Mechanism of the antialcohol effect of gamma-hydroxybutyric acid

Prevalence and Correlates of GHB Use among Adults in the United States

Gamma-hydroxybutyrate (GHB) was a somewhat prevalent club drug two decades ago, but research has been lacking regarding the current epidemiology of use. In this study, prevalence and correlates of past-year GHB use were estimated based on noninstitutionalized US adults participating in the 2015-2020 National Survey of Drug Use and Health (N= 241,675). An estimated 0.05% (95% CI: 0.04-0.07) of adults in the US have used GHB in the past year. Compared to those age 18-25, those age 35-49 were at increased odds for use (aOR = 2.28, 95% CI: 1.02-5.10), and compared to heterosexual men, gay men in particular were at high odds for use (aOR = 27.82, 95% CI: 11.09-69.80). Those identifying as bisexual men (aOR = 3.39, 95% CI: 1.17-9.82) and lesbian/bisexual women (aOR = 3.37, 95% CI: 1.44-7.90) were also at high odds for use. Despite all drugs examined being significant correlates of use in bivariable models (ps < .001), only past-year use of methamphetamine (aOR = 15.68, 95% CI: 7.40-33.25), ketamine (aOR = 8.52, 95% CI: 2.67-27.20), and ecstasy (aOR = 4.41, 95% CI: 1.80-10.75) was associated with increased odds of use in the multivariable model. Results suggest that GHB use is currently rare, but gay men and people who use other party drugs are at particularly high risk for use.

Ethanol metabolism: The good, the bad, and the ugly

Throughout the world, ethanol is both an important commercial commodity and a source of major medical and social problems. Ethanol readily passes through biological membranes and distributes throughout the body. It is oxidized, first to acetaldehyde and then to acetate, and finally by the citric acid cycle in virtually all tissues. The oxidation of ethanol is irreversible and unregulated, making the rate dependent only on local concentration and enzyme activity. This unregulated input of reducing equivalents increases reduction of both cytoplasmic and intramitochondrial NAD and, through the latter, cellular energy state {[ATP]/([ADP][Pi])}. In brain, this increase in energy state stimulates dopaminergic neural activity signalling reward and a sense of well being, while suppressing glutamatergic neural activity signalling anxiety and unease. These positive responses to ethanol ingestion are important to social alcohol consumption. Importantly, decreased free [AMP] decreases AMP-dependent protein kinase (AMPK) activity, an important regulator of cellular energy metabolism. Oxidation of substrates used for energy metabolism in the absence of ethanol is down regulated to accommodate the input from ethanol. In liver, chronic ethanol metabolism results in fatty liver and general metabolic dysfunction. In brain, transport of other oxidizable metabolites through the blood-brain barrier and the enzymes for their oxidation are both down regulated. For exposures of short duration, ethanol induced regulatory changes are rapid and reversible, recovering completely when the concentrations of ethanol and acetate fall again. Longer periods of ethanol exposure and associated chronic suppression of AMPK activity activates regulatory mechanisms, including gene expression, that operate over longer time scales, both in onset and reversal. If chronic alcohol consumption is abruptly ended, metabolism is no longer able to respond rapidly enough to compensate. Glutamatergic neural activity adapts to chronic dysregulation of glutamate metabolism and suppression of glutamatergic neural activity by increasing excitatory and decreasing inhibitory amino acid receptors. A point is reached (ethanol dependence) where withdrawal of ethanol results in significant metabolic energy depletion in neurons and other brain cells as well as hyperexcitation of the glutamatergic system. The extent and regional specificity of energy depletion in the brain, combined with hyperactivity of the glutamatergic neuronal system, largely determines the severity of withdrawal symptoms.

Ethnopharmacological Applications Targeting Alcohol Abuse: Overview and Outlook

Excessive alcohol consumption is the cause of several diseases and thus is of a major concern for society. Worldwide alcohol consumption has increased by many folds over the past decades. This urgently calls for intervention and relapse counteract measures. Modern pharmacological solutions induce complete alcohol self-restraint and prevent relapse, but they have many side effects. Natural products are most promising as they cause fewer adverse effects. Here we discuss in detail the medicinal plants used in various traditional/folklore medicine systems for targeting alcohol abuse. We also comprehensively describe preclinical and clinical studies done on some of these plants along with the possible mechanisms of action.

Diagnosis and treatment of acute alcohol intoxication and alcohol withdrawal syndrome: position paper of the Italian Society on Alcohol

The chronic use of alcohol can lead to the onset of an alcohol use disorder (AUD). About 50% of subjects with an AUD may develop alcohol withdrawal syndrome (AWS) when they reduce or discontinue their alcohol consumption and, in 3-5% of them, convulsions and delirium tremens (DTs), representing life-threatening complications, may occur. Unfortunately, few physicians are adequately trained in identifying and treating AWS. The Italian Society on Alcohol has, therefore, implemented a task force of specialists to draw up recommendations for the treatment of AWS with the following main results: (1) while mild AWS may not require treatment, moderate and severe AWS need to be pharmacologically treated; (2) out-patient treatment is appropriate in patients with mild or moderate AWS, while patients with severe AWS need to be treated as in-patients; (3) benzodiazepines, BDZs are the "gold standard" for the treatment of AWS and DTs; (4) alpha-2-agonists, beta-blockers, and neuroleptics may be used in association when BDZs do not completely resolve specific persisting symptoms of AWS; (5) in the case of a refractory form of DTs, the use of anaesthetic drugs (propofol and phenobarbital) in an intensive care unit is appropriate; (6) alternatively to BDZs, sodium oxybate, clomethiazole, and tiapride approved in some European Countries for the treatment of AWS may be employed for the treatment of moderate AWS; (7) anti-convulsants are not sufficient to suppress AWS, and they may be used only in association with BDZs for the treatment of refractory forms of convulsions in the course of AWS.

An open-label study of sodium oxybate in Spasmodic dysphonia

OBJECTIVES/HYPOTHESIS

Spasmodic dysphonia (SD) is a task-specific laryngeal dystonia that affects speech production. Co-occurring voice tremor (VT) often complicates the diagnosis and clinical management of SD. Treatment of SD and VT is largely limited to botulinum toxin injections into laryngeal musculature; other pharmacological options are not sufficiently developed.

STUDY DESIGN

Open-label study.

METHODS

We conducted an open-label study in 23 SD and 22 SD/VT patients to examine the effects of sodium oxybate (Xyrem), an oral agent with therapeutic effects similar to those of alcohol in these patients. Blinded randomized analysis of voice and speech samples assessed symptom improvement before and after drug administration.

RESULTS

Sodium oxybate significantly improved voice symptoms (P = .001) primarily by reducing the number of SD-characteristic voice breaks and severity of VT. Sodium oxybate further showed a trend for improving VT symptoms (P = .03) in a subset of patients who received successful botulinum toxin injections for the management of their SD symptoms. The drug's effects were observed approximately 30 to 40 minutes after its intake and lasted about 3.5 to 4 hours.

CONCLUSIONS

Our study demonstrated that sodium oxybate reduced voice symptoms in 82.2% of alcohol-responsive SD patients both with and without co-occurring VT. Our findings suggest that the therapeutic mechanism of sodium oxybate in SD and SD/VT may be linked to that of alcohol, and as such, sodium oxybate might be beneficial for alcohol-responsive SD and SD/VT patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:1402-1407, 2017.

Sodium oxybate plus nalmefene for the treatment of alcohol use disorder: A case series

The treatment of alcohol use disorder still remains a challenge. The efficacy of the combined pharmacological treatment for alcohol use disorder has been widely investigated with controversial results. The aim of our case series was to investigate the effect of nalmefene in patients not responding to sodium oxybate therapy. We describe seven cases of consecutive patients affected by alcohol use disorder, and treated with sodium oxybate (50 mg/kg per day) who did not achieve complete alcohol abstinence after at least one month of pharmacological treatment. Then, in partial- and non-responder patients to sodium oxybate treatment, administration of nalmefene, 18 mg as needed, was commenced. Our data show that, during the first month of the combined treatment of sodium oxybate plus nalmefene, patients were able to achieve alcohol abstinence (two patients), to suppress (five cases) or reduce (two patients) episodes of heavy drinking days, and to suppress the onset of craving for sodium oxybate (one patient). Likely, nalmefene may act in modulating the excessive reward effect of sodium oxybate, which may be responsible for the persistence of alcohol intake and for the onset of craving for sodium oxybate. However, controlled clinical trials to confirm the safety and efficacy of sodium oxybate plus nalmefene in treating alcohol use disorder are warranted.

A Brief Up-Date of the Use of Sodium Oxybate for the Treatment of Alcohol Use Disorder

The treatment of alcohol use disorder (AUD) with sodium oxybate (SMO) or gamma-hydroxybutyric acid (GHB) was introduced in Italy and Austria more than 20 years and 15 years ago, respectively, and it is now widely employed to treat alcohol withdrawal syndrome (AWS) and to maintain alcohol abstinence. These indications derive from its similar structure to the inhibitory neurotransmitter γ-amino-butyric acid (GABA), exerting an ethanol-mimicking effect, because it binds to GABAB receptors. Craving for, and abuse of, SMO remain a controversial issue; even though these unfavorable effects are evident in poly-drug addicted patients and in those with psychiatric diagnosis of borderline personality disorder. In addition, despite cases of severe intoxication and deaths being widely documented when GHB is used as "street drug"; its clinical use remains safe. Thus, the aim of the present review is to examine the role of SMO in the treatment of AUD, its possible implications in reducing alcohol consumption, and cases of abuse, and severe intoxication due to SMO during its clinical use in the treatment of AUD.

Pharmacotherapy of alcoholic liver disease in clinical practice

AIMS

Alcohol is the most commonly used addictive substance and alcoholic liver disease (ALD) is a major cause of chronic liver disease worldwide, responsible for 47.9% of all liver chronic deaths. Despite ALD has a significant burden on the health, few therapeutic advances have been made in the last 40 years, particularly in the long-term management of these patients.

METHODS

we searched in PubMed, Scopus, Google Scholar, and MEDLINE databases to identify relevant English language publications focused on long-term therapy of ALD.

RESULTS

From the huge literature on this topic, including about 755 studies, 75 were selected as eligible including clinical trials and meta-analysis.

CONCLUSIONS

Abstinence remains the cornerstone of ALD therapy but it is also the most difficult therapeutic target to achieve and the risk of recidivism is very high at any time. Several drugs (disulfiram, naltrexone, acamprosate, sodium oxybate) have proven to be effective to prevent alcohol relapse and increase the abstinence, although the psychotherapeutic support remains crucial. Baclofen seems to be effective to improve abstinence, showing an excellent safety and tolerability. ALD is often complicated by a state of malnutrition, which is related to a worst mortality. A nutritional therapy may improve survival in cirrhotic patients, reversing muscle wasting, weight loss and specific nutritional deficiencies. While in aggressive forms of alcoholic hepatitis are recommended specific drug treatments, including glucocorticoids or pentoxifylline, for the long-term treatment of ALD, specific treatments aimed at stopping the progression of fibrosis are not yet approved, but there are some future perspective in this field, including probiotics and antibiotics, caspase inhibitors, osteopontin and endocannabinoids.

Pharmacodynamic interactions of a solid formulation of sodium oxybate and ethanol in healthy volunteers

AIM

The pharmacologic effects of sodium oxybate (SO) have a number of similarities with those of alcohol. This study evaluated the pharmacodynamic interaction of SMO.IR (a solid immediate release formulation of SO) and alcohol (0.7 (males) or 0.57 (females) g kg(-1) alcohol using 40% vodka).

METHODS

In a randomized, double-blind, double-dummy, crossover trial, 24 healthy volunteers received randomly a) 2.25 g SMO.IR and placebo alcohol preparation, b) 2.25 g f SMO.IR and alcohol, c) 2.25 g SMO.IR matching placebo and alcohol and d) 2.25 g of SMO.IR matching placebo and placebo alcohol preparation. Objective and subjective cognitive parameters, adverse events and vital signs were assessed before, 15 and 165 min after treatment administration.

RESULTS

Alcohol produced the expected cognitive impairment and the expected subjective sedation rapidly after intake (from 15 min). The objective effects of SMO.IR were much less pronounced than those of alcohol. The reverse was observed for subjective complaints, which were related to lesser stimulation and greater sedation. Nevertheless, 165 min after administration this sedation feeling was less with SMO.IR than with alcohol. There was a significant interaction between SMO.IR and alcohol at 15 min (i.e. increase in alertness and stimulation and decrease in sedation). In addition, an isolated mild decrease in digit vigilance accuracy occurred at 165 min post-dose after the combination. The co-administration of SMO.IR and alcohol was safe and well-tolerated.

CONCLUSION

SMO.IR and alcohol have distinct adverse effect profiles. The objective effects of SMO.IR are much less marked than those of alcohol. No deleterious interaction was observed.

Identification and management of alcohol withdrawal syndrome

Symptoms of alcohol withdrawal syndrome (AWS) may develop within 6-24 h after the abrupt discontinuation or decrease of alcohol consumption. Symptoms can vary from autonomic hyperactivity and agitation to delirium tremens. The gold-standard treatment for AWS is with benzodiazepines (BZDs). Among the BZDs, different agents (i.e., long-acting or short-acting) and different regimens (front-loading, fixed-dose or symptom-triggered) may be chosen on the basis of patient characteristics. Severe withdrawal could require ICU admission and the use of barbiturates or propofol. Other drugs, such as α2-agonists (clonidine and dexmetedomidine) and β-blockers can be used as adjunctive treatments to control neuroautonomic hyperactivity. Furthermore, neuroleptic agents can help control hallucinations. Finally, other medications for the treatment for AWS have been investigated with promising results. These include carbamazepine, valproate, sodium oxybate, baclofen, gabapentin and topiramate. The usefulness of these agents are discussed.

Sodium oxybate in the treatment of alcohol withdrawal syndrome: a randomized double-blind comparative study versus oxazepam. The GATE 1 trial

BACKGROUND

Benzodiazepines (BDZs) are the gold standard in the treatment of alcohol withdrawal syndrome (AWS). Sodium oxybate (SMO) has been tested as a treatment for AWS with encouraging results. The aim of this phase IV, multicenter, randomized, double-blind, double-dummy study was to evaluate the efficacy of SMO in comparison with oxazepam in the treatment of uncomplicated AWS.

METHODS

Alcohol-dependent outpatients (n = 126) affected by uncomplicated AWS according to the Clinical Institute Withdrawal Assessment for Alcohol-revised (CIWA-Ar) scale were enrolled in the study and randomized in two groups: 61 patients received SMO and 65 patients received oxazepam for 10 days. The primary endpoint was the reduction of symptoms of AWS measured by the change in the total CIWA-Ar score from baseline (day 1) to the end of the study (day 10). This study is registered with ClinicalTrials.gov, number: NCT02090504 RESULTS: A significant decrease of the mean total CIWA-Ar score from baseline to the end of the study was found in both the SMO (p < 0.0001) and the oxazepam group (p < 0.0001), with no significant differences between the two treatments (p = 0.21). Treatment with SMO and oxazepam resulted in a marked decrease in the severity of the mean CIWA subscales, i.e. sweating, tremor, and anxiety, with no significant differences between the two treatments. Both drugs were well tolerated and no severe side effects were reported.

CONCLUSION

SMO is as effective as oxazepam, one of the gold standard BDZs, in the treatment of uncomplicated AWS. Due to its tolerability and absence of significant side effects, SMO may be considered a valid alternative choice in the treatment of AWS.

Pharmacological management of alcohol dependence: from mono-therapy to pharmacogenetics and beyond

Almost 10% of the world's population is affected by alcohol use disorders, and the treatment of alcohol dependence (AD) still remains a challenge. Patients with AD can differ in many traits. Three drugs (disulfiram, naltrexone, and acamprosate) have been approved by the FDA for the treatment of AD, and in some European countries sodium oxybate is also approved for this purpose. Combined pharmacological therapy has not provided such convincing results. Considering the fact that the "ideal" and effective drug for all types of alcoholic patients does not exists, the future challenge will be to identify a personalized approach. Recent data has shown that this objective can be achieved by investigating the genetic variability of the patient. Moreover, the use of replacement molecules can probably be considered an advantageous therapeutic opportunity (i.e. sodium oxybate). In addition, reduction of alcohol consumption is increasingly accepted as a viable treatment goal, and the use of nalmefene "as-needed" (a pharmacological approach similar to naltrexone, but, possibly, with lower hepatotoxicity) may help in the treatment of AD. Thus, it is important to stress that a pharmacological approach to treat AD should be preceded by the definition of patient characteristics; this may help in the choice of the most appropriate drug and it can be done more easily when more pharmacological options approved for the treatment of AD are also available.

Sodium oxybate in maintaining alcohol abstinence in alcoholic patients according to Lesch typologies: a pilot study

Sodium oxybate (SO) is a γ-amino-butyric acid (GABA)-ergic drug currently used for the treatment of alcohol dependence (AD) in some European countries. The aim of this study was to describe the effect of SO administration in alcoholics classified according to Lesch alcoholism typology (LAT). Forty-eight patients were enrolled and classified into four groups according to LAT. All patients were treated with oral SO (50 mg/kg of body weight t.i.d.) for 12 weeks. All patients significantly reduced their alcohol intake (p<0.001). Alcohol abstinence during the 12 weeks of treatment did not differ between the four groups at the end of treatment. Craving for SO did not significantly differ amongst groups; cases of SO abuse were very limited and were observed in almost 10% of patients. In conclusion, our study showed an overall efficacy of SO in the treatment of AD irrespective of LAT categories. However, our results confirm that alcoholics with psychiatric co-morbidity, particularly with a borderline personality disorder of Axis II, are at a greater risk of developing craving for and abuse of the drug: until craving for alcohol and craving for SO are characterized in depth, SO should be used with caution in these patients.

Management of alcohol dependence in patients with liver disease

Alcohol dependence represents a chronic and relapsing disease affecting nearly 10 % of the general population both in the USA and in Europe, with a widespread burden of morbidity and mortality. Alcohol dependence represents the most common cause of liver damage in the Western world. Although alcoholic liver disease is associated primarily with heavy drinking, continued alcohol consumption, even in low doses after the onset of liver disease, increases the risk of severe consequences, including mortality. Consequently, the ideal treatment of patients affected by alcohol dependence and alcoholic liver disease should aim at achieving long-term total alcohol abstinence and preventing relapse. The aim of the present review is to provide an update on the management of alcohol dependence in patients with alcoholic liver disease. Increasing evidence suggests the usefulness of psychosocial interventions and medications combined in order to reduce alcohol intake, promote abstinence and prevent relapse in alcohol-dependent patients. Disulfiram, naltrexone and acamprosate have been approved for this indication; gamma-hydroxybutyric acid (GHB) is approved in Italy and Austria. However, these drugs have not been tested in patients with advanced liver disease. Amongst other emerging pharmacotherapies for alcoholism, topiramate, ondansetron, and baclofen seem the most promising ones. Both topiramate and ondansetron have a safe profile in alcoholic patients; however, none of them has been tested in alcoholic patients with advanced liver disease. To date, baclofen represents the only anti-craving medication formally tested in a randomized clinical trial in alcoholic patients affected by liver cirrhosis, although additional confirmatory studies are warranted.

[Clinical Practice Guide for Early Detection, Diagnosis and Treatment of the Acute Intoxication Phase in Patients with Alcohol Abuse or Dependence: Part II: Evaluation and Management of Patients with Acute Alcohol Intoxication]

INTRODUCTION

Worldwide, alcohol is the second most-used psychotropic substance and the third risk factor for early death and disability. Its noxious use is a world public health problem given its personal, labor, family, economic and social impact. The identification of acute alcohol intoxication is extremely important, as well as the alcohol withdrawal syndrome and its complications, such as delirium tremens and Wernicke's encephalopathy in order to grant a timely treatment for those patients. This article introduces the evidence found so as to face and treat these clinic manifestations.

METHODOLOGY

Systematic revision of the evidence available together with an evaluation of pertinent guidelines found in literature so as to decide whether to adopt or adapt the existing recommendation for each question or to develop de novo recommendations. For de novo recommendations as well as those adapted, it was carried out an evidence synthesis, together with evidence tables and formulation of recommendations based on the evidence.

RESULTS

Evidence was found and recommendations were made for the diagnosis and treatment of acute alcohol intoxication, withdrawal syndrome, delirium tremens and Wernicke's encephalopathy.

Animal models for medications development targeting alcohol abuse using selectively bred rat lines: neurobiological and pharmacological validity

The purpose of this review paper is to present evidence that rat animal models of alcoholism provide an ideal platform for developing and screening medications that target alcohol abuse and dependence. The focus is on the 5 oldest international rat lines that have been selectively bred for a high alcohol-consumption phenotype. The behavioral and neurochemical phenotypes of these rat lines are reviewed and placed in the context of the clinical literature. The paper presents behavioral models for assessing the efficacy of pharmaceuticals for the treatment of alcohol abuse and dependence in rodents, with particular emphasis on rats. Drugs that have been tested for their effectiveness in reducing alcohol/ethanol consumption and/or self-administration by these rat lines and their putative site of action are summarized. The paper also presents some current and future directions for developing pharmacological treatments targeting alcohol abuse and dependence.

A Qualitative Descriptive Study of Perceived Sexual Effects of Club Drug Use in Gay and Bisexual Men

Club drug use is often associated with unsafe sexual practices and use remains prevalent among gay and bisexual men. Although epidemiological studies commonly report the risk of engaging in unsafe sex due to the effects of particular club drugs, there remain gaps in the literature regarding the specific sexual effects of such substances and the context for their use in this population. We examined secondary data derived from interviews with 198 club drug using gay and bisexual males in New York City and qualitatively describe subjective sexual effects of five drugs: ecstasy, GHB, ketamine, powder cocaine and methamphetamine. Differences and commonalities across the five drugs were examined. Results suggest that each drug tends to provide: 1) unique sexual effects, 2) its own form of disinhibition, and 3) atypical sexual choices, often described as "lower sexual standards." Differences across drugs emerged with regard to social, sensual and sexual enhancement, sexual interest, and impotence. Although some common perceived sexual effects exist across drugs, the wide variation in these effects suggests different levels of risk and may further suggest varying motivations for using each substance. This study seeks to educate public health officials regarding the sexual effects of club drug use in this population.

Sodium oxybate in maintaining alcohol abstinence in alcoholic patients with and without psychiatric comorbidity

Sodium oxybate (SMO) is a GABA-ergic drug currently used for the treatment of alcohol-dependence in some European countries. In particular, clinical studies have shown a role of SMO in promoting alcohol abstinence, as well as in relieving withdrawal symptoms. The aim of this study was to describe alcohol abstinence and the onset of craving for and abuse of SMO in alcohol-dependent subjects with and without psychiatric co-morbidity. Forty-eight patients were enrolled and classified into two groups: group A (20 alcoholics without any psychiatric co-morbidity) and group B (28 alcoholics with a psychiatric co-morbidity). All patients were treated with oral SMO (50 mg/kg of body weight t.i.d.) for 12 weeks. Alcohol abstinence as well as alcohol drinking during the 12 weeks of treatment did not differ between the two groups at the end of treatment (p=0.9). In addition, a reduction of alcohol intake in both groups has been observed (p<0.0001). On the other hand, craving for SMO was significantly more frequent in group B than group A (p=0.001). Cases of SMO abuse were observed in almost 10% of group B patients. In conclusion, alcohol abstinence achieved through SMO administration does not differ in patients with and without psychiatric co-morbidity. However, alcoholics with co-morbid borderline disorders appear to be at high risk of developing craving for and abuse of the drug; therefore, SMO may not be indicated in these patients.

Sodium oxybate in the treatment of binge eating disorder: an open-label, prospective study

OBJECTIVE

To assess preliminarily the effectiveness of sodium oxybate in binge eating disorder.

METHOD

This was an open-label, prospective, 16-week, flexible dose study of sodium oxybate in binge eating disorder. The primary outcome was binge eating episode frequency.

RESULTS

Twelve individuals received sodium oxybate, 10 completed at least one postbaseline evaluation, and five completed the study. Mean dose at endpoint was 7.1 (2.0) g/day. Sodium oxybate was associated with significant reductions in frequency of binge days and binge episodes, as well as measures of clinical severity, eating pathology, obsessive-compulsive symptoms, food cravings, body mass index, and body weight. Nine participants had remission of binge eating and five lost ≥5% of their baseline weight; all five of the latter participants had remission of binge eating.

DISCUSSION

In this open-label trial, sodium oxybate was effective in binge eating disorder, but associated with high a discontinuation rate.

Gamma-hydroxybutyrate (GHB) for treatment of alcohol withdrawal and prevention of relapses

BACKGROUND

Chronic excessive alcohol consumption may lead to dependence, and to alcohol withdrawal syndrome (AWS) in case of abrupt drinking cessation. Gamma-hydroxybutyric acid (GHB) can prevent and suppress withdrawal symptoms, and improve the medium-term abstinence rate. A clear balance between effectiveness and harmfulness has not been yet established.

OBJECTIVES

To evaluate the efficacy and safety of GHB for treatment of AWS and prevention of relapse

SEARCH STRATEGY

We searched Cochrane Drugs and Alcohol Group' Register of Trials (October 2008), PubMed, EMBASE, CINAHL (January 2005 - October 2008), EconLIT (1969 to February 2008), reference list of retrieved articles

SELECTION CRITERIA

Randomized controlled trials (RCTs) and Controlled Prospective Studies (CPS) evaluating the efficacy and the safety of GHB vs placebo or other pharmacological treatments.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data and assessed the methodological quality of studies.

MAIN RESULTS

Thirteen RCTs were included. Eleven studies were conducted in Italy.For withdrawal syndrome, comparing GHB 50mg with placebo, results from 1 study, 23 participants favour GHB for withdrawal symptoms: WMD -12.1 (95% CI, -15.9 to -8.29) and side effects were more frequent in the placebo group: RR 16.2 (95% CI, 1.04 to 254.9).In the comparison with Chlormetiazole, for GHB 50mg, results from 1 study, 21 participants favour GHB for withdrawal symptoms: MD -3.40 (95% CI -5.09 to -1.71), for GHB 100mg, results from 1 study, 98 participants favour anticonvulsants for side effects: RR 1.84 (95% CI 1.19 to 2.85).At mid-term, comparing GHB with placebo, results favour GHB for abstinence rate (RR 5.35; 1.28-22.4), controlled drinking (RR 2.13; 1.07-5.54), relapses (RR 0.36; 0.21-0.63), and number of daily drinks (WMD -4.60; -6.18 to -3.02). GHB performed better than NTX and Disulfiram on abstinence (RR 2.59; 1.35-4.98, RR 1.66; 0.99-2.80 respectively). The association of GHB and NTX was better than NTX on abstinence (RR 12.2; 1.79-83.9), as well was the association of NTX, GHB and Escitalopram versus Escitalopram alone (RR 4.58; 1.28-16.5). For Alcohol Craving Scale results favour GHB versus placebo (WMD -1.90; -2.45 to 1.35) and Disulfiram (WMD -1.40; -1.86 to-0.94).

AUTHORS' CONCLUSIONS

GHB 50mg is effective compared to placebo in the treatment of AWS, and in preventing relapses in previously detoxified alcoholics at 3 months follow-up, but the results of this review do not provide sufficient evidence in favour of GHB compared to benzodiazepines and Chlormethiazole for AWS prevention. GHB is better than NTX and Disulfiram in maintaining abstinence and it has a better effect on craving than placebo and Disulfiram. Side effects of GHB are not statistically different from those with BZD, NTX or Disulfiram. However, concern has been raised regarding the risk of developing addiction, misuse or abuse, especially in polydrug abusers.

Incidence of craving for and abuse of gamma-hydroxybutyric acid (GHB) in different populations of treated alcoholics: an open comparative study

Gamma-hydroxybutyric acid (GHB) is a drug currently used for the treatment of alcohol dependence. The aim of our study was to investigate the incidence of craving for and abuse of GHB in 47 patients enrolled and divided into four groups: group A (pure alcoholics), group B (alcoholics with a sustained full remission from cocaine dependence), group C (alcoholics with a sustained full remission from heroin dependence) and group D (alcoholics in a methadone maintenance treatment [MMT] programme). All patients were treated with an oral dose of GHB (50 mg/kg of body weight t.i.d.) for three months. Craving for GHB was statistically significant higher in group B than in group A (P < 0.001), C (P = 0.01) and D (P < 0.001), and in group C than in group D (P < 0.05). Abuse of GHB proved to be statistically significant higher in group B than in group A (P < 0.001) and D (P < 0.01), and in group C than in group A (P = 0.01) and D (P < 0.05). Thus, the administration of GHB in alcoholics with a sustained full remission from heroin or cocaine dependence is not recommended; however, this should not discourage physicians from using GHB for the treatment of pure alcoholics or alcohol dependents following a MMT.

Gamma-Hydroxybutyrate Reduces both Withdrawal Syndrome and Hypercortisolism in Severe Abstinent Alcoholics: An Open Study vs. Diazepam

In 42 alcoholic inpatients we performed an open randomized study to compare the effects of diazepam and gamma-hydroxybutyrate (GHB) on the suppression of severe alcohol withdrawal syndrome and hypercortisolism. Both diazepam (.5 mg/kg bodyweight, q.i.d.) and GHB (50 mg/kg bodyweight, q.i.d.) were orally administered for three weeks. During all study period, GHB was more able than diazepam in reducing both withdrawal syndrome and hypercortisolism. These effects were evident during the first week of treatment and persisted throughout the study period. The results confirm a strict correlation between high levels of plasma cortisol and alcohol withdrawal symptoms and they show a slight superiority of GHB over diazepam in the suppression of both ethanol withdrawal and hypercortisolism. Taken together, our data suggest that GHB may act as potent anti-withdrawal agent in severe abstinent alcoholics.

Gamma hydroxybutyric acid (GHB) for the treatment of alcohol dependence: a review

Gamma-hydroxybutyric acid (GHB) is a short-chain fatty acid structurally similar to the inhibitory neurotransmitter gamma-aminobutyric acid. Clinical trials have demonstrated that 50-100 mg/kg of GHB fractioned into three or six daily doses is able to suppress alcohol withdrawal symptoms and facilitates the maintenance of abstinence from alcohol. These studies have also shown that GHB craving episodes are a very limited phenomenon (about 10-15%). Thus, physicians with access should consider the clinical efficacy of GHB as a valid pharmacological tool for the treatment of alcohol addiction.

Characterization and pharmacology of the GHB receptor

Radioligand binding using [(3)H]NCS-382, an antagonist of the GHB receptor, revealed specific binding sites in the rat cerebrocortical and hippocampal membranes. Scatchard analysis of saturation isotherms revealed two different populations of binding sites. NCS-382 was about 10 times more potent than GHB in inhibiting [(3)H]NCS-382 binding. A variety of ligands for other receptors did not affect [(3)H]NCS-382 binding. Quantitative autoradiographic analysis of [(3)H]NCS-382 binding revealed similar characteristics. Thus [(3)H]NCS-382, being more potent and selective, offers advantage over [(3)H]GHB as a radioligand. Unlike GHB, several analogues of GHB such as UMB68 (a tertiary alcohol analogue of GHB), UMB86 (4-hydroxy-4-napthylbutanoic acid, sodium salt), UMB72 [4-(3-phenylpropyloxy)butyric acid, sodium salt], UMB73 (4-benzyloxybutyric acid, sodium salt), UMB66 (3-chloropropanoic acid), gamma-hydroxyvaleric acid (that is, GHV, a 4-methyl-substituted analogue of GHB), 3-HPA (3-hydroxyphenylacetic acid), and ethers of 3-hydroxyphenylacetic acid (UMB108, UMB109, and UMB119) displaced [(3)H]NCS-382 without affecting [(3)H]GABA binding to GABA(B) receptor. Thus these compounds offer an advantage over GHB as an experimental tool. Our study, aimed at exploring the potential involvement of the GHB receptor in the pharmacology of ethanol, indicated that ethanol does not affect [(3)H]NCS-382 binding in the rat brain, thereby suggesting that ethanol does not interact directly with the GHB receptor. Our study, aimed at exploring the involvement of the GHB receptor in the pathology of succinate semialdehyde dehydrogenase deficiency, which is known to cause elevation of GHB levels, revealed no change in the affinity, receptor density or displacement potency as determined by using [(3)H]NCS-382 as a radioligand in Aldh5a1(-/-) vs. Aldh5a1(+/+) mouse brain.

Gamma-hydroxybutyric acid in male and female cynomolgus monkeys trained to discriminate 1.0 or 2.0 g/kg ethanol

Gamma-hydroxybutyric acid has been proposed as a pharmacotherapy for alcoholism in part based on similar discriminative stimulus effects as ethanol. To date, drug discrimination studies with gamma-hydroxybutyric acid and ethanol have exclusively used rodents or pigeons as subjects. To evaluate possible differences between species, sex, and route of administration, this study investigated the substitution of gamma-hydroxybutyric acid (intragastrically or intramuscularly) for ethanol 30 or 60 min after administration in male (n=6) and female (n=7) cynomolgus monkeys trained to discriminate 1.0 and 2.0 g/kg ethanol. At least one dose of gamma-hydroxybutyric acid completely or partially substituted for ethanol in three of the 13 monkeys tested, with each case occurring in female monkeys. Ethanol-appropriate responding did not increase with gamma-hydroxybutyric acid dose. Monkeys were more sensitive to the response rate decreasing effects of gamma-hydroxybutyric acid administered intramuscularly compared with intragastrically. The lack of gamma-hydroxybutyric acid substitution for ethanol suggests that these drugs have different receptor bases for discrimination. Furthermore, the data do not strongly support shared discriminative stimulus effects as the rationale for gamma-hydroxybutyric acid pharmacotherapy for alcoholism.

New developments for the pharmacological treatment of alcohol withdrawal syndrome. A focus on non-benzodiazepine GABAergic medications

Alcohol withdrawal syndrome (AWS) can be a life-threatening condition affecting some alcohol-dependent patients who abruptly discontinue or decrease their alcohol consumption. The main objectives of the clinical management of AWS include: to decrease the severity of symptoms, prevent more severe withdrawal clinical manifestations and facilitate entry of the patient into a treatment program in order to attempt to achieve and maintain long-term abstinence from alcohol. At present, benzodiazepines represent the drugs of choice in the treatment of AWS. However, in line with the possible side effects and addictive properties related to benzodiazepine use, there is growing evidence to suggest that non-benzodiazepine GABAergic compounds represent promising medications in the treatment of alcohol-dependent patients. This review focuses on research into non-benzodiazepine GABAergic medications for the treatment of AWS. Among them, carbamazepine, gabapentin and valproic acid are the most studied. The studies on carbamazepine seem to be the most compelling. Preliminary data have also suggested the possible utility of baclofen and topiramate, although further evidence is needed. The promising results in terms of both safety and efficacy are reported. However, we also note the need of more methodologically controlled studies on a greater number of patients, involving more complicated forms of AWS.

gamma-Hydroxybutyric acid (GHB) suppresses alcohol's motivational properties in alcohol-preferring rats

gamma-Hydroxybutyric acid (GHB) reduces alcohol drinking, promotes abstinence from alcohol, suppresses craving for alcohol, and ameliorates alcohol withdrawal syndrome in alcoholics. At preclinical level, GHB suppresses alcohol withdrawal signs and alcohol intake in rats. The present study was designed to investigate whether GHB administration was capable of affecting alcohol's motivational properties (the possible animal correlate of human craving for alcohol) in selectively bred Sardinian alcohol-preferring rats. To this aim, rats were initially trained to lever press for alcohol (15%, vol/vol) under a procedure of operant, oral alcohol self-administration (fixed ratio 4 in 30-min daily sessions). Once responding for alcohol had stabilized, rats were divided into two groups and allocated to two independent experiments. Experiment 1 assessed the effect of GHB (0, 25, 50, and 100mg/kg, i.p.) on breakpoint for alcohol, defined as the lowest response requirement not achieved by each rat when exposed to a single-session progressive ratio schedule of reinforcement. Experiment 2 assessed the effect of GHB (0, 25, 50, and 100mg/kg, i.p.) on single-session extinction responding for alcohol (alcohol was absent and unreinforced responding was recorded). Breakpoint and extinction responding for alcohol are reliable indexes of alcohol's motivational strength. In Experiment 1, all doses of GHB reduced--by approximately 20% in comparison to saline-treated rats--breakpoint for alcohol. In Experiment 2, administration of 25, 50, and 100mg/kg GHB reduced--by approximately 25%, 40%, and 50%, respectively, in comparison to saline-treated rats--extinction responding for alcohol. Conversely, no dose of GHB altered breakpoint and extinction responding for sucrose (3%, wt/vol) in two independent subsets of Sardinian alcohol-preferring rats. Together, these data suggest that GHB administration specifically suppressed alcohol's motivational properties in Sardinian alcohol-preferring rats. These results are consistent with the anticraving properties of GHB observed in clinical studies.

Use, function, and subjective experiences of gamma-hydroxybutyrate (GHB)

Self-reported use of gamma-hydroxybutyrate (GHB) among clubbers has increased over the last decade, and is often reported in the scientific literature in association with negative events such as amnesia, overdose, and use in drug facilitated sexual assault. However, there has been relatively little work investigating the phenomenology of GHB intoxication, and the reasons underlying use. In this study, 189 individuals reporting at least one lifetime use of GHB completed an online questionnaire recording GHB use behaviours, GHB use function, and subjective GHB effects. The most frequently reported primary GHB use functions were for recreation (but not in nightclubs) (18.3%); to enhance sex (18.3%); to be sociable (13.1%); and to explore altered states of consciousness (13.1%). GHB was more commonly used within the home (67%) compared to nightlife environments (26.1%) such as clubs, although this differed on the basis of respondent's sexuality. Principle components analysis of GHB user responses to the subjective questionnaire revealed six components: general intoxication effects, positive intoxication effects, negative intoxication effects, negative physiological effects, positive sexual effects and negative sexual effects. Component scores predicted function of use.

Comparing and combining gamma-hydroxybutyric acid (GHB) and naltrexone in maintaining abstinence from alcohol: an open randomised comparative study

Maintaining abstinence from alcohol is the main goal in treating alcohol dependence. Our aim was to evaluate the efficacy of gamma-hydroxybutyric acid (GHB) and naltrexone (NTX), and their combination in maintaining abstinence. Fifty-five alcoholics were randomly enrolled in three groups and treated for 3 months with GHB, GHB plus NTX, and NTX, respectively. At the end of treatments, abstinence was maintained by 13 patients (72.2%) in combination group, 8 patients (40%; P=0.03) in GHB group, and one patient (5.9%; P=0.0001) in NTX group. Relapses in heavy drinking tended to occur more frequently in GHB group (15%) than in either combination group (no cases) or NTX group (5.9%), but such differences were not statistically significant. The GHB/NTX combination was more effective than either drug given alone; this suggests that the two drugs combine their different actions synergistically without suppressing the favourable effects of each other.

Effects of gamma-hydroxybutyric acid and flunitrazepam on ethanol intake in male rats

Both gamma-hydroxybutyric acid (GHB) and flunitrazepam are often used illicitly in combination with ethanol. Nevertheless, the effects that these and other drugs of abuse have on the reinforcing effects of ethanol remain inconclusive. To test the effects of GHB and flunitrazepam on contingent ethanol intake, twelve male Long-Evans rats were trained to orally consume ethanol using a saccharin-fading procedure. After training, all animals preferentially consumed ethanol instead of water at each of five ethanol concentrations (0-32%) when tested with a two-bottle preference test in the homecage. Animals then received a noncontingent dose of ethanol (0.32, 0.56, 1, and 1.33 g/kg), flunitrazepam (0.032, 0.1, and 0.32 mg/kg), or GHB (100, 180, 320, and 560 mg/kg) prior to each subject's daily access to ethanol (18% v/v). Noncontingent doses of ethanol decreased ethanol intake, however, the subjects consumed enough ethanol to maintain a consistent total ethanol dose in g/kg. Flunitrazepam did not affect ethanol intake at any dose tested, whereas GHB only affected intake at the highest dose (560 mg/kg), a dose that also produced sedation. These data suggest that there are perceptible or qualitative differences between GHB, flunitrazepam, and ethanol in terms of their capacity for modulating oral ethanol intake in outbred rats.

Preference for palatable food is reduced by the gamma-hydroxybutyrate analogue GET73, in rats

Palatability and variety of foods are major reasons for "hedonic" eating, and hence for overeating and obesity. Palatable food and drugs of abuse share a common reward mechanism, and compounds that block the reinforcing effect of drugs of abuse preferentially suppress the intake of palatable foods. This research was aimed at studying the influence of the gamma-hydroxybutyrate analogue N-(4-trifluoromethylbenzyl)-4-methoxybutanamide (GET73) - that inhibits alcohol consumption - on consumption and reinforcing effect of palatable food. Adult male rats were used. For place preference conditioning, sweetened corn flakes were used as the reinforcer, and GET73 (50, 100 and 200mgkg(-1)) or vehicle were orally (p.o.) administered either 30min before each training session and the test session, or only before the test session. To study the influence on consumption, GET73 was given p.o. at the same doses once daily for 12 days to rats given free access to both palatable and varied food (cafeteria diet) or to standard chow. Both acquisition and expression of palatable food-induced conditioned place preference were inhibited by GET73, either administered throughout the conditioning period or only before the test session. GET73 reduced also the consumption of cafeteria food, while that of standard chow was increased. At these doses, GET73 had no detrimental effect on open-field behaviour. GET73 seems to specifically attenuate the gratification produced by varied and palatable food, without affecting the consumption of not particularly palatable chow. Since, overweight and obesity are mostly due to the overeating of palatable and varied foods, drugs like GET73 could represent a somewhat ideal and rational approach to obesity treatment.

GHB use among gay and bisexual men

The recreational use of gamma-hydroxybutyrate (GHB) has been relatively understudied, despite its popularity in gay communities. We examined the use of GHB in a sample of 450 club drug using gay and bisexual men. Of these, 29% indicated use of the substance in the recent past. GHB users were similar to those in the sample who reported no use along key demographic factors, although GHB users were more likely to identify as gay than bisexual and were slightly older. Poly-drug use was common, with close to half of GHB users combining with methamphetamine, MDMA, or ketamine; approximately one quarter also used GHB with alcohol. Participants reported that GHB was often used at nightclubs, circuit parties, sex parties, and sex clubs, with HIV-positive men more likely to use the substance in sexual contexts. Use of GHB is common among a certain subset of gay men despite warnings within the community about the potentially fatal effects of the substance, suggesting that more effort be given to educate drug using gay men about GHB.

Comorbidity between alcohol dependence and illicit drug dependence in adolescents with antisocial behavior and matched controls

BACKGROUND

Knowledge regarding the causes of comorbidity among substance use disorders can have significant impact on future research examining the etiology of these disorders. Unfortunately, the conclusions of past studies examining the comorbidity among substance use disorders are conflicting; some studies emphasize familial influences common to multiple substances, while others emphasize substance-specific influences. Discrepancies in results may reflect different analytical approaches or differences in the samples. Here, we examine the causes of comorbidity between alcohol dependence and illicit drug dependence in adolescents.

METHODS

We ascertained a clinical sample of adolescents treated for antisocial behavior and substance use disorders and their siblings and a matched control sample. A model fitting approach was used to test 13 alternative hypotheses for the causes of comorbidity.

RESULTS

The best supported hypothesis for the comorbidity between alcohol dependence and illicit drug dependence was a model hypothesizing that comorbid disorders are alternate forms of a single underlying liability. The next best fitting models were two of the correlated liabilities models (correlated risk factors and reciprocal causation).

DISCUSSION

The results suggest that the best hypotheses explaining the comorbidity between alcohol and illicit drug dependence in adolescents are that alcohol dependence and illicit drug dependence are manifestations of a single general liability to develop substance dependence or that there are separate liabilities that are highly correlated.

Understanding and treating alcohol dependence

This article represents the proceedings of a symposium presented at the 158th Annual Meeting of the American Psychiatric Association held in Atlanta, Georgia, on May 24, 2005. The organizer/chairman was Bankole A. Johnson, DSc, MD, PhD. The presentations included the following: (1) Neuropharmacological Basis of Alcohol Dependence, by George F. Koob, PhD; (2) Recent Developments in the Genetics of Alcohol Dependence, by Marc A. Schuckit, MD; (3) New Pharmacological Strategies for Treating Alcohol Dependence, by Barbara J. Mason, PhD; (4) New Medications: The Use of Anticonvulsants, Both Alone and in Combination, with Various Forms of Psychotherapy, by Bankole A. Johnson, DSc, MD, PhD; and (5) Differential Effects of Pharmacological Agents on Craving, by Nassima Ait-Daoud, MD.

A qualitative analysis of GHB use among gay men: Reasons for use despite potential adverse outcomes

This paper examines the use of gamma-hydroxybutyrate (GHB) among a sample of gay men in New York City, who identify GHB as their most frequently used club drug. The sample was drawn from a larger longitudinal investigation of club drug using men. Thematic analysis yielded findings regarding perceived stigma for GHB use, tolerance of potential adverse side effects, and reasons for why some prefer this substance to other club drugs. Specifically, our findings suggest that GHB is viewed unfavorably in many social circles, that side effects are tolerated by frequent GHB users, and that the drug is chosen over other substances because the short duration of action, energy boost, sleep assistance, increase in libido, and limited after-effects. Examining the reasons why men use this substance will lead to the development of GHB specific prevention strategies, which accurately address the consequences of use as well as the motivations that individuals possess for using the substance.

Recent advances in the development of treatments for alcohol and cocaine dependence: focus on topiramate and other modulators of GABA or glutamate function

Neuroscientific developments have promulgated interest in developing efficacious medications for the treatment of substance dependence. Previous pharmacological strategies that involve the use of relatively specific medications to alter corticomesolimbic dopaminergic neuronal activity--the critical pathway for expression of the reinforcing effects of abused drugs--have yielded modest efficacy in the treatment of alcohol dependence, and no medication has been established as a treatment for cocaine dependence. Since corticomesolimbic dopaminergic neurons interact with other neurotransmitters that modulate the effects of dopamine in the nucleus accumbens, would it not be possible to control these dopaminergic effects more reliably with a medication that acts contemporaneously on more than one neuromodulator of dopaminergic function? Further, since the long-term use of either alcohol or cocaine results in neuronal adaptations as a result of sensitisation, would the chances of effective therapy not be bolstered by administering a medication that was also able to mitigate these chronic effects? Thus, a new conceptual approach is needed. My proposal is that a medication--in this case topiramate--that principally potentiates inhibitory GABA(A) receptor-mediated input and antagonises excitatory glutamatergic afferents to the corticomesolimbic dopaminergic system should have therapeutic potential in treating either alcohol or cocaine dependence or perhaps both. This is because the principal neurochemical effects of topiramate would not only serve to decrease the acute reinforcing effects of alcohol or cocaine, but might also facilitate cessation of their use following a period of long-term use by decreasing neuronal sensitisation. This overview highlights the scientific concepts and clinical evidence for the development of topiramate in the treatment of alcohol dependence and introduces preliminary evidence to indicate that it might also have utility in treating cocaine dependence. Finally, to place the material on topiramate in context, information has been included on the utility and development of other medications that modulate GABA- or glutamate-mediated neuronal systems for the treatment of alcohol or cocaine dependence.

Chemosynthesis of bioresorbable poly(γ-butyrolactone) by ring-opening polymerisation: a review

Recent advances in the synthesis of poly(gamma-butyrolactone) have yielded homopolymers of up to 50,000 Mw from the low-cost monomer gamma-butyrolactone. This monomer has for the better part of a century been thought impossible to polymerise. Poly(gamma-butyrolactone) displays properties that are ideal for tissue-engineering applications and the bacterially derived equivalent, poly(4-hydroxybutyrate) (P4HB), has been evaluated for such uses. The glass transition temperature (-48 to -51 degrees C), melting point (53-60 degrees C), tensile strength (50 MPa), Young's modulus (70 MPa) and elongation at break (1000%) of P4HB make it a very useful biomaterial. Poly(gamma-butyrolactone) degrades to give gamma-hydroxybutyric acid which is a naturally occurring metabolite in the body and it has been shown to be bioresorbable. Investigation into the synthesis of poly(gamma-butyrolactone) has recently produced homo-oligomeric diols 400-1000 Mw that are suitable for reacting with diisocyanates to form polyurethanes. Biodegradable polyurethanes made from diols of polyglycolide (PGA) and poly(epsilon-caprolactone) (PCL) have the disadvantage of high glass transition and slow degradation, respectively. Poly(gamma-butyrolactone) can be thought of as being the missing link in the biodegradable polyester family immediately between PGA and PCL and displaying intermediate properties.

How many cravings? Pharmacological aspects of craving treatment in alcohol addiction: a review

In the last decade, craving has increasingly been considered an important target for the treatment of patients with alcohol problems, and several drugs able to interfere with the neurotransmitters involved in craving mechanisms have been experimented. However, different subtypes of patients could have different mechanisms at the basis of alcohol craving. In this review, the main drugs currently used in the treatment of patients with alcohol problems are described. A hypothesis of pharmacological treatment of the different types of craving is also discussed.

Suppression of Craving for γ-Hydroxybutyric Acid by Naltrexone Administration

Gamma-hydroxybutyric acid (GHB) is currently used to induce and maintain abstinence from alcohol. Cases of craving and desire to increase doses of GHB have been reported in both clinical trials and nonclinical self-administration. The enhancement of dopamine activity induced by GHB receptor activation might play a role in the euphoric effect and potential craving and the consequent abuse of this drug. Naltrexone (NTX), a mu-opioid antagonist, is effective in inducing and maintaining abstinence from alcohol, reducing relapses in heavy drinking and craving for alcohol in alcohol-dependent outpatients. Taking into account the alcohol antireward property of NTX, we tested its activity in reducing craving for GHB in 3 consecutive cases of alcoholics who manifested craving for this drug. In all patients the combination with NTX suppressed the craving for GHB. The antireward effect of NTX likely results from its interference with the GHB-induced dopamine release, leading to a partial blockade of the GHB reinforcing effect responsible of the craving for the drug. A combined therapy with GHB and NTX seems to be able to suppress craving for the former, thus improving the manageability and safety of treatment.

Safety and Efficacy of GABAergic Medications for Treating Alcoholism

This article highlights the proceedings of a symposium presented at the 27th Annual Scientific Meeting of the Research Society on Alcoholism in Vancouver, British Columbia, Canada, June 29, 2004. The organizers and co-chairs were Bankole A. Johnson, MD, PhD, and Robert M. Swift, MD, PhD. The presentations included (1) Introduction, by Bankole A. Johnson; (2) Safety, Tolerability, and Efficacy of gamma-Hydroxybutyric Acid and Baclofen in the Treatment of Alcohol Addiction, by Giovanni Addolorato; (3) Safety of Gabapentin in Treating Alcoholism, by Hugh Myrick; (4) New Data on the Safety and Effectiveness of Topiramate in the Treatment of Alcohol Dependence, by Bankole A. Johnson; (5) Evaluating the Risk of Benzodiazepine Prescription to Alcohol-Dependent Individuals, by Domenic A. Ciraulo; and (6) Safety and Efficacy of GABAergic Agents in Treating Alcoholics: Discussion, by Robert M. Swift.

Failure of gamma-hydroxybutyric acid both to increase neuroactive steroid concentrations in adrenalectomized-orchiectomized rats and to induce tolerance to its steroidogenic effect in intact animals

Gamma-Hydroxybutyric acid (GHB), a drug proposed in the treatment of alcohol withdrawal syndrome, increases the cerebrocortical and plasma concentrations of the neuroactive steroids allopregnanolone and allotetrahydrodeoxycorticosterone (THDOC). In the present study, we examined the role of hypothalamic-pituitary-adrenal (HPA) axis in the effect of GHB by measuring the concentrations of these steroids in the brain and plasma of adrenalectomized-orchiectomized (Adx-Orx) rats. The acute administration of GHB (500 mg/kg, i.p.) induced in 30 min an increase in the concentrations of allopregnanolone, THDOC and their precursors pregnenolone and progesterone in different brain areas (cerebral cortex, hypothalamus and cerebellum) and plasma of sham-operated rats but had no effect on the concentrations of these compounds in Adx-Orx rats, suggesting that activation of the HPA axis mediates the effect of GHB on brain and plasma concentrations of neuroactive steroids. Moreover, we evaluated whether repeated exposure of GHB induces tolerance to its steroidogenic effects. Chronic administration of GHB (500 mg/kg, i.p., twice a day for 10 days) to intact animals failed to affect the levels of progesterone, allopregnanolone, or THDOC measured 3 or 48 h after the last drug administration, whereas a challenge injection of GHB or ethanol was still able to increase the concentrations of these steroids in brain and plasma. These results indicate that repeated exposure to GHB fails to induce tolerance or cross-tolerance to the steroidogenic action of GHB or ethanol, respectively.

Gamma-hydroxybutyrate and ethanol depress spontaneous excitatory postsynaptic currents in dopaminergic neurons of the substantia nigra

Gamma-hydroxybutyrate (GHB) has been shown to have therapeutical properties in various psychiatric disorders, especially in alcohol abuse, and to mimic different actions of ethanol at the cellular and system level. Using whole-cell patch-clamp recordings on brain slices of 21- to 25-day-old rats, the present study investigated the effects of GHB and ethanol on spontaneous excitatory postsynaptic currents (sEPSCs) in dopaminergic neurons of the substantia nigra pars compacta (SNc). sEPSCs are an index of glutamate release from the excitatory input to dopamine cells, which play a key role in different reward-related behaviors. We found that GHB and ethanol depressed both the frequency and the amplitude of sEPSCs. These effects were GABA(B)-independent and the GHB-induced depression was blocked by the GHB receptor antagonist 6,7,8,9-tetrahydro-5[H]benzocyclohepte-5-ol-4-ylidene acetic acid (NCS-382), pointing to a specific effect of this drug. The effects of ethanol were not affected by NCS-382. This study indicates that GHB and ethanol share the effect of reducing the efficacy of excitatory glutamatergic neurotransmission in the SNc by acting through different mechanisms.