Diazepam maintenance of alcohol preference during alcohol withdrawal

GABAergic mechanisms in alcohol dependence

The target of alcohol's effect on the central nervous system has been sought for more than 50 years in the brain's GABA system. The behavioral and emotional effects of alcohol in humans and rodents are very similar to those of barbiturates and benzodiazepines, and GABAA receptors have been shown to be one of the sites of alcohol action. The mechanisms of GABAergic inhibition have been a hotspot of research but have turned out to be complex and controversial. Genetics support the involvement of some GABAA receptor subunits in the development of alcohol dependence and in alcohol use disorders (AUD). Since the effect of alcohol on the GABAA system resembles that of a GABAergic positive modulator, it may be possible to develop GABAergic drug treatments that could substitute for alcohol. The adaptation mechanisms of the GABA system and the plasticity of the brain are a big challenge for drug development: the drugs that act on GABAA receptors developed so far also may cause adaptation and development of additional addiction. Human polymorphisms should be studied further to get insight about how they affect receptor function, expression or other factors to make reasonable predictions/hypotheses about what non-addictive interventions would help in alcohol dependence and AUD.

The effectiveness of pharmacological approaches in the treatment of alcohol withdrawal syndrome (AWS): a literature review

Mortality statistics for excessive alcohol consumption show no signs of abatement, with a report published in 2011 from the World Health Organization (WHO) estimating that 2.5 million people worldwide died because of their alcohol consumption. Serious physiological, psychological, social and legal problems are thought to affect many more. Alcohol withdrawal syndrome (AWS) is a potentially life-threatening condition that often occurs in those individuals who significantly reduce or stop their intake after a prolonged and excessive period of drinking. Pharmacological treatment of the AWS has traditionally been undertaken by the use of the benzodiazepines, but recent years have witnessed the emergence of several alternatives. The aim of this paper was (1) to review the evidence base supporting the use of various pharmacological agents currently employed to treat AWS, and (2) to consider the efficacy and safety of the emerging alternatives to the benzodiazepines. The Cochrane Database of Systematic Reviews, CINAHL, Embase, PsycINFO, MEDLINE and BNI databases were extensively searched in order to retrieve the maximum number of relevant articles. Reference lists from relevant literature were also used to identify other potential studies for inclusion. All studies concerned with measuring the efficacy and safety of the various pharmacological treatment options for AWS were considered and a total of 63 trials were included in this review. Findings support the use of benzodiazepines as the recommended drug of choice for the treatment of AWS in the absence of adequate evidence to support the use of alternative agents. There is a lack of evidence of a superior pharmacological agent to the benzodiazepines for the treatment of AWS. There are several studies that have shown that there are pharmacological alternatives that could compete or act as an adjunct with the benzodiazepines in terms of high efficacy and safety in the treatment of AWS, but there is a need for further quality research to be carried out before definitive conclusions can be drawn.

Substitution therapy for alcoholism: time for a reappraisal?

A number of compounds already in use as medications for various indications substitute for ethanol at clinically relevant brain pathways, in particular, at gamma-aminobutyric acid (GABA) receptors. Nevertheless, although substitute medications have been recognized for heroin and tobacco dependence, patients with alcohol dependence are rarely offered an analogous approach. Benzodiazepines may have paradoxical effects, and abuse and dependence are known. Baclofen (GABA(B) agonist) has not been associated with dependence or misuse and has been effective in several trials in preventing relapse, although research is required to establish the optimal dosing regimen. GABA-ergic anticonvulsants, helpful in treating withdrawal, have yet to emerge as effective in relapse prevention. Clomethiazole and sodium oxybate, the latter having been shown to be effective in relapse prevention, have incurred a reputation for dependence and abuse. However, data have emerged showing that the risk of abuse of sodium oxybate is lower than many clinicians had foreseen. For a condition where existing therapies are only effective in a proportion of patients, and which has high morbidity and mortality, the time now seems right for reappraising the use of substitute prescribing for alcohol dependence.

Preclinical studies of alcohol binge drinking

Binge drinking is prevalent and has serious biomedical consequences. In children, adolescents, and young adults, it is a prominent risk factor for later development of alcohol-use disorders. Many preclinical models have been employed to study the genetic risks for and biomedical consequences of alcohol drinking. However, these models historically did not result in blood-alcohol concentrations (BACs) exceeding 80 mg%; this relatively modest level is the threshold that currently defines a binge session, according to the NIAAA and CDC. Nevertheless, in alcohol-dependent rodents, binge drinking has been well documented. Key neurobiological substrates localized to brain reward and stress systems have been identified. Studies of newer models of binge drinking without dependence are reviewed here. In these models, rodents, non-human primates, and flies will drink enough to reach high BACs. They often display observable signs of intoxication. The neurobiological consequences of these episodes of binge drinking without dependence are reviewed, and preliminary evidence for roles for GABA, glutamate, opioid peptides, and corticotropin releasing factor are discussed, as is the need for more work to identify the antecedents and consequences of binge drinking in both animal models and humans.

Activation of σ-receptors induces binge-like drinking in Sardinian alcohol-preferring rats

Sigma (σ) receptors have been implicated in the behavioral and motivational effects of alcohol and psychostimulants. Sigma receptor antagonists reduce the reinforcing effects of alcohol and excessive alcohol intake in both genetic (alcohol-preferring rats) and environmental (chronic alcohol-induced) models of alcoholism. The present study tested the hypothesis that pharmacological activation of σ-receptors facilitates ethanol reinforcement and induces excessive, binge-like ethanol intake. The effects of repeated subcutaneous treatment with the selective σ-receptor agonist 1,3-di-(2-tolyl)guanidine (DTG; 15 mg/kg, twice a day for 7 days) on operant ethanol (10%) self-administration were studied in Sardinian alcohol-preferring (sP) rats. To confirm that the effect of DTG was mediated by σ-receptors, the effects of pretreatment with the selective σ-receptor antagonist BD-1063 (7 mg/kg, subcutaneously) were determined. To assess the specificity of action, the effects of DTG on the self-administration of equally reinforcing solutions of saccharin or sucrose were also determined. Finally, gene expression of opioid receptors in brain areas implicated in ethanol reinforcement was analyzed in ethanol-naive sP rats treated acutely or repeatedly with DTG, because of the well-established role of the opioid system in alcohol reinforcement and addiction. Repeatedly administered DTG progressively and dramatically increased ethanol self-administration in sP rats and increased blood alcohol levels, which reached mean values close to 100 mg% in 1 h drinking sessions. Repeated DTG treatment also increased the rats' motivation to work for alcohol under a progressive-ratio schedule of reinforcement. BD-1063 prevented the effects of DTG, confirming that σ-receptors mediate the effects of DTG. Repeated DTG treatment also increased the self-administration of the non-drug reinforcers saccharin and sucrose. Naive sP rats repeatedly treated with DTG showed increased mRNA expression of μ- and δ-opioid receptors in the ventral tegmental area. These results suggest a key facilitatory role for σ-receptors in the reinforcing effects of alcohol and identify a potential mechanism that contributes to binge-like and excessive drinking.

Schedule of passive ethanol exposure affects subsequent intragastric ethanol self-infusion

BACKGROUND

Many studies have shown that chronic ethanol exposure can enhance later self-administration of ethanol, but only a few studies have identified critical parameters for such exposure. The present studies examined temporal and other parameters of chronic ethanol exposure on subsequent intragastric (IG) self-infusion of ethanol.

METHODS

Sprague-Dawley rats implanted with IG catheters were passively infused with ethanol for 5 to 6 days and then allowed to self-infuse ethanol or water using a procedure in which infusions were contingent upon licking fruit-flavored solutions. Experiment 1 examined the time interval between consecutive periods of passive infusion (Massed Group: 12 hours vs. Spaced Group: 36 hours). Experiment 2 studied the interval between the final passive infusion and onset of self-infusion (12 vs. 36 hours). Finally, Experiment 3 tested the effect of inserting self-infusion days within the passive infusion phase.

RESULTS

Passive ethanol exposure on consecutive days induced relatively large amounts of ethanol self-infusion (4.1 to 7.9 g/kg/d). Increasing the duration of the ethanol-free interval between periods of passive exposure to 36 hours significantly reduced ethanol self-infusion (2.2 g/kg/d; Exp. 1). The time delay between the last passive ethanol exposure and onset of self-infusion had no effect on self-infusion (Exp. 2). Moreover, inserting no-choice self-infusion days between the last few passive exposure days did not increase self-infusion (Exp. 3).

CONCLUSIONS

Measurement of withdrawal signs indicated that Massed passive exposure produced stronger dependence than Spaced passive exposure, suggesting that enhanced ethanol self-infusion in Massed Groups might be explained by the opportunity for greater negative reinforcement by ethanol. Although enhanced negative reinforcement might also explain why the Massed Group showed a weaker aversion for the ethanol-paired flavor than the Spaced Group, this observation could also be explained by the development of greater tolerance to ethanol's aversive pharmacological effects in the Massed Group.

Alcohol withdrawal seizures

The topic of alcohol withdrawal syndrome (AWS), including delirium tremens and especially seizures, is reviewed. From mice and rat studies, it is known that both N-methyl-d-aspartate (NMDA) and gamma-aminobutyric acid (GABA) receptors are involved in AWS. During alcohol intoxication chronic adaptations of NMDA and GABA receptors occur, and during alcohol withdrawal a hyperexcitable state develops. In studies on humans, during intoxication the NMDA receptors are activated and mediate tonic inhibition. In withdrawal, a rebound activation of these receptors occurs. Both GABA-A and GABA-B receptors, especially the alpha2 subunit of GABA-A receptors, are also likely involved. Homocysteine increases with active drinking, and in withdrawal, excitotoxicity likely is induced by a further increase in homocysteine, viewed as a risk factor for AWS and also as a screening tool. The dopamine transporter gene is also associated with AWS. Characteristics involves changes in the ECG, especially an increase in QT interval, and EEG changes, including abnormal quantified EEG, at times periodic lateralized epileptiform discharges, and especially seizures, usually occurring 6-48h after the cessation of drinking. Therapy has emphasized benzodiazepines, mainly diazepam and lorazepam, but more standard antiepileptic drugs, like carbamazepine and topiramate, are also effective and safe.

Reestablishing an intragastric ethanol self-infusion model in rats

BACKGROUND

There is a scarcity of behavioral models that will reliably produce ethanol intakes in rodents at levels that induce or maintain dependence. The present experiments were designed to reestablish a model that uses passive intragastric (IG) infusion of ethanol to induce tolerance/dependence/withdrawal before allowing rats to self-infuse ethanol intragastrically.

METHODS

Sprague-Dawley rats were surgically implanted with IG catheters and allowed to recover. During the passive infusion phase (3-6 days), rats in the experimental group were passively infused with 10% (v/v) ethanol (3.3-12.2 g/kg/d). Rats in the control group were not infused. During the self-infusion phase (5-6 days), all rats had access to 2 flavored solutions. Licks on 1 solution were paired with ethanol infusions (20%, v/v) whereas licks on the other solution were unpaired. Experiments differed in the specific passive infusion parameters and in the ethanol intake limit during self-infusion.

RESULTS

Rats in the experimental groups self-infused more ethanol per day (means of 4-7 g/kg/d) than did rats in the control group (means of 0-2.6 g/kg/d). Across all 3 studies, individual total daily intakes exceeded 5 g/kg on 35% of the self-infusion days in ethanol-preexposed rats compared with <1% of the self-infusion days in the control rats. Ethanol-exposed rats also infused a substantially higher percentage (42%) of their total ethanol intake in relatively large bouts (>1.5 g/kg) compared with control rats (<10%). The addition of a daily 6-hour ethanol-free period during the passive infusion phase (in Experiments 2 and 3) led to higher ethanol intakes than in Experiment 1. Results of a control experiment showed that differences between experimental and control groups in Experiments 1 to 3 were a result of ethanol experience and not a general effect of differential infusion experience.

CONCLUSIONS

Relatively short periods of passive IG infusion of ethanol induced levels of ethanol self-infusion in genetically heterogeneous rats that were comparable with drinking intakes previously reported in rats selectively bred for ethanol intake/preference. Although the induction of dependence/withdrawal may have played a role in this outcome, an alternative interpretation is that experimental rats self-infused more ethanol because passive exposure produced tolerance to aversive pharmacological effects that would otherwise limit intake of the paired flavor because of development of conditioned taste aversion. The current findings provide a strong basis for future work designed to identify parametric determinants of this form of self-administration, its sensitivity to genetic influences, and its neurobiological substrates.

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

OBJECTIVE

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

DESIGN

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

SETTING

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

PATIENTS

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

INTERVENTIONS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Nucleus accumbens dopamine release modulation by mesolimbic GABAA receptors-an in vivo electrochemical study

The role of GABA receptors in regulating the mesolimbic dopamine (DA) system and drug reinforced behaviors has not been well characterized. Using fast-cyclic voltammetry, the effects of specific GABA receptor modulation on DA release in the nucleus accumbens (NAcc) and heroin self-administration (SA) behavior was investigated. The GABAA agonist muscimol, administered either intravenously or directly into the ventral tegmental area (VTA), significantly increased DA release in the NAcc in 7 of the 10 rats tested. DA release decreased in the remaining three rats; both effects were blocked by pretreatment with the GABAA receptor antagonist bicuculline. In contrast, the GABAB agonist baclofen decreased, while 2-OH-saclofen (a GABAB antagonist) increased DA release in the NAcc. However, when VTA GABAB receptors were previously activated or inactivated by microinjections of baclofen or 2-OH-saclofen, systemic injections of muscimol caused an inhibition of NAcc DA release. These results suggest that GABAA receptors may be co-localized on both DA neurons and non-DA (GABAergic) interneurons in the VTA, with the effects of GABAA determined by the net effect of both direct inhibition and indirect disinhibition of DA neurons. Finally, although a DA releaser, muscimol was neither self-administered in drug naive rats, nor did it substitute for heroin in rats previously trained to self-administer heroin, suggesting that GABAA receptors appear to play a complex role in mediating drug reinforcement, depending upon the dynamic functional state of GABAA receptors on both tegmental DA and non-DA neurons.

Molecular genetic analysis of the role of GABAergic systems in the behavioral and cellular actions of alcohol

Recent studies implicate the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in many neurochemical actions of ethanol and a variety of behavioral responses to acute and chronic ethanol treatment. However, the molecular mechanisms responsible for genetic differences in initial neurochemical or behavioral sensitivity to ethanol, and adaptation following chronic or repeated ethanol administration, remain to be elucidated. Pharmacogenetic research will increasingly move toward mapping, cloning, identification, and functional analysis of the genes underlying the actions of ethanol. The approaches discussed here permit molecular analysis of both known and previously unknown genes regulating behavioral sensitivity to ethanol. The synthesis of molecular methods and behavioral genetics offers immediate hope for delineating the role of the GABA(A) receptor complex, and other determinants of GABAergic neurotransmission, in determining genetic variation in behavioral responses to ethanol.

GABAergic transmission in the nucleus accumbens is involved in the termination of ethanol self-administration in rats

Long-Evans rats (n = 12) were trained to lever-press on a fixed-ratio 4 schedule of reinforcement with ethanol (10% v/v) presented as the reinforcer. After implantation of bilateral stainless-steel guide cannulae aimed at the nucleus accumbens, site-specific microinjections of muscimol (1-30 ng) and bicuculline (1-10 ng) were tested for effects on ethanol-reinforced responding. Baseline response patterns were characterized by initial high rates that terminated abruptly after approximately 20 min. Muscimol administration in the nucleus accumbens decreased the total number of ethanol-reinforced responses and obtained reinforcers. Bicuculline also decreased ethanol-reinforced responses and reinforcers at the highest dose tested. When a dose of bicuculline (1 ng) that was ineffective by itself was coadministered with an effective dose of muscimol (10 ng), the muscimol-induced decreases in responding were blocked. Analysis of response patterns showed that muscimol decreased ethanol self-administration by terminating responding, normally lasting 20 min, after approximately 10 min with no changes in local response rate. Bicuculline decreased total responding by producing parallel, but nonsignificant, changes in time course and response rate. These data suggest that GABAergic transmission in the nucleus accumbens is involved in the termination, but not the onset or maintenance of ethanol self-administration. The specificity of this effect gives emphasis to the importance of measuring behavioral parameters, as well as products of behavior (such as intake volume) in the study of ethanol self-administration.

Neuropharmacology of Cocaine and Ethanol Dependence

Drug addiction includes two important characteristics, chronic compulsive or uncontrollable drug use and a withdrawal syndrome when use of the drug is stopped. Animal models for the motivational components of drug dependence have been developed allowing a systematic exploration of the neurobiological mechanisms of drug dependence. The reinforcing actions of acute cocaine as measured by intravenous cocaine self-administration appear to be mediated by the presynaptic release of dopamine in the region of the nucleus accumbens and may preferentially involve the dopamine D-1 receptor subtype. The nucleus accumbens circuitry involved in the reinforcing actions of cocaine may include the ventral pallidum and may be modulated by serotonin. Chronic cocaine produces increases in brain reward thresholds that may reflect the "dysphoria" and anhedonia associated with cocaine dependence and suggests a dysregulation of brain reward systems possibly involving dopamine. Reliable measures for the acute reinforcing effects of ethanol in nondependent animals have been established in the rat using a lever press operant and a taste habituation procedure. Important roles have been established for serotonin, GABA, dopamine, and opioids in the acute reinforcing properties of ethanol, perhaps acting on some of the same neural circuitry subsuming the reinforcing actions of other drugs of abuse. Studies of the motivational aspects of ethanol dependence have suggested a functional role for brain corticotropin-releasing factor. These results suggest that the neurobiology of drug dependence involves not only neurotransmitters that mediate the acute reinforcing properties of drugs, but also the aversive motivational and emotional aspects of drug withdrawal. Advances in our understanding of brain changes associated with the switch from acute effects to chronic actions may provide a key to our understanding of not only drug dependence, but also psychopathology such as, anxiety, and affective disorders.

Neuroadaptive responses to chronic ethanol

Cellular responses of neuronal tissue to chronic ethanol exposure are reviewed. Evidence for adaptive responses to the acute actions of ethanol is available for five systems: GABA-activated chloride channels, voltage-sensitive calcium channels, NMDA-activated cation channels, receptors coupled through stimulatory guanine nucleotide binding proteins, and membrane lipid order. We suggest that at least some of these adaptive responses occur because of ethanol actions at the level of gene expression.

Benzodiazepines in the treatment of alcoholism

This chapter comprises three sections that cover the main aspects of benzodiazepines and alcohol: (1) the basic pharmacology of benzodiazepines; (2) use of benzodiazepines in the treatment of withdrawal; and (3) the use of benzodiazepines in treating alcoholics. The basic studies suggest that a major site of action of alcohol may be the GABA/benzodiazepine receptor complex and that compensatory alterations in this complex may underly withdrawal. In the section on alcohol withdrawal, interactions between the GABA/benzodiazepine receptor complex, sympathetic nervous system, and hypothalamic-pituitary-adrenal axis are discussed. Use of benzodiazepines in the treatment of the alcohol withdrawal syndrome are reviewed, including the possibility that the benzodiazepines may prevent withdrawal-induced "kindling." Lastly, we review indications for, and efficacy of, benzodiazepines in long-term treatment of patients with alcoholism. Benzodiazepines are not indicated for the treatment of alcoholism. Furthermore, they have very few indications in alcoholics and their dependency-producing potency has to be appreciated when they are used in patients with alcoholism.

Treatment of chronic organic mental disorders associated with alcoholism

Considering the magnitude of the problem, the treatment of alcoholism-associated chronic organic mental disorders has not been extensively studied. Alcoholic organic brain disease is heuristically viewed as the admixture of clinical syndromes of impairment [alcoholic amnestic disorder or Korsakoff's psychosis (KP) and dementia associated with alcoholism (DAA)], each with its distinguishing cognitive, neuropathological, and neurochemical characteristics. Differences between KP and DAA are highlighted by studies that compare KP patients with those having Alzheimer's disease or depression. Furthermore, treatment of cognitive deficits in KP and DAA may be modeled after strategies that have proved effective for these other neuropsychiatric disorders. Although abstinence and proper nutrition remain the cornerstones of treatment, pharmacological modification of neurotransmitter function and/or enhancement of cerebral metabolism combined with behavioral methods may also be beneficial. Serotonergic approaches to improve memory in detoxified alcoholics may also reduce alcohol intake, and this has implication for treatment of less impaired alcoholics.

Acute ethanol poisoning and the ethanol withdrawal syndrome

Ethanol, a highly lipid-soluble compound, appears to exert its effects through interactions with the cell membrane. Cell membrane alterations indirectly affect the functioning of membrane-associated proteins, which function as channels, carriers, enzymes and receptors. For example, studies suggest that ethanol exerts an effect upon the gamma-aminobutyric acid (GABA)-benzodiazepine-chloride ionophore receptor complex, thereby accounting for the biochemical and clinical similarities between ethanol, benzodiazepines and barbiturates. The patient with acute ethanol poisoning may present with symptoms ranging from slurred speech, ataxia and incoordination to coma, potentially resulting in respiratory depression and death. At blood alcohol concentrations of greater than 250 mg% (250 mg% = 250 mg/dl = 2.5 g/L = 0.250%), the patient is usually at risk of coma. Children and alcohol-naive adults may experience severe toxicity at blood alcohol concentrations less than 100 mg%, whereas alcoholics may demonstrate significant impairment only at concentrations greater than 300 mg%. Upon presentation of a patient suspected of acute ethanol poisoning, cardiovascular and respiratory stabilisation should be assured. Thiamine (vitamin B1) and then dextrose should be administered, and the blood alcohol concentration measured. Subsequent to stabilisation, alternative aetiologies for the signs and symptoms observed should be considered. There are presently no agents available for clinical use that will reverse the acute effects of ethanol. Treatment consists of supportive care and close observation until the blood alcohol concentration decreases to a non-toxic level. In the non-dependent adult, ethanol is metabolised at the rate of approximately 15 mg%/hour. Haemodialysis may be considered in cases of a severely ill child or comatose adult. Follow-up may include referral for counselling for alcohol abuse, suicide attempts, or parental neglect (in children). The ethanol withdrawal syndrome may be observed in the ethanol-dependent patient within 8 hours of the last drink, with blood alcohol concentrations in excess of 200 mg%. Symptoms consist of tremor, nausea and vomiting, increased blood pressure and heart rate, paroxysmal sweats, depression, and anxiety. Alterations in the GABA-benzodiazepine-chloride receptor complex, noradrenergic overactivity, and hypothalamic-pituitary-adrenal axis stimulation are suggested explanations for withdrawal symptomatology.(ABSTRACT TRUNCATED AT 400 WORDS)

Special aspects of human alcohol withdrawal

There are still surprising gaps in our knowledge of alcohol withdrawal. While quantitative alcohol consumption accounts for about one third of the variability in severity of acute withdrawal, there is little systematic knowledge about the other factors involved. Thus, we cannot precisely predict the severity of withdrawal in individual patients. Controversy exists as to the role of medical vs. social detoxification approaches to acute withdrawal, the influence of acute withdrawal and its treatment on the long-term outcome of alcoholism, and the importance (or even existence) of chronic withdrawal. There is little systematic data to guide withdrawal treatment in special clinical settings, e.g., with concurrent medical or psychiatric illness or with mixed substance dependence. This chapter reviews the published literature, tries to point out methodological and conceptual problems, and suggests areas for future research.

Ability of calcium bis acetyl homotaurine, a GABA agonist, to prevent relapse in weaned alcoholics

After they had been weaned off alcohol in hospital 85 severe alcoholics (above 200 g alcohol/day) were included in a double-blind study of calcium bis acetyl homotaurine (Ca AOTA, 25 mg/kg/day), a new gamma-aminobutyric acid agonist, versus placebo. Patients were treated as outpatients during the 3-month study. The only other treatment that patients received was meprobamate, 800 to 1200 mg/day, in the first month. The criterion for success was abstinence at 3 months (with normal gamma-glutamyl transpeptidase being one of the criteria). Of the 70 patients who completed the study, 33 received Ca AOTA and 37 placebo. 20 patients on Ca AOTA did not relapse, compared with 12 on placebo (p less than 0.02 by X2 test). Side-effects were noted by 7 patients on Ca AOTA and 2 on placebo. The results suggest that Ca AOTA may be useful in helping severe alcoholics who have been weaned off alcohol not to relapse.

Effects of combined alcohol and benzodiazepine: a review

Both human and animal studies relating to the combined effects of alcohol and benzodiazepine (BZD) are reviewed. Although the combination of alcohol and BZD is sometimes associated with drug-induced deaths, drug overdoses and traffic accidents or fatalities, epidemiological information is lacking on the true extent of the combined abuse and on the patterns and prevalence of use of these two drugs. Since BZD are widely used for the short- and long-term treatment of alcoholics, these patients are deemed more at risk of developing BZD or alcohol/BZD dependence than the general population. There is a dire need for large-scale controlled studies concerning the efficacy of BZD in the long-term treatment of alcoholics. Compared to men, women are at a higher risk as far as the potential for BZD addiction is concerned, since they tend to use BZD more often. Epidemiologic studies on the patterns of use of BZD, alcohol or alcohol/BZD in pregnant women are called for. Animal models are also needed to ascertain whether prenatal exposure to both alcohol and BZD can impart long-lasting behavioral changes in the progeny. It is possible that BZD can exacerbate the damaging prenatal effects of alcohol.

Influence of chlordiazepoxide on alcohol consumption in mice

In a free-choice situation, chlordiazepoxide (CDP; 12.5 or 25 mg/100 ml; groups B or C), when incorporated in ethanol solutions (2 to 20%, v/v), caused a significant decrease in ethanol preference index (P.I.). This was probably due to the combined CNS effects of both drugs rather than a taste effect, since the mice did not discriminate between aqueous CDP solutions and water. However, when the mice had prior exposure to ethanol and CDP was incorporated intermittently, no significant decreases in P.I. resulted. In a no-choice situation, ethanol intake was increased only on the first day of each intermittent incorporation of CDP (3 days for each 6-day cycle), being more persistent in group B (2 to 15% ethanol) than in group C (2 to 6.5%). Ethanol intake decreased in group C when alcohol concentrations exceeded 10%. The "first-day" CDP effect also occurred in the no-choice situation of an ethanolic liquid diet. Possible factors for this effect are discussed. Thus the effects of CDP on alcohol consumption in non-deprived mice vary with experimental designs.

The benzodiazepine/GABA receptor complex during severe ethanol intoxication and withdrawal in the rat

The benzodiazepine/GABA (gammaaminobutyric acid) receptor complex was investigated during severe ethanol intoxication and withdrawal in the rat. The intragastric intubation technique was used to establish physical ethanol dependence in the animals. Cerebral cortex from male Wistar rats was studied 1) after 3 1/2 days of severe ethanol intoxication, 2) during the ethanol withdrawal reaction and 3) in a control group. The effect of GABA-ergic activation by muscimol and THIP (4,5,6,7-tetrahydroisoxazole(5,4-c)pyridin-3-01) on 3H-diazepam binding was unchanged during ethanol intoxication and withdrawal, as was the affinity constant (KD) and the maximal number of binding sites (Bmax) for 3H-flunitrazepam. In conclusion, the benzodiazepine/GABA receptor complex is unlikely to play any causal part in physical ethanol dependence.

Benzodiazepine withdrawal

As with most psychotropic sedative drugs, the potential for withdrawal reactions is present with the benzodiazepines (19). Signs suggesting the potential for withdrawal reactions can be gleaned from the clinical course of events such as the development of tolerance anc psychological and physiological dependence. If high doses are reached, the risk of withdrawal reactions increases with the length of treatment and the abruptness of cessation. The long-acting benzodiazepines have a built-in mechanism against withdrawal reactions through their active metabolites. Abrupt cessation of drug therapy in high-dose patients should be avoided to reduce the risk of withdrawal reactions.