Long-term outcome of alcohol withdrawal seizures

BACKGROUND AND PURPOSE

Alcohol withdrawal seizures (AWS) are a well-known complication of chronic alcohol abuse, but there is currently little knowledge of their long-term relapse rate and prognosis. The aims of this study were to identify risk factors for AWS recurrence and to study the overall outcome of patients after AWS.

METHODS

In this retrospective single-center study, we included patients who were admitted to the Emergency Department after an AWS between January 1, 2013 and August 10, 2021 and for whom an electroencephalogram (EEG) was requested. AWS relapses up until April 29, 2022 were researched. We compared history, treatment with benzodiazepines or antiseizure medications (ASMs), laboratory, EEG and computed tomography findings between patients with AWS relapse (r-AWS) and patients with no AWS relapse (nr-AWS).

RESULTS

A total of 199 patients were enrolled (mean age 53 ± 12 years; 78.9% men). AWS relapses occurred in 11% of patients, after a median time of 470.5 days. Brain computed tomography (n = 182) showed pathological findings in 35.7%. Risk factors for relapses were history of previous AWS (p = 0.013), skull fractures (p = 0.004) at the index AWS, and possibly epileptiform EEG abnormalities (p = 0.07). Benzodiazepines or other ASMs, taken before or after the index event, did not differ between the r-AWS and the nr-AWS group. The mortality rate was 2.9%/year of follow-up, which was 13 times higher compared to the general population. Risk factors for death were history of AWS (p < 0.001) and encephalopathic EEG (p = 0.043).

CONCLUSIONS

Delayed AWS relapses occur in 11% of patients and are associated with risk factors (previous AWS >24 h apart, skull fractures, and pathological EEG findings) that also increase the epilepsy risk, that is, predisposition for seizures, if not treated. Future prospective studies are mandatory to determine appropriate long-term diagnostic and therapeutic strategies, in order to reduce the risk of relapse and mortality associated with AWS.

[Assessment of alcohol withdrawal syndrome: new perspectives]

Alcohol withdrawal syndrome is one of the most important consequences of alcohol use disorder, a complex neuropsychiatric disorder, which is firstly treated in non-specific and secondly in psychiatric/addictive in- or outpatient units. On the other hand, alcohol withdrawal syndrome is one of the most important outcomes of the severity of alcohol use disorder, further, it can lead to the development of alcohol-related seizure and delirium tremens. Hence, early recognition and optimal treatment of alcohol withdrawal syndrome have a critical importance. Therefore, the main goal of the present review was - by systematically summarizing the scientific data published during the past two decades - to form a unique diagnostic and therapeutic algorithm. During the recognition and the course of alcohol withdrawal syndrome, the Clinical Institute Withdrawal Assessment for Alcohol, Revised scale, while in the risk assessment the Prediction of Alcohol Withdrawal Severity Scale are the recommended psychometric tools. Benzodiazepines are the key elements of the pharmacotherapy of alcohol withdrawal syndrome. Many studies have evaluated that diazepam, chlordiazepoxide, lorazepam and oxazepam with distinct indications have sufficient evidence in the treatment of alcohol withdrawal syndrome. However, in the past few years some authors have recommended the importance of non-benzodiazepine medications. The efficacy of propofol, phenobarbital, carbamazepin, oxcarbamazepin and alpha-2 receptor agonists in the treatment of alcohol withdrawal syndrome have been revealed. Furthermore, it has been evaluated that benzodiazepines are recommended in the treatment of alcohol-related seizure and delirium tremens. In the present review, our aim was to construct a unique, up-to-date diagnostic and therapeutic algorithm by summarizing the related papers published during the past two decades. Hence this scheme may be useful in the optimal treatment of patients diagnosed with alcohol use disorder and it could help to conduct further clinical researches. Orv Hetil. 2023; 164(38): 1487-1496.

Adjunctive Use of Ketamine for Benzodiazepine-Resistant Severe Alcohol Withdrawal: a Retrospective Evaluation

INTRODUCTION

Benzodiazepine (BZD)-resistant alcohol withdrawal remains a challenge for most institutions due to limited evidence with available agents. One published study currently exists utilizing the N-methyl-D-aspartate antagonist, ketamine, for alcohol withdrawal.

OBJECTIVE

The purpose of our study was to evaluate the effect of adjunctive ketamine continuous infusion on symptom control and lorazepam infusion requirements for BZD-resistant alcohol withdrawal patients in the intensive care unit.

METHODS

A retrospective review was conducted of patients receiving ketamine adjunctively with a lorazepam infusion for severe alcohol withdrawal between August 2012 and August 2014. Outcomes included time to symptom control, lorazepam infusion requirements, ketamine initial and maximum daily infusion rates, and adverse effects of ketamine.

RESULTS

Thirty patients were included in the analysis. Mean time to initiation of ketamine after the initiation of a lorazepam infusion was 41.4 h. All patients achieved initial symptom control within 1 h of ketamine initiation. Median initial ketamine infusion rate was 0.75 mg/kg/h and the average maximum daily rate was 1.6 mg/kg/h. Significant decreases in lorazepam infusion rates from baseline were observed at 24 h (- 4 mg/h; p = 0.01) after ketamine initiation. No patients experienced documented CNS adverse effects. Two patients experienced hypertension and no patients experienced tachycardia related to ketamine.

CONCLUSION

Adjunctive ketamine could provide symptom control for BZD-refractory patients and may potentially reduce lorazepam infusion requirements. Future studies to determine optimal dosing, timing of initiation, and place in therapy for BZD-resistant alcohol withdrawal are needed. The mechanism of action via the NMDA receptor with ketamine may provide benefit for BZD-resistant alcohol withdrawal.

[Management of alcohol withdrawal]

This article proposes an update and summary of current knowledge in the management of alcohol withdrawal, based on a review of recent literature. The issues open to debate and the areas whith new developments will be addressed, such as: the entry into treatment, the withdrawal setting, the withdrawal medications, the various possible protocols and the introduction of relapse prevention treatments.

[Benzodiazepines should still be first-line treatment for alcohol withdrawal]

In this review, we summarize the evidence for benzodiazepines and barbiturates as alcohol withdrawal treatment and outline a treatment guideline. A number of randomized controlled trials (RCTs) indicate that benzodiazepine treatment decreases alcohol withdrawal seizures and is safe. For barbiturates, only a few RCTs have been undertaken, and barbiturates were not found to be superior to benzodiazepines. Consequently, we suggest that benzodiazepines should still be first-line treatment for alcohol withdrawal.

Clinical applications of sodium oxybate (GHB): from narcolepsy to alcohol withdrawal syndrome

Gamma-hydroxybutyrate (GHB) is a short chain fatty acid endogenously produced within the central nervous system (CNS) and acts as a precursor and metabolite of the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Although, it is an illegal recreational drug of abuse, its sodium salt (sodium oxybate) has been utilized as a medication for a number of medical conditions. The first aim of this review was to focus on current applications of sodium oxybate for the treatment of narcolepsy, with a particular emphasis on the key symptoms of this disorder: cataplexy and excessive daytime sleepiness (EDS). Secondly, the effectiveness of sodium oxybate therapy for the treatment of alcohol withdrawal syndrome (AWS) and the maintenance of alcohol abstinence has been assessed. Nowadays, sodium oxybate is the first-line treatment for narcolepsy and it is highly effective in meliorating sleep architecture, decreasing EDS and the frequency of cataplexy attacks in narcoleptic patients. Sodium oxybate currently finds also application in the treatment of AWS and the maintenance of alcohol abstinence in alcoholics. Most of the studies evaluating the efficacy of GHB in the treatment of AWS use a dosage of 50 mg/kg divided in three or four administrations per day. Human studies showed that GHB (dose of 50 mg/kg, divided in three administrations per day) is capable to increase the number of abstinent days, reduce alcohol craving and decrease the number of drinks per day. However, there is limited randomized evidence and, thus, GHB cannot be reliably compared to clomethiazole or benzodiazepines. Some randomized data suggest that GHB is better than naltrexone and disulfiram regarding abstinence maintenance and prevention of craving in the medium term i.e. 3-12 months. It is recommended that GHB should be used only under strict medical supervision, since concerns about the abuse/misuse of the drug and the addiction potential have been arisen.

Altered voltage-gated calcium channels in rat inferior colliculus neurons contribute to alcohol withdrawal seizures

We have previously reported that enhanced susceptibility to alcohol withdrawal seizures (AWS) parallels the enhancement of the current density of high-threshold voltage-gated Ca(2+) (CaV) channels in rat inferior colliculus (IC) neurons. However, whether this increased current density is a cause or consequence of AWS is unclear. Here, I report changes in the current density of CaV channels in IC neurons during the course of alcohol withdrawal and the potential anticonvulsant effect of intra-IC infusions of L- and P-type CaV channel antagonists. Whole-cell currents were activated by depolarizing pulses using barium as the charge carrier. Currents and seizure susceptibility were evaluated in control animals 3h after alcohol intoxication, as well as 3h (before AWS), 24h (when AWS susceptibility is maximal), and 48h (when AWS susceptibility is no longer present) after alcohol withdrawal. Nifedipine, nimodipine (L-type antagonists) or ω-agatoxin TK (P-type antagonist) were infused intra-IC to probe the role of CaV channels in the pathogenesis of AWS. CaV current density and conductance in IC neurons were significantly increased 3 and 24h after alcohol withdrawal compared with the control group or the group tested 3h following ethanol intoxication. Blockade of L-type CaV channels within the IC completely suppressed AWS, and inhibition of P-type channels reduced AWS severity. These findings suggest that the enhancement of CaV currents in IC neurons occurs prior to AWS onset and that alterations in L- and P-type CaV channels in these neurons may underlie the pathogenesis of AWS.

Multicenter evaluation of pharmacologic management and outcomes associated with severe resistant alcohol withdrawal

INTRODUCTION

A subset of patients with alcohol withdrawal syndrome does not respond to benzodiazepine treatment despite escalating doses. Resistant alcohol withdrawal (RAW) is associated with higher incidences of mechanical ventilation and nosocomial pneumonia and longer intensive care unit (ICU) stay. The objective of this study is to characterize pharmacologic management of RAW and outcomes.

METHODS

Adult patients were identified retrospectively via International Classification of Diseases, Ninth Revision codes for severe alcohol withdrawal from 2009 to 2012 at 3 hospitals. Data collected included pharmacologic management and clinical outcomes.

RESULTS

A total of 184 patients met inclusion criteria. Sixteen medications and 74 combinations of medications were used for management. Propofol was the most common adjunct agent, with dexmedetomidine and antipsychotics also used. One hundred seventy-five patients (96.2%) were admitted to the ICU, with 149 patients (81.9%) requiring ventilator support. Median time to resolution of alcohol withdrawal syndrome from RAW designation was 6.0 days. Median ICU and hospital length of stay were 9.0 and 12.7 days, respectively.

CONCLUSION

Diverse patterns exist in the management of patients meeting RAW criteria, indicating lack of refined approach to treatment. High doses of sedatives used for these patients may result in a high level of care, illustrating a need for evidence-based clinical guidelines to optimize outcomes.

Magnesium for alcohol withdrawal

BACKGROUND

Patients have been given magnesium to treat or prevent alcohol withdrawal syndrome (AWS). Evidence to support this practice is limited, and is often based on the controversial link between hypomagnesaemia and AWS.

OBJECTIVES

To assess the effects of magnesium for the prevention or treatment of AWS in hospitalised adults.

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Group Register of Controlled Trials (August 2012), PubMed (from 1966 to August 2012 ), EMBASE (from 1988 to August 2012), CINAHL (from 1982 to March 2010), Web of Science (1965 to August 2012). We also carried out Internet searches.

SELECTION CRITERIA

Randomised or quasi-randomised trials of magnesium for hospitalised adults with, or at risk for, acute alcohol withdrawal.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data with a standardised data extraction form, contacting the correspondence investigator if the necessary information was not available in the reports. Dichotomous outcomes were analysed by calculating the risk ratio (RR) for each trial, with the uncertainty in each result expressed with a 95% confidence interval (CI). Continuous outcomes were to be analysed by calculating the standardised mean difference (SMD) with 95% CI. For outcomes assessed by scales we compared and pooled the mean score differences from the end of treatment to baseline (post minus pre) in the experimental and control groups.

MAIN RESULTS

Four trials involving 317 people met the inclusion criteria. Three trials studied oral magnesium, with doses ranging from 12.5 mmol/day to 20 mmol/day. One trial studied parenteral magnesium (16.24 mEq q6h for 24 hours). Each trial demonstrated a high risk of bias in at least one domain. There was significant clinical and methodological variation between trials.We found no study that measured all of the identified primary outcomes and met the objectives of this review. Only one trial measured clinical symptoms of seizure, delirium tremens or components of the Clinical Institute Withdrawal Assessment for Alcohol (CIWA) score. A single outcome (handgrip strength) in three trials (113 people), was amenable to meta-analysis. There was no significant increase in handgrip strength in the magnesium group (SMD 0.04; 95% CI -0.22 to 0.30). No clinically important changes in adverse events were reported.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine whether magnesium is beneficial or harmful for the treatment or prevention of alcohol withdrawal syndrome.

Efficacy and safety of pharmacological interventions for the treatment of the Alcohol Withdrawal Syndrome

BACKGROUND

Alcohol abuse and dependence represents a very serious health problem worldwide with major social, interpersonal and legal interpolations. Pharmacological treatments presently used are of uncertain effectiveness and there is even more doubt on the comparative effects and value for money.

OBJECTIVES

To summarize Cochrane reviews that assess the effectiveness and safety of pharmacological interventions in the treatment of alcohol withdrawal.

METHODS

We searched the Cochrane Database of Systematic Reviews (30 November 2010). Two authors independently screened, extracted data, summarised key characteristics of the included reviews and assessed their quality using AMSTAR; the quality of the evidence was summarised according to the GRADE methodology.

MAIN RESULTS

Five reviews, 114 studies, 7333 participants, satisfied criteria for inclusions. The outcomes considered were alcohol withdrawal seizures, adverse events and dropouts. Comparing the five treatments with placebo, benzodiazepines performed better for seizures, three studies, 324 participants, RR 0.16 (95% CI 0.04 to 0.69), moderate quality of evidence. Comparing each of the five treatments versus specific class of drugs, benzodiazepines performed better than antipsychotics for seizures, 4 studies, 633 participants, RR 0.24 (95% CI 0.07 to 0.88) high quality of the evidence. Comparing different benzodiazepines and anticonvulsants among themselves, 28 comparisons, results never reached statistical significance but chlordiazepoxide performed better. The quality of evidence was high for 3% of the results, moderate for 28%, low for 48% and very low for 20%.

AUTHORS' CONCLUSIONS

Among the treatments considered, benzodiazepines showed a protective benefit against seizures, when compared to placebo and a potentially protective benefit for many outcomes when compared with antipsychotics. Nevertheless, no definite conclusions about the effectiveness and safety of benzodiazepines were possible, because of the heterogeneity of the trials both in interventions and in the assessment of outcomes. Data on potential harms are sparse and fragmented. Results do not provide sufficient evidence in favour of anticonvulsants for the treatment of AWS, but anticonvulsants seem to have limited side effects. There is also not enough evidence of effectiveness and safety of baclofen, because only one study consider this treatment and of GHB for which no strong differences were observed in the comparisons with placebo, benzodiazepines and anticonvulsants.

Anticonvulsants for alcohol withdrawal

BACKGROUND

Alcohol abuse and dependence represents a most serious health problem worldwide with major social, interpersonal and legal interpolations. Besides benzodiazepines, anticonvulsants are often used for the treatment of alcohol withdrawal symptoms. Anticonvulsants drugs are indicated for the treatment of alcohol withdrawal syndrome, alone or in combination with benzodiazepine treatments. In spite of the wide use, the exact role of the anticonvulsants for the treatment of alcohol withdrawal has not yet bee adequately assessed.

OBJECTIVES

To evaluate the effectiveness and safety of anticonvulsants in the treatment of alcohol withdrawal.

SEARCH STRATEGY

We searched Cochrane Drugs and Alcohol Group' Register of Trials (December 2009), PubMed, EMBASE, CINAHL (1966 to December 2009), EconLIT (1969 to December 2009). Parallel searches on web sites of health technology assessment and related agencies, and their databases.

SELECTION CRITERIA

Randomized controlled trials (RCTs) examining the effectiveness, safety and overall risk-benefit of anticonvulsants in comparison with a placebo or other pharmacological treatment. All patients were included regardless of age, gender, nationality, and outpatient or inpatient therapy.

DATA COLLECTION AND ANALYSIS

Two authors independently screened and extracted data from studies.

MAIN RESULTS

Fifty-six studies, with a total of 4076 participants, met the inclusion criteria. Comparing anticonvulsants with placebo, no statistically significant differences for the six outcomes considered.Comparing anticonvulsant versus other drug, 19 outcomes considered, results favour anticonvulsants only in the comparison carbamazepine versus benzodiazepine (oxazepam and lorazepam) for alcohol withdrawal symptoms (CIWA-Ar score): 3 studies, 262 participants, MD -1.04 (-1.89 to -0.20), none of the other comparisons reached statistical significance.Comparing different anticonvulsants no statistically significant differences in the two outcomes considered.Comparing anticonvulsants plus other drugs versus other drugs (3 outcomes considered), results from one study, 72 participants, favour paraldehyde plus chloral hydrate versus chlordiazepoxide, for the severe-life threatening side effects, RR 0.12 (0.03 to 0.44).

AUTHORS' CONCLUSIONS

Results of this review do not provide sufficient evidence in favour of anticonvulsants for the treatment of AWS. There are some suggestions that carbamazepine may actually be more effective in treating some aspects of alcohol withdrawal when compared to benzodiazepines, the current first-line regimen for alcohol withdrawal syndrome. Anticonvulsants seem to have limited side effects, although adverse effects are not rigorously reported in the analysed trials.

Benzodiazepines for alcohol withdrawal

BACKGROUND

Alcohol abuse and dependence represents a serious health problem worldwide with social, interpersonal and legal interpolations. Benzodiazepines have been widely used for the treatment of alcohol withdrawal symptoms. Moreover it is unknown whether different benzodiazepines and different regimens of administration may have the same merits.

OBJECTIVES

To evaluate the effectiveness and safety of benzodiazepines in the treatment of alcohol withdrawal.

SEARCH STRATEGY

Cochrane Drugs and Alcohol Group' Register of Trials (December 2009), PubMed, EMBASE, CINAHL (January 1966 to December 2009), EconLIT (1969 to December 2009). Parallel searches on web sites of health technology assessment and related agencies, and their databases.

SELECTION CRITERIA

Randomized controlled trials examining effectiveness, safety and risk-benefit of benzodiazepines in comparison with placebo or other pharmacological treatment and between themselves. All patients were included regardless of age, gender, nationality, and outpatient or inpatient therapy.

DATA COLLECTION AND ANALYSIS

Two authors independently screened and extracted data from studies.

MAIN RESULTS

Sixty four studies, 4309 participants, met the inclusion criteria.- Comparing benzodiazepines versus placebo, benzodiazepines performed better for seizures, 3 studies, 324 participants, RR 0.16 (0.04 to 0.69), no statistically significant difference for the other outcomes considered.- Comparing benzodiazepines versus other drugs, there is a trend in favour of benzodiazepines for seizure and delirium control, severe life threatening side effect, dropouts, dropouts due to side effects and patient's global assessment score. A trend in favour of control group was observed for CIWA-Ar scores at 48 hours and at the end of treatment. The results reach statistical significance only in one study, with 61 participants, results on Hamilton anxiety rating scale favour control MD -1.60 (-2.59 to -0.61)- Comparing different benzodiazepines among themselves,results never reached statistical significance but chlordiazepoxide performed better- Comparing benzodiazepine plus other drug versus other drug, results never reached statistical significance.- In the comparison of fixed-schedule versus symptom-triggered regimens, results from a single study, with 159 participants, favour symptom-triggered regimens MD -1.10 [-3.27, 1.07] for CIWA-Ar scores at the end of treatment. Differences in isolated trials should be interpreted very cautiously.

AUTHORS' CONCLUSIONS

Benzodiazepines showed a protective benefit against alcohol withdrawal symptoms, in particular seizures, when compared to placebo and a potentially protective benefit for many outcomes when compared with other drugs. Nevertheless, no definite conclusions about the effectiveness and safety of benzodiazepines was possible, because of the heterogeneity of the trials both in interventions and the assessment of outcomes.

Pregabalin is effective against behavioral and electrographic seizures during alcohol withdrawal

AIMS

Pregabalin has been shown to possess anticonvulsant, analgesic, and anxiolytic properties in a variety of testing situations. This study was designed to evaluate the ability of pregabalin to exert its anticonvulsant effects against behavioral and electrographic measures of CNS hyperexcitability associated with alcohol withdrawal in a mouse model of ethanol dependence.

METHODS

Adult mice were chronically exposed to ethanol and, upon withdrawal, were tested for behavioral signs of seizure activity (handling-induced convulsions) or abnormalities in spontaneous EEG activity recorded from cortical and subcortical sites.

RESULTS

Pregabalin (50-200 mg/kg) administered 1 and 4 h into withdrawal dose dependently reduced severity of handling-induced convulsions in comparison to vehicle-treated mice. Similarly, pregabalin reduced the frequency in which EEG activity was interrupted by trains of high-voltage synchronous activity in a dose-related fashion. Finally, pregabalin treatment of repeated withdrawals was effective in blocking the development of withdrawal sensitization observed in vehicle-treated mice.

CONCLUSIONS

Collectively, these results suggest that pregabalin may be an effective therapeutic agent for medical management of alcohol detoxification.

Alterations in alcohol consumption, withdrawal seizures, and monoamine transmission in rats treated with phentermine and 5-hydroxy-L-tryptophan

We have previously shown that coadministration of the dopamine (DA) agonist phentermine plus the serotonergic agonist fenfluramine suppresses alcohol intake and withdrawal seizures in rats. In the present study, phentermine and the serotonin (5-HT) precursor, 5-hydroxy-L-tryptophan (5-HTP), were administered alone, or in combination, to rats fed on a 6% alcohol-containing diet or an isocaloric control diet. Following a 9-h withdrawal period from the alcohol-containing diet, phentermine enhanced the effects of 5-HTP on both reduction of alcohol withdrawal seizures as well as changes in striatal serotonin. Food intake was monitored for 24 h after drug treatment, and neurochemical measures were examined at various time points. Phentermine alone reduced food intake in all diet conditions, but this anorectic effect was followed by hyperphagia in control rats. Phentermine plus 5-HTP reduced the consumption of the alcohol-containing diet, while its effects on consumption of control diets were mixed. In vivo microdialysis in rat nucleus accumbens revealed that phentermine increased extracellular DA, whereas 5-HTP caused marked elevations in extracellular 5-HT. Coadministration of phentermine and 5-HTP evoked simultaneous elevations in extracellular DA and 5-HT that mirrored the effects of each drug alone. Collectively, these findings show that coadministered phentermine plus 5-HTP is effective in reducing alcohol intake and suppressing alcohol withdrawal seizures. These therapeutic actions may be related to elevations in synaptic DA and 5-HT in critical brain regions.

Anticonvulsants for alcohol withdrawal

BACKGROUND

Alcohol withdrawal syndrome is a cluster of symptoms that occurs in alcohol-dependent people after cessation or reduction in alcohol use. This systematic review focuses on the evidence of anticonvulsants' use in the treatment of alcohol withdrawal symptoms.

OBJECTIVES

To evaluate the effectiveness and safety of anticonvulsants in the treatment of alcohol withdrawal.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2004); MEDLINE (1966 to October 2004); EMBASE (1988 to October 2004) and EU-PSI PSI-Tri database with no language and publication restrictions and references of articles.

SELECTION CRITERIA

All randomized controlled trials examining the effectiveness, safety and overall risk-benefit of an anticonvulsant in comparison with a placebo or other pharmacological treatment or another anticonvulsant were considered.

DATA COLLECTION AND ANALYSIS

The authors independently assessed trial quality extracted data.

MAIN RESULTS

Forty-eight studies, involving 3610 people were included. Despite the considerable number of randomized controlled trials, there was a variety of outcomes and of different rating scales that led to a limited quantitative synthesis of data. For the anticonvulsant versus placebo comparison, therapeutic success tended to be more common among the anticonvulsant-treated patients (relative risk (RR) 1.32; 95% confidence interval (CI) 0.92 to 1.91), and anticonvulsant tended to show a protective benefit against seizures (RR 0.57; 95% CI 0.27 to 1.19), but no effect reached formal statistical significance. For the anticonvulsant versus other drug comparison, CIWA-Ar score showed non-significant differences for the anticonvulsants compared to the other drugs at the end of treatment (weighted mean difference (WMD) -0.73; 95% CI -1.76 to 0.31). For the subgroup analysis of carbamazepine versus benzodiazepine, a statistically significant protective effect was found for the anticonvulsant (WMD -1.04; 95% CI -1.89 to -0.20), p = 0.02), but this was based on only 260 randomized participants. There was a non-significant decreased incidence of seizures (RR 0.50; 95% CI 0.18 to 1.34) favouring the patients that were treated with anticonvulsants than other drugs, and side-effects tended to be less common in the anticonvulsant-group (RR 0.56; 95% CI 0.31 to 1.02).

AUTHORS' CONCLUSIONS

It is not possible to draw definite conclusions about the effectiveness and safety of anticonvulsants in alcohol withdrawal, because of the heterogeneity of the trials both in interventions and the assessment of outcomes. The extremely small mortality rate in all these studies is reassuring, but data on other safety outcomes are sparse and fragmented.

Benzodiazepines for alcohol withdrawal

BACKGROUND

Alcohol withdrawal syndrome is a cluster of symptoms that occurs in alcohol-dependent people after cessation or reduction in alcohol use. This systematic review focuses on the evidence of benzodiazepines' use in the treatment of alcohol withdrawal symptoms.

OBJECTIVES

To evaluate the effectiveness and safety of benzodiazepines in the treatment of alcohol withdrawal.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 4, 2004), MEDLINE (1966 to October 2004) and EU-PSI PSI-Tri database with no language and publication restrictions. We also screened references of retrieved articles.

SELECTION CRITERIA

All randomized controlled trials examining the effectiveness and safety of a benzodiazepine in comparison with a placebo or other pharmacological intervention or other benzodiazepine were considered.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data.

MAIN RESULTS

Fifty-seven trials, with a total of 4,051 people were included. Despite the considerable number of randomized controlled trials, there was a very large variety of outcomes and of different rating scales and relatively limited quantitative synthesis of data was feasible. Benzodiazepines offered a large benefit against alcohol withdrawal seizures compared to placebo (relative risk [RR] 0.16; 95% confidence interval [CI] 0.04 to 0.69; p = 0.01). Benzodiazepines had similar success rates as other drugs (RR 1.02; 95% CI 0.92 to 1.12) or anticonvulsants in particular (RR 1.00; 95% CI 0.87 to 1.16) and offered a significant benefit for seizure control against non-anticonvulsants (RR 0.23; 95% CI 0.07 to 0.75; p = 0.02), but not against anticonvulsants (RR 1.99; 95% CI 0.46 to 8.65). Changes in Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar) scores at the end of treatment were similar with benzodiazepines versus other drugs, although some small studies showed isolated significant differences for other, less commonly, used scales. Data on other comparisons were very limited, thus making quantitative synthesis for various outcomes not very informative.

AUTHORS' CONCLUSIONS

Benzodiazepines are effective against alcohol withdrawal symptoms, in particular seizures, when compared to placebo. It is not possible to draw definite conclusions about the relative effectiveness and safety of benzodiazepines against other drugs in alcohol withdrawal, because of the large heterogeneity of the trials both in interventions and assessment of outcomes but the available data do not show prominent differences between benzodiazepines and other drugs in success rates.

Fols�ure gegen Hyperhomocystein�mie

There is growing evidence that chronic alcoholism is associated with a derangement in the sulfur amino acid metabolism. Excitatory aminoacids such as glutamate, aspartate, and homocysteine have been shown to be increased in patients with chronic alcoholism who underwent alcohol withdrawal. Furthermore, sustained hyperhomocysteinemia occurred in chronic alcoholics with active drinking pattern. Excitotoxicity can be induced by increased hormocysteine levels via rebound activation of NMDA receptor-mediated glutamatergic neurotransmission upon the removal of ethanol-evoked inhibition. Therefore, hyperhomocysteinemia may be responsible for the higher incidence of complications during alcohol withdrawal (e.g.stroke,convulsions). In addition, an association between brain atrophy and increased levels of homocysteine in chronic alcoholism was shown. This may have important implications for the pathogenesis of brain atrophy in alcoholics. Taking into account that high plasma homocysteine levels are helpful in the prediction of alcohol withdrawal seizures, early anti-convulsive therapy could prevent this severe complication. Supplementation of folate, a cofactor of the homocysteine metabolism, lowers raised homocysteine levels and therefore could be established as a new therapeutic strategy in alcohol withdrawal treatment. The results of various studies highlight the need for further research to prove whether alcoholics benefit from a reduced homocysteine level with respect to both, alcohol-related disorders and alcohol withdrawal symptoms.

A study of gabapentin in the treatment of tonic-clonic seizures of alcohol withdrawal syndrome

In this study for thirty (30) patients with alcohol withdrawal syndrome, the response to anticolvusant gabapentin was assessed. Thirty (30) patients with median age of 57.0 years and median body weight of 79.1 kg were treated with gabapentin 3 x 300 mg daily for up 30 days. The preliminary findings of this study suggest that gabapentin is very effective against tonic-clonic seizures in alcohol withdrawal syndrome. Gabapentin was safe and well tolerated. For twenty (20) patients no side effect were observed.

Examination of the evidence for off-label use of gabapentin

OBJECTIVES

(1) Describe the relevance of off-label use of gabapentin to managed care pharmacy; (2) summarize recent FDA warnings and media reports related to off-label gabapentin use; (3) review medical information pertaining to the off-label use of gabapentin; (4) outline alternatives to off-label use of gabapentin in an evidence-based fashion, where literature exists to support such alternatives; and (5) encourage key clinicians and decision makers in managed care pharmacy to develop and support programs that restrict the use of gabapentin to specific evidence-based situations.

SUMMARY

Gabapentin is approved by the U.S. Food and Drug Administration (FDA) for adjunctive therapy in treatment of partial seizures and postherpetic neuralgia. Various off-label (unapproved) uses have been reported, and the use of gabapentin for off-label purposes has reportedly exceeded use for FDAapproved indications. Pharmaceutical marketing practices and physician dissatisfaction with currently available pharmacological treatment options may be key factors that contribute to this prescribing trend. Recently, the media has focused on these issues, noting that many cases of reported safety and effectiveness of gabapentin for off-label use may have been fabricated. A thorough review of the medical and pharmacy literature related to off-label use of gabapentin was performed, and a summary of the literature for the following conditions is presented: bipolar disorder, peripheral neuropathy, diabetic neuropathy, complex regional pain syndrome, attention deficit disorder, restless legs syndrome, trigeminal neuralgia, periodic limb movement disorder of sleep, migraine headaches, and alcohol withdrawal syndrome. A common theme in the medical literature for gabapentin is the prevalence of open-label studies and a lack of randomized controlled clinical trials for all but a small number of indications.

CONCLUSIONS

In the majority of circumstances where it has reported potential for.off-label. use, gabapentin is not the optimal treatment. The off-label use of gabapentin for indications not approved by the FDA should be reserved for cases where there is solid research support (e.g., diabetic neuropathy and prophylaxis of frequent migraine headaches). Managed care pharmacists should develop programs to restrict the use of gabapentin to these specific evidence-based situations, and key decision makers in managed care practice should feel confident in supporting these use restrictions for gabapentin.

Gabapentin for the treatment of ethanol withdrawal

Benzodiazepines (BZDs) are the drug of choice for the suppression of alcohol withdrawal symptoms. Gabapentin, a drug approved for use as adjunctive therapy in the treatment of partial seizures, has none of the BZD-type difficulties (drug interactions, abuse potential). We retrospectively report on the use of gabapentin for ethanol withdrawal in 49 patients. Thirty-one patients were treated in the outpatient program and 18 in the general inpatient psychiatric unit. Positive outcomes as evidenced by completion of gabapentin therapy were achieved in 25 out of 31 outpatients and 17 out of 18 inpatients. Statistical significance was reached regarding the positive relationship between prior ethanol use and inpatient "as needed" benzodiazepine use. Both sets of data suggest that gabapentin works well for the mild to moderate alcohol withdrawal patient.

[Alcohol and epilepsy]

BACKGROUND

Although alcohol-related seizures have been recognized since antiquity, their pathophysiology, classification and treatment options remain unsettled.

MATERIAL AND METHODS

On the basis of clinical studies experience and literature searches, a review of classification, diagnostics and treatment of alcohol-related seizures is given.

RESULTS

The best-described entity is the alcohol withdrawal seizure, usually occurring within 48 hours after cessation of drinking. However, alcohol can also trigger seizures unrelated to withdrawal, impair seizure control in epilepsy, and has the potential to induce epilepsy. Approximately one third of patients being hospitalized for acute seizures have overused alcohol prior to the seizure. The clinical diagnosis is based on a thorough medical history. The Alcohol Use Disorders Identification Test (AUDIT) provides a reliable measure of drinking habits. Carbohydrate-deficient transferrin (CDT) is the best biomarker for alcohol abuse available and a good supplement to the clinical investigation. The diagnostic value of EEG is limited.

INTERPRETATION

Acute seizure management does not differ from that of other seizures. After a withdrawal seizure, prophylactic medication should be restricted to the first few days: In co-existing epilepsy and alcohol abuse, anti-epileptic drugs should be used with caution. There is little evidence to support the general advice that well-controlled epilepsy patients need to abstain completely from alcohol.

Alcohol withdrawal treatment in intoxicated vs non-intoxicated patients: a controlled open-label study with tiapride/carbamazepine, clomethiazole and diazepam

AIMS AND METHODS

Alcohol withdrawal treatment efficacy of tiapride/carbamazepine (A) vs clomethiazole (B) vs diazepam (C) in non-intoxicated patients and vs tiapride/carbamazepine in intoxicated patients (D; breath alcohol concentration > or = 1 g/l) was tested (n = 127) in a controlled randomized open-label study.

RESULTS

Efficacy and safety were not different between groups (total group: delirium, 3.9%; seizure, 0.8%), except for a lack of efficacy in 18% of intoxicated tiapride/carbamazepine patients. A change of medication in this group was necessary only when primarily intoxicated patients had reached the non-intoxicated range.

CONCLUSIONS

Treatment with tiapride/carbamazepine in alcohol-intoxicated patients proved to be safe.

A pilot study of Topiramate (Topamax) in the treatment of tonic-clonic seizures of alcohol withdrawal syndromes

In this study for the first time in alcohol withdrawal syndrome, the response to topiramate was assessed. 12 patients with median age of 49.5 years and median body weight of 76.3 kg were treated with topiramate twice daily for up 30 days, starting with a dose of 50 mg in the morning and 50 mg in the evening. The preliminary findings of this study suggest that topiramate is very effective against tonic-clonic seizures in alcohol withdrawal syndrome. No side effects were observed. Only two patients had loss of body weight (3-3.5 kg/4 weeks).

Effects of lorazepam treatment for multiple ethanol withdrawals in mice

BACKGROUND

Although many alcohol-dependent patients present with a history of prior detoxifications, the efficacy and safety of pharmacotherapy in the context of multiple ethanol withdrawal experiences have not been extensively studied. The purpose of this study was to evaluate the ability of lorazepam treatment for multiple withdrawals to prevent or blunt the development/expression of sensitized central nervous system hyperexcitability during a subsequent untreated withdrawal episode. A mouse model of withdrawal sensitization involving repeated ethanol withdrawals was used.

METHODS

Adult male C3H/He mice were exposed to different patterns of chronic ethanol vapor in inhalation chambers. One group received four cycles of 16 hr of ethanol exposure separated by 8-hr withdrawal periods, another group was tested after a single 16-hr exposure period, and a final group served as ethanol-naïve controls. These groups were further divided into lorazepam dosage (0.25-1.0 mg/kg) conditions. Lorazepam was administered 1 hr into each of the first three withdrawal cycles (or equivalent times); no drug injections were given during the final (fourth) withdrawal cycle. The ability of lorazepam treatment to alter development and expression of sensitized handling-induced convulsions (HIC), as well as changes in pentylenetetrazol seizure threshold dosage during an untreated withdrawal episode, was examined. Separate animals were used to assess the effects of lorazepam treatment on blood ethanol clearance and plasma levels of the benzodiazepine during the test withdrawal cycle.

RESULTS

Lorazepam dose-dependently reduced HIC activity during successive withdrawal cycles, and this resulted in attenuated expression of the sensitized HIC response during the acute phase of a subsequent untreated withdrawal episode. However, HIC activity was exacerbated at later time points during this final test withdrawal in mice that had received lorazepam treatment for earlier withdrawals. A similar pattern of results was obtained for changes in pentylenetetrazol seizure threshold dosage. These results do not seem to be due to pharmacokinetic factors, because peak blood ethanol levels, rate of ethanol elimination, and plasma levels of lorazepam did not significantly differ among groups during the final test withdrawal cycle.

CONCLUSIONS

Blocking central nervous system hyperexcitability during repeated ethanol withdrawals with lorazepam effectively blunts the development and expression of sensitized seizure activity during the acute phase of a subsequent unmedicated withdrawal episode. At later time points, withdrawal-related seizure activity was exacerbated, and this is possibly reflective of an interaction between protracted ethanol withdrawal and withdrawal from the benzodiazepine. The clinical implications of these findings suggest that repeated use of benzodiazepines for treatment of multiple ethanol withdrawals may have some initial beneficial effects, but such treatment may also place patients at increased risk of seizures at later time points.

Symptom-triggered therapy for alcohol withdrawal syndrome in medical inpatients

OBJECTIVE

To assess the efficacy of symptom-triggered therapy vs usual care for alcohol withdrawal syndrome (AWS) in medical inpatients.

PATIENTS AND METHODS

This study was a retrospective analysis of patients admitted to general medical services between January 1, 1995, and December 31, 1998, who experienced AWS during the admission. This study was conducted at Saint Marys Hospital, Rochester, Minn. Patients were identified from hospital discharge diagnoses and pharmacy data. Symptom-triggered therapy for AWS was initiated in 1997. Patients were divided into preimplementation (1995-1996) and postimplementation (1997-1998) cohorts. Age, sex, medical comorbid conditions, previous AWS (including seizures and delirium tremens), duration of treatment for AWS, benzodiazepine use and dose, complications of AWS, and adverse outcomes of treatment during the incident admission were abstracted from the medical records of eligible patients. Comorbid conditions were classified according to the Charlson comorbidity index. Differences between the cohorts were assessed with use of logistic regression models and analysis of covariance.

RESULTS

Review of medical records from 638 admissions (536 patients) yielded 216 admissions eligible for this study. After adjustment for age, sex, Charlson comorbidity index, previous AWS, previous alcohol withdrawal seizures, and previous delirium tremens, we found no significant difference between cohorts for duration of treatment (P=.16), benzodiazepine use (P=.21), total dose of benzodiazepine (P=.38), or total complication rate (P=.053). We did observe a significant difference in the occurrence of delirium tremens between the 2 treatment groups (P=.04). This was especially apparent for patients with no history of delirium tremens.

CONCLUSIONS

Symptom-triggered therapy is effective treatment for AWS in medical inpatients. In this retrospective study, it did not result in shorter duration of treatment but was associated with a decreased occurrence of delirium tremens, the most severe and life-threatening complication of AWS. This result was most apparent in patients with no history of delirium tremens.

Influence of clonazepam and carbamazepine on alcohol withdrawal syndrome, preference and development of tolerance to ethanol in rats

The effects of clonazepam (0.3 and 1.0 mg/kg or 0.1 mg/kg, b.i.d., 5 days) and carbamazepine (50 and 100 mg/kg or 12.5 and 50 mg/kg b.i.d., 5 days) on alcohol withdrawal syndrome in rats were investigated. Moreover, the influence of clonazepam (0.3 mg/kg, single dose, or repeated doses for 8 days) and carbamazepine (50 mg/kg, single dose, or repeated doses for 8 days) on the development of tolerance to ethanol was also examined. To study the influence of clonazepam and carbamazepine on preference to ethanol, both drugs were administered for 5 days during the last week of the experiment, (clonazepam at 0.1 mg/kg, b.i.d., i.p. and carbamazepine at 12.5 mg/kg, b.i.d, i.p.). Clonazepam and carbamazepine administered at single doses as well as multiple doses diminished the symptoms of withdrawal syndrome. Clonazepam did not prevent the development of tolerance to sleep-inducing and hypothermal action of ethanol, while carbamazepine prevented the development of tolerance to hypnotic effect of ethanol. Carbamazepine clearly reduced preference to ethanol (significantly vs. the control group and vs. the baseline values). Clonazepam also diminished preference to alcohol, but only in comparison with baseline values.

Effects of a novel uncompetitive NMDA receptor antagonist, MRZ 2/579 on ethanol self-administration and ethanol withdrawal seizures in the rat

It has been repeatedly reported that NMDA receptors may contribute to ethanol-induced discriminative stimulus effects and withdrawal syndrome. However, the role of NMDA receptors in the reinforcing properties of ethanol remains unclear. The aim of the present study was to evaluate effects of the novel low-affinity, uncompetitive NMDA receptor antagonist, 1-amino-1,3,3,5,5-pentamethyl-cyclohexane hydrochloride (MRZ 2/579), on ethanol self-administration and ethanol withdrawal-associated seizures in rats. Both an operant (lever pressing for ethanol) and non-operant two-bottle choice setups were employed to initiate ethanol self-administration. In another procedure, forced treatment with high doses (9--15 g/kg/day) was used to induce physical dependence on ethanol. MRZ 2/579 delivered chronically by osmotic minipumps (9.6 mg/day, s.c.) did not alter either operant or non-operant ethanol drinking behaviour in a maintenance phase of ethanol self-administration. In contrast, repeated daily injections of the drug (5 mg/kg, i.p.) led to a progressive decrease in operant responding for ethanol. MRZ 2/579 (0.5--7.5 mg/kg, i.p.) and another low-affinity NMDA receptor antagonist, memantine (1--10 mg/kg, i.p.) dose-dependently suppressed ethanol withdrawal seizures with efficacies comparable with that of a standard benzodiazepine derivative, diazepam. The results of the present study indicate that: (i) intermittent administration of MRZ 2/579 may lead to a gradual decrease of operant responding for ethanol; and (ii) the group of low-affinity uncompetitive NMDA receptor antagonists may be an interesting alternative to benzodiazepines in the treatment of alcohol withdrawal.

Diazepam during prior ethanol withdrawals does not alter seizure susceptibility during a subsequent withdrawal

The number of cycles of alcohol detoxification is suggested to be an important variable in the predisposition to severe withdrawal seizures in alcohol-dependent individuals. Several clinical studies have suggested that exposure to repeated alcohol withdrawals may lead to increased severity of subsequent withdrawal episodes. Consistent with these observations, exposure to multiple cycles of ethanol withdrawal in our previous study significantly increased sensitivity to the convulsive effects of the GABA(A) receptor inverse agonist, Ro15-4513, in comparison to continuous ethanol exposure with no intermittent withdrawals. There was also a selective increase in the occurrence of spontaneous spike and sharp wave (SSW) activity in the EEG recorded from hippocampal area CA(3) in proportion to the number of withdrawal episodes experienced. It is hypothesized that during such repeated episodes of ethanol intoxication and withdrawal, changes in neuronal excitation during prior withdrawals could serve as initially subconvulsive kindling stimuli that might eventually result in the increased severity of the withdrawal syndrome. There is some evidence of the successful suppression of such neuronal excitation during acute ethanol withdrawal by positive modulators of the GABA(A) receptor. In the present study, the benzodiazepine agonist, diazepam, at a dose (4.0 mg/kg) that suppresses acute withdrawal symptoms, when administered during intermittent withdrawals, did not alter seizure sensitivity during a subsequent nonmedicated withdrawal. Diazepam treatment during prior withdrawals also did not have any effect on the multiple withdrawal-associated increase in SSW activity in hippocampal area CA(3) during an untreated withdrawal. This finding suggests that suppression of acute withdrawal symptoms by diazepam does not prevent long-lasting changes in CNS function resulting from repeated exposures to ethanol withdrawal.

S-methyl-N,N-diethylthiocarbamate sulfoxide elicits neuroprotective effect against N-methyl-D-aspartate receptor-mediated neurotoxicity

Glutamatergic neurotransmission, particularly of the NMDA receptor type, has been implicated in the excitotoxic response to several external and internal stimuli. In the present investigation, we report that S-methyl-N,N-diethylthiocarbamate sulfoxide (DETC-MeSO) selectively and specifically blocks the NMDA receptor subtype of the glutamate receptors, and attenuates glutamate-induced neurotoxicity in rat-cultured primary neurons. Other major ionotropic glutamate receptor subtypes, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and kainate, were insensitive to DETC-MeSO both in vitro and in vivo. Disulfiram, the parent compound of DETC-MeSO, also inhibits glutamate receptors partially in vivo; however, it fails to inhibit glutamate receptors in mice pretreated with N-butyl imidazole, a cytochrome P450 enzyme inhibitor, implicating the need for bioactivation of disulfiram to be an effective antagonist. We showed that glutamate-induced increase in (45)Ca2+ was attenuated in rat-cultured primary neurons following pretreatment with DETC-MeSO. The Ca2+ influx into primary neurons, studied by confocal microscopy of the fluorescent Ca2+ dye fura-2, demonstrated a complete attenuation of NMDA-induced Ca2+ influx. Similarly, DETC-MeSO attenuated NMDA-induced (45)Ca2+ uptake. Glutamate-induced (45)Ca2+ uptake and Ca2+ influx, however, were partially blocked by DETC-MeSO, and this is consistent with both in vitro and in vivo studies in which DETC-MeSO partially blocked mouse brain glutamate receptors. In addition, DETC-MeSO pretreatment effectively prevented seizures in mice induced either by NMDA, ammonium acetate, or ethanol-induced kindling seizures, all of which are believed to be mediated by NMDA receptors. These data demonstrate that DETC-MeSO produces the neuroprotective effect through antagonism of NMDA receptors in vivo.

Clinical characteristics as predictors of recurrent alcohol-related seizures

OBJECTIVE

To determine whether clinical data available in the emergency department can accurately predict a subset of patients at low risk of developing recurrent seizures following one or more initial alcohol-related seizures in the out-of-hospital arena.

METHODS

This was a retrospective secondary analysis of data obtained from the placebo arms of two prospective, randomized trials of drug treatments for the prevention of recurrent alcohol-related seizures. Subjects with and without one or more recurrent alcohol-related seizures during the study period were compared according to the following characteristics: 1) age, 2) gender, 3) daily ethanol consumption, 4) years of ethanol abuse, 5) previous alcohol-related seizure, 6) previous seizure of other etiology, 7) temperature, 8) heart rate, 9) systolic blood pressure, 10) diastolic blood pressure, 11) respiratory rate, and 12) ethanol level. Data were analyzed with t-tests and chi-square where appropriate.

RESULTS

One hundred five placebo-treated patients were analyzed and 31 (30%) developed recurrent alcohol-related seizures. None of the listed characteristics were statistically different between the two groups except for the initial ethanol level. Subjects with an ethanol level higher than 100 mg/dL were less likely (0%) to develop recurrent seizures than patients with a level equal to or below 100 mg/dL (36%) (p < 0.01).

CONCLUSIONS

An initial ethanol level higher than 100 mg/dL was significantly associated with a low risk for recurrent alcohol-related seizures during the observation period. No other low-risk clinical characteristics could be identified.

Modulation of audiogenic seizures by histamine and adenosine receptors in the inferior colliculus

Susceptibility to behaviorally similar audiogenic seizures (AGS) occurs genetically and is inducible during ethanol withdrawal (ETX). Comparisons between AGS mechanisms of genetically epilepsy-prone rats (GEPR-9s) and ethanol-withdrawn rats (ETX-Rs) are yielding information about general pathophysiological mechanisms of epileptogenesis. The inferior colliculus (IC) is the AGS initiation site. Excitatory amino acid (EAA) abnormalities in the IC are implicated in AGS, and histamine and adenosine receptor activation each reduce EAA release and inhibit several seizure types. Previous studies indicate that focal infusion of an adenosine receptor agonist into the IC blocked AGS in GEPR-9s, but the effects of adenosine receptor activation in the IC on AGS in ETX-Rs are unknown. The effects of histamine receptor activation on either form of AGS are also unexamined. The present study evaluated effects of histamine or a nonselective adenosine A(1) agonist, 2-chloroadenosine, on AGS by focal microinjection into the IC. Ethanol dependence and AGS susceptibility were induced in normal rats by intragastric ethanol. Histamine (40 or 60 nmol/side) significantly reduced AGS in GEPR-9s, but histamine in doses up to 120 nmol/side did not affect AGS in ETX-Rs. 2-Chloroadenosine (5 or 10 nmol/side) did not affect AGS in ETX-Rs, despite the effectiveness of lower doses of this agent in GEPR-9s reported previously. Thus, histamine and adenosine receptors in the IC modulate AGS of GEPR-9s, but do not modulate ETX-induced AGS. The reasons for this difference may involve the chronicity of AGS susceptibility in GEPR-9s, which may lead to more extensive neuromodulation as compensatory mechanisms to limit the seizures compared to the acute AGS of ETX-Rs.

Nifedipine alleviates alterations in hippocampal kindling after repeated ethanol withdrawal

BACKGROUND

Current clinical treatment of alcohol detoxification commonly includes pharmacotherapy to lessen the potential for seizures, especially in those patients undergoing repeated treatment. Basic research continues to study the alcohol withdrawal-related "kindling" of seizures both to understand the mechanisms involved and to identify alternative treatments. Ethanol withdrawal has been shown to result in the delay of electrical kindling at several brain sites, which suggests a long-lasting disruption of neuronal function.

METHODS

This study focused on the participation of the L-type voltage-gated calcium channels in this process by the treatment of animals during withdrawal with nifedipine, an agent that blocks these channels. Animals were randomly assigned to ethanol (ethanol-exposed/ethanol-naive) and drug treatment (nifedipine/vehicle) groups. Subjects receiving ethanol were exposed to five cycles of 3 days' ethanol exposure, with each exposure cycle separated by a 1-day withdrawal period. Drug treatment was administered twice during each withdrawal period. Twenty days after completion of ethanol exposure, animals received daily kindling stimulations to hippocampal area CA3 until the kindling criterion was attained.

RESULTS

Ethanol-exposed animals that received vehicle treatment during ethanol withdrawal required more daily stimulations to become fully kindled than did ethanol-naive controls. This delay in seizure development was most pronounced in the progression from focal seizure behaviors to more generalized seizures. Animals that received the same ethanol exposure but that were treated with nifedipine required significantly fewer stimulations than did ethanol-exposed animals that received vehicle. Ethanol-exposed/ nifedipine-treated animals did not differ from ethanol-naive controls that received vehicle or nifedipine.

CONCLUSIONS

Alcohol withdrawal-related alterations in seizure-sensitive neural circuitry such as the hippocampus persist long after cessation of ethanol exposure. Furthermore, the L-type voltage-gated calcium channels are involved in this effect in that blockade of these channels during acute withdrawal alleviates alterations in seizure mechanisms on a long-term basis.

Effects of phentermine and fenfluramine on alcohol consumption and alcohol withdrawal seizures in rats

The drug combination of phentermine plus fenfluramine has been used clinically in both the treatment of obesity and alcoholism. The aim of the current study was to assess the interaction of the two drugs on consumption of both an alcohol-containing and a nonalcoholic diet. Furthermore, the efficacy of the drug combination on suppression of withdrawal seizures was determined. Animals were either maintained on a 6% alcohol-containing diet, free-fed an isocaloric control, or pair-fed the control diet. It was observed that, with regard to body weight growth curves, alcohol provides about 2.5 kcal/g. Both phentermine and fenfluramine caused a decrease in consumption 1 h after administration; however, during the next 23 h, 4 mg/kg phentermine significantly increased consumption of all diets. At doses of 1 and 2 mg/kg, fenfluramine selectively reduced consumption of the alcohol-containing diet as compared to the isocaloric diets. Lower doses of fenfluramine blocked the increases in consumption induced by phentermine. Furthermore, in animals fed the nonalcoholic diet, the drug combination of 2 mg/kg fenfluramine plus 8 mg/kg phentermine produced a 63-82% reduction in consumption, an effect not seen when either drug was administered alone. This greater than additive effect was also seen in the earlier time periods in animals pair-fed the control diet. Neurochemical analysis from these animals revealed that the alcohol-dependent animals displayed a significant reduction of DOPAC and 5-HIAA levels in the striatum, frontal cortex, and hypothalamus after a 9-h withdrawal period, further implicating the serotonergic and dopaminergic systems in mediation of withdrawal symptoms and alcohol craving. Finally, 8 mg/kg phentermine plus 8 mg/kg fenfluramine completely abolished alcohol withdrawal seizures, compared to a 78% rate in saline treated rats. In conclusion, the coadministration of phentermine plus fenfluramine produced a moderate reduction of alcohol consumption and was completely effective at reducing alcohol withdrawal seizures.

Prolonged sedation requiring mechanical ventilation and continuous flumazenil infusion after routine doses of clorazepam for alcohol withdrawal syndrome

We report the cases of two patients who developed prolonged sedation after routine doses of clorazepam for alcohol withdrawal syndrome. They required prolonged mechanical ventilation (10 days for both patients) followed by continuous flumazenil infusion (16 days for one patient and 3 days for the other) to avoid reintubation. In the two patients, nordazepam accumulation (main active metabolite of clorazepam) was demonstrated as the cause of the coma. This accumulation could be attributed, in one case, to impaired hepatic cytochrome P 450 3A4 activity. Caution is required when prescribing benzodiazepines to alcoholic patients and the use of benzodiazepine which do not undergo hepatic oxidation by cytochrome P 450 such as oxazepam or lorazepam is suggested.