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.