Kyle M. Kampman

A Double-Blind, Placebo-Controlled Trial of Modafinil for Cocaine Dependence

Despite years of active research, there are still no approved medications for the treatment of cocaine dependence. Modafinil is a glutamate-enhancing agent that blunts cocaine euphoria under controlled conditions, and the current study assessed whether modafinil would improve clinical outcome in cocaine-dependent patients receiving standardized psychosocial treatment. This was a randomized, double-blind, placebo-controlled trial conducted at a university outpatient center (from 2002 to 2003) on a consecutive sample of 62 (predominantly African American) cocaine-dependent patients (aged 25–63) free of significant medical and psychiatric conditions. After screening, eligible patients were randomized to a single morning dose of modafinil (400 mg), or matching placebo tablets, for 8 weeks while receiving manual-guided, twice-weekly cognitive behavioral therapy. The primary efficacy measure was cocaine abstinence based on urine benzoylecgonine levels. Secondary measures were craving, cocaine withdrawal, retention, and adverse events. Modafinil-treated patients provided significantly more BE-negative urine samples (p=0.03) over the 8-week trial when compared to placebos, and were more likely to achieve a protracted period (⩾3 weeks) of cocaine abstinence (p=0.05). There were no serious adverse events, and none of the patients failed to complete the study as a result of adverse events. This study provides preliminary evidence, which should be confirmed by a larger study, that modafinil improves clinical outcome when combined with psychosocial treatment for cocaine dependence.

Limbic Activation to Cigarette Smoking Cues Independent of Nicotine Withdrawal: A Perfusion fMRI Study

Exposure to cigarette smoking cues can trigger physiological arousal and desire to smoke. The brain substrates of smoking cue-induced craving (CIC) are beginning to be elucidated; however, it has been difficult to study this state independent of the potential contributions of pharmacological withdrawal from nicotine. Pharmacological withdrawal itself may have substantial effects on brain activation to cues, either by obscuring or enhancing it, and as CIC is not reduced by nicotine replacement strategies, its neuro-anatomical substrates may differ. Thus, characterizing CIC is critical for developing effective interventions. This study used arterial spin-labeled (ASL) perfusion fMRI, and newly developed and highly appetitive, explicit smoking stimuli, to examine neural activity to cigarette CIC in an original experimental design that strongly minimizes contributions from pharmacological withdrawal. Twenty-one smokers (12 females) completed smoking and nonsmoking cue fMRI sessions. Craving self-reports were collected before and after each session. SPM2 software was employed to analyze data. Blood flow (perfusion) in a priori-selected regions was greater during exposure to smoking stimuli compared to nonsmoking stimuli (p<0.01; corrected) in ventral striatum, amygdala, orbitofrontal cortex, hippocampus, medial thalamus, and left insula. Perfusion positively correlated with intensity of cigarette CIC in both the dorsolateral prefrontal cortex (r2=0.54) and posterior cingulate (r2=0.53). This pattern of activation that includes the ventral striatum, a critical reward substrate, and the interconnected amygdala, cingulate and OFC, is consistent with decades of animal research on the neural correlates of conditioned drug reward.

Reliability and validity of the cocaine selective severity assessment

This article assesses the reliability and validity of the Cocaine Selective Severity Assessment (CSSA), a measure of cocaine abstinence signs and symptoms. Interrater reliability and scale internal consistency were high. Initial CSSA scores were significantly higher in cocaine-dependent subjects than in alcohol-dependent subjects. Initial CSSA scores were highly correlated with recent cocaine use and with severity measures from the Addiction Severity Index (ASI) including the interviewer severity rating and composite score in the drug section. Among cocaine-dependent subjects, initial CSSA scores were higher for those who failed to achieve abstinence or who subsequently dropped out of treatment. Further, CSSA scores showed consistent and marked declines over time for subjects who continued in treatment and remained abstinent. The CSSA appears to be a reliable and valid measure of cocaine abstinence symptoms and a useful predictor of negative outcomes in cocaine dependence treatment.

Modafinil and cocaine: a double-blind, placebo-controlled drug interaction study

Modafinil is a novel compound that is approved for the treatment of narcolepsy. It is now being studied as a potential treatment for cocaine dependence. Cocaine withdrawal symptoms are associated with poor clinical outcome and are likely to be reversed by modafinil. In addition, the neurotransmitter actions of modafinil are opposite to cocaine-induced neuroadaptations affecting dopamine and glutamate reward circuits. Since cocaine-dependent subjects might use cocaine during a clinical trial with modafinil, this study tested the safety of intravenous cocaine (30 mg) in combination with modafinil. Each of seven subjects received a baseline (open-label) cocaine infusion. Three subsequent cocaine infusions were administered after subjects received 4 days of low dose modafinil (200 mg/day), high dose modafinil (400 mg/day), or placebo in randomized double-blind sequences. One subject received placebo prior to all infusions. Our results indicate that co-administering modafinil and a single dose of intravenous cocaine is not associated with medical risk in terms of blood pressure, pulse, temperature, or electrocardiogram measures. Furthermore, pretreatment with modafinil did not intensify cocaine euphoria or cocaine-induced craving. In fact, cocaine euphoria was significantly blunted (P=0.02) in one of our subjective measures.

A Double-Blind, Placebo-Controlled Trial Combining Sertraline and Naltrexone for Treating Co-Occurring Depression and Alcohol Dependence

OBJECTIVE Empirical evidence has only weakly supported antidepressant treatment for patients with co-occurring depression and alcohol dependence. While some studies have demonstrated that antidepressants reduce depressive symptoms in individuals with depression and alcohol dependence, most studies have not found antidepressant treatment helpful in reducing excessive drinking in these patients. The authors provide results from a double-blind, placebo-controlled trial that evaluated the efficacy of combining approved medications for depression (sertraline) and alcohol dependence (naltrexone) in treating patients with both disorders. METHOD A total of 170 depressed alcohol-dependent patients were randomly assigned to receive 14 weeks of treatment with sertraline (200 mg/day [N=40]), naltrexone (100 mg/day [N=49]), the combination of sertraline plus naltrexone (N=42), or double placebo (N=39) while receiving weekly cognitive-behavioral therapy. RESULTS The sertraline plus naltrexone combination produced a higher alcohol abstinence rate (53.7%) and demonstrated a longer delay before relapse to heavy drinking (median delay=98 days) than the naltrexone (abstinence rate: 21.3%; delay=29 days), sertraline (abstinence rate: 27.5%; delay=23 days), and placebo (abstinence rate: 23.1%; delay=26 days) groups. The number of patients in the medication combination group not depressed by the end of treatment (83.3%) approached significance when compared with patients in the other treatment groups. The serious adverse event rate was 25.9%, with fewer reported with the medication combination (11.9%) than the other treatments. CONCLUSIONS More depressed alcohol-dependent patients receiving the sertraline plus naltrexone combination achieved abstinence from alcohol, had delayed relapse to heavy drinking, reported fewer serious adverse events, and tended to not be depressed by the end of treatment.

Effectiveness of propranolol for cocaine dependence treatment may depend on cocaine withdrawal symptom severity

Propranolol may reduce symptoms of autonomic arousal associated with early cocaine abstinence and improve treatment outcome. This trial was an 8-week, double-blind, placebo-controlled trial of propranolol in 108 cocaine dependent subjects. The primary outcome measure was quantitative urinary benzoylecgonine levels. Secondary outcome measures included treatment retention, addiction severity index results, cocaine craving, mood and anxiety symptoms, cocaine withdrawal symptoms, and adverse events. Propranolol treated subjects had lower cocaine withdrawal symptom severity but otherwise did not differ from placebo treated subjects in any outcome measure. However, in a secondary, exploratory analysis, subjects with more severe cocaine withdrawal symptoms responded better to propranolol in comparison to placebo. In these subjects, propranolol treatment was associated with better treatment retention and lower urinary benzoylecgonine levels as compared with the placebo treatment. Propranolol may be useful only for the treatment of cocaine dependent patients with severe cocaine withdrawal symptoms.

Topiramate treatment for heavy drinkers: moderation by a GRIK1 polymorphism.

OBJECTIVE Topiramate has been shown to reduce drinking and heavy drinking in individuals with alcohol dependence whose goal was to stop drinking. The authors evaluated the efficacy and tolerability of topiramate in heavy drinkers whose treatment goal was to reduce drinking to safe levels. METHOD A total of 138 individuals (62.3% men) were randomly assigned to receive 12 weeks of treatment with topiramate (N=67), at a maximal daily dose of 200 mg, or matching placebo (N=71). Both groups received brief counseling to reduce drinking and increase abstinent days. It was hypothesized that topiramate-treated patients would be better able to achieve these goals, and it was predicted that based on prior research, the effects would be moderated by a single nucleotide polymorphism (rs2832407) in GRIK1, encoding the kainate GluK1 receptor subunit. RESULTS The rate of treatment completion was 84.9% and equal by treatment group. Topiramate treatment significantly reduced heavy drinking days and increased abstinent days relative to placebo. Patients receiving topiramate also had lower concentrations of the liver enzyme γ-glutamyl transpeptidase and lower scores on a measure of alcohol-related problems than the placebo group. In a European American subsample (N=122), topiramates effect on heavy drinking days was significantly greater than that for placebo only in rs2832407 C-allele homozygotes. CONCLUSIONS These findings support the use of topiramate at a daily dose of 200 mg to reduce heavy drinking in problem drinkers. The moderator effect of rs2832407, if validated, would facilitate the identification of heavy drinkers who are likely to respond well to topiramate treatment and provide an important personalized treatment option. The pharmacogenetic findings also implicate the kainate receptor in the mechanism of topiramates effects on heavy drinking.

Buprenorphine Implants for Treatment of Opioid Dependence: A Randomized Controlled Trial

CONTEXT Limitations of existing pharmacological treatments for opioid dependence include low adherence, medication diversion, and emergence of withdrawal symptoms. OBJECTIVE To determine the efficacy of buprenorphine implants that provide a low, steady level of buprenorphine over 6 months for the treatment of opioid dependence. DESIGN, SETTING, AND PARTICIPANTS A randomized, placebo-controlled, 6-month trial conducted at 18 sites in the United States between April 2007 and June 2008. One hundred sixty-three adults, aged 18 to 65 years, diagnosed with opioid dependence. One hundred eight were randomized to receive buprenorphine implants and 55 to receive placebo implants. INTERVENTION After induction with sublingual buprenorphine-naloxone tablets, patients received either 4 buprenorphine implants (80 mg per implant) or 4 placebo implants. A fifth implant was available if a threshold for rescue use of sublingual buprenorphine-naloxone treatment was exceeded. Standardized individual drug counseling was provided to all patients. MAIN OUTCOME MEASURE The percentage of urine samples negative for illicit opioids for weeks 1 through 16 and for weeks 17 through 24. RESULTS The buprenorphine implant group had significantly more urine samples negative for illicit opioids during weeks 1 through 16 (P = .04). Patients with buprenorphine implants had a mean percentage of urine samples that tested negative for illicit opioids across weeks 1 through 16 of 40.4% (95% confidence interval [CI], 34.2%-46.7%) and a median of 40.7%; whereas those in the placebo group had a mean of 28.3% (95% CI, 20.3%-36.3%) and a median of 20.8%. A total of 71 of 108 patients (65.7%) who received buprenorphine implants completed the study vs 17 of 55 (30.9%) who received placebo implants (P < .001). Those who received buprenorphine implants also had fewer clinician-rated (P <.001) and patient-rated (P = .004) withdrawal symptoms, had lower patient ratings of craving (P <.001), and experienced a greater change on clinician global ratings of severity of opioid dependence (P<.001) and on the clinician global ratings of improvement (P < .001) than those who received placebo implants. Minor implant site reactions were the most common adverse events: 61 patients (56.5%) in the buprenorphine group and 29 (52.7%) in the placebo group. CONCLUSION Among persons with opioid dependence, the use of buprenorphine implants compared with placebo resulted in less opioid use over 16 weeks as assessed by urine samples. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00447564.

DAT Genotype Modulates Brain and Behavioral Responses Elicited by Cigarette Cues

We previously demonstrated differential activation of the mesocorticolimbic reward circuitry in response to cigarette cues independent of withdrawal. Despite robust effects, we noted considerable individual variability in brain and subjective responses. As dopamine (DA) is critical for reward and its predictive signals, genetically driven variation in DA transmission may account for the observed differences. Evidence suggests that a variable number of tandem repeats (VNTRs) polymorphism in the DA transporter (DAT) SLC6A3 gene may influence DA transport. Brain and behavioral responses may be enhanced in probands carrying the 9-repeat allele. To test this hypothesis, perfusion fMR images were acquired during cue exposure in 19 smokers genotyped for the 40 bp VNTR polymorphism in the SLC6A3 gene. Contrasts between groups revealed that 9-repeat (9-repeats) had a greater response to smoking (vs nonsmoking) cues than smokers homozygous for the 10-repeat allele (10/10-repeats) bilaterally in the interconnected ventral striatal/pallidal/orbitofrontal cortex regions (VS/VP/OFC). Activity was increased in 9-repeats and decreased in 10/10-repeats in the VS/VP/OFC (p<0.001 for all analyses). Brain activity and craving was strongly correlated in 10/10-repeats in these regions and others (anterior cingulate, parahippocampal gyrus, and insula; r2=0.79–0.86, p<0.001 in all regions). Alternatively, there were no significant correlations between brain and behavior in 9-repeats. There were no differences in cigarette dependence, demographics, or resting baseline neural activity between groups. These results provide evidence that genetic variation in the DAT gene contributes to the neural and behavioral responses elicited by smoking cues.

A cocaine-positive baseline urine predicts outpatient treatment attrition and failure to attain initial abstinence

The primary study objective was to ascertain whether a prior finding that the baseline cocaine urine toxicology predicted treatment dropout for cocaine dependent outpatients could be extended to three additional cocaine dependent outpatient treatment samples and whether the urine toxicology also predicted attainment of initial abstinence for the four samples. A secondary objective was to ascertain the extent to which other baseline variables accounted for additional outcome variance over and above that afforded by urine toxicology. To evaluate the first objective, the relationships between the baseline cocaine urine and each of two measures of within treatment response--the completion of treatment or the attainment of initial abstinence--were determined for each of the treatment samples. The second objective was evaluated by a stepwise, hierarchical logistic regression analysis, with the urine toxicology entered in the first step, baseline Addiction Severity Index (ASI) variables in the second step, and achievement of initial abstinence as the outcome. In all four samples, patients with a urine indicative of recent cocaine use were less than half as likely to complete treatment or achieve initial abstinence. Individual ASI baseline variables did not contribute statistically significant variance over and above that predicted by the cocaine urine toxicology. The findings confirm the utility of the initial cocaine urine as a predictor of unfavorable outpatient treatment response.