Julia Shi

Varenicline Reduces Alcohol Self-Administration in Heavy-Drinking Smokers

BACKGROUND Alcohol and tobacco dependence are highly comorbid disorders, with preclinical evidence suggesting a role for nicotinic acetylcholine receptors (nAChRs) in alcohol consumption. Varenicline, a partial nicotinic agonist with high affinity for the alpha4beta2 nAChR receptor, reduced ethanol intake in rodents. We aimed to test whether varenicline would reduce alcohol consumption and alcohol craving in humans. METHODS This double-blind, placebo-controlled investigation examined the effect of varenicline (2 mg/day vs. placebo) on alcohol self-administration using an established laboratory paradigm in non-alcohol-dependent heavy drinkers (n = 20) who were daily smokers. Following 7 days of medication pretreatment, participants were first administered a priming dose of alcohol (.3 g/kg) and subjective, and physiologic responses were assessed. A 2-hour alcohol self-administration period followed during which participants could choose to consume up to 8 additional drinks (each .15 g/kg). RESULTS Varenicline (.5 +/- SE = .40) significantly reduced the number of drinks consumed compared to placebo (2.60 +/- SE = .93) and increased the likelihood of abstaining from any drinking during the self-administration period. Following the priming drink, varenicline attenuated alcohol craving and reduced subjective reinforcing alcohol effects (high, like, rush, feel good, intoxicated). Adverse events associated with varenicline were minimal and, when combined with alcohol, produced no significant effects on physiologic reactivity, mood, or nausea. CONCLUSIONS This preliminary investigation demonstrated that varenicline significantly reduced alcohol self-administration and was well tolerated, alone and in combination with alcohol in heavy-drinking smokers. Varenicline should be investigated as a potential treatment for alcohol use disorders.

A randomized clinical trial of a manual-guided risk reduction intervention for HIV-positive injection drug users.

This study randomized 90 HIV-seropositive, methadone-maintained injection drug users (IDUs) to an HIV Harm Reduction Program (HHRP+) or to an active control that included harm reduction components recommended by the National AIDS Demonstration Research Project. The treatment phase lasted 6 months, with follow-ups at 6 and 9 months after treatment entry. Patients in both treatments showed reductions in risk behaviors. However, patients assigned to HHRP+ were less likely to use illicit opiates and were more likely to adhere to antiretroviral medications during treatment; at follow-up, they had lower addiction severity scores and were less likely to have engaged in high risk behavior. Findings suggest that enhancing methadone maintenance with an intervention targeting HIV-seropositive IDUs increases both harm reduction and health promotion behaviors.

Predictors of Nonadherence to HIV-Related Medication Regimens During Methadone Stabilization

Nonadherence to HIV-related medication regimens among drug-abusing patients decreases therapeutic effectiveness and may limit patient access to newer, highly active antiretroviral therapies (HAART). A number of factors have been associated with medication nonadherence; however, few studies have examined predictors of nonadherence specifically in HIV-positive drug abusers. In the current study, a comprehensive assessment battery was administered to 42 HIV-positive, injection drug users beginning methadone maintenance. HIV-related medication adherence was assessed weekly by self-report during the 4-week methadone stabilization phase. Thirty-six percent of patients reported less than 80% adherence to their medication regimen at entry into methadone. Medication adherence increased significantly during the 4-week stabilization phase. Significant zero-order correlations were found between nonadherence during stabilization and viral load, low educational attainment, depression, and neuropsychological tests of problem solving ability and cognitive flexibility. Independent predictors of nonadherence were low levels of education and poor emotional functioning. Implications for early intervention are discussed.

Family History of Alcoholism Influences Naltrexone-Induced Reduction in Alcohol Drinking

BACKGROUND The purpose of this study was to examine the interactive effects of family history of alcoholism (FH+, FH-) and naltrexone dose (0, 50, 100 mg/day) on alcohol drinking. METHODS Ninety-two, non-treatment-seeking alcohol-dependent participants received naltrexone daily for 6 days. On the 6th day, they participated in a laboratory paradigm involving exposure to a priming dose of alcohol followed by a 2-hour drinking period in which they made choices between consuming alcoholic drinks and receiving money. RESULTS Total number of drinks consumed during the drinking period was significantly decreased by the 100-mg dose of naltrexone in FH+ drinkers. Secondary analyses in male drinkers (n = 70) indicated that 100 mg of naltrexone significantly decreased drinking in FH+ participants and increased drinking in FH- drinkers. CONCLUSIONS These results suggest that family history of alcoholism might be a significant clinical predictor of response to naltrexone and that FH+ men are more likely to benefit from naltrexone therapy for alcohol drinking.

Developing and Validating a Human Laboratory Model to Screen Medications for Smoking Cessation

INTRODUCTION To facilitate translational work in medications development for smoking cessation, we have developed a human laboratory analogue of smoking lapse behavior. Our paradigm models 2 critical features of smoking lapse: the ability to resist the first cigarette and subsequent ad libitum smoking. In this paper we present the results of 2 studies designed to develop and validate the effect of nicotine deprivation on smoking lapse behavior. METHODS Study 1 (n = 30) was designed to develop the model parameters by examining varying levels of nicotine deprivation (1, 6, and 18 hr; within-subject) and identifying optimum levels of monetary reinforcement to provide while modeling the ability to resist smoking. Study 2 was designed to validate the model by screening smoking cessation medications with known clinical efficacy. Subjects (n = 62) were randomized to either varenicline 2 mg/day, bupropion 300 mg/day, or placebo, and we then modeled their ability to resist smoking and subsequent ad libitum smoking. RESULTS In Study 1, increasing levels of nicotine deprivation and decreasing levels of monetary reinforcement decreased the ability to resist smoking. In Study 2, the lapse model was found to be sensitive to medication effects among smokers who demonstrated a pattern of heavy, uninterrupted, and automated smoking (i.e., smoked within 5 min of waking). Ratings of craving, mood, withdrawal, and subjective cigarette effects are presented as secondary outcomes with results mirroring clinical findings. CONCLUSIONS Our smoking lapse model demonstrates promise as a translational tool to screen novel smoking cessation medications. Next steps in this line of research will focus on evaluating predictive validity.

Ethyl Glucuronide and Ethyl Sulfate Assays in Clinical Trials, Interpretation, and Limitations: Results of a Dose Ranging Alcohol Challenge Study and 2 Clinical Trials

BACKGROUND The ethanol metabolites, ethyl glucuronide (EtG) and ethyl sulfate (EtS), are biomarkers of recent alcohol consumption that provide objective measures of abstinence. Our goals are to better understand the impact of cutoff concentration on test interpretation, the need for measuring both metabolites, and how best to integrate test results with self-reports in clinical trials. METHODS Subjects (n = 18) were administered, 1 week apart, 3 alcohol doses calibrated to achieve blood concentrations of 20, 80, and 120 mg/dl, respectively. Urinary EtG/EtS was measured at timed intervals during a 24-hour hospitalization and twice daily thereafter. In addition, participants from 2 clinical trials provided samples for EtG/EtS and drinking histories. Cutoffs for EtG/EtS of 100/50, 200/100, and 500/250 ng/ml were evaluated. RESULTS Twelve hours following each challenge, EtG was always positive at the 100 and 200 cutoffs, but at 24 hours sensitivity was poor at all cutoffs following the low dose, and poor after 48 hours regardless of dose or cutoff. Similarly, in the clinical trials EtG sensitivity was good for detecting any drinking during the last 24 hours at the 2 lowest cutoffs, but under 40% during the last 24 to 48 hours. Sensitivity was reduced at the 500 ng/ml cutoff. Discrepancies between EtG and EtS were few. Comparison of self-reports of abstinence and EtG-confirmed abstinence indicated underreporting of drinking. CONCLUSIONS Any drinking the night before should be detectable the following morning with EtG cutoffs of 100 or 200 ng/ml. Twenty-four hours after drinking, sensitivity is poor for light drinking, but good for heavier consumption. At 48 hours, sensitivity is low following 6 drinks or less. Increasing the cutoff to 500 ng/ml leads to substantially reduced sensitivity. Monitoring both EtG and EtS should usually be unnecessary. We recommend EtG-confirmed self-reports of abstinence for evaluation of outcomes in clinical trials.

A preliminary study on the effect of combined nicotine replacement therapy on alcohol responses and alcohol self-administration

BACKGROUND AND OBJECTIVES Limiting alcohol consumption may help prevent alcohol-mediated smoking relapse in heavy drinking smokers. This pilot study examined whether combining a nicotine patch with nicotine nasal spray has stronger attenuating effects on alcohol response and consumption than a nicotine patch alone. METHODS Twenty-two non-alcohol dependent heavy drinking smokers completed the double-blind cross-over, placebo-controlled study (21 mg nicotine patch + nicotine or placebo nasal spray). Six hours after 21 mg nicotine patch application, subjective and physiological responses to a priming drink (0.3 g/kg) were assessed, followed by two 1-hr alcohol self-administration periods, with possible consumption of up to 4 drinks per period (each 0.15 g/kg). Nasal spray (1 mg [active] or 0 mg [placebo] per dose) was administered 10 min prior to the priming dose and each self-administration period. RESULTS Active nasal spray did not increase serum nicotine levels, compared with placebo administration. The number of drinks consumed did not differ by the nasal spray conditions. However, positive subjective responses to the priming drink were lower in the active nasal spray condition than the placebo nasal spray condition. During the self-administration period, urge to drink was also lower in the active spray condition than the placebo condition. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE Augmenting the nicotine patch with nicotine nasal spray attenuated positive subjective alcohol response and craving and suggests that future studies should investigate whether these findings translate to a clinical setting.