Dopamine agonists for the treatment of cocaine dependence

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 We also searched for ongoing and unpublished studies via two trials registries.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.

Testing the effects of the GLP-1 receptor agonist exenatide on cocaine self-administration and subjective responses in humans with cocaine use disorder

BACKGROUND

Preclinical rodent studies have demonstrated reduced cocaine taking after administration of glucagon-like peptide 1 (GLP-1) analogues. We investigated effects of a GLP-1 analogue (exenatide) on behavioral and subjective effects of cocaine in individuals with cocaine use disorder (CUD).

METHODS

Non-treatment-seeking CUD subjects underwent two human laboratory cocaine self-administration test sessions following an acute 3 -h pre-treatment with exenatide (5 mcg; subcutaneously) or placebo. Primary outcomes consisted of infusions of cocaine and visual analog scale self-ratings of euphoria and wanting cocaine. Secondary outcomes consisted of pertinent hormone levels (GLP-1, insulin, and amylin).

RESULTS

Thirteen individuals completed the study. Acute pretreatment with exenatide versus placebo did not change cocaine infusions (8.5 ± 1.2 vs. 9.1 ± 1.2; p = 0.39), self-reported euphoria (4.4 ± 0.8 vs. 4.1 ± 0.8; p = 0.21), or wanting of cocaine (5.6 ± 0.9 vs. 5.4 ± 0.9; p = 0.46). Exenatide vs. placebo reduced levels of GLP-1 (p = 0.03) and insulin (p = 0.02). Self-administered cocaine also reduced levels of GLP-1 (p < 0.0001), insulin (p < 0.0001), and amylin (p < 0.0001).

CONCLUSIONS

We did not find evidence that low dose exenatide alters cocaine self-administration or the subjective effects of cocaine in people with CUD. Limitations such as single acute rather than chronic pre-treatment, as well as evaluation of only one dose, preclude drawing firm conclusions about the efficacy of exenatide. Exenatide and cocaine independently reduced levels of GLP-1 and insulin, while cocaine also reduced levels of amylin.

Prescription psychostimulants for the treatment of stimulant use disorder: a systematic review and meta-analysis

RATIONALE

Agonist-based pharmacologic intervention is an accepted approach in treatment of opioid and tobacco use disorders.

OBJECTIVES

We conducted a systematic review and meta-analysis to evaluate usefulness of an agonist approach as treatment of (psycho)stimulant use disorder (PSUD).

METHODS

We reviewed PubMed/Medline, LILACS, and ClinicalTrials.gov databases searching for randomized, double-blind, placebo-controlled, parallel-design studies evaluating outcomes of individuals treated for cocaine- or amphetamine-type substance use disorder. We combined results of all trials that included the following prescription psychostimulants (PPs): modafinil, methylphenidate, or amphetamines (mixed amphetamine salts, lisdexamphetamine, and dextroamphetamine). The combined sample consisted of 2889 patients. Outcomes of interest included the following: drug abstinence (defined as 2-3 weeks of sustained abstinence and the average maximum days of consecutive abstinence), percentage of drug-negative urine tests across trial, and retention in treatment. We conducted random-effects meta-analyses and assessed quality of evidence using the GRADE system.

RESULTS

Thirty-eight trials were included. Treatment with PPs increases rates of sustained abstinence [risk ratio (RR) = 1.45, 95% confidence interval (CI) = (1.10, 1.92)] and duration of abstinence [mean difference (MD) = 3.34, 95% CI = (1.06, 5.62)] in patients with PSUD, particularly those with cocaine use disorder (very low-quality evidence). Prescription amphetamines were particularly efficacious in promoting sustained abstinence in patients with cocaine use disorder [RR = 2.44, 95% CI = (1.66, 3.58)], and higher doses of PPs were particularly efficacious for treatment of cocaine use disorder [RR = 1.95, 95% CI = (1.38, 2.77)] (moderate-quality evidence). Treatment with prescription amphetamines also yielded more cocaine-negative urines [MD = 8.37%, 95% CI = (3.75, 12.98)]. There was no effect of PPs on the retention in treatment.

CONCLUSION

Prescription psychostimulants, particularly prescription amphetamines given in robust doses, have a clinically significant beneficial effect to promote abstinence in the treatment of individuals with PSUD, specifically the population with cocaine use disorder.

The effect of tai chi and Qigong exercise on depression and anxiety of individuals with substance use disorders: a systematic review and meta-analysis

Background

Previous studies have acknowledged Tai Chi and Qigong exercise could be potential effective treatments for reducing depression and anxiety in both healthy and clinical populations. However, there is a scarcity of systematic reviews summarizing the clinical evidence conducted among individuals with substance use disorders. This study tries to fill up this gap.

Methods

A systematic search using Medline, EMbase, PsychINFO, Eric, SPORTDiscus, CINAHL, the Cochrane Central Register of Controlled Trials (CENTRAL), the Chinese National Knowledge Infrastructure (CNKI), Wanfang, and the Chinese Scientific Journal (VIP) databases was initiated to identify randomized controlled trials (RCTs) and non-randomized comparison studies (NRS) assessing the effect of Tai Chi and Qigong versus various comparison groups on depression and anxiety related outcomes. Study quality was evaluated using a Checklist to Evaluate a Report of a Nonpharmacological Trial (CLEAR-NPT) designed for nonpharmacological trial.

Results

One RCT and six NRS with a total of 772 participants were identified. Some of them were meta-analyzed to examine the pooled effects based on different types of intervention and controls. The results of meta-analyses suggested the effect of Tai Chi was comparable to treatment as usual (TAU) on depression (standardized mean difference (SMD) = − 0.17[− 0.52, 0.17]). Qigong exercise appears to result in improvement on anxiety compared to that of medication (SMD = -1.12[− 1.47, − 0.78]), and no treatment control (SMD = -0.52[− 0.77, − 0.27]).

Conclusion

The findings suggest potentially beneficial effect of Qigong exercise on symptoms of anxiety among individuals with drug abuse. Considering the small number and overall methodological weakness of included studies and lack of RCTs, results should be interpreted with caution and future rigorously designed RCTs are warranted to provide more reliable evidence.

Neural circuitry and mechanisms of waiting impulsivity: relevance to addiction

Impatience-the failure to wait or tolerate delayed rewards (e.g. food, drug and monetary incentives)-is a common behavioural tendency in humans. However, when rigidly and rapidly expressed with limited regard for future, often negative consequences, impatient or impulsive actions underlie and confer susceptibility for such diverse brain disorders as drug addiction, attention-deficit hyperactivity disorder (ADHD) and major depressive disorder. Consequently, 'waiting' impulsivity has emerged as a candidate endophenotype to inform translational research on underlying neurobiological mechanisms and biomarker discovery for many of the so-called impulse-control disorders. Indeed, as reviewed in this article, this research enterprise has revealed a number of unexpected targets and mechanisms for intervention. However, in the context of drug addiction, impulsive decisions that maximize short-term gains (e.g. acute drug consumption) over longer-term punishment (e.g. unemployment, homelessness, personal harm) defines one aspect of impulsivity, which may or may not be related to rapid, unrestrained actions over shorter timescales. We discuss the relevance of this distinction in impulsivity subtypes for drug addiction with reference to translational research in humans and other animals. This article is part of the theme issue 'Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications'.

Levodopa prevents the reinstatement of cocaine self-administration in rats via potentiation of dopamine release in the medial prefrontal cortex

Dopamine agonists have been proposed as therapeutic tools for cocaine addiction. We have recently demonstrated that indirect dopamine agonists, including levodopa (L-DOPA), markedly increase cocaine-induced dopamine release in the medial prefrontal cortex (mPFC) of rats leading to the suppression of cocaine-seeking behavior. This study was aimed to understand the behavioral and neurochemical effects of L-DOPA on cocaine-taking and cocaine-seeking in rats. After reaching a stable pattern of intravenous cocaine self-administration under a continuous fixed ratio (FR-1) schedule of reinforcement, male rats were treated with L-DOPA at different steps of the self-administration protocol. We found that L-DOPA reduced cocaine self-administration under FR-1 schedule of reinforcement and decreased the breaking points and the amount of cocaine self-administered under the progressive ratio schedule of reinforcement. Levodopa also decreased cocaine-seeking behavior both in a saline substitution test and in the cue priming-induced reinstatement test, without affecting general motor activity. Importantly, L-DOPA greatly potentiated cocaine-induced dopamine release in the mPFC of self-administering rats while reducing their cocaine intake. In the same brain area, L-DOPA also increased dopamine levels during cue priming-induced reinstatement of cocaine-seeking behavior. The potentiating effect was also evident in the mPFC but not nucleus accumbens core of drug-naïve rats passively administered with cocaine. Altogether, these findings demonstrate that L-DOPA efficaciously reduces the reinforcing and motivational effects of cocaine likely potentiating dopamine transmission in the mPFC. Its ability to prevent cue priming-induced reinstatement of cocaine-seeking suggests that it might be effective in reducing the risk to relapse to cocaine in abstinent patients.

Norepinephrine regulates cocaine-primed reinstatement via α1-adrenergic receptors in the medial prefrontal cortex

Drug-primed reinstatement of cocaine seeking in rats is thought to reflect relapse-like behavior and is mediated by the integration of signals from mesocorticolimbic dopaminergic projections and corticostriatal glutamatergic innervation. Cocaine-primed reinstatement can also be attenuated by systemic administration of dopamine β-hydroxylase (DBH) inhibitors, which prevent norepinephrine (NE) synthesis, or by α1-adrenergic receptor (α1AR) antagonists, indicating functional modulation by the noradrenergic system. In the present study, we sought to further discern the role of NE in cocaine-seeking behavior by determining whether α1AR activation can induce reinstatement on its own or is sufficient to permit cocaine-primed reinstatement in the absence of all other AR signaling, and identifying the neuroanatomical substrate within the mesocorticolimbic reward system harboring the critical α1ARs. We found that while intracerebroventricular infusion of the α1AR agonist phenylephrine did not induce reinstatement on its own, it did overcome the blockade of cocaine-primed reinstatement by the DBH inhibitor nepicastat. Furthermore, administration of the α1AR antagonist terazosin in the medial prefrontal cortex (mPFC), but not the ventral tegmental area (VTA) or nucleus accumbens (NAc) shell, attenuated cocaine-primed reinstatement. Combined, these data indicate that α1AR activation in the mPFC is required for cocaine-primed reinstatement, and suggest that α1AR antagonists merit further investigation as pharmacotherapies for cocaine dependence.

Which medications are suitable for agonist drug maintenance?

BACKGROUND AND AIMS

We examine the feasibility of agonist maintenance treatment for the major psychoactive drug classes: opioids, nicotine, benzodiazepines, cannabis, psychostimulants and alcohol.

METHODS

Eight clinical criteria for an agonist maintenance drug were assessed for each major drug class. These related to pharmacological aspects of the drug (agonist, pharmacological stability, dose-response, non-toxic) and neurocognitive sequelae (psychiatric, cognitive, craving, salience).

RESULTS

Opioids and nicotine met all eight criteria for a maintenance drug. While nicotine has not been promoted widely or used for maintenance, it has the potential to fulfil that role. Cannabis met five criteria and has potential, but long-term data on cognitive impairment are required. Benzodiazepine maintenance would appear an option for the high-dose chaotic abuser, also meeting five criteria, although clinic dosing appears the safest option. Psychostimulants (three of eight criteria) and alcohol (one of eight) appear poor propositions for maintenance, in terms of both their pharmacological and their neurocognitive characteristics.

CONCLUSIONS

Drug classes have properties that distinguish them in their suitability for maintenance treatment. Some classes not yet used for maintenance (notably nicotine and cannabis) have potential to fulfil such a role. Others, however, by their inherent nature, appear unsuitable for such a treatment regimen.

Psychotic Symptoms Associated with the use of Dopaminergic Drugs, in Patients with Cocaine Dependence or Abuse

BACKGROUND

In the field of dual diagnosis, physicians are frequently presented with pharmacological questions. Questions about the risk of developing psychotic symptoms in cocaine users who need treatment with dopaminergic drugs could lead to an undertreatment.

OBJECTIVE

Review the presence of psychotic symptoms in patients with cocaine abuse/dependence, in treatment with dopaminergic drugs.

METHODS

Systematic PubMed searches were conducted including December 2014, using the keywords: "cocaine", dopaminergic drug ("disulfuram-methylphenidate-bupropion-bromocriptine-sibutramineapomorphine- caffeine") and ("psychosis-psychotic symptoms-delusional-paranoia"). Articles in English, Spanish, Portuguese, French, and Italian were included. Articles in which there was no history of cocaine abuse/dependence, absence of psychotic symptoms, systematic reviews, and animal studies, were excluded.

RESULTS

313 papers were reviewed. 7 articles fulfilled the inclusion-exclusion criteria. There is a clinical trial including 8 cocaine-dependent patients using disulfiram in which 3 of them presented psychotic symptoms and 6 case-reports: disulfuram (1), methylphenidate (1), disulfiram with methylphenidate (2), and bupropion (2), reporting psychotic symptoms, especially delusions of reference and persecutory ideation.

CONCLUSION

Few cases have been described, which suggests that the appearance of these symptoms is infrequent. The synergy of dopaminergic effects or the dopaminergic sensitization in chronic consumption are the explanatory theories proposed by the authors. In these cases, a relationship was found between taking these drugs and the appearance of psychotic symptoms. Given the low number of studies found, further research is required. The risk of psychotic symptoms seems to be acceptable if we compare it with the benefits for the patients but a closer monitoring seems to be advisable.

Pilot study of the effects of lisdexamfetamine on cocaine use: A randomized, double-blind, placebo-controlled trial

BACKGROUND

Amphetamine analogs have been demonstrated to have some efficacy in reducing use in cocaine dependent individuals. However, these agents also have potential for abuse. Lisdexamfetamine (LDX), a lysine+dextroamphetamine formulation, has been approved for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD) and as a prodrug, has less abuse potential.

OBJECTIVE

This pilot study sought to evaluate the safety, tolerability, and efficacy of LDX as a candidate treatment for cocaine dependence.

METHODS

A randomized, double-blind, placebo-controlled parallel group study served to evaluate LDX in 43 cocaine-dependent individuals: (1) placebo (PBO; 0mg, n=21), (2) LDX (70mg, n=22). Participants received medication for 14 weeks. Cocaine use was determined based on urine analysis for benzoylecgonine (BE; a cocaine metabolite).

RESULTS

Retention rates were higher though not significantly different in the PBO (71.4%) than the LDX condition (57.1%). Compared to those in the PBO condition, those receiving LDX were more likely to report experiencing (ps<0.05) diarrhea (45.5% vs. 14.3%), headaches (45.5% vs. 9.5%), and anxiety (31.8% vs. 4.8%). No differences in medication conditions were observed for blood pressure, heart rate, or body weight. In the randomized sample, no differences in cocaine use were seen. Those receiving LDX reported significantly less craving for cocaine than participants receiving PBO.

CONCLUSIONS

LDX did not significantly reduce cocaine use compared to PBO in the randomized sample.

Dopamine agonists for the treatment of cocaine dependence

BACKGROUND

Cocaine misuse is a disorder for which no pharmacological treatment of proven efficacy exists. Advances in neurobiology could guide future medication development.

OBJECTIVES

To investigate the efficacy and acceptability of dopamine agonists alone or in combination with any psychosocial intervention for the treatment of of people who misuse cocaine.

SEARCH METHODS

We run the search on 12 January 2015. We searched the Cochrane Drugs and Alcohol Group (CDAG) Specialized Register, PubMed, EMBASE, CINAHL, PsycINFO, ICTRP, clinicaltrials.gov and screened reference lists.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing dopamine agonists alone or associated with psychosocial intervention with placebo, no treatment or other pharmacological interventions.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures.

MAIN RESULTS

Twenty four studies, including 2147 participants, met the inclusion criteria. Comparing any dopamine agonist versus placebo, we found no differences for any of the outcomes considered: dropout (moderate quality of evidence), abstinence (low quality of evidence), severity of dependence (low quality of evidence), adverse events (moderate quality of evidence). This was also observed when single dopamine agonists were compared against placebo. Comparing amantadine versus antidepressants, we found low quality of evidence that antidepressants performed better for abstinence (RR 0.25, 95% CI 0.12 to 0.53) based on two studies with 44 participants. No differences were found for dropout or adverse events, for both moderate quality of evidence.The major flaws of the included studies concerned selection bias because most studies did not report information about sequence generation (80%) and allocation concealment methods (86%): half of the included studies were judged at unclear risk of performance bias and 62.5% at unclear risk of detection bias for what concerns subjective outcomes.

AUTHORS' CONCLUSIONS

Current evidence from RCTs does not support the use of dopamine agonists for treating cocaine misuse. This absence of evidence may leave to clinicians the alternative of balancing the possible benefits against the potential adverse effects of the treatment. Even the potential benefit of combining a dopamine agonist with a more potent psychosocial intervention, which was suggested by the previous Cochrane Review (Soares 2003), is not supported by the results of this Cochrane Review update.

Anticonvulsants for cocaine dependence

BACKGROUND

Cocaine dependence is a major public health problem that is characterised by recidivism and a host of medical and psychosocial complications. Although effective pharmacotherapy is available for alcohol and heroin dependence, none is currently available for cocaine dependence, despite two decades of clinical trials primarily involving antidepressant, anticonvulsivant and dopaminergic medications. Extensive consideration has been given to optimal pharmacological approaches to the treatment of individuals with cocaine dependence, and both dopamine antagonists and agonists have been considered. Anticonvulsants have been candidates for use in the treatment of addiction based on the hypothesis that seizure kindling-like mechanisms contribute to addiction.

OBJECTIVES

To evaluate the efficacy and safety of anticonvulsants for individuals with cocaine dependence.

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Group Trials Register (June 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 6), MEDLINE (1966 to June 2014), EMBASE (1988 to June 2014), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to June 2014), Web of Science (1991 to June 2014) and the reference lists of eligible articles.

SELECTION CRITERIA

All randomised controlled trials and controlled clinical trials that focus on the use of anticonvulsant medications to treat individuals with cocaine dependence.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included a total of 20 studies with 2068 participants. We studied the anticonvulsant drugs carbamazepine, gabapentin, lamotrigine, phenytoin, tiagabine, topiramate and vigabatrin. All studies compared anticonvulsants versus placebo. Only one study had one arm by which the anticonvulsant was compared with the antidepressant desipramine. Upon comparison of anticonvulsant versus placebo, we found no significant differences for any of the efficacy and safety measures. Dropouts: risk ratio (RR) 0.95, 95% confidence interval (CI) 0.86 to 1.05, 17 studies, 20 arms, 1695 participants, moderate quality of evidence. Use of cocaine: RR 0.92, 95% CI 0.84 to 1.02, nine studies, 11 arms, 867 participants, moderate quality of evidence; side effects: RR 1.39, 95% CI 1.01 to 1.90, eight studies, 775 participants; craving: standardised mean difference (SMD) -0.25, 95% CI -0.59 to 0.09, seven studies, eight arms, 428 participants, low quality of evidence.

AUTHORS' CONCLUSIONS

Although caution is needed when results from a limited number of small clinical trials are assessed, no current evidence supports the clinical use of anticonvulsant medications in the treatment of patients with cocaine dependence. Although the findings of new trials will improve the quality of study results, especially in relation to specific medications, anticonvulsants as a category cannot be considered first-, second- or third-line treatment for cocaine dependence.

Psychosocial interventions for pregnant women in outpatient illicit drug treatment programs compared to other interventions

BACKGROUND

Illicit drug use in pregnancy is a complex social and public health problem. The consequences of drug use in pregnancy are high for both the woman and her child. Therefore, it is important to develop and evaluate effective treatments. There is evidence for the effectiveness of psychosocial interventions in drug treatment but it is unclear whether they are effective in pregnant women. This is an update of a Cochrane review originally published in 2007.

OBJECTIVES

To evaluate the effectiveness of psychosocial interventions in pregnant women enrolled in illicit drug treatment programmes on birth and neonatal outcomes, on attendance and retention in treatment, as well as on maternal and neonatal drug abstinence. In short, do psychosocial interventions translate into less illicit drug use, greater abstinence, better birth outcomes, or greater clinic attendance?

SEARCH METHODS

We conducted the original literature search in May 2006 and performed the search update up to January 2015. For both review stages (original and update), we searched the Cochrane Drugs and Alcohol Group Trial's register (May 2006 and January 2015); the Cochrane Central Register of Trials (CENTRAL; the Cochrane Library 2015, Issue 1); PubMed (1996 to January 2015); EMBASE (1996 to January 2015); and CINAHL (1982 to January 2015).

SELECTION CRITERIA

We included randomized controlled trials comparing any psychosocial intervention vs. a control intervention that could include pharmacological treatment, such as methadone maintenance, a different psychosocial intervention, counselling, prenatal care, STD counselling and testing, transportation, or childcare.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration. We performed analyses based on three comparisons: any psychosocial intervention vs. control, contingency management (CM) interventions vs. control, and motivational interviewing based (MIB) interventions vs.

MAIN RESULTS

In total, we included 14 studies with 1298 participants: nine studies (704 participants) compared CM vs. control, and five studies (594 participants) compared MIB interventions vs.

CONTROL

We did not find any studies that assessed other types of psychosocial interventions. For the most part, it was unclear if included studies adequately controlled for biases within their studies as such information was not often reported. We assessed risk of bias in the included studies relating to participant selection, allocation concealment, personnel and outcome assessor blinding, and attrition.The included trials rarely captured maternal and neonatal outcomes. For studies that did measure such outcomes, no difference was observed in pre-term birth rates (RR 0.71, 95% confidence interval (CI) 0.34 to 1.51; three trials, 264 participants, moderate quality evidence), maternal toxicity at delivery (RR 1.18, 95% CI 0.52 to 2.65; two trials, 217 participants, moderate quality evidence), or low birth weight (RR 0.72, 95% CI 0.36 to 1.43; one trial, 160 participants, moderate quality evidence). However, the results did show that neonates remained in hospital for fewer days after delivery in CM intervention groups (RR -1.27, 95% CI -2.52 to -0.03; two trials, 103 participants, moderate quality evidence). There were no differences observed at the end of studies in retention or abstinence (as assessed by positive drug test at the end of treatment) in any psychosocial intervention group compared to control (Retention: RR 0.99, 95% CI 0.93 to 1.06, nine trials, 743 participants, low quality evidence; and Abstinence: RR 1.14, 95% CI 0.75 to 1.73, three trials, 367 participants, low quality evidence). These results held for both CM and MIB combined. Overall, the quality of the evidence was low to moderate.

AUTHORS' CONCLUSIONS

The present evidence suggests that there is no difference in treatment outcomes to address drug use in pregnant women with use of psychosocial interventions, when taken in the presence of other comprehensive care options. However, few studies evaluated obstetrical or neonatal outcomes and rarely did so in a systematic way, making it difficult to assess the effect of psychosocial interventions on these clinically important outcomes. It is important to develop a better evidence base to evaluate psychosocial modalities of treatment in this important population.

Effects of oral and intravenous administration of buspirone on food-cocaine choice in socially housed male cynomolgus monkeys

Drugs acting at D3 dopamine receptors have been suggested as medications for cocaine dependence. These experiments examined the effects of intravenously and orally administered buspirone, a D2-like receptor antagonist with high affinity for D3 and D4 receptors, on the relative reinforcing strength of cocaine in group-housed male cynomolgus monkeys. Use of socially housed monkeys permitted the assessment of whether social status, known to influence D2-like receptor availability, modulates the behavioral effects of buspirone. Buspirone was administered acutely to monkeys self-administering cocaine under a food-drug choice procedure in which a cocaine self-administration dose-effect curve was determined daily. When administered by either route, buspirone significantly decreased cocaine choice in dominant-ranked monkeys. In subordinate monkeys, however, i.v. buspirone was ineffective on average, and oral buspirone increased choice of lower cocaine doses. The effects of buspirone only differed according to route of administration in subordinate monkeys. Moreover, it is noteworthy that the effects of buspirone were similar to those of the D3 receptor-selective antagonist PG01037 and qualitatively different than those of less selective drugs that act at D2-like or serotonin (5-HT)1A receptors, suggesting a D3 and possibly D4 receptor mechanism of action for buspirone. Taken together, the data support the utility of drugs targeting D3/D4 receptors as potential treatments for cocaine addiction, particularly in combination with enriching environmental manipulations.

Factors associated with willingness to participate in a pharmacologic addiction treatment clinical trial among people who use drugs

BACKGROUND AND OBJECTIVES

Although new medications are needed to address the harms of drug addiction, rates of willingness to participate in addiction treatment trials among people who use drugs (PWUD), have not been well characterized.

METHODS

One thousand twenty PWUD enrolled in two community-recruited cohorts in Vancouver, Canada, were asked whether they would be willing to participate in a pharmacologic addiction treatment trial. Logistic regression was used to identify factors independently associated with a willingness to participate.

RESULTS

Among the 1,020 PWUD surveyed between June 1, 2013 and November 30, 2013, 58.3% indicated a willingness to participate. In multivariate analysis, factors independently associated with a willingness to participate in a pharmacologic addiction treatment trial included: daily heroin injection (Adjusted Odds Ratio [AOR] = 1.75; 95% Confidence Interval [CI]: 1.13 - 2.72); daily crack smoking (AOR = 1.81; 95% CI: 1.23 - 2.66); sex work involvement (AOR = 2.22; 95% CI: 1.21 - 4.06); HIV seropositivity (AOR = 1.49; 95% CI: 1.15 - 1.94); and methadone maintenance therapy participation (AOR = 1.77; 95% CI: 1.37-2.30).

DISCUSSION AND CONCLUSIONS

High rates of willingness to participate in a pharmacologic addiction treatment trial were observed in this setting. Importantly, high-risk drug and sexual activities were positively associated with a willingness to participate, which may suggest a desire for new treatment interventions among PWUD engaged in high-risk behavior.

SCIENTIFIC SIGNIFICANCE

These results highlight the viability of studies seeking to enroll representative samples of PWUD engaged in high-risk drug use.

Sex differences in guanfacine effects on drug craving and stress arousal in cocaine-dependent individuals

Currently, no FDA-approved medication exists for the treatment of cocaine use disorder. Furthermore, as women become increasingly more at risk for the consequences of cocaine addiction, the need to establish better-tailored treatment medications is paramount. We examine the effects of the alpha2 adrenergic agonist, guanfacine HCl, on responses to stress and drug cue in a group of cocaine-dependent men and women who also abuse alcohol and nicotine. Forty early abstinent treatment-seeking cocaine-dependent males and females were randomly assigned to receive either daily placebo (12 M/7 F) or guanfacine (2 or 3 mg) (15 M/6 F) for 3 weeks. In week 4, they participated in a laboratory experiment and were exposed to three 10-min guided imagery conditions (stress/stress, cue/cue, and stress/cue), one per day, consecutively in a random, counterbalanced order. Craving, negative emotion, anxiety, and cardiovascular function were assessed at baseline, immediately following imagery exposure, and at various recovery time points. Guanfacine significantly attenuated cocaine craving, alcohol craving, anxiety, and negative emotion following exposure to all three imagery conditions in females, but not males. Guanfacine did, however, reduce sympathetic tone as well as stress and cue-induced nicotine craving and systolic blood pressure (SBP) in both males and females. These findings highlight sex-specific effects of guanfacine on drug craving, anxiety, and negative mood with significant effects in women and not men. The findings suggest further evaluation of guanfacine in the treatment of cocaine use disorder with a specific focus on sex differences in treatment response.

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.

Pharmacological strategies for detoxification

Detoxification refers to the safe discontinuation from a substance of dependence and is distinct from relapse prevention. Detoxification usually takes between a few days and a few weeks to complete, depending on the substance being misused, the severity of dependence and the support available to the user. Psychosocial therapies alongside pharmacological treatments are essential to improve outcome. The dependencies considered in this overview are detoxification from opioids (with methadone, buprenorphine, α2-adrenoceptor agonists and adjunct medications), alcohol (with benzodiazepines, anti-glutamatergics and γ-aminobutyric acid (GABA)-ergic drugs), stimulants and cannabis (with no clear recommended pharmacological treatments), benzodiazepines (with dose tapering) and nicotine (with nicotine replacement therapy, antidepressants and partial agonists). Evidence is limited by a lack of controlled trials robust enough for review bodies, and more research is required into optimal treatment doses and regimes, alone and in combination.

Pharmacotherapeutics for substance-use disorders: a focus on dopaminergic medications

INTRODUCTION

Illicit substance-use is a substantial public health concern, contributing over $150 billion in costs annually to Americans. A complex disease, a substance-use disorder affects neural circuits involved in reinforcement, motivation, learning and memory, and inhibitory control.

AREAS COVERED

The modulatory influence of dopamine in mesocorticolimbic circuits contributes to encoding the primary reinforcing effects of substances and numerous studies suggest that aberrant signaling within these circuits contributes to the development of a substance-use disorder in some individuals. Decades of research focused on the clinical development of medications that directly target dopamine receptors has led to recent studies of agonist-like dopaminergic treatments for stimulant-use disorders and, more recently, cannabis-use disorder. Human studies evaluating the efficacy of dopaminergic agonist-like medications to reduce reinforcing effects and substance-use provide some insight into the design of future pharmacotherapy trials. A search of PubMed using specific brain regions, medications, and/or the terms 'dopamine', 'cognition', 'reinforcement', 'cocaine', 'methamphetamine', 'amphetamine', 'cannabis', 'treatment/pharmacotherapy', 'addiction/abuse/dependence' identified articles relevant to this review.

EXPERT OPINION

Conceptualization of substance-use disorders and their treatment continues to evolve. Current efforts increasingly focus on a strategy fostering combination pharmacotherapies that target multiple neurotransmitter systems.

Imaging addiction: D2 receptors and dopamine signaling in the striatum as biomarkers for impulsivity

Dependence to drugs of abuse is closely associated with impulsivity, or the propensity to choose a lower, but immediate, reward over a delayed, but more valuable outcome. Here, we review clinical and preclinical studies showing that striatal dopamine signaling and D2 receptor levels - which have been shown to be decreased in addiction - directly impact impulsivity, which is itself predictive of drug self-administration. Based on these studies, we propose that the alterations in D2 receptor binding and dopamine release seen in imaging studies of addiction constitute neurobiological markers of impulsivity. Recent studies in animals also show that higher striatal dopamine signaling at the D2 receptor is associated with a greater willingness to expend effort to reach goals, and we propose that this same relationship applies to humans, particularly with respect to recovery from addiction. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

Substance-specific environmental influences on drug use and drug preference in animals and humans

Epidemiological, clinical, and preclinical evidence indicate that the setting of drug use can exert a powerful modulatory influence on drug reward and that this influence is substance-specific. When heroin and cocaine co-abusers, for example, report on the circumstances of drug use, they indicate distinct settings for the two drugs: heroin being used preferentially at home and cocaine being used preferentially outside the home. Similar results were obtained in laboratory rats. These findings will be interpreted in the light of a novel model of drug reward, based on the emotional appraisal of central and peripheral drug effects as a function of environmental context. I argue here that drug addiction research has not paid sufficient attention to the substance-specific aspects of drug abuse and this may have contributed to the present dearth of effective treatments. Pharmacological and cognitive-behavioral therapy, for example, should be tailored so as to allow the addict to anticipate, and cope with, the risks associated, in a substance-specific manner, to the different settings of drug use.

The neurocircuitry of illicit psychostimulant addiction: acute and chronic effects in humans

Illicit psychostimulant addiction remains a significant problem worldwide, despite decades of research into the neural underpinnings and various treatment approaches. The purpose of this review is to provide a succinct overview of the neurocircuitry involved in drug addiction, as well as the acute and chronic effects of cocaine and amphetamines within this circuitry in humans. Investigational pharmacological treatments for illicit psychostimulant addiction are also reviewed. Our current knowledge base clearly demonstrates that illicit psychostimulants produce lasting adaptive neural and behavioral changes that contribute to the progression and maintenance of addiction. However, attempts at generating pharmacological treatments for psychostimulant addiction have historically focused on intervening at the level of the acute effects of these drugs. The lack of approved pharmacological treatments for psychostimulant addiction highlights the need for new treatment strategies, especially those that prevent or ameliorate the adaptive neural, cognitive, and behavioral changes caused by chronic use of this class of illicit drugs.

Pharmacogenetic randomized trial for cocaine abuse: disulfiram and dopamine β-hydroxylase

BACKGROUND

Disulfiram has been an effective cocaine addiction pharmacotherapy, and one of its possible mechanisms of efficacy is through copper chelation and inhibition of an enzyme involved in catecholamine metabolism, dopamine β-hydroxylase (DβH), which converts dopamine to norepinephrine. A variant in the gene encoding DβH leads to reduced DβH activity, and as such, disulfiram might not be an effective treatment of cocaine dependence for individuals with this variant. This study explored that potential matching.

METHODS

Seventy-four cocaine- and opioid-codependent (DSM-V) subjects were stabilized on methadone for 2 weeks and subsequently randomized into disulfiram (250 mg/day, n = 34) and placebo groups (n = 40) for 10 weeks. We genotyped the DBH gene polymorphism, -1021C/T (rs1611115), that reduces DβH enzyme levels and evaluated its role for increasing cocaine free urines with disulfiram.

RESULTS

With repeated measures analysis of variance, corrected for population structure, disulfiram pharmacotherapy reduced cocaine-positive urines from 80% to 62% (p = .0001), and this disulfiram efficacy differed by DBH genotype group. Patients with the normal DβH level genotype dropped from 84% to 56% on disulfiram (p = .0001), whereas those with the low DBH level genotype showed no disulfiram effect.

CONCLUSIONS

This study indicates that the DBH genotype of a patient could be used to identify a subset of individuals for which disulfiram treatment might be an effective pharmacotherapy for cocaine dependence.

Kappa-opioid receptor signaling in the striatum as a potential modulator of dopamine transmission in cocaine dependence

Cocaine addiction is accompanied by a decrease in striatal dopamine signaling, measured as a decrease in dopamine D2 receptor binding as well as blunted dopamine release in the striatum. These alterations in dopamine transmission have clinical relevance, and have been shown to correlate with cocaine-seeking behavior and response to treatment for cocaine dependence. However, the mechanisms contributing to the hypodopaminergic state in cocaine addiction remain unknown. Here we review the positron emission tomography (PET) imaging studies showing alterations in D2 receptor binding potential and dopamine transmission in cocaine abusers and their significance in cocaine-seeking behavior. Based on animal and human studies, we propose that the kappa receptor/dynorphin system, because of its impact on dopamine transmission and upregulation following cocaine exposure, could contribute to the hypodopaminergic state reported in cocaine addiction, and could thus be a relevant target for treatment development.

The neurocircuitry of illicit psychostimulant addiction: acute and chronic effects in humans

Illicit psychostimulant addiction remains a significant problem worldwide, despite decades of research into the neural underpinnings and various treatment approaches. The purpose of this review is to provide a succinct overview of the neurocircuitry involved in drug addiction, as well as the acute and chronic effects of cocaine and amphetamines within this circuitry in humans. Investigational pharmacological treatments for illicit psychostimulant addiction are also reviewed. Our current knowledge base clearly demonstrates that illicit psychostimulants produce lasting adaptive neural and behavioral changes that contribute to the progression and maintenance of addiction. However, attempts at generating pharmacological treatments for psychostimulant addiction have historically focused on intervening at the level of the acute effects of these drugs. The lack of approved pharmacological treatments for psychostimulant addiction highlights the need for new treatment strategies, especially those that prevent or ameliorate the adaptive neural, cognitive, and behavioral changes caused by chronic use of this class of illicit drugs.

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.