04–1.48, and to the no disulfiram groups g = .43, 95%CI = .17–.69.

Limits include: (1) a population of 89% male subjects and (2) a high but unavoidable heterogeneity of the studies with a substantial I-square in most subgroups of studies.

Conclusions

Blinded studies were incapable of distinguishing a difference between treatment groups and thus are incompatible with disulfiram research. Based on results with open-label studies, disulfiram is a safe and efficacious treatment compared to other abstinence supportive pharmacological treatments or to no disulfiram in supervised studies for problems of alcohol abuse or dependence.

Meta-analysis of naltrexone and acamprosate for treating alcohol use disorders: when are these medications most helpful?

AIMS

Although debates over the efficacy of oral naltrexone and acamprosate in treating alcohol use disorders tend to focus on their global efficacy relative to placebo or their efficacy relative to each other, the underlying reality may be more nuanced. This meta-analysis examined when naltrexone and acamprosate are most helpful by testing: (i) the relative efficacy of each medication given its presumed mechanism of action (reducing heavy drinking versus fostering abstinence) and (ii) whether different ways of implementing each medication (required abstinence before treatment, detoxification before treatment, goal of treatment, length of treatment, dosage) moderate its effects.

METHODS

A systematic literature search identified 64 randomized, placebo-controlled, English-language clinical trials completed between 1970 and 2009 focused on acamprosate or naltrexone.

RESULTS

Acamprosate had a significantly larger effect size than naltrexone on the maintenance of abstinence, and naltrexone had a larger effect size than acamprosate on the reduction of heavy drinking and craving. For naltrexone, requiring abstinence before the trial was associated with larger effect sizes for abstinence maintenance and reduced heavy drinking compared with placebo. For acamprosate, detoxification before medication administration was associated with better abstinence outcomes compared with placebo.

CONCLUSIONS

In treatment for alcohol use disorders, acamprosate has been found to be slightly more efficacious in promoting abstinence and naltrexone slightly more efficacious in reducing heavy drinking and craving. Detoxification before treatment or a longer period of required abstinence before treatment is associated with larger medication effects for acamprosate and naltrexone respectively.

Process-of-care measures as predictors of client outcome among a methamphetamine-dependent sample at 12- and 36-month follow-ups

This study examines the utility of several process-of-care performance measures (initiation, engagement, retention, and monitoring of drug use during treatment) as predictors of methamphetamine (MA) use outcomes at 12- and 36-month follow-ups. MA-dependent individuals (n = 871) participated in a randomized, controlled trial of outpatient psychosocial treatment from 1999-2002 and completed 12- and 36-month follow-up interviews. This sample included a treatment-as-usual group (n = 436) and a 16-week Matrix treatment (n = 435) group. Significant associations were observed between select process-of-care measures and MA use outcomes at both follow-ups. While correlational analyses showed an association between MA abstinence at follow-up and enhanced treatment engagement and retention, mixed logistic regression analyses indicated that sustained abstinence from MA during outpatient treatment was the strongest predictor of testing negative for MA use at both follow-ups. Results suggest that monitoring client drug use during treatment may be a useful process-of-care measure with MA-dependent users.

Chronic inhibition of dopamine β-hydroxylase facilitates behavioral responses to cocaine in mice

The anti-alcoholism medication, disulfiram (Antabuse), decreases cocaine use in humans regardless of concurrent alcohol consumption and facilitates cocaine sensitization in rats, but the functional targets are unknown. Disulfiram inhibits dopamine β-hydroxylase (DBH), the enzyme that converts dopamine (DA) to norepinephrine (NE) in noradrenergic neurons. The goal of this study was to test the effects of chronic genetic or pharmacological DBH inhibition on behavioral responses to cocaine using DBH knockout (Dbh −/−) mice, disulfiram, and the selective DBH inhibitor, nepicastat. Locomotor activity was measured in control (Dbh +/−) and Dbh −/− mice during a 5 day regimen of saline+saline, disulfiram+saline, nepicastat+saline, saline+cocaine, disulfiram+cocaine, or nepicastat+cocaine. After a 10 day withdrawal period, all groups were administered cocaine, and locomotor activity and stereotypy were measured. Drug-naïve Dbh −/− mice were hypersensitive to cocaine-induced locomotion and resembled cocaine-sensitized Dbh +/− mice. Chronic disulfiram administration facilitated cocaine-induced locomotion in some mice and induced stereotypy in others during the development of sensitization, while cocaine-induced stereotypy was evident in all nepicastat-treated mice. Cocaine-induced stereotypy was profoundly increased in the disulfiram+cocaine, nepicastat+cocaine, and nepicastat+saline groups upon cocaine challenge after withdrawal in Dbh +/− mice. Disulfiram or nepicastat treatment had no effect on behavioral responses to cocaine in Dbh −/− mice. These results demonstrate that chronic DBH inhibition facilitates behavioral responses to cocaine, although different methods of inhibition (genetic vs. non-selective inhibitor vs. selective inhibitor) enhance qualitatively different cocaine-induced behaviors.

The impact of disulfiram treatment on the reinforcing effects of cocaine: a randomized clinical trial

Background

Clinical trials indicate that disulfiram (250 mg/d) reduces cocaine use, though one study found that treatment with lower doses of disulfiram (62.5 and 125 mg/d) increased cocaine use. We conducted the present study to better understand how disulfiram alters the reinforcing effects of cocaine in cocaine users.

Methods

Seventeen non-treatment seeking, cocaine-dependent volunteers participated in this double-blind, placebo-controlled, laboratory-based study. A cross-over design was utilized in which participants received placebo in one phase and disulfiram (250 mg/d) in the other. Following three days of study medication participants completed two choice sessions. In one they made 10 choices between receiving an intravenous infusion of saline or money that increased in value (US$ 0.05–16) and in the other cocaine (20 mg) or money.

Results

Participants chose cocaine more than saline under both disulfiram and placebo conditions (p<0.05). Unexpectedly, disulfiram increased both the number of cocaine and saline infusion choices (p<0.05). We next examined the relationship between disulfiram dose and cocaine choices. Disulfiram dose (mg/kg bodyweight) was negatively correlated with number of choices for cocaine (p<0.05). Disulfiram also enhanced cocaine-induced increases in cardiovascular measures (p's<0.05–0.01).

Conclusions

Disulfiram's impact on the reinforcing effects of cocaine depends on dose relative to body weight. Our results suggest that the use of weight-based medication doses would produce more reliable effects, consistent with weight-based dosing used in pediatrics and in preclinical research.

Trial Registration

Clinicaltrials.gov NCT00729300

Efficacy of disulfiram and Twelve Step Facilitation in cocaine-dependent individuals maintained on methadone: a randomized placebo-controlled trial

BACKGROUND

Cocaine use remains a major problem within methadone maintenance programs. Disulfiram's efficacy in reducing cocaine use has been demonstrated in several trials, but its relative efficacy among individuals who use versus abstain from alcohol remains unclear. Treatment approaches which seek to enhance substance users' involvement in self-help activities (Twelve Step Facilitation, TSF) have been associated with better outcomes among alcohol and cocaine users, but have rarely been evaluated among methadone-maintained cocaine-opioid users.

METHODS

We conducted a randomized, placebo-controlled, double blind (for medication condition), factorial (2×2) trial with 4 treatment conditions: Disulfiram plus TSF, disulfiram plus standard counseling only, placebo plus TSF, and placebo plus standard counseling in the context of a community-based methadone maintenance program. Participants (N=112) received either disulfiram (250 mg/d) or placebo in conjunction with daily methadone maintenance.

RESULTS

Assignment to TSF was associated with less cocaine use throughout treatment and a higher number of cocaine-negative urines. While there were no significant main effects of disulfiram versus placebo, individuals without an alcohol use disorder demonstrated greater reductions in cocaine use over time when assigned to disulfiram.

CONCLUSIONS

TSF appears feasible in this methadone maintenance program and was associated with modest reductions in cocaine use, an often intractable problem in this setting. Support for the efficacy of disulfiram was weaker, as it appeared effective only for those without a current alcohol use disorder for this sample.

BAP updated guidelines: evidence-based guidelines for the pharmacological management of substance abuse, harmful use, addiction and comorbidity: recommendations from BAP

The British Association for Psychopharmacology guidelines for the treatment of substance abuse, harmful use, addiction and comorbidity with psychiatric disorders primarily focus on their pharmacological management. They are based explicitly on the available evidence and presented as recommendations to aid clinical decision making for practitioners alongside a detailed review of the evidence. A consensus meeting, involving experts in the treatment of these disorders, reviewed key areas and considered the strength of the evidence and clinical implications. The guidelines were drawn up after feedback from participants. The guidelines primarily cover the pharmacological management of withdrawal, short- and long-term substitution, maintenance of abstinence and prevention of complications, where appropriate, for substance abuse or harmful use or addiction as well management in pregnancy, comorbidity with psychiatric disorders and in younger and older people.

Validity of Timeline Follow-Back for self-reported use of cannabis and other illicit substances--systematic review and meta-analysis

BACKGROUND

Timeline Follow-Back (TLFB) is a widely used, calendar-based measure of self-reported use of (among other things) illicit substances. We examined agreement between TLFB and biological measures for illicit substances.

METHODS

PubMed, PsycINFO, Cochrane CENTRAL, and EMBASE were searched in December 2010. 16,633 papers screened to identify those that measured illicit substance use by both TLFB and biological measures. We extracted data on agreement between TLFB and biological measures, sample size, study type, inclusion criteria of participants, and length of recall of TLFB.

RESULTS

Twenty-nine papers were included, almost exclusively in substance-use-disorder populations. Some studies reported several overall agreement rates, e.g. over time. Lowest and highest weighted average agreement rates were: for cannabis, 87.3% (95% confidence interval 86.9% to 87.7%) and 90.9% (90.5% to 91.4%); for cocaine, 79.3% (79.1% to 79.6%) and 84.1% (83.9% to 84.2%); for opiates 94.0% (93.5% to 94.5%) for both weighted averages; and for studies not distinguishing between substances, 88.5% (88.4 to 88.7%) and 91.0% (90.7% to 91.2%). Higher agreement was found in populations without psychiatric comorbidity, and lower agreement in randomized controlled trials. Publication bias or selective outcome reporting bias was not detected.

CONCLUSIONS

TLFB validly detects use of illicit substances in populations with substance use disorders. Using TLFB may limit the need for biological samples, making information on illicit substance use easier and less costly to obtain and analyze.

Pharmacotherapeutics directed at deficiencies associated with cocaine dependence: focus on dopamine, norepinephrine and glutamate

Much effort has been devoted to research focused on pharmacotherapies for cocaine dependence yet there are no FDA-approved medications for this brain disease. Preclinical models have been essential to defining the central and peripheral effects produced by cocaine. Recent evidence suggests that cocaine exerts its reinforcing effects by acting on multiple neurotransmitter systems within mesocorticolimibic circuitry. Imaging studies in cocaine-dependent individuals have identified deficiencies in dopaminergic signaling primarily localized to corticolimbic areas. In addition to dysregulated striatal dopamine, norepinephrine and glutamate are also altered in cocaine dependence. In this review, we present these brain abnormalities as therapeutic targets for the treatment of cocaine dependence. We then survey promising medications that exert their therapeutic effects by presumably ameliorating these brain deficiencies. Correcting neurochemical deficits in cocaine-dependent individuals improves memory and impulse control, and reduces drug craving that may decrease cocaine use. We hypothesize that using medications aimed at reversing known neurochemical imbalances is likely to be more productive than current approaches. This view is also consistent with treatment paradigms used in neuropsychiatry and general medicine.

A double-blind, placebo-controlled assessment of the safety of potential interactions between intravenous cocaine, ethanol, and oral disulfiram

BACKGROUND

A majority of cocaine addicts have a comorbid alcohol use disorder. Previous studies demonstrated efficacy of disulfiram in the treatment of cocaine dependence among patients with comorbid alcohol use disorder or opioid dependence. However, the cardiac risks of a disulfiram-ethanol reaction (DER) in individuals who drink, when coupled with the cardiac effects of cocaine, could result in significant toxicity or lethality due to the 3-way drug interaction.

AIMS

This study examined the safety of combining cocaine (30 mg i.v.) and ethanol (0.4 g/kg i.v.) in disulfiram-treated (0, 250, and 500 mg/d, p.o.) cocaine-dependent research volunteers.

RESULTS

The results showed that disulfiram did not enhance the cardiovascular effects of cocaine and may have reduced the subjective high from cocaine. In contrast, ethanol produced adverse ECG changes including QTc prolongation and a DER consisting of hypotension, tachycardia, nausea, and flushing in disulfiram-treated subjects. The severity of the DER was related to disulfiram dose and the trial with 500 mg/d was stopped prematurely due to safety concerns. The DER-related hypotension and tachycardia seen with ethanol infusion alone in disulfiram-treated subjects, was not exacerbated when combined with cocaine. In fact, cocaine tended to counteract the ethanol-related hypotension though it did exacerbate the tachycardia in two of seven subjects.

CONCLUSIONS

Though conclusions are limited by the moderate doses of cocaine, ethanol, and disulfiram tested, the data do suggest that the risks of the moderate use of cocaine and ethanol in individuals treated with moderate doses of disulfiram (≤ 250 mg/d) may not be as problematic as some may assume.

[Disulfiram and addiction: reminders and new perspectives of use]

Disulfiram is a relatively old molecule, which today remains marginal in the treatment of alcoholics diseases. Using this type of treatment is the subject of ethical debate. The prescription of this therapeutic requires clinical and biological rigorous evaluations before treatment. Its main action in treatment of alcoholism is related to the restraint of acetaldehyde dehydrogenase action causing the antabuse reaction. Prescription of disulfiram, supported by specialized programs of compartmental integrated care, brings significant benefit for alcoholic patients. Recently, following the discovery of its action on dopamine metabolism, disulfiram has been a renewed interest in the treatment of addictions to cocaine and pathological gambling. Although current data are insufficient to generalize its use in routine practice, they constitute a line of research interest for the future.

Hypothalamic opioid-melanocortin appetitive balance and addictive craving

Whilst the parallels between drug and food craving are receiving increasing attention, the recently elucidated complex physiology of the hypothalamic appetite regulatory centres has been largely overlooked in the efforts to understand drug craving which is one of the most refractory and problematic aspects of drug and behavioural addictions. Important conceptual gains could be made by researchers from both appetite and addiction neuroscience if they were to have an improved understanding of each others' disciplines. It is well known in addiction medicine that the use of many substances is elevated in opiate dependency. There is voluminous evidence of very high rates of drug use in opiate agonist maintained patients, and the real possibility exists that opiate agonist therapy therefore increases drug craving. Conversely, opiate antagonist therapy with naloxone or naltrexone has been shown to reduce most chemical and behavioural addictions, and naltrexone is now being developed together with bupropion as the anti-obesity drug "Contrave". Hypothalamic melanocortins, particularly α-MSH, are known to constitute the main brake to consumptive behaviour of food. There is a well described antagonism between melanocortins and opioids at many loci including the hypothalamus. Administration of exogenous opiates is known to both suppress α-MSH and to stimulate hedonic food consumption. Opiate maintenance programs are associated with weight gain. As monoamines, opioids and cannabinoids are known to be involved in appetite regulation, and as endorphin opioids are known to be perturbed in other addictions, further exploration of the hypothalamic appetite regulatory centre would appear to be an obvious, albeit presently largely overlooked, locus in which to study drug and other craving mechanisms.

Opioid antagonists for alcohol dependence

BACKGROUND

Alcohol dependence belongs to the globally leading health risk factors. Therapeutic success of psychosocial programs for relapse prevention is moderate and could be increased by an adjuvant treatment with the opioid antagonists naltrexone and nalmefene.

OBJECTIVES

To determine the effectiveness and tolerability of opioid antagonists in the treatment of alcohol dependence.

SEARCH STRATEGY

We searched the Cochrane Drugs and Alcohol Group (CDAG) Specialized Register, PubMed, EMBASE and CINAHL in January 2010 and inquired manufacturers and researchers for unpublished trials.

SELECTION CRITERIA

All double-blind randomised controlled trials (RCTs) which compare the effects of naltrexone or nalmefene with placebo or active control on drinking-related outcomes.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted outcome data. Trial quality was assessed by one author and cross-checked by a second author.

MAIN RESULTS

Based on a total of 50 RCTs with 7793 patients, naltrexone reduced the risk of heavy drinking to 83% of the risk in the placebo group RR 0.83 (95% CI 0.76 to 0.90) and decreased drinking days by about 4%, MD -3.89 (95% CI -5.75 to -2.04). Significant effects were also demonstrated for the secondary outcomes of the review including heavy drinking days, MD - 3.25 (95% CI -5.51 to -0.99), consumed amount of alcohol, MD - 10.83 (95% CI -19.69 to -1.97) and gamma-glutamyltransferase, MD - 10.37 (95% CI -18.99 to -1.75), while effects on return to any drinking, RR 0.96 (95 CI 0.92 to 1.00) missed statistical significance. Side effects of naltrexone were mainly gastrointestinal problems (e.g. nausea: RD 0.10; 95% CI 0.07 to 0.13) and sedative effects (e.g. daytime sleepiness: RD 0.09; 95% CI 0.05 to 0.14). Based on a limited study sample, effects of injectable naltrexone and nalmefene missed statistical significance. Effects of industry-sponsored studies, RR 0.90 (95% CI 0.78 to 1.05) did not significantly differ from those of non-profit funded trials, RR 0.84 (95% CI 0.77 to 0.91) and the linear regression test did not indicate publication bias (P = 0.765).

AUTHORS' CONCLUSIONS

Naltrexone appears to be an effective and safe strategy in alcoholism treatment. Even though the sizes of treatment effects might appear moderate in their magnitudes, these should be valued against the background of the relapsing nature of alcoholism and the limited therapeutic options currently available for its treatment.

LC-MS/MS method for the determination of carbamathione in human plasma

Liquid chromatography-tandem mass spectrometry methodology is described for the determination of S-(N,N-diethylcarbamoyl)glutathione (carbamathione) in human plasma samples. Sample preparation consisted of a straightforward perchloric acid medicated protein precipitation, with the resulting supernatant containing the carbamathione (recovery ~98%). For optimized chromatography/mass spec detection a carbamathione analog, S-(N,N-di-i-propylcarbamoyl)glutathione, was synthesized and used as the internal standard. Carbamathione was found to be stable over the pH 1-8 region over the timeframe necessary for the various operations of the analytical method. Separation was accomplished via reversed-phase gradient elution chromatography with analyte elution and re-equilibration accomplished within 8 min. Calibration was established and validated over the concentration range of 0.5-50 nM, which is adequate to support clinical investigations. Intra- and inter-day accuracy and precision determined and found to be <4% and <10%, respectively. The methodology was utilized to demonstrate the carbamathione plasma-time profile of a human volunteer dosed with disulfiram (250 mg/d). Interestingly, an unknown but apparently related metabolite was observed with each human plasma sample analyzed.

Disulfiram attenuates drug-primed reinstatement of cocaine seeking via inhibition of dopamine β-hydroxylase

The antialcoholism medication disulfiram (Antabuse) inhibits aldehyde dehydrogenase (ALDH), which results in the accumulation of acetaldehyde upon ethanol ingestion and produces the aversive 'Antabuse reaction' that deters alcohol consumption. Disulfiram has also been shown to deter cocaine use, even in the absence of an interaction with alcohol, indicating the existence of an ALDH-independent therapeutic mechanism. We hypothesized that disulfiram's inhibition of dopamine β-hydroxylase (DBH), the catecholamine biosynthetic enzyme that converts dopamine (DA) to norepinephrine (NE) in noradrenergic neurons, underlies the drug's ability to treat cocaine dependence. We tested the effects of disulfiram on cocaine and food self-administration behavior and drug-primed reinstatement of cocaine seeking in rats. We then compared the effects of disulfiram with those of the selective DBH inhibitor, nepicastat. Disulfiram, at a dose (100 mg/kg, i.p.) that reduced brain NE by ∼40%, did not alter the response for food or cocaine on a fixed ratio 1 schedule, whereas it completely blocked cocaine-primed (10 mg/kg, i.p.) reinstatement of drug seeking following extinction. A lower dose of disulfiram (10 mg/kg) that did not reduce NE had no effect on cocaine-primed reinstatement. Nepicastat recapitulated the behavioral effects of disulfiram (100 mg/kg) at a dose (50 mg/kg, i.p.) that produced a similar reduction in brain NE. Food-primed reinstatement of food seeking was not impaired by DBH inhibition. Our results suggest that disulfiram's efficacy in the treatment of cocaine addiction is associated with the inhibition of DBH and interference with the ability of environmental stimuli to trigger relapse.