Carbamazepine treatment of cocaine dependence: a placebo-controlled trial

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.

Measuring Outcome in the Treatment of Cocaine Dependence

BACKGROUND

Little in known about the extent to which outcome measures used in studies of the treatment of cocaine dependence are associated with longer-term use and with broader measures of clinical improvement. The current study examined reductions in use, and abstinence-oriented measures, in relation to functioning and longer-term clinical benefits in the treatment of cocaine dependence.

METHODS

Overall drug use, cocaine use, and functioning in a number of addiction-related domains for 487 patients diagnosed with DSM-IV cocaine dependence and treated with one of four psychosocial interventions in the NIDA Cocaine Collaborative Treatment Study were assessed monthly during 6 months of treatment and at 9, 12, 15, and 18 month follow-up.

RESULTS

Measures of during-treatment reduction in use were moderately correlated with drug and cocaine use measures 12 months, but showed non-significant or small correlations with measures of functioning at 12 months. Highest correlations were evident for abstinence measures (maximum consecutive days abstinence and completely abstinent) during treatment in relation to sustained (3 month) abstinence at 12 months. Latent class analysis of patterns of change over time revealed that most patients initially (months 1 to 4 of treatment) either became abstinent immediately or continued to use every month. Over the couse of follow-up, patients either maintained abstinence or used regularly - intermittent use was less common.

CONCLUSIONS

There were generally small associations between various measures of cocaine use and longer-term clinical benefits, other than abstinence was associated with continued abstinence. No one method of measuring outcome of treatment of cocaine dependence appears superior to others.

Mood stabilizers in the treatment of substance use disorders

Individuals suffering from drug addiction may also manifest features of bipolar spectrum disorders. Hyperthymic and cyclothymic temperaments may render individuals vulnerable to later development of substance abuse. Bipolar disorders themselves may be altered or precipitated by substance use, most notably by stimulants (amphetamines), alcohol, and cannabinoids. The clinical usefulness of mood stabilizers, particularly antiepileptics, has been established as safe and effective in substance abusers with and without comorbid mood disorders. Most studies on this issue have been of short duration and focused on the resolution of a currently manifest period of illness. Few studies have been conducted on the usefulness of these drugs on the long-term longitudinal course of these diseases, such as frequently encountered recurrent relapses into states of agitation, impulsivity, and/or dissatisfaction. As opposed to the clinical experience with traditional antidepressants and neuroleptics, antiepileptics do not induce counter-polar states (depressed patients abruptly turning manic or hypomanic; nor patients currently hypomanic or manic turning abruptly depressed). Many clinicians consider antiepileptic mood stabilizers to be the preferred category of medications for the treatment of such patients. Valproate appears to be a potentially fruitful medication to study in these dual diagnosis patients due to preliminary evidence demonstrating its anticraving efficacy.

WITHDRAWN: Carbamazepine for cocaine dependence

BACKGROUND

Cocaine dependence has become a public health problem, developing a significant number of medical, psychological and social problems. Although there is no consensus regarding how to treat cocaine dependence, effective pharmacotherapy has a potentially major role to play as part of a broader treatment milieu. The anti-convulsant carbamazepine, a tricyclic medication that is widely used to treat a variety of neurological and psychiatric disorders, has been used for treatment of cocaine dependence, although its effectiveness has not been established.

OBJECTIVES

To determine whether carbamazepine is effective for the treatment of cocaine dependence.

SEARCH STRATEGY

We searched: Cochrane Controlled Trials Register (Cochrane Library issue 1, 1999), MEDLINE (f1966 - October 1997), EMBASE (1980 - October 1997), PsycLIT (1974 - July 1997), Biological Abstracts and LILACS (1982 - 1997); scan of reference list of relevant articles; personal communication; conference abstracts; unpublished trials from pharmaceutical industry; book chapters on treatment of cocaine dependence. The specialised register of trials of Cochrane Group on Drugs and Alcohol until February 2003.

SELECTION CRITERIA

All randomised controlled trials focused on the use of carbamazepine versus placebo on the treatment of cocaine dependence. Trials including patients with additional diagnosis such as opiate dependence were also eligible.

DATA COLLECTION AND ANALYSIS

The reviewers extracted the data independently, Odds Ratios, weighted mean difference and number needed to treat were estimated. Qualitative assessments of the methodology of eligible studies were carried out using validated checklists. The reviewers assumed that people who died or dropped out had no improvement and tested the sensitivity of the final results to this assumption. Where possible analysis was carried out according to the "intention to treat" principles.

MAIN RESULTS

5 studies were included (455 participants). No differences regarding positive urine sample for cocaine metabolites. Scores on Spielberg State Anxiety Inventory slightly favoured carbamazepine, but not statistical significance. Dropouts were high in both groups, less dropout occurred in the carbamazepine group (RR 0.87 95%CI 0.71-1.06). When no retention in treatment was due to side effects no differences were found. The number of participants presenting at least one side effect, was higher in the carbamazepine group (RR 4.33 95% CI 1.45-12.91).

AUTHORS' CONCLUSIONS

There is no current evidence supporting the clinical use of Carbamazepine in the treatment of cocaine dependence. Larger randomised investigation must be considered taking into account that these time-consuming efforts should be reserved for medications showing more relevant and promising evidence.

Meta-analysis of depression and substance use and impairment among cocaine users

BACKGROUND

The study evaluated, among cocaine users, the hypothesized positive association of depression and concurrent cocaine use and impairment, alcohol use and impairment, and general drug use and impairment. The hypothesis that gender would moderate these associations, with women showing a stronger correlation between depression and measures of substance use and impairment, was also tested. Also examined was the association of depression with future cocaine use and impairment and substance use treatment participation.

METHODS

Empirical reports on adult cocaine users published in English in peer-reviewed journals since 1986 that contained data on depression and substance use outcome(s) were obtained using a systematic search. Studies that placed restrictions on range of depression scores to select the sample, experiments that administered cocaine to subjects, and trials of antidepressant medications were excluded. The search yielded 60 studies for the analysis including 53 reports that collected data from clinical venues and seven that were community-based.

RESULTS

As hypothesized, the analyses showed that depression is associated with concurrent cocaine-, alcohol-, and general drug use and impairment. Effect sizes were small. Hypothesized moderating effects of gender were not supported. Depression was not associated, at a statistically significant level, with treatment participation or future cocaine use and impairment.

CONCLUSIONS

Depression is consistently but modestly associated with measures of cocaine-, alcohol-, and general drug use and impairment among cocaine users. Associations of depression with treatment participation and with future cocaine use and impairment are not immediately evident, although limitations of data warrant cautious interpretation.

Anticonvulsants for cocaine dependence

BACKGROUND

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

OBJECTIVES

To evaluate the efficacy and the acceptability of anticonvulsants for cocaine dependence

SEARCH STRATEGY

We searched the Cochrane Drugs and Alcohol Groups specialised register (issue 4, 2007), MEDLINE (1966 - march 2007), EMBASE (1988 - march 2007), CINAHL (1982- to march 2007)

SELECTION CRITERIA

All randomised controlled trials and controlled clinical trials which focus on the use of anticonvulsants medication for cocaine dependence

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated the papers, extracted data, rated methodological quality

MAIN RESULTS

Fifteen studies (1066 participants) met the inclusion criteria for this review: the anticonvulsants drugs studied were carbamazepine, gabapentin, lamotrigine, phenytoin, tiagabine, topiramate, valproate. No significant differences were found for any of the efficacy measures comparing any anticonvulsants with placebo. Placebo was found to be superior to gabapentin in diminishing the number of dropouts, two studies, 81 participants, Relative Risk (RR) 3.56 (95% CI 1.07 to 11.82) and superior to phenythoin for side effects, two studies, 56 participants RR 2.12 (95% CI 1.08 to 4.17). All the other single comparisons are not statistically significant.

AUTHORS' CONCLUSIONS

Although caution is needed when assessing results from a limited number of small clinical trials at present there is no current evidence supporting the clinical use of anticonvulsants medications in the treatment of cocaine dependence. Aiming to answer the urgent demand of clinicians, patients, families, and the community as a whole for an adequate treatment for cocaine dependence, we need to improve the primary research in the field of addictions in order to make the best possible use out of a single study and to investigate the efficacy of other pharmacological agent.

Update: new uses for lithium and anticonvulsants

Anticonvulsants are being used clinically as monotherapy and adjuncts in mental illnesses other than affective disorders. This review focuses on the literature for anticonvulsants and lithium in substance use disorders, anxiety disorders, and schizophrenia. Given the abuse potential and other difficulties with prescribing benzodiazepines for alcohol and benzodiazepine withdrawal, anticonvulsants have been considered as an alternative. Promising therapeutic effects have been demonstrated in many of the anxiety disorders, with the greatest number of trials and positive results in posttraumatic stress disorder. Although anticonvulsant and lithium augmentation for schizophrenia is common in practice and has been studied in double-blind, randomized, controlled trials, the sum of the evidence has been inconclusive.

Zonisamide decreases ethanol intake in rats and mice

Several anticonvulsant agents, including topiramate and valproate, have been found to reduce alcohol consumption in rodent models of drinking. The question of whether the novel anticonvulsant agent, zonisamide, shares similar actions in either mice or rats was investigated in the present experiments. In an initial experiment, the consumption of a 10% ethanol-5% sucrose solution, available for one hour, by Wistar rats treated with lactose, topiramate, or zonisamide was determined. In a second experiment, the intake of a 10% ethanol/water solution, accessible for two hours, by C57BL/B6N mice treated with either zonisamide or vehicle was assessed. In the rat, 50 mg/kg (PO) doses of either topiramate or zonisamide produced significant, but moderate decreases in ethanol/sucrose intake. The administration of a 50 mg/kg (IP) dose of zonisamide to mice resulted in a marked lowering in ethanol consumption. These results provide evidence that zonisamide administration will decrease ethanol consumption by both mice and rats in limited access models of drinking, and might, like topiramate, be useful as a medication for alcoholism.

An overview of medications for the treatment of alcohol withdrawal and alcohol dependence with an emphasis on the use of older and newer anticonvulsants

There is a growing interest in the development of new pharmacological tools for treating alcohol withdrawal and dependence. A number of anticonvulsants including valproate and carbamazepine have been shown to be safe and effective alternatives to benzodiazepines for treating alcohol withdrawal. These agents are relatively safe, are free from demonstrated abuse liability, and do not usually potentiate the psychomotor and cognitive effects of alcohol. For the treatment of alcohol dependence, there is a growing literature on the utility of medications that have neurochemical effects at opioid, serotonergic, GABAergic, and glutamate receptors. Furthermore, as a class of medication, there appears to be a growing interest in investigating the utility of novel anticonvulsants such as topiramate for the treatment of alcohol dependence.

Development of novel pharmacotherapies for the treatment of alcohol dependence: focus on antiepileptics

This article represents the proceedings of a symposium, "Development of Novel Pharmacotherapies for the Treatment of Alcohol Dependence: Focus on Antiepileptics," presented at the 2003 annual meeting of the Research Society on Alcoholism in Fort Lauderdale, FL. The organizers and cochairs were Bankole A. Johnson and Robert M. Swift. The presentations were (1) Development of topiramate in the treatment of alcoholism, by Bankole A. Johnson; (2) Craving as a predictor of treatment outcome in pharmacotherapy trials for the treatment of alcoholism, by Nassima Ait-Daoud; (3) Use of biomarkers as a predictor of treatment response in treating alcoholism, by Martin A. Javors; (4) Psychotherapy to enhance compliance with pharmacotherapy in treatment trials for alcohol dependence, by Carlo C. DiClemente; (5) Synopsis of promising medications to treat alcoholism, by Robert M. Swift; and (6) New knowledge on the development of antiepileptic medications for the treatment of alcoholism, by Robert J. Malcolm, Jr.

Pharmacological treatment of cocaine dependence: a systematic review

AIMS

Cocaine dependence is a common and serious condition, associated with severe medical, psychological and social problems, including the spread of infectious diseases. This systematic review assesses critically the efficacy of pharmacotherapy for treating cocaine dependence.

METHODS

The literature search strategy included: electronic searches of Cochrane Library holdings, EMBASE, MEDLINE, PsycLIT, Biological Abstracts and LILACS; scans of reference lists of relevant articles, personal communications, conference abstracts, unpublished trials from the pharmaceutical industry and book chapters on the treatment of cocaine dependence. Randomized controlled trials (RCTs) focusing on the use of antidepressants (ADs), carbamazepine (CBZ), dopamine agonists (DAs) and other drugs used in the treatment of cocaine dependence were included. The reviewers extracted data independently, and relative risks (RR) with 95% confidence interval (CI) were estimated. Qualitative assessments were carried out using a Cochrane validated checklist. Where possible, analysis was carried out according to 'intention-to-treat' principles.

FINDINGS

The search strategy generated 45 different trials. Most studied drugs were ADs (20 studies), DAs and CBZ. Data were very heterogeneous, with dropout rates within the studies between 0 and 84%. A non-significant trend favoring CBZ was found in terms of dropouts (RR 0.88; 95% CI 0.75-1.03) and results from one trial suggest that fluoxetine patients are less likely to drop out. The main efficacy outcome reported in the studies was the presence of cocaine metabolites in the urine. No significant results were found, regardless the type of drug or dose used for all relevant outcomes assessed.

CONCLUSIONS

There is no current evidence supporting the clinical use of CBZ, antidepressants, dopamine agonists, disulfiram, mazindol, phenytoin, nimodipine, lithium and NeuRecover-SA in the treatment of cocaine dependence. Larger randomized investigation must be considered, while taking into account that these time-consuming efforts should be reserved for medications showing more relevant and promising evidence. Given the high dropout rate among the test population, clinicians may wish to consider adding psychotherapeutic supportive measures aimed at keeping patients in treatment programs.

The effects of carbamazepine and lorazepam on single versus multiple previous alcohol withdrawals in an outpatient randomized trial

OBJECTIVE

Benzodiazepines are the mainstay of treatment for mild-to-moderate alcohol withdrawal in outpatient settings, but they can interact with alcohol, cause motor incoordination, or be abused. This study compared the therapeutic responses of the benzodiazepine lorazepam and the anticonvulsant carbamazepine for the outpatient treatment of acute alcohol withdrawal in terms of patients' previous detoxification histories, and compared the effects of these 2 medications on drinking behaviors in the immediate postdetoxification period.

DESIGN

This was a randomized double-blind trial comparing patient responses to carbamazepine and lorazepam across 2 levels of detoxification histories (0-1 or >or=2 previous medicated detoxifications).

SETTING

A university medical center substance abuse clinic in Charleston, SC.

PATIENTS

One hundred thirty-six patients in moderate alcohol withdrawal were randomized. Major exclusions were significant hepatic or hematologic abnormalities and use of medications that could alter withdrawal symptoms.

INTERVENTIONS

Patients received 600-800 mg of carbamazepine or 6-8 mg of lorazepam in divided doses on day 1 tapering to 200 mg of carbamazepine or 2 mg of lorazepam.

MAIN OUTCOME MEASURES

The Clinical Institute Withdrawal Assessment for Alcohol-Revised was used to assess alcohol withdrawal symptoms on days 1 through 5 and postmedication at days 7 and 12. Daily drinking was measured by patient report using a daily drinking log and a breath alcohol level with each visit. Side effects were recorded daily.

RESULTS

Carbamazepine and lorazepam were equally effective at decreasing the symptoms of alcohol withdrawal. In the post-treatment period, 89 patients drank on at least 1 day; on average, carbamazepine patients drank less than 1 drink per drinking day and lorazepam patients drank almost 3 drinks per drinking day (P =.003). Among those with multiple past detoxifications, the carbamazepine group drank less than 1 drink per day on average and the lorazepam group drank about 5 drinks per day on average (P =.033). Lorazepam-treated patients had a significant rebound of alcohol withdrawal symptoms post-treatment (P =.007) and the risk of having a first drink was 3 times greater (P =.04) than for carbamazepine-treated patients. Twenty percent of lorazepam-treated patients had dizziness, motor incoordination, or ataxia and did not recognize their impairment. Twenty percent of carbamazepine-treated patients reported pruritus but no rash.

CONCLUSIONS

Carbamazepine and lorazepam were both effective in decreasing the symptoms of alcohol withdrawal in relatively healthy, middle-aged outpatients. Carbamazepine, however, was superior to lorazepam in preventing rebound withdrawal symptoms and reducing post-treatment drinking, especially for those with a history of multiple treated withdrawals.

Carbamazepine for cocaine dependence

BACKGROUND

Cocaine dependence has become a substantial public health problem, developing a significant number of medical, psychological and social problems, including the spread of infectious diseases (e.g. AIDS, hepatitis and tuberculosis), crime, violence and neonatal drug exposure. Although there is no consensus regarding how to treat cocaine dependence, effective pharmacotherapy has a potentially major role to play as part of a broader treatment milieu. The anti-convulsant carbamazepine, a tricyclic medication that is widely used to treat a variety of neurological and psychiatric disorders, has also been used for treatment of cocaine dependence, although its effectiveness has not been established.

OBJECTIVES

To determine whether carbamazepine (CBZ) is effective for the treatment of cocaine dependence.

SEARCH STRATEGY

We searched: the Cochrane Controlled Trials Register (Cochrane Library issue 1, 1999), MEDLINE (from 1966 - October 1997), EMBASE (from 1980 - October 1997), PsycLIT (from 1974 - July 1997), Biological Abstracts and LILACS (from 1982 - 1997); scan of reference list of relevant articles; personal communication; conference abstracts; unpublished trials from pharmaceutical industry; book chapters on treatment of cocaine dependence.

SELECTION CRITERIA

The inclusion criteria for all randomised controlled trials were that they should focus on the use of carbamazepine drugs versus placebo on the treatment of cocaine dependence. Trials including patients with additional diagnosis such as opiate dependence were also eligible.

DATA COLLECTION AND ANALYSIS

The reviewers extracted the data independently and Odds Ratios, weighted mean difference and number needed to treat were estimated. Qualitative assessments of the methodology of eligible studies were carried out using validated checklists. The reviewers assumed that people who died or dropped out had no improvement and tested the sensitivity of the final results to this assumption. Where possible analysis was carried out according to the "intention to treat" principles.

MAIN RESULTS

5 studies were included in the review, with 455 people randomised. No differences were found regarding positive urine sample for cocaine metabolites. Scores on Spielberg State Anxiety Inventory slightly favoured carbamazepine, but didn't reach statistical significance. Dropouts were high in both groups up to 70% in the placebo group. Less dropout occurred in the carbamazepine group (RR 0.87 95%CI 0.71-1.06). When no retention in treatment was due to side effects no differences were found. The number of participants presenting at least one side effect, reported in Kranzler (Kranzler 1995), was higher in the carbamazepine group (RR 4.33 95% CI 1.45-12.91).

REVIEWER'S CONCLUSIONS

There is no current evidence supporting the clinical use of CBZ in the treatment of cocaine dependence. Larger randomised investigation must be considered taking into account that these time-consuming efforts should be reserved for medications showing more relevant and promising evidence.

Alcohol and substance abuse

Substance abuse and dependence is a public health problem with far-reaching societal implications. The acute toxicity of substances of abuse and medical consequences of chronic use are substantial. On a more optimistic note, a great deal of progress has been made in understanding and treating substance use disorders. Expanding knowledge concerning the neurobiology of substances of abuse and substance use disorders has led to a growth in pharmacotherapeutic treatment options. A growth in understanding of behavioral processes, motivational issues, and processes of behavioral change has been important in designing new and increasingly more effective psychosocial treatments. A growing body of evidence indicates that the treatment of substance use disorders can be effective, making early diagnosis and treatment or referral increasingly important.

A pilot, open clinical study of depakote in the treatment of cocaine abuse

The effectiveness of increasing levels of valproic acid on cocaine abstinence was evaluated in an open-label trial of 55 subjects. Significantly lower percentages of individuals with valproate serum levels above 50 mcg/ml reported cocaine use and had less positive urinalyses as compared to those with serum levels less than 50 mcg/ml. The total number of days of cocaine use decreased significantly (p < 0.001) and improved levels of subject functioning were found with increasing serum levels of valproic acid. This pilot study offers confirmation that the divalproex sodium form of valproic acid, when used in sufficient serum levels, may provide an effective pharmacologic adjunct in the management and treatment of cocaine dependency. Copyright 2001 John Wiley & Sons, Ltd.

Pharmacotherapies for cocaine dependence

This article reviews the history of pharmacologic trials for the treatment of cocaine dependence as well as current treatments under investigation. The rationale for use of agents such as dopaminergic agents, antidepressants, and anticonvulsants is discussed. Early clinical trials with pharmacologic agents have demonstrated both positive and negative results; the possible reasons for these mixed outcomes is also discussed. Recent studies focusing on disulfiram, dopamine-selective antagonists, citicoline, aspirin, and a cocaine-specific vaccine are presented to highlight innovative and potentially effective treatments for individuals with cocaine dependence.

Improving the quality of substance dependency treatment with pharmacotherapy

This article provides an overview of current pharmacological treatments for alcohol, opioid, cocaine, and nicotine use disorders. Guidelines for a "patient-treatment" matching framework to physicians working with various "substance-abusing" patients are presented, as well as recommendations regarding when to initiate and discontinue pharmacotherapy. Standard and newer pharmacological treatments for substance dependence are reviewed, as well as therapies that may be especially useful when treating the patient with comorbid substance dependency and psychiatric disorders. To maximize the therapeutic benefits of substance dependency treatment, patients should be individually assessed and provided adjunctive medications as clinically indicated. Specific areas for future laboratory and/or clinical research are recommended.

Neurobiological adaptations to psychostimulants and opiates as a basis of treatment development

Abuse of illicit substances, in particular psychostimulants and opiates, is a worldwide public health issue. Chronic use of cocaine and amphetamine causes common neurobiological adaptations that may guide new treatment development. These include perturbations in dopamine and serotonin neurotransmission, leading to trials of antidepressants, and serotonin and dopamine augmentation strategies. The detection of cerebral perfusion abnormalities caused by psychostimulants has led to examination of antiplatelet and excitatory amino acid (EAA) antagonist therapies. Further, development of cocaine vaccines allows for testing of peripheral blockade approaches to cocaine addiction. New approaches to behavioral treatments for cocaine dependence are also reviewed. For opiate dependence, understanding of heroin's effects on mu and kappa opiate receptors has led to investigations of the partial mu agonist buprenorphine in opiate maintenance. Evidence for hyper-excitability of locus coeruleus (LC) noradrenergic neurons and EEA inputs to the LC guides trials of new alpha 2-adrenergic agonists and EEA antagonists to alleviate opiate withdrawal. Finally, clinical experience with withdrawal from methadone and LAAM has led to trials of antagonist-accelerated opiate withdrawal. Improved treatment of psychostimulant and opiate addiction is critically needed, and likely to have wide-reaching impact in health care and society.

GABA modulation of cocaine self-administration

Recent experiments suggest that GABA compounds produce a clinically relevant modulation of cocaine reinforcement. This review summarizes the results of a number of studies that examined the effect of the GABAB agonist baclofen on cocaine self-administration using a variety of schedules of reinforcement. The results demonstrate that baclofen causes a dramatic reduction in cocaine self-administration which does not appear to be accounted for by a general disruption of behavior. However, the effect is dependent on the unit injection dose of cocaine and on the response requirements of the schedule. These results predict that in a clinical setting any potential therapeutic effect of baclofen will interact with the cost and availability of cocaine.

Effects of lamotrigine on behavioral and cardiovascular responses to cocaine in human subjects

We evaluated the effects of acute pretreatment with lamotrigine, a putative glutamate release inhibitor, on the physiological and behavioral responses to intranasal cocaine in cocaine-dependent volunteers (N = 8). The study employed a double-blind, placebo-controlled, within-subject design. Subjects participated in six experimental sessions. On each study day, placebo, lamotrigine 125 mg, or lamotrigine 250 mg was administered orally in the morning, followed 2 hours later by intranasal cocaine 120 mg/70 kg or placebo. Measurements of heart rate and blood pressure were acquired, and subjects responded to mood state questionnaires at predetermined time intervals. Cocaine alone produced increases in heart rate, blood pressure, and several measures of pleasurable mood and drug effects. Lamotrigine alone produced a mild relaxing effect. Lamotrigine pretreatment altered neither the physiological responses nor the subjective ratings of cocaine's pleasurable or aversive mood effects.

Neuropsychologic findings in cocaine-dependent outpatients

1. Nineteen recently abstinent cocaine-dependent males were compared to 16 control subjects on a battery of neuropsychological tests. 2. The performance of cocaine-dependent subjects was inferior to the control group on tasks assessing higher level verbal skills, and on a task requiring logical sequencing of complex visual stimuli. 3. Cocaine users also performed poorly on a delayed visual memory task and on a verbal generation task, but performed better than the control group on a task assessing simple visual-motor speed. 4. Possible reasons for these findings are discussed, as are the treatment implications of these findings.

Effects of naltrexone on cue-elicited craving for alcohol and cocaine

This study examined the effects of naltrexone (50 mg/day) on mood and self-reported desire for alcohol and cocaine in 26 patients with comorbid alcohol and cocaine abuse/dependence. Two laboratory sessions were conducted, separated by 1 week. During the sessions, subjects viewed 5-min films containing either cocaine, alcohol, or neutral cues. The first session occurred prior to random assignment to medication group and the second session was held after 1 week of double-blind treatment with either naltrexone or placebo. The cocaine-related film induced a greater desire to use cocaine than the desire for alcohol that was induced by the alcohol-related film. This finding was observed using both a simple, one-item analog scale administered during the films and more complex craving questionnaires administered immediately after the films. Collectively, the alcohol and cocaine-related films evoked greater levels of self-reported anxiety and elation, and lower levels of concentration, than the neutral film. Naltrexone did not differ from placebo in reducing the desire to use either cocaine or alcohol.

Pharmacotherapy for opioid and cocaine abuse

The need for continued development of medications to address opioid and cocaine addiction is unequivocal. Methadone maintenance, despite its limitations, remains the best-established pharmacologic treatment for opioid dependence. Continued participation in methadone programs is associated with decreased risk of acquiring HIV infection. Clonidine alone or combined with naltrexone may be used for opioid detoxification in the office practice. At the present time, no proven pharmacologic therapy for cocaine addiction exists.

A randomized double-blind study of carbamazepine in the treatment of cocaine abuse

A 12-week, randomized, double-blind, placebo-controlled, fixed-dose outpatient study of carbamazepine (400 mg and 800 mg) in the treatment of cocaine dependence was performed. Data were analyzed with respect to both treatment condition and carbamazepine serum levels. Outcome variables included subject retention, cocaine urinalysis, self-reported cocaine use, cocaine craving, patient and clinical global impressions, the Drug Impairment Rating Scale for Cocaine, and side effects. Compared with placebo, the 400 mg treatment condition exhibited a greater decrease in the rate of positive cocaine urinalyses and a reduction in intensity and duration of craving over the course of the study. Higher serum carbamazepine levels were associated with a lower rate of positive cocaine urinalysis, fewer days of self-reported cocaine use, briefer craving episodes, and greater subject interval retention. The clinical and methodologic implications of these findings and of the study design are discussed.

Psychostimulant abuse: the case for combined behavioral and pharmacological treatments

Behavioral and pharmacological therapies have been used alone and in combination for the treatment of substance abuse; however, to date, no single treatment approach for psychostimulant abuse has demonstrated widespread efficacy. This paper describes the various functions that are served by both behavioral therapies and pharmacotherapies and their respective mechanisms of action. It is argued that combined treatments can be expected to produce additive effects because the two approaches operate through different and potentially complementary mechanisms. Illustrations of these underlying principles and experimental support for the use of combined treatments are drawn from smoking cessation research, which has broadly applied combined behavioral and pharmacological therapies for treating abuse of nicotine, a mild stimulant. In addition, the results of recent studies that have evaluated the efficacy of behavioral techniques and/or potential pharmacotherapies for treating cocaine abuse are reviewed. Finally, methodological strategies are recommended for future evaluations of combined therapy approaches to conclusively evaluate separate and combined efficacy of treatments for psychostimulant abuse.

Assessment of medication compliance in alcoholics through UV light detection of a riboflavin tracer

Compliance with the medication regimen in treatment trials for alcoholism appears to be a key determinant of treatment outcome. However, there is no consensus as to the best method to assess medication compliance. This study examines the feasibility of using ultraviolet light detection of a urinary riboflavin tracer to determine compliance with medication therapy. Six sets of urine specimens (with n ranging from 15 to 38) were rated independently by two judges. Test-retest reliability was high: 90 and 95% agreement for two judges. Inter-rater reliability ranged from 73 to 95% agreement between judges (mean = 88%), with correspondence kappa values ranging from 0.46 to 0.85 (mean = 0.69). Diaries, capsule counts, and spectrofluorimetric data were used to validate judges' ratings in four trials, including one in which subjects were alcohol-dependent participants in one of three pharmacotherapy trials. Rating accuracy was influenced by dosage, time interval between ingestion and urine collection, and previous dosing. Overall, ratings tended to be accurate, with incorrect judgments limited to specimens with low concentrations of urinary riboflavin. The results indicate that ultraviolet light detection of urinary riboflavin is a useful method for the assessment of patient compliance with medication regimens, including compliance of patients assigned to receive placebo in clinical trials of medications for alcoholism treatment.

Phenytoin in the treatment of cocaine abuse: a double-blind study

OBJECTIVES

To evaluate the effectiveness of phenytoin in the treatment of cocaine abuse.

SUBJECTS AND METHODS

A 12-week, double-blind, placebo-controlled outpatient study of phenytoin in the treatment of cocaine abuse was conducted. Sixty cocaine-using subjects were randomly assigned to a daily fixed dose of 300 mg phenytoin or placebo. Forty-four subjects initiated treatment and returned for weekly visits. Primary measures of outcome included weekly quantitative and qualitative cocaine urinalysis, self-reported cocaine use, global functioning and improvement, craving intensity, and subject retention.

RESULTS

Cocaine use, as measured both by weekly urinalysis and self-report, was significantly lower in the phenytoin group. The phenytoin group was also rated as significantly less impaired and more improved than the placebo group. Craving intensity was lower in the phenytoin group, but the difference was not statistically significant. Among phenytoin subjects, serum phenytoin levels above 6.0 micrograms/ml were associated with lower rates of positive cocaine urine specimens and longer cocaine-free periods. No differences were observed between groups in study retention.

CONCLUSIONS

These findings suggest that phenytoin may be useful in the treatment of cocaine abuse. Further studies are needed to replicate these findings.

Carbamazepine and cocaine-cue reactivity

Subjective and electroencephalographic reactions to cocaine cues were evaluated in 33 cocaine-dependent out-patients and 17 non-cocaine-dependent controls. Subjective, EEG, and autonomic reactions to three 5-min videos (cocaine-associated, erotic, neutral) were evaluated twice with an interpolated 1-week interval. Between evaluations, cocaine-dependent patients received carbamazepine 400 mg daily or matching placebo in double-blind fashion. In all three groups the cocaine-associated and erotic videos produced a comparable increase in the self-rated desire for cocaine and reduction in total EG power. Carbamazepine treatment increased EEG fast alpha power and self-rated fatigue, and decreased self-rated concentration and vigor. However, it had no specific effect on subjective or physiological reactivity to either the cocaine-associated or erotic videos. This negative finding is consistent with recent clinical trials of carbamazepine for cocaine dependence.