A Comparison of Pergolide and Bromocriptine in the Initial Rehabilitation of Cocaine Dependence

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.

Dopamine agonists for the treatment of cocaine dependence

BACKGROUND

Cocaine dependence is a disorder for which no pharmacological treatment of proven efficacy exists, advances in the 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 cocaine abuse and dependence

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Group (CDAG) Specialized Register, PubMed, EMBASE and CINAHL, PsycINFO in June 2011 and researchers for unpublished trials

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data

MAIN RESULTS

Twenty three studies, 2066 participants, met the inclusion criteria. Comparing any dopamine agonist versus placebo, placebo performed better for severity of dependence, four studies, 232 participants, SMD 0.43 (95% CI 0.15 to 0.71), depression, five studies, 322 participants, SMD 0.42 (95% CI 0.19 to 0.65) and abstinent at follow up RR 0.57 (95% CI 0.35 to 0.93). No statistically significant different for the other outcomes considered. Comparing amantadine versus placebo, results never gain the statistical significance, but there is a trend in favour of amantadine for dropouts and depression. Results on adverse events and depression, were in favour of placebo although the difference do not reach the statistical significance. Comparing bromocriptine and Ldopa/Carbidopa versus placebo, results never reached statistical significance. Comparing amantadine versus antidepressants, antidepressants performed better for abstinence. The other two outcomes considered did not show statistically significant differences although dropouts and adverse events tended to be more common in the antidepressant group.The quality of evidence, assessed according to GRADE method, may be judged as moderate for the efficacy of any dopamine agonist versus placebo and as moderate to high for amantadine versus placebo and versus antidepressants.

AUTHORS' CONCLUSIONS

Current evidence from randomised controlled trials does not support the use of dopamine agonists for treating cocaine dependence. 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 updated review.

WITHDRAWN: Dopamine agonists for cocaine dependence

BACKGROUND

Cocaine dependence is a common and serious condition, which has become a substantial public health problem. There is a wide and well documented range of consequences associated to chronic use of cocaine, such as medical, psychological and social problems.. Therapeutic management of the cocaine addicts includes an initial period of abstinence from the drug. During this phase the subjects may experience, besides the intense craving for cocaine, symptoms such as depression, fatigue, irritability, anorexia, and sleep disturbances. It was demonstrated that the acute use of cocaine may enhance dopamine transmission and chronically it decreases dopamine concentrations in the brain. Pharmacological treatment that affects dopamine could theoretically reduce these symptoms and contribute to a more successful therapeutic approach.

OBJECTIVES

To evaluate the efficacy and acceptability of dopamine agonists for treating cocaine dependence.

SEARCH STRATEGY

Electronic searches of Cochrane Library, EMBASE, MEDLINE, PsycLIT, Biological Abstracts and LILACS; reference searching; personal communication; conference abstracts; unpublished trials from pharmaceutical industry; book chapters on treatment of cocaine dependence, was performed for the primary version of this review in 2001. Another search of the electronic databases was done in December of 2002 for this update. The specialised register of trials of the Cochrane Group on Drugs and Alcohol was searched until February 2003.

SELECTION CRITERIA

The inclusion criteria for all randomised controlled trials were that they should focus on the use of dopamine agonists on the treatment of cocaine dependence.

DATA COLLECTION AND ANALYSIS

The reviewers extracted the data independently and Relative Risks, weighted mean difference and number needed to treat were estimated. The reviewers assumed that people who died or dropped out had no improvement and tested the sensitivity of the final results to this assumption.

MAIN RESULTS

Seventeen studies were included, with 1224 participants randomised. Amantadine, bromocriptine, and pergolide were the drugs evaluated. The main outcomes evaluated were positive urine sample for cocaine metabolites, for efficacy, and retention in treatment, as an acceptability measure. There were no significant differences between interventions, and in trials where participants had primary cocaine dependence or had additional diagnosis of opioid dependence and/or were in methadone maintenance treatment.

AUTHORS' CONCLUSIONS

Current evidence does not support the clinical use of dopamine agonists in the treatment of cocaine dependence. Given the high rate of dropouts in this population, clinicians may consider adding other supportive measures aiming to keep patients in treatment.

An open-label trial of N-acetylcysteine for the treatment of cocaine dependence: a pilot study

Recent preclinical studies implicate N-acetylcysteine (NAC), a cysteine prodrug, as a potential medication for preventing relapse to cocaine use; however, little is known about the safety and tolerability of NAC in cocaine-dependent subjects in an outpatient setting. This pilot study examines the safety and tolerability of 3 doses of NAC for the treatment of cocaine dependence. Twenty three treatment-seeking cocaine-dependent patients participated in a 4-week medication trial and received NAC at doses of 1200 mg/day, 2400 mg/day or 3600 mg/day. Results suggested that the three doses were well tolerated. Overall, the retention rates appeared to favor higher doses of NAC (2400 mg/day and 3600 mg/day). The majority of subjects who completed the study (n=16) either terminated use of cocaine completely or significantly reduced their use of cocaine during treatment. Overall the findings suggest that it is feasible to treat cocaine-dependent treatment seekers with N-acetylcysteine on an outpatient basis.

Reversal of cocaine-induced behavioral sensitization and associated phosphorylation of the NR2B and GluR1 subunits of the NMDA and AMPA receptors

Cocaine abusers remain vulnerable to drug craving and relapse for many years after abstinence is achieved. We have recently shown that ondansetron (a 5-HT3 receptor antagonist) given 3.5 h after each daily cocaine injection reverses previously established behavioral sensitization. The purpose of the present investigation was two-fold. First, as cocaine cannot be used as therapy, we examined whether pergolide (a D1/D2 receptor agonist with reduced abuse potential) and ondansetron could reverse behavioral sensitization. Second, we investigated whether these behavioral changes were associated with parallel alterations in expression levels and/or phosphorylation changes in the NR2B and GluR1 subunits of the respective NMDA and AMPA receptors. Rats were injected for 5 consecutive days with cocaine or saline followed by 9 days of withdrawal. Starting on withdrawal day 10, animals were given vehicle, pergolide/saline, or pergolide/ondansetron for 5 consecutive days. Following a second 9-day period of withdrawal, all animals were challenged with cocaine for assessment of behavioral sensitization and tissues were collected on the following day for Western blot. Sensitization was associated with increased NR2B expression in the accumbens (NAc) shell and decreased Tyr1472 phosphorylation in the NAc core, as well as increased Ser845 phosphorylation of the GluR1 subunit in prefrontal cortex, NAc core, and shell. Pergolide/ondansetron treatment, but not pergolide alone, consistently reversed both the behavioral sensitization and the associated changes in the NMDA and AMPA receptor subunits. To the extent that sensitization plays a role in chronic cocaine abuse, a combination of these clinically available drugs may be useful in treatment of the disorder.

Use of dopamine agonist pergolide in outpatient treatment of cocaine dependence

The dopamine agonist pergolide was evaluated in the treatment of 42 men who manifested cocaine dependence in a single-blind, 4-week-long placebo-controlled study, during 1998-1999 in São Paulo, Brazil. The patients were randomly assigned to two groups: the first group received pergolide (0.05-0.2 mg per day) and the second group received placebo (one to four tablets per day). Urine toxicology screens were obtained. The groups were compared in terms of depressive symptoms, "craving," use of cocaine, side effects of medications, results of urine tests, and retention in treatment. At 3 months' follow-up, the participants were reassessed. No differences were found between the two groups.

Dopamine agonists for cocaine dependence

BACKGROUND

Cocaine dependence is a common and serious condition, which has become nowadays a substantial public health problem. There is a wide and well documented range of consequences associated to chronic use of this drug, such as medical, psychological and social problems, including the spread of infectious diseases (e.g. AIDS, hepatitis and tuberculosis), crime, violence and neonatal drug exposure. Therapeutic management of the cocaine addicts includes an initial period of abstinence from the drug. During this phase the subjects may experience, besides the intense craving for cocaine, symptoms such as depression, fatigue, irritability, anorexia, and sleep disturbances. It was demonstrated that the acute use of cocaine may enhance dopamine transmission and chronically it decreases dopamine concentrations in the brain. Pharmacological treatment that affects dopamine could theoretically reduce these symptoms and contribute to a more successful therapeutic approach.

OBJECTIVES

To evaluate the efficacy and acceptability of dopamine agonists for treating cocaine dependence.

SEARCH STRATEGY

Electronic searches of Cochrane Library, EMBASE, MEDLINE, PsycLIT, Biological Abstracts and LILACS; reference searching; personal communication; conference abstracts; unpublished trials from pharmaceutical industry; book chapters on treatment of cocaine dependence, was performed for the primary version of this review in 2001. Another search of the electronic databases was done in December of 2002 for this update. The specialised register of trials of the Cochrane Group on Drugs and Alcohol was searched until February 2003.

SELECTION CRITERIA

The inclusion criteria for all randomised controlled trials were that they should focus on the use of dopamine agonists on the treatment of cocaine dependence.

DATA COLLECTION AND ANALYSIS

The reviewers extracted the data independently and Relative Risks, weighted mean difference and number needed to treat were estimated. The reviewers assumed that people who died or dropped out had no improvement and tested the sensitivity of the final results to this assumption.

MAIN RESULTS

Seventeen studies were included, with 1224 participants randomised. Amantadine, bromocriptine, and pergolide were the drugs evaluated. The main outcomes evaluated were positive urine sample for cocaine metabolites, for efficacy, and retention in treatment, as an acceptability measure. There were no significant differences between interventions, and in trials where participants had primary cocaine dependence or had additional diagnosis of opioid dependence and/or were in methadone maintenance treatment.

REVIEWER'S CONCLUSIONS

Current evidence does not support the clinical use of dopamine agonists in the treatment of cocaine dependence. Given the high rate of dropouts in this population, clinicians may consider adding other supportive measures aiming to keep patients in treatment.

Utilização do agonista dopaminérgico pergolida no tratamento da "fissura" por cocaína

OBJETIVOS: O estudo avaliou a eficácia e a segurança terapêutica do agonista dopaminérgico pergolida no tratamento ambulatorial da ''fissura" por cocaína. MÉTODOS: Participaram de estudo controlado simples-cego, com duração de quatro semanas, em tratamento ambulatorial, 42 pacientes do sexo masculino com idade entre 18 e 50 anos, com diagnóstico de dependência de cocaína pelo DSM-IV e primeiro grau completo. Transtornos clínicos e/ou psiquiátricos que necessitassem de internação, uso de medicação psiquiátrica, quadros psicóticos prévios independentes do consumo de cocaína e hipersensibilidade à pergolida foram critérios de exclusão. Os pacientes foram divididos aleatoriamente em dois grupos: o primeiro recebeu pergolida (0,05-0,2 mg ao dia), e o segundo, placebo (1 a 4 comprimidos ao dia). Os grupos foram comparados quanto à ''fissura'' por cocaína e aos efeitos colaterais das medicações. RESULTADOS: Não foram encontradas diferenças estatisticamente significativas entre os dois grupos em relação à incidência de efeitos colaterais ou ao relato da redução da ''fissura'' por cocaína. CONCLUSÃO: A amostra pequena e o uso de medicação por tempo curto podem ter influído nos resultados. A pergolida se mostrou segura, com poucos efeitos colaterais. A pergolida não se mostrou superior ao placebo no tratamento da "fissura" por cocaína.

Adverse outcomes in a controlled trial of pergolide for cocaine dependence

We conducted a double-blind, multiple dose comparison study of pergolide versus placebo for the treatment of cocaine dependence. In the present study, we examined patients who met criteria for cocaine dependence without comorbid alcohol dependence (N = 255). Study completion rates favored placebo (48.9%) over the low dose (33.3%) and high dose (21.5%) pergolide subjects (chi2(2) = 14.17, p < or = 0.001). Treatment effectiveness scores (TES) were significantly higher for the placebo group (31.7) than the low dose (25.2) and high dose (14.2) pergolide groups (F2,252 = 6.21, p = 0.002). There were no significant differences in side effect profiles after first dose of pergolide or placebo, or at study termination. Results of this study suggest that pergolide was not efficacious in the treatment of cocaine dependence due to reduced study participation. Caution regarding the outpatient use of pergolide in similar populations is warranted.

A double-blind, placebo-controlled outpatient trial of pergolide for cocaine dependence

Results of preclinical studies suggest that pergolide, a mixed D(1)/D(2) dopamine receptor agonist, may be useful in treating cocaine dependence. To empirically investigate this possibility, we conducted a 5-year, double-blind, placebo-controlled clinical trial of two doses of pergolide (0.05 and 0.25 mg bid) in subjects with cocaine dependence and combined cocaine/alcohol dependence. Data analysis was performed on an intent to treat population (N=358) and a per protocol population (N=108) with urine drug screens (UDS) used as the main outcome measure. There were no significant effects on UDS at either pergolide dose. Pergolide had no significant effect on alcohol use in the comorbid alcohol/cocaine dependence group. Pergolide does not appear to have clinical value in the treatment of cocaine dependence or in decreasing alcohol use in cocaine-dependent individuals at the presently studied doses.