Cocaine Addiction Treatments to improve Control and reduce Harm (CATCH): new pharmacological treatment options for crack-cocaine dependence in the Netherlands

Análise Crítica Sobre Medicamentos Prescritos para o Uso Problemático de Crack

Resumo Estudo de abordagem descritiva, exploratória e retrospectiva que analisou prontuários de pacientes em tratamento pelo uso problemático de crack. Foram levantadas as prescrições, as interações medicamentosas e o perfil sociodemográfico destes pacientes. Foram feitas revisões de literaturas narrativas para verificar quais medicamentos apresentam maiores potenciais terapêuticos e para caracterizar o perfil dos usuários; dados dos prontuários e da literatura foram triangulados. Os resultados sugerem que os medicamentos utilizados no tratamento do uso problemático de crack são limitados, os medicamentos utilizados na prática não possuem evidências de eficácia, há interações relevantes nas prescrições e o perfil sociodemográfico desses usuários é semelhante com a literatura. Estudos adicionais são desejáveis para buscar um tratamento medicamentoso eficaz para o uso problemático de crack.

Longitudinal patterns of cocaine use among patients receiving injectable hydromorphone or diacetylmorphine for the treatment of opioid use disorder: A growth curve modeling approach

BACKGROUND AND AIMS

Cocaine use is prevalent among people receiving injectable opioid agonist treatment. Investigations of cocaine use in this population have been descriptive and the potential heterogeneity existing in patterns of use have not been characterized. As such, among patients receiving injectable opioid agonist treatment, this study aimed to: 1) quantify intra- and inter-individual variation in cocaine use over 24-months and; 2) determine how predictors of interest explained this variation.

METHODS

Participants were patients receiving injectable opioid agonist treatment for opioid use disorder. Study visits were completed at baseline prior to receiving treatment, and 3,6,9,12,18, and 24 months after baseline. A multi-level regression approach to growth curve modeling was employed to estimate and explain intra- (within-person) and inter-individual (between-person) variation in cocaine use.

RESULTS

Significant intra and inter-individual variation in cocaine use was identified over 24-months. Treatment engagement was on average associated with reductions in the prior month number of days of cocaine use (range: 0-30)(Estimate (standard error): -0.05(0.02), p = 0.003). On average, men reported less cocaine use compared to women (Estimate (standard error): -5.91(1.57), p=<0.001), and participants reporting ever regularly using cocaine at baseline reported more cocaine use over 24-months compared to participants reporting never regularly using cocaine (Estimate (standard error): 4.72 (1.91), p = 0.013).

CONCLUSIONS

Significant reductions in cocaine use were observed and significant heterogeneity in patterns of cocaine use was identified. These heterogeneous cocaine use profiles suggest that an individualized approach to care will be critical in responding to patients' cocaine use in injectable opioid agonist treatment.

Clinical Trials for Stimulant Use Disorders: Addressing Heterogeneities That May Undermine Treatment Outcomes

In recent years, use of cocaine and amphetamines and deaths associated with stimulants have been on the rise, and there are still no FDA-approved medications for stimulant use disorders. One contributing factor may involve heterogeneity. At the neurobiological level, dual dopamine dysfunction may be undermining medication efficacy, suggesting a need for combination pharmacotherapies. At the population level, individual variability is expressed in a number of ways and, if left unaddressed, may interfere with medication efficacy. This chapter reviews studies investigating medications to address dopamine dysfunction, and it also identifies several prominent heterogeneities associated with stimulant (and other substance) use disorders. The chapter has implications for improving interventions to treat stimulant use disorders, and the theme of individual heterogeneity may have broader application across substance use disorders.

Critical remarks on strategies aiming to reduce drug related harm: substance misuse and HIV/AIDS in a world in turmoil

In the last decades, the initiatives implemented under the conceptual umbrella of Harm Reduction have gained momentum, with a vigor and scope (both from a geographic and social perspective) never seen before. A more balanced reevaluation could and should rather say such initiatives have resumed, to a large extent, ideas and actions launched much earlier, in the first decades of the 20th century. Notwithstanding, the dissemination of HIV/AIDS in recent years conferred an exceptional visibility and legitimacy to proposals formerly viewed as subsidiary or openly neglected. Nowadays, initiatives inspired by the Harm Reduction philosophy have faced an "identity crisis", not secondary (according to our perspective) to challenges faced by its concepts and operations, but rather as consequence of a world in a turmoil. Such fast-changing dynamics have reconfigured both drug scenes and the patterns and prospects of HIV/AIDS worldwide. This article briefly summarizes some of such recent, ongoing, changes, which have been deeply affecting both concepts and practices to the point of asking for a deep reformulation of most of the initiatives implemented so far.

Topiramate for cocaine dependence: a systematic review and meta-analysis of randomized controlled trials

AIMS

To assess the efficacy of topiramate in treating cocaine use disorder (i.e. retention, efficacy, safety and craving reduction) through a systematic review and meta-analysis.

METHODS

We searched six scientific databases from inception to 23 December 2014 with no date limits. Data were reviewed, extracted and analysed systematically. Studies were included if they were peer-reviewed randomized control trials with participants meeting diagnostic criteria for cocaine dependence or cocaine use disorder, with the treatment arm involving topiramate with or without psychosocial intervention, and the control arm involving no intervention or psychosocial intervention with or without placebo. A random-effects meta-analytical model was computed.

RESULTS

Five studies met inclusion criteria (n = 518). Topiramate was compared with placebo (four studies) and no medication (one study). In a meta-analysis, we observed no significant differences between topiramate and placebo in improving treatment retention risk ratio (RR) = 0.85; 95% confidence interval (CI) = 0.60-1.22, P = 0.38. However, compared with a placebo, use of topiramate was associated with increased continuous abstinence in two of five studies (RR = 2.43; 95% CI = 1.31-4.53, P = 0.005). No differences were observed in frequency of adverse effects reported between topiramate and placebo (RR = 1.06; 95% CI = 0.91-1.23, P = 0.48). Topiramate was associated significantly (P < 0.05) with a reduction in craving in only one of five studies.

CONCLUSIONS

Evidence does not currently support the use of topiramate to improve treatment retention for cocaine use disorder, although it may extend cocaine abstinence with a similar risk of adverse events compared with placebo.

Sustained-release dexamfetamine in the treatment of chronic cocaine-dependent patients on heroin-assisted treatment: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Heroin-assisted treatment is effective for methadone treatment-refractory heroin-dependent patients, but continued comorbid cocaine dependence remains problematic. Sustained-release dexamfetamine is a promising agonist pharmacotherapy for cocaine dependence and we aimed to assess its acceptance, efficacy, and safety.

METHODS

In this multicentre, randomised, double-blind, placebo-controlled trial, patients who were treatment-refractory, as indicated by at least two earlier failed treatments aimed at reducing or abstaining from cocaine use, and who regularly (≥8 days/month) used crack-cocaine were enrolled from four heroin-assisted treatment centres in the Netherlands. Eligible patients were randomly assigned (1:1) to receive either 12 weeks of daily, supervised prescription of 60 mg/day oral sustained-release dexamfetamine or placebo in addition to co-prescribed methadone and diacetylmorphine. Randomisation was done by the collaborating pharmacist, using a computer-generated random number sequence with stratification by treatment centre in blocks of four per stratum. Randomisation was masked to patients, staff, and researchers throughout the study. The primary outcome was the number of self-reported days of cocaine use during study treatment, assessed every 4 weeks. Primary and safety analyses were done in the intention-to-treat population. The study was registered with the European Union Drug Regulating Authorities Clinical Trials (EUdraCT 2013-004024-11) and with The Netherlands Trial Register (NTR2576).

FINDINGS

Between Aug 8, 2014, and Feb 27, 2015, 111 patients were assessed for eligibility, of whom 73 were enrolled and randomised; 38 patients were assigned to the sustained-release dexamfetamine group and 35 to the placebo group. Sustained-release dexamfetamine treatment resulted in significantly fewer days of cocaine use than placebo treatment (mean 44·9 days [SD 29·4] vs 60·6 days [24·3], respectively [95% CI of difference 3·1-28·4]; p=0·031; Cohen's standardised effect size d=0·58). One or more adverse events were reported by 28 (74%) patients in the dexamfetamine group and by 16 (46%) patients in the placebo group. Most adverse events were transient and well-tolerated.

INTERPRETATION

Sustained-release dexamfetamine is a well accepted, effective, and safe agonist pharmacotherapy for comorbid treatment-refractory cocaine dependence in heroin-dependent patients in heroin-assisted treatment. Future research should aim to replicate these findings in chronic cocaine-dependent and other stimulant-dependent patients in more routine treatment settings, including strategies to optimise treatment adherence like medication management interventions and contingency management.

FUNDING

Netherlands Organisation for Health Research and Development.

Modafinil in the treatment of crack-cocaine dependence in the Netherlands: Results of an open-label randomised controlled feasibility trial

BACKGROUND

Crack-cocaine dependence is a serious disorder with no approved pharmacological treatment. Modafinil is a promising medication with increased cocaine abstinence and reduced craving in some previous studies. In the present study, we examined the acceptance, safety and potential benefits of modafinil as an add-on treatment to cognitive behavioural therapy (CBT) in crack-cocaine dependent patients.

METHODS

Sixty-five crack-cocaine dependent outpatients participated in an open-label, randomised feasibility trial. Patients were randomised to receive either 12-week individual CBT plus 400 mg/day modafinil or 12-week individual CBT only. The primary outcome measure was CBT treatment retention. Secondary outcomes included modafinil adherence, tolerability and safety, use of cocaine and other substances, cocaine craving, health, social functioning and patient satisfaction.

RESULTS

Modafinil adherence was low, with only 10% treatment completers. Intent-to-treat analyses showed that modafinil did not improve CBT treatment retention or any of the secondary cocaine-related outcomes. Both groups showed similar, large reductions in cocaine use during the study treatment. Post hoc exploratory analyses within the CBT plus modafinil group showed significantly larger baseline to week 12 reductions in cocaine use days in high (⩾ 8 weeks) modafinil adherent patients.

CONCLUSIONS

Acceptance and benefits of modafinil were not demonstrated in the present study. Since reduction in cocaine use was observed in high modafinil adherent patients, further research in the treatment of cocaine dependence, in which modafinil adherence is optimised, is warranted.

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.

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.

Criminal involvement and crime specialization among crack users in the Netherlands

BACKGROUND/AIMS

Crack users in the Netherlands are an ageing and diverse population with longstanding criminal careers. Our aim was to assess factors associated with current criminal involvement and specialization in selling drugs, property crime and violence.

METHOD

A sample of 1,039 frequent crack users was recruited in three major Dutch cities, combining respondent-driven sampling with random institutional sampling. Bivariate and logistic regression analyses were performed to find factors associated with current criminality.

RESULTS

A total of 431 participants (41.5%) had engaged in crime in the past 30 days, mostly selling drugs (68.9%), followed by property crimes (34.4%) and a few cases of violent crime (9.7%). Younger age, homelessness, heavier patterns of use and a more prolific criminal justice history were associated with current criminality. Those receiving welfare benefits tended to be more likely to specialize only in selling drugs as opposed to (also) property crimes.

CONCLUSION

Reducing drug use among criminally involved crack users and addressing their housing conditions could have a significant impact on reducing drug-related crime. Welfare benefits might act as protective factor against committing property crimes but not against the selling of drugs.

Treatment of crack-cocaine dependence with topiramate: a randomized controlled feasibility trial in The Netherlands

BACKGROUND

Crack-cocaine dependence is a complex disorder with limited treatment options. Topiramate is one of the promising medications with reported reductions in cocaine use and craving in former studies. The present study evaluated the acceptance and effectiveness of topiramate as an add-on to cognitive behavioral therapy (CBT) in crack-cocaine dependent patients.

METHODS

Seventy-four crack-cocaine dependent outpatients participated in an open-label, randomized feasibility trial. They were randomized to receive either 12-week CBT plus topiramate (200mg/day) or 12-week CBT only. The primary outcome measure was treatment retention. Secondary outcomes included medication adherence, safety, cocaine and other substance use, health, social functioning, and patient satisfaction.

RESULTS

Adherence to topiramate treatment was low. In the intent-to-treat analyses, topiramate neither improved treatment retention nor reduced cocaine and other substance use. Post hoc, exploratory analyses suggested a moderation effect of comorbid opioid dependence, with a significant effect of topiramate on cocaine use reduction only in crack-cocaine dependent patients with comorbid opioid dependence.

CONCLUSIONS

Topiramate was safe and well-tolerated in this sample of crack-cocaine dependent patients, but efficacy was not supported probably due to low acceptance of the treatment. Given the equivocal results of previous studies and the negative findings in our study, the potential of topiramate in the treatment of cocaine dependence seems limited.

The effectiveness of treatments for cocaine dependence in schizophrenic patients: a systematic review

Objectives:

To evaluate and compare the effectiveness of available treatments for cocaine dependence in schizophrenic patients.

Method:

We searched articles published between May 2002 and June 2012 in the following databases: Scopus, Pubmed and Web of Knowledge. The key words utilised were “schizophrenia”, "dementia praecox", "schizophrenic disorder", "cocaine related disorder", "cocaine abuse", "cocaine addiction", "cocaine dependence", “treatment”, “therapeutic”, and "drug therapy”.

Selection of studies and data extraction:

Original articles in English, Portuguese and Spanish were selected. Controlled, double-blind and open-label studies involving only human subjects were included in this review.

Data Synthesis:

We found studies on typical and atypical antipsychotics and one monoamine transporter antagonist. There were few indications of the effectiveness of atypical antipsychotic medications for the treatment of cocaine dependence in patients with schizophrenia.

Conclusions:

We suggest that further studies be conducted with atypical antipsychotic medicationsand greater methodological strictness, including using a placebo group in the studies, so that health professionals can determine the real effectiveness of this class of medication for the treatment of cocaine dependence in schizophrenic patients.

Patterns, determinants and barriers of health and social service utilization among young urban crack users in Brazil

Background

Crack use is prevalent across the Americas, and specifically among marginalized urban street drug users in Brazil. Crack users commonly feature multiple physical and mental health problems, while low rates of and distinct barriers to help service use have been observed in these populations. This study examined profiles and determinants of social and health service utilization, and unmet service needs, in a two-city sample of young (18–24 years), marginalized crack users in Brazil.

Methods

N = 160 study participants were recruited by community-based methods from impoverished neighborhoods in the cities of Rio de Janeiro (n = 81) and Salvador (n = 79). A mixed methods protocol was used. Participants’ drug use, health, and social and health service utilization characteristics were assessed by an anonymous interviewer-administered questionnaire completed in a community setting; descriptive statistics on variables of interest were computed. Service needs and barriers were further assessed by way of several focus groups with the study population; narrative data were qualitatively analyzed. The study protocol was approved by institutional ethics review boards; data were collected between November 2010 and June 2011.

Results

The majority of the sample was male, without stable housing, and used other drugs (e.g., alcohol, marijuana). About half the sample reported physical and mental health problems, yet most had not received medical attention for these problems. Only small minorities had utilized locally available social or health services; utilization appeared to be influenced by sex, race and housing characteristics in both sites. Participants cited limited service resources, lack of needs-specific professional skills, bureaucratic barriers and stigma as obstacles to better service access. However, most respondents stated strong interest and need for general social, health and treatment services designed for the study population, for which various key features were emphasized as important.

Conclusions

The study contributes substantive evidence to current discussions about the development and utilization of health and treatment interventions for crack use in Brazil. Based on our data, crack users’ social, service needs are largely unmet; these gaps appear to partly root in systemic barriers of access to existing services, while improved targeted service offers for the target population seem to be needed also.

Role of nucleus accumbens glutamatergic plasticity in drug addiction

Substance dependence is characterized by a group of symptoms, according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR). These symptoms include tolerance, withdrawal, drug consumption for alleviating withdrawal, exaggerated consumption beyond original intention, failure to reduce drug consumption, expending a considerable amount of time obtaining or recovering from the substance's effects, disregard of basic aspects of life (for example, family), and maintenance of drug consumption, despite facing adverse consequences. The nucleus accumbens (NAc) is a brain structure located in the basal forebrain of vertebrates, and it has been the target of addictive drugs. Different neurotransmitter systems at the level of the NAc circuitry have been linked to the different problems of drug addiction, like compulsive use and relapse. The glutamate system has been linked mainly to relapse after drug-seeking extinction. The dopamine system has been linked mainly to compulsive drug use. The glutamate homeostasis hypothesis centers around the dynamics of synaptic and extrasynaptic levels of glutamate, and their impact on circuitry from the prefrontal cortex (PFC) to the NAc. After repetitive drug use, deregulation of this homeostasis increases the release of glutamate from the PFC to the NAc during drug relapse. Glial cells also play a fundamental role in this hypothesis; glial cells shape the interactions between the PFC and the NAc by means of altering glutamate levels in synaptic and extrasynaptic spaces. On the other hand, cocaine self-administration and withdrawal increases the surface expression of subunit glutamate receptor 1 (GluA1) of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors at the level of the NAc. Also, cocaine self-administration and withdrawal induce the formation of subunit glutamate receptor 2 (GluA2), lacking the Ca(2+)-permeable AMPA receptors (CP-AMPARs) at the level of the NAc. Antagonism of the CP-AMPARs reduces cravings. It is necessary to pursue further exploration of the AMPA receptor subunit composition and variations at the level of the NAc for a better understanding of glutamatergic plastic changes. It is known that cocaine and morphine are able to induce changes in dendritic spine morphology by modifying actin cycling. These changes include an initial increase in spine head diameter and increases in AMPA receptor expression, followed by a second stage of spine head diameter retraction and reduction of the AMPA receptors' expression in spines. Besides glutamate and dopamine, other factors, like brain-derived neurotrophic factor (BDNF), can influence NAc activity and induce changes in dendritic spine density. BDNF also induces drug-related behaviors like self-administration and relapse. Neither apoptosis nor neurogenesis plays a relevant role in the neurobiological processes subjacent to cocaine addiction in adults (rodent or human). Different therapeutic drugs like N-acetylcysteine (NAC), modafinil, acamprosate, and topiramate have been tested in preclinical and/or clinical models for alleviating drug relapse. Moreover, these therapeutic drugs target the glutamatergic circuitry between the PFC and the NAc. NAC and acamprosate have shown inconsistent results in clinical trials. Modafinil and topiramate have shown some success, but more clinical trials are necessary. Based on the current review findings, it could be recommendable to explore therapeutic approaches that include synergism between different drugs and neurotransmitter systems. The discrepancy in the results of some therapeutic drugs between preclinical versus clinical trials for alleviating relapse or drug dependence could be linked to the scarce exploration of preclinical models that mimic polydrug abuse patterns, for example, cocaine plus alcohol. At the clinical level, the pattern of polydrug consumption is a phenomenon of considerable frequency. Finally, as a complement at the end, an updated summary is included about the role of glutamate in other neuropsychiatric disorders (for example, mood disorders, schizophrenia, and others).