Ketone Supplementation Dampens Subjective and Objective Responses to Alcohol: Evidence From a Preclinical Rat Study and a Randomized, Cross-Over Trial in Healthy Volunteers.

BACKGROUND: Previous preclinical and human studies have shown that a high-fat ketogenic diet and ketone supplements (KS) are efficacious in reducing alcohol craving, alcohol consumption, and signs of alcohol withdrawal. However, the effects of KS on alcohol sensitivity are unknown. METHODS: In this single-blind, cross-over study, 10 healthy participants (3 females) were administered a single, oral dose of a KS (25 g of ketones from D-ß-hydroxybutyric acid and R-1,3-butanediol) or placebo 30 minutes before an oral alcohol dose (0.25 g/kg for women; 0.31 g/kg for men). Assessments of breath alcohol concentration and blood alcohol levels (BAL) and responses on the Drug Effect Questionnaire were repeatedly obtained over 180 minutes after alcohol consumption. In a parallel preclinical study, 8 Wistar rats (4 females) received an oral gavage of KS (0.42 g ketones/kg), water, or the sweetener allulose (0.58 g/kg) followed 15 minutes later by an oral alcohol dose (0.8 g/kg). BAL was monitored for 240 minutes after alcohol exposure. RESULTS: In humans, the intake of KS before alcohol significantly blunted breath alcohol concentration and BAL, reduced ratings of alcohol liking and wanting more, and increased disliking for alcohol. In rats, KS reduced BAL more than either allulose or water. CONCLUSION: KS altered physiological and subjective responses to alcohol in both humans and rats, and the effects were likely not mediated by the sweetener allulose present in the KS drink. Therefore, KS could potentially reduce the intoxicating effects of alcohol.

Ketone supplementation dampens subjective and objective responses to alcohol in rats and humans.

Previous preclinical and human studies have shown that high-fat ketogenic diet and ketone supplements (KS) are efficacious in reducing alcohol craving, alcohol consumption, and signs of alcohol withdrawal. However, the effects of KS on alcohol sensitivity are unknown. In this single-blind, cross-over study, 10 healthy participants (3 females) were administered a single, oral dose of a KS (25 g of ketones from D-ß-hydroxybutyric acid and R-1,3-butanediol) or placebo 30 min prior to an oral alcohol dose (0.25 g/kg for women; 0.31 g/kg for men). Assessments of breath alcohol concentration (BrAC) and blood alcohol levels (BAL) and responses on the Drug Effect Questionnaire were repeatedly obtained over 180 min after alcohol consumption. In a parallel preclinical study, 8 Wistar rats (4 females) received an oral gavage of KS (0.42 g ketones/kg), water, or the sweetener allulose (0.58 g/kg) followed 15 min later by an oral alcohol dose (0.8 g/kg). BAL were monitored for 240 min after alcohol exposure. In humans, the intake of KS prior to alcohol significantly blunted BrAC and BAL, reduced ratings of alcohol liking and wanting, and increased disliking for alcohol. In rats, KS reduced BAL more than either allulose or water. In conclusion, KS altered physiological and subjective responses to alcohol in both humans and rats and the effects were likely not mediated by the sweetener allulose present in the KS drink. Therefore, KS could potentially reduce the intoxicating and rewarding effects of alcohol and thus be a novel intervention for treating alcohol use disorder.

Pharmacokinetic effects of a single-dose nutritional ketone ester supplement on brain ketone and glucose metabolism in alcohol use disorder - a pilot study.

Introduction: Acute alcohol intake decreases brain glucose metabolism and increases brain uptake of acetate, a metabolite of alcohol. Individuals with alcohol use disorder (AUD) show elevated brain acetate metabolism at the expense of glucose, a shift in energy utilization that persists beyond acute intoxication. We recently reported that nutritional ketosis and administration of ketone bodies as an alternative energy source to glucose reduce alcohol withdrawal severity and alcohol craving in AUD. However, the regional effects of nutritional ketosis on brain ketone (beta-hydroxybutyrate [BHB]) and glucose metabolism have not been studied in AUD. Methods: Five participants with AUD underwent two magnetic resonance imaging (MRI) sessions and 4 participants with AUD underwent two positron emission tomography (PET) sessions with 18 F-fluorodeoxyglucose. All participants completed one session without KE intervention and one session during which they consumed 395 mg/kg (R) -3-hydroxybutyl (R) -3-hydroxybutyrate Ketone Ester (KE) intervention (TdeltaS Global Inc.) before the scan. The order of the sessions was randomized. For the PET cohort, blood glucose and ketone levels were assessed and voxel-wise maps of the cerebral metabolic rate of glucose (CMRglc) were computed at each session. For the MRI cohort, brain anterior cingulate BHB levels were assessed using magnetic resonance spectroscopy. Results: A single dose of KE elevated blood BHB and anterior cingulate BHB levels compared to baseline. Moreover, blood glucose levels were lower with KE than baseline, and whole-brain CMRglc decreased by 17%. The largest KE-induced CMRglc reductions were in the frontal, occipital, cortex, and anterior cingulate cortices. Conclusion: These findings provide preliminary evidence that KE administration elevates ketone and reduces brain glucose metabolism in humans, consistent with a shift from glucose to ketones as a brain energy source. Average reductions in CMRglc of 17% are similar to global average reductions documented with administration of 0.25-0.5 g/kg of alcohol. Documenting the clinical and neurometabolic effects of nutritional ketosis will yield fundamental knowledge as to its potential beneficial effects as a treatment for AUD and its underlying neural mechanisms.

Peripheral and Central Iron Measures in Alcohol Use Disorder and Aging: A Quantitative Susceptibility Mapping Pilot Study.

Chronic excessive alcohol use has neurotoxic effects, which may contribute to cognitive decline and the risk of early-onset dementia. Elevated peripheral iron levels have been reported in individuals with alcohol use disorder (AUD), but its association with brain iron loading has not been explored. We evaluated whether (1) serum and brain iron loading are higher in individuals with AUD than non-dependent healthy controls and (2) serum and brain iron loading increase with age. A fasting serum iron panel was obtained and a magnetic resonance imaging scan with quantitative susceptibility mapping (QSM) was used to quantify brain iron concentrations. Although serum ferritin levels were higher in the AUD group than in controls, whole-brain iron susceptibility did not differ between groups. Voxel-wise QSM analyses revealed higher susceptibility in a cluster in the left globus pallidus in individuals with AUD than controls. Whole-brain iron increased with age and voxel-wise QSM indicated higher susceptibility with age in various brain areas including the basal ganglia. This is the first study to analyze both serum and brain iron loading in individuals with AUD. Larger studies are needed to examine the effects of alcohol use on iron loading and its associations with alcohol use severity, structural and functional brain changes, and alcohol-induced cognitive impairments.

An intensive longitudinal examination of topiramate treatment for alcohol use disorder: a secondary analysis of data from a randomized controlled trial.

BACKGROUND AND AIMS: Previous findings have been equivocal as to whether a single-nucleotide polymorphism (rs2832407) in GRIK1, which encodes a glutamate receptor subunit, moderates the effects of topiramate treatment for drinking reduction. We leveraged intensive longitudinal data to provide greater precision and allow an examination of intermediate outcomes addressing this question. We used data from a randomized controlled trial (RCT) to test the hypotheses that topiramate treatment reduces daily heavy drinking, desire to drink and positive alcohol expectancies and that these effects are stronger in rs2832407*C-allele homozygotes. DESIGN: Secondary data analysis of a randomized controlled trial. SETTING: University of Pennsylvania Treatment Research Center in the United States. PARTICIPANTS/CASES: Participants were 164 individuals (70.1% male, mean age = 51.42, 36.0% rs2832407*C-allele homozygotes) who sought to reduce or stop drinking. INTERVENTION AND COMPARATOR: Participants were assigned to medication (topiramate or placebo), with stratification by genotype group (CC versus AA/AC) and treatment goal (reduce versus abstain). MEASUREMENTS: During the 12-week treatment period, participants completed daily interactive voice response (IVR) surveys. FINDINGS: On any given day during treatment, participants who received topiramate had lower odds of IVR-reported heavy drinking [odds ratio (OR) = 0.259, b (standard error, SE) = -1.351 (0.334), P < 0.001] and lower levels of desire to drink [b (SE) = -0.323 (0.122), P = 0.009] and positive alcohol expectancies [b (SE) = -0.347 (0.138), P = 0.013] than those who received placebo. Participants who received topiramate also reported greater reductions in positive alcohol expectancies during the first 2 weeks of treatment than those who received placebo [b (SE) = -0.028 (0.008), P = 0.001], but topiramate did not impact the daily rate of change in heavy drinking or desire to drink. Genotype did not moderate the effects of topiramate on any outcomes examined (P > 0.05). CONCLUSIONS: Topiramate is an effective medication for individuals seeking to reduce heavy drinking. The effects are not moderated by the single-nucleotide polymorphism rs2832407.

A randomized, double-blind, placebo-controlled, pharmacogenetic study of ondansetron for treating alcohol use disorder.

BACKGROUND: In a previous study, ondansetron, a serotonin 5-HT3 receptor antagonist, reduced drinking intensity (drinks/drinking day [DPDD]) among European-ancestry (EA) participants with moderate-to-severe alcohol use disorder (AUD) and variants in genes encoding the serotonin transporter (SLC6A4) and 5-HT3A (HTR3A), and 5-HT3B (HTR3B) receptors. We tested whether (1) ondansetron reduces DPDD among individuals of either European or African ancestry (AA), and (2) that reductions in DPDD are greatest among ondansetron-treated individuals with population-specific combinations of genotypes at SLC6A4, HTR3A, and HTR3B. METHODS: In this 16-week, double-blind, placebo-controlled, parallel-group clinical trial, adults with AUD were randomized to receive low-dose oral ondansetron (0.33 mg twice daily) or placebo stratified by "responsive" versus "nonresponsive" genotype defined using population-specific genotypes at the three genetic loci. Generalized estimating equation regression models and a modified intent-to-treat analysis were used to compare the treatment groups on the primary outcome-DPDD-and two secondary outcomes-heavy drinking days per week [HDD] and drinks per day [DPD] across the 16 weeks of treatment. RESULTS: Of 296 prospective participants screened, 95 (58 EA and 37 AA) were randomized and received at least one dose of study medication. In the modified intent-to-treat analysis, the ondansetron group averaged 0.40 more DPDD (p = 0.51), 1.35 times as many HDD (p = 0.16), and 1.06 times as many DPD (p = 0.59) as the placebo group. There were no significant interactions with genotype. There were no study-related serious adverse events (AEs) and similar proportions of participants in the two treatment groups experienced AEs across organ systems. CONCLUSIONS: We found no evidence that low-dose oral ondansetron is beneficial in the treatment of AUD, irrespective of genotype, thus failing to confirm prior study findings. However, the study was underpowered to identify medication by genotype interactions.

Post-treatment effects of topiramate on alcohol-related outcomes: A combined analysis of two placebo-controlled trials.

Topiramate reduces drinking and alcohol-related problems and is increasingly being used to treat alcohol use disorder (AUD). In a randomized controlled trial (RCT) of topiramate, rs2832407, a single nucleotide polymorphism (SNP) in the GRIK1 gene moderated topiramate's effects (Study 1). However, a second RCT (Study 2) did not replicate the SNP's moderating effect during treatment. The current analysis combines data from these two studies to examine topiramate's effects on alcohol-related outcomes and on its pharmacogenetic moderation during a 6-month post-treatment period. This analysis includes 308 individuals with problematic alcohol use (67% male; mean age = 51.1; topiramate: 49%, placebo: 51%). It uses generalized linear mixed models to examine changes in self-reported alcohol consumption and alcohol-related problems and concentrations of the liver enzyme γ-glutamyltransferase. The report combines published 3- and 6-month follow-up data from Study 1 with similar, unpublished data from Study 2. Despite robust effects of topiramate on drinking during treatment, the overall multivariate medication effects on outcomes during 3- and 6-month follow-up were not significant (p = 0.08 and p = 0.26, respectively). The moderating effect of the SNP on primary treatment outcomes was also not significant during either follow-up period (p = 0.13 and p = 0.16, respectively). However, during the 3-month post-treatment period, drinks per day was significantly lower in the topiramate group than the placebo group in the rs2832407*CC-genotype group. The robust effects of topiramate on alcohol-related outcomes during treatment diminish substantially once the medication is discontinued. Research is needed both to determine the optimal treatment duration and to identify clinically useful pharmacogenetic moderators of topiramate for treating AUD.

World Health Organization risk drinking levels as a treatment outcome measure in topiramate trials.

BACKGROUND: Although abstinence has traditionally been considered the only suitable outcome for alcohol treatment, reduced drinking is also associated with improved functioning and medical and psychiatric outcomes. The World Health Organization (WHO) risk drinking levels (RDLs) have been shown to be valid outcome measures in treatment trials for alcohol use disorder (AUD). METHODS: We conducted a secondary analysis of two 12-week, randomized controlled trials (RCTs), in which a total of 308 individuals with problematic alcohol use received topiramate or placebo treatment. We compared the utility of the WHO RDLs with other treatment outcomes, including self-reported measures of alcohol consumption, alcohol-related problems, and quality of life, and the biomarker gamma-glutamyltransferase. RESULTS: Topiramate treatment was associated with small effect sizes for both a 1-level (d = 0.26) and a 2-level (d = 0.19) reduction in WHO RDL, effects that were not significant after correction for multiple comparisons. No heavy drinking days, one of the outcome measures recommended by the US Food and Drug Administration for alcohol medication registration trials, also exhibited a small effect (0.21), while an effect size for abstinence could not be calculated. There were medium effects of topiramate on continuous measures of percent heavy drinking days (d = 0.49) and alcohol-related problems (d = 0.41). CONCLUSIONS: Topiramate is an efficacious pharmacotherapy for AUD. Although continuous measures of drinking and alcohol-related problems yielded larger effect sizes than the WHO RDLs, the latter nonetheless provide a categorical alternative for use in both clinical care and pharmacotherapy trials.

Combined analysis of the moderating effect of a GRIK1 polymorphism on the effects of topiramate for treating alcohol use disorder.

BACKGROUND: In an initial study, we reported that topiramate reduced heavy drinking among individuals who sought to reduce their drinking and that the effect was moderated by a single nucleotide polymorphism (SNP; rs2832407) in GRIK1, which encodes the kainate GluK1 receptor subunit (Kranzler et al., 2014). In a subsequent study that prospectively randomized patients to medication group based on their rs2832407 genotype, we replicated the main effect of topiramate but not the moderating effect of the SNP (Kranzler et al., 2021). Given the similar design of the two studies, here we combined the findings to provide greater statistical power to test the pharmacogenetic effect. MATERIAL AND METHODS: This secondary analysis of two 12-week, randomized controlled trials of topiramate included a total of 292 European-ancestry individuals (67.1 % male; topiramate: 48.3 %, placebo: 51.7 %) with problematic alcohol use. Using MANOVA, we examined changes in self-reported alcohol consumption, problems resulting from alcohol use, and quality of life, and the biomarker γ-glutamyltransferase. To test the pharmacogenetic hypothesis, all patients were genotyped for rs2832407. RESULTS: There was a significant overall effect of topiramate on the alcohol-related outcomes (partial η2 = 0.134, p < 0.001), with follow-up analyses showing significant reductions in percent heavy drinking days (Cohen's d = 0.49), percent days abstinent (d = 0.23), drinks/day (d = 0.29) and alcohol-related problems (d = 0.45). Overall, the moderating effect of the SNP was non-significant (partial η² = 0.026, p = 0.37). CONCLUSIONS: Although topiramate is an efficacious medication for reducing drinking and alcohol-related problems among patients with problematic alcohol use, rs2832407 does not appear to moderate its therapeutic effects. www.clinicaltrials.gov registrations: NCT00626925 and NCT02371889.

Prospective randomized pharmacogenetic study of topiramate for treating alcohol use disorder.

In a prior study, topiramate reduced heavy drinking among individuals who sought to reduce their drinking, with the effect moderated by a single nucleotide polymorphism (SNP; rs2832407) in GRIK1, which encodes the kainate GluK1 receptor subunit (Kranzler et al. 2014). The present study sought to replicate prospectively the effect of topiramate and rs2832407 in patients with DSM-5 alcohol use disorder (AUD) who sought to reduce or stop their drinking. We stratified the randomization on genotype (rs2832407*C-allele homozygotes vs. A-allele carriers) and assigned 170 European-American participants (71.2% male) to receive 12 weeks of treatment with topiramate (N = 85), at a maximal daily dosage of 200 mg, or matching placebo (N = 85). At each of nine treatment visits participants received brief counseling to reduce drinking and increase abstinent days. We hypothesized that topiramate-treated patients with the rs2832407*CC genotype would reduce heavy drinking days (HDDs) more than the other three groups. The rate of treatment completion was 91.8% in both groups. The mean number of HDDs per week in the placebo group was 1.67 (95% CI = (1.29, 2.16), p = 0.0001) times greater than in the topiramate group, which was confirmed by the topiramate group's significantly greater reduction in the concentration of the liver enzyme γ-glutamyltransferase and lower alcohol-related problems score. There was no significant difference in topiramate's effect on HDDs between genotype groups. Although consistent with other studies showing a reduction in heavy drinking with topiramate treatment, the prior finding of a moderating effect of rs2832407 genotype was not replicated in this prospective trial.

Effects of topiramate on neural responses to alcohol cues in treatment-seeking individuals with alcohol use disorder: preliminary findings from a randomized, placebo-controlled trial.

Topiramate, a GABA/glutamate modulator, is efficacious in reducing alcohol consumption, though the mechanisms underlying this effect are not well characterized. This study analyzed functional magnetic resonance imaging (fMRI) data from 22 heavy drinkers enrolled in a 12-week placebo-controlled, randomized clinical trial of topiramate to examine the effects of topiramate on alcohol cue-elicited brain responses, craving, and heavy drinking in individuals with DSM-5 alcohol use disorder. Patients were randomized to receive either topiramate (maximal daily dosage of 200 mg/day) or placebo and were administered an fMRI alcohol cue-reactivity task at baseline (before starting medication) and after 6 weeks of double-blind treatment. Analyses compared the topiramate (n = 12) and placebo (n = 8) groups on (1) the change in brain responses during alcohol cue exposure (vs non-alcohol cues) within five a priori regions of interest related to reward-the bilateral and medial orbitofrontal cortex (OFC) and bilateral ventral striatum (VS) and (2) change in craving and heavy drinking days (HDDs) from baseline and scan 2. Topiramate, relative to placebo, reduced alcohol cue-elicited activation of the left VS, bilateral OFC, and medial OFC, alcohol cue-elicited craving, and HDDs between baseline and 6 weeks of treatment. The reduction in alcohol cue-elicited activation in the medial OFC correlated with reductions in craving, and reduced activation in the right VS, right OFC, and medial OFC correlated with the reduction in HDD. This preliminary study provides evidence that topiramate's attenuation of alcohol cue-elicited brain activation and craving are key elements of the drug's neurobiological mechanism of action in reducing heavy drinking.

Effects of Recent Alcohol Consumption Level on Neurocognitive Performance in HIV+ Individuals.

OBJECTIVES: Although HIV+ individuals may be at increased risk of alcohol-related cognitive impairment, the relations between drinking level and cognitive performance in these individuals are not well understood. We examined whether higher levels of recent drinking in HIV+ individuals were associated with poorer cognitive performance, particularly in executive functioning (EF) and memory. METHODS: We administered a comprehensive cognitive battery to 120 seropositive subjects (101 men) who reported alcohol consumption in the preceding 90 days. Participants were excluded if they were seeking alcohol treatment or showed evidence of dementia. Using the computerized CogState battery, we measured performance in EF, verbal learning/memory, visual learning/memory, attention, working memory, and psychomotor speed. The computerized Iowa Gambling Task was used to assess decision-making. RESULTS: The HIV+ subjects showed significantly slower psychomotor speed than a normative sample. Although across most domains, neurocognitive performance in our sample was not significantly associated with recent alcohol consumption, performance on the CogState measures of visual memory and attention was significantly poorer with a higher level of drinking in the past 3 months and a current alcohol use disorder, respectively. CONCLUSIONS: Although cognitive weaknesses were detectable among these non-treatment-seeking HIV+ drinkers, the level of alcohol consumption was not a primary determinant of neurocognitive performance in this group. A comprehensive profile analysis may be most valuable for detecting cognitive strengths and weaknesses given the heterogeneity of this population. Longitudinal studies are needed to examine the potential additive or synergistic effects of heavy drinking and HIV seropositivity on cognitive performance.

Self-efficacy mediates the effects of topiramate and GRIK1 genotype on drinking.

Previous studies indicate that topiramate reduces alcohol use among problem drinkers, with one study showing that the effect was moderated by a polymorphism (rs2832407) in GRIK1, the gene encoding the GluK1 kainate subunit. We examined whether the interactive effect of medication and genotype (1) altered the association between daily self-efficacy and later-day drinking; and (2) had an indirect effect on drinking via self-efficacy. In a 12-week, placebo-controlled trial of topiramate, we used daily interactive voice response technology to measure self-efficacy (i.e. confidence in avoiding heavy drinking later in the day) and drinking behavior in 122 European-American heavy drinkers. Topiramate's effects on both self-efficacy and drinking level were moderated by rs2832407. C-allele homozygotes treated with topiramate showed higher levels of self-efficacy and lower levels of nighttime drinking across the 12-week trial. Further, the interactive effect of topiramate and genotype on mean nighttime drinking levels was mediated by mean levels of self-efficacy. By modeling topiramate's effects on nighttime drinking across multiple levels of analysis, we found that self-efficacy, a key psychologic construct, mediated the effect of topiramate, which was moderated by rs2832407 genotype. Thus, it may be possible to use an individualized assessment (i.e. genotype) to select treatment to optimize the reduction in heavy drinking and thereby provide a personalized treatment approach.

Smoking and Cellular Telephone Use Among Pregnant Women Seeking Prenatal Care: Opportunities for Intervention.

OBJECTIVES: Although smoking during pregnancy is associated with poor pregnancy outcomes, many women continue to smoke throughout pregnancy. Behavioral interventions for smoking cessation yield modest benefits, particularly in lower socioeconomic groups. Pharmacotherapy, a first-line option for smoking cessation, has not shown clear benefits for pregnant smokers, partly due to limited adherence. We evaluated the feasibility of conducting a pharmacotherapy trial for smoking cessation in pregnant women, using text messaging to enhance medication adherence. METHODS: We surveyed 724 predominantly minority pregnant women to examine the prevalence and correlates of smoking and the use of cellular telephones and text messaging. RESULTS: Nearly 18% of the respondents were current smokers, with a majority (67.7%) expressing interest in participating in a smoking cessation trial. Only about 6% of women with a smoking history ever received nicotine dependence treatment. Smokers were significantly more likely to be depressed than non-smokers. The vast majority of respondents (92.1%) owned cell phones, with 93.2% having an unlimited text-messaging plan. CONCLUSIONS: These data support the feasibility of conducting a pharmacotherapy smoking cessation trial and using text messaging to enhance medication adherence in a predominantly minority population of pregnant smokers.

Topiramate's reduction of body mass index in heavy drinkers: lack of moderation by a GRIK1 polymorphism.

Topiramate, which interacts with multiple neurotransmitter and enzyme systems, is approved by the Food and Drug Administration to treat seizure disorder, prevent migraine, and (in combination with phentermine) reduce weight. Topiramate has also been shown in multiple studies to reduce heavy drinking. The authors found that topiramate 200 mg/day significantly reduced heavy drinking in heavy drinkers with a treatment goal of reduced drinking (Kranzler et al., 2014). Further, in the European American (EA) subsample (n = 122), a single nucleotide polymorphism (rs2832407) in GRIK1, which encodes the GluK1 subunit of the kainate receptor, moderated the effect on heavy drinking days. Here the authors examined the effects of topiramate on body mass index (BMI) and the moderating effect of rs2832407 in the EA subsample from Kranzler et al. (2014). Across the 12 weeks of treatment, BMI was reduced by 1.2 kg/m2 (p < .001) in the topiramate group but was unchanged in the placebo group. There was no evidence of moderation by rs2832407 of topiramate's effects on BMI. Controlling for changes in drinking and other potential confounders did not alter the findings. These results suggest that the effect of topiramate on drinking behavior, in which the GluK1-containing kainate receptor appears to play a key role, can be dissociated from its effect on weight, the specific mechanism of which remains to be determined.

Dutasteride reduces alcohol's sedative effects in men in a human laboratory setting and reduces drinking in the natural environment.

RATIONALE: Preclinical studies support the hypothesis that endogenous neuroactive steroids mediate some effects of alcohol. OBJECTIVES: The aim of this study was to examine the effect of dutasteride inhibition of 5α-reduced neuroactive steroid production on subjective responses to alcohol in adult men. METHODS: Using a within-subject factorial design, 70 men completed four randomly ordered monthly sessions in which pretreatment with 4 mg dutasteride or placebo was paired with a moderate dose of alcohol (0.8 g/kg) or placebo beverage. The pharmacologic effect of dutasteride was measured by an assay of serum androstanediol glucuronide. Self-reports of alcohol effects were obtained at 40-min intervals following alcohol administration using the Biphasic Alcohol Effects Scale (BAES) and the Alcohol Sensation Scale (SS). We used linear mixed models to examine the effects of dutasteride and alcohol on BAES and SS responses and the interaction of dutasteride with the GABRA2 alcohol dependence-associated polymorphism rs279858. We also examined whether exposure to dutasteride influenced drinking in the weeks following each laboratory session. RESULTS: A single 4-mg dose of dutasteride produced a 70 % reduction in androstanediol glucuronide. Dutasteride pretreatment reduced alcohol effects on the BAES sedation and SS anesthesia scales. There was no interaction of dutasteride with rs279858. Heavy drinkers had fewer heavy drinking days during the 2 weeks following the dutasteride sessions and fewer total drinks in the first week after dutasteride. CONCLUSIONS: These results provide evidence that neuroactive steroids mediate some of the sedative effects of alcohol in adult men and that dutasteride may reduce drinking, presumably through its effects on neuroactive steroid concentrations.

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), topiramate's 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 topiramate's effects on heavy drinking.

Posttreatment effects of topiramate treatment for heavy drinking.

BACKGROUND: We examined whether the effects of topiramate and a single nucleotide polymorphism (rs2832407) in GRIK1, which encodes a kainate receptor subunit, persisted following a 12-week, placebo-controlled trial in 138 heavy drinkers with a treatment goal of reduced drinking. During treatment, topiramate 200 mg/d significantly reduced heavy drinking days and increased the frequency of abstinent days (Am J Psychiatry, 2014, 171:445). In the European-American (EA) subsample (n = 122), rs2832407 moderated the treatment effect on heavy drinking. METHODS: Patients were re-interviewed 3 and 6 months after the end of treatment. During treatment, we obtained 92.4% of drinking data, with 89.1 and 85.5% complete data at the 3- and 6-month follow-up visits, respectively. We examined 4 outcomes over time in the overall sample and the EA subsample: percent heavy drinking days (PHDD), percent days abstinent (PDA), serum γ-glutamyl transpeptidase (GGTP) concentration, and a measure of alcohol-related problems. RESULTS: In the full sample, the lower PHDD and higher PDA seen with topiramate treatment were no longer significant during follow-up. Nonetheless, the topiramate-treated patients had lower alcohol-related problem scores during treatment and both follow-up periods. Further, in the EA subsample, the greater reduction in PHDD seen with topiramate treatment in rs2832407*C-allele homozygotes persisted throughout follow-up, with no significant effects in A-allele carriers. A reduction in GGTP concentration was consistent with the reduction in heavy drinking, but did not reach statistical significance. CONCLUSIONS: There are persistent therapeutic effects of topiramate in heavy drinkers, principally in rs2832407*C-allele homozygotes.

A GABRA2 variant is associated with increased stimulation and 'high' following alcohol administration.

AIMS: Variation in genes encoding GABAA receptor subunits has been implicated in the risk of alcohol dependence (AD). We sought to replicate and extend previous findings of a moderating effect of single nucleotide polymorphisms (SNPs) in GABRA2 (which encodes the GABAA α-2 subunit) on the subjective effects of alcohol by examining SNPs in this and the adjacent GABRG1 gene on chromosome 4. METHODS: Fifty-two European-Americans (22 males, 28 light drinkers and 24 heavy drinkers) completed 3 laboratory sessions, during which they drank low-dose, high-dose, or placebo alcohol prior to undergoing periodic assessments of stimulation, sedation and drug enjoyment. We genotyped subjects for three SNPs previously associated with AD: rs279858 in GABRA2, and rs7654165 and rs6447493 in GABRG1. RESULTS: Two SNPs were associated with altered stimulatory effects of alcohol as measured on the Biphasic Alcohol Effects Scale, (rs279858: P = 0.0046; rs6447493: P = 0.0023); both effects were in the opposite direction of previous findings. Carriers of the rs279858 C allele experienced greater stimulation from alcohol. Further inspection of the rs6447493 interaction did not support a pharmacogenetic effect. The effects of rs279858 (but not the other two SNPs) on items from a secondary outcome measure, the Drug Effects Questionnaire (DEQ), were significant. Higher ratings by individuals with the C allele were observed on the DEQ items 'feel the alcohol effect' (P < 0.001), 'like the alcohol effect' (P < 0.001) and feel 'high' (P < 0.001). CONCLUSION: We did not find that the GABRG1 SNPs rs7654165 and rs6447493 moderated the effects of alcohol. Greater stimulatory and euphoric effects of alcohol in carriers of the rs279858 C allele may, in part, explain the previously reported association of this allele with AD.