Two cases of severe gamma-hydroxybutyrate withdrawal delirium on a psychiatric unit: recommendations for management

Phenobarbital to manage severe gamma-hydroxybutyrate withdrawal: A case series

INTRODUCTION

Management of a withdrawal syndrome following cessation of regular gamma-hydroxybutyrate (GHB) use, and its precursors, can represent a clinical challenge due to rapid onset delirium and/or seizures. Severe GHB withdrawal can be characterised by persistent or worsening features despite increasing benzodiazepine doses and regular baclofen. Barbiturates, such as phenobarbital, are an appealing option in this context due to their unique GABA-A receptor action.

CASE SERIES

This series describes the use of phenobarbital in 13 cases, 12 patients, across two hospitals in Sydney, Australia, with persistent or progressive GHB withdrawal despite benzodiazepine-based management. A median cumulative dose of oral diazepam prior to commencing phenobarbital was 120 mg (range 80-255 mg). The median time from the last GHB use to the first dose of phenobarbital was 24 h (range 7-57 h). Eight cases received phenobarbital orally on a general ward and 5 intravenously in intensive care units. An improvement in GHB withdrawal symptoms was observed after phenobarbital in all cases and there were no adverse events related to phenobarbital.

DISCUSSION AND CONCLUSION

This case series suggests that phenobarbital for the management of benzodiazepine-resistant GHB withdrawal can be safe, even in general inpatient settings, and may avert the progression of delirium. Most data on the management of GHB withdrawal comes from case reports or series, such as this one. This highlights the need for prospective trials to establish an evidence base for therapeutic approaches, including validated measures of withdrawal severity and more information relating to the safe and effective dosing of phenobarbital.

Withdrawal of Gamma-Hydroxybutyrate in a Saudi Male Patient: A Case Report

Gamma-hydroxybutyrate (GHB) is a central nervous system (CNS) depressant with limited clinical use but has been misused in the last few decades. During intoxication, the patient may develop CNS depression and may have agitation, while during withdrawal, the patient can present with severe agitation or delirium. Here, we report the case of a 30-year-old Saudi male patient who was brought by his brother to the emergency department (ED) with agitation and delirium. The patient's friend stated the patient had been misusing GHB mixed with alcohol for the last seven months, with the last use occurring 24 hours before the ED presentation. The patient was put on a five-point restraint for safety concerns and received supportive therapy. After two days of admission, the patient completely recovered. As the patient provided a limited history of his GHB misuse, the clinician lacked sufficient information to determine whether the patient was intoxicated or withdrawing. Clinicians in Saudi Arabia need to be highly suspicious of GHB misuse when treating patients with drug intoxication or withdrawal.

Successful treatment of severe, treatment resistant GHB withdrawal through thiopental-coma

BACKGROUND

In patients with gamma-hydroxybutyrate (GHB) use disorder (GUD), withdrawal can have a fulminant course with rapid progression of severe, potentially life-threatening complications. Case: We present a 45-year old man with severe GHB withdrawal, resistant to conventional treatment with pharmaceutical GHB, high doses of benzodiazepines and baclofen. GHB withdrawal finally responded to thiopental-induced coma therapy, with burst suppression pattern on electroencephalography (EEG). The patient fully recovered, without withdrawal or residual neuropsychiatric symptoms. Discussion: To our knowledge, this is the first case report in which barbiturates were used to induce a coma to treat severe, treatment resistant GHB withdrawal. This case suggests barbiturate coma therapy might be considered in severe GHB withdrawal which does not respond to conventional treatment.

[Course and complications of GHB detoxification treatment: a 1-year case series]

BACKGROUND

Gamma-hydroxybutyrate (GHB) and its precursors have gained popularity over the last decade as a drug in the party and club scene; however, the clinical knowledge of these substances is low. In the literature there have been case reports of severe dependence and withdrawal but there is a lack of systematic knowledge about the clinical course and complications of detoxification treatment.

OBJECTIVE

The aim of this article is to evaluate the prevalence, treatment course, complications and compliance of GHB patients seeking inpatient qualified detoxification treatment (QDT).

METHODS

A retrospective evaluation of the hospital charts of all patients admitted to this clinic in 2017 for QDT of GHB. The Jewish Hospital in Berlin (Jüdisches Krankenhaus Berlin) provides specialized inpatient units for addictive diseases and a general intensive care unit. The control population came from a prospective study of all patients with addictive diseases who were treated in the same hospital in 2012.

RESULTS

In 2017 a total of 18 patients with GHB addiction were treated in this hospital. This corresponds to a 1‑year prevalence of 2.28% of all addictive diseases in this year. During detoxification treatment 52% of the GHB patients had to be temporarily transferred to the intensive care unit, 5% had to be temporarily mechanically ventilated and 26% suffered from withdrawal delirium. Of the patients 42% terminated treatment prematurely against medical advice.

CONCLUSION

Withdrawal treatment from GHB is a severe and potentially dangerous condition, the prevalence of complications was higher than for most other drugs and the rate of intensive care and withdrawal delirium was very high. Further studies are urgently needed with the aim of reducing the complication rates of GHB withdrawal and enhancing therapy adherence.

Alcohol addiction - the safety of available approved treatment options

INTRODUCTION

Alcohol Use Disorders (AUD) is a leading cause of mortality and morbidity worldwide. At present disulfiram, naltrexone and acamprosate are approved for the treatment of AUD in U.S. and Europe. Nalmefene is approved in Europe and sodium oxybate is approved in Italy and Austria only. Baclofen received a 'temporary recommendation for use' in France.

AREAS COVERED

The safety of the above mentioned medications on liver, digestive system, kidney function, nervous system, pregnancy and lactation and their possible side effects are described and discussed.

EXPERT OPINION

Mechanism of action and metabolism of these drugs as well as patients' clinical characteristics can affect the safety of treatment. All approved medications are valid tools for the treatment of AUD in patients without advanced liver disease. For some drugs, attention should be paid to patients with renal failure and medications may be used with caution, adjusting the dosage according to kidney function. In patients with AUD and advanced liver disease, at present only baclofen has been formally tested in randomized controlled trials showing its safety in this population.

Pharmacological Treatment in γ-Hydroxybutyrate (GHB) and γ-Butyrolactone (GBL) Dependence: Detoxification and Relapse Prevention

The misuse of γ-hydroxybutyrate (GHB) for recreational purposes has resulted in an increase in GHB-related problems such as intoxications, dependence and withdrawal in several countries in Europe, Australia and the US over the last decade. However, prevalence rates of misuse of GHB and its precursor, γ-butyrolactone (GBL), are still relatively low. In this qualitative review paper, after a short introduction on the pharmacology of GHB/GBL, followed by a summary of the epidemiology of GHB abuse, an overview of GHB dependence syndrome and GHB/GBL withdrawal syndrome is provided. Finally, the existing literature on management of GHB detoxification, both planned and unplanned, as well as the available management of GHB withdrawal syndrome, is summarized. Although no systematic studies on detoxification and management of withdrawal have been performed to date, general recommendations are given on pharmacological treatment and preferred treatment setting.

The Neurobiological Mechanisms of Gamma-Hydroxybutyrate Dependence and Withdrawal and Their Clinical Relevance: A Review

OBJECTIVE

x03B3;-Hydroxybutyrate (GHB) has gained popularity as a drug of abuse. In the Netherlands the number of patients in treatment for GHB dependence has increased sharply. Clinical presentation of GHB withdrawal can be life threatening. We aim, through this overview, to explore the neurobiological pathways causing GHB dependency and withdrawal, and their implications for treatment choices.

METHODS

In this work we review the literature discussing the findings from animal models to clinical studies focused on the neurobiological pathways of endogenous but mainly exogenous GHB.

RESULTS

Chronic abuse of GHB exerts multifarious neurotransmitter and neuromodulator effects on x03B3;-aminobutyric acid (GABA), glutamate, dopamine, serotonin, norepinephrine and cholinergic systems. Moreover, important effects on neurosteroidogenesis and oxytocin release are wielded. GHB acts mainly via a bidirectional effect on GABAB receptors (GABABR; subunits GABAB1 and GABAB2), depending on the subunit of the GIRK (G-protein-dependent ion inwardly rectifying potassium) channel involved, and an indirect effect of the cortical and limbic inputs outside the nucleus accumbens. GHB also activates a specific GHB receptor and β1-subunits of α4-GABAAR. Reversing this complex interaction of neurobiological mechanisms by the abrupt cessation of GHB use results in a withdrawal syndrome with a diversity of symptoms of different intensity, depending on the pattern of GHB abuse.

CONCLUSION

The GHB withdrawal symptoms cannot be related to a single mechanism or neurological pathway, which implies that different medication combinations are needed for treatment. A single drug class, such as benzodiazepines, gabapentin or antipsychotics, is unlikely to be sufficient to avoid life-threatening complications. Detoxification by means of titration and tapering of pharmaceutical GHB can be considered as a promising treatment that could make polypharmacy redundant.

GHB pharmacology and toxicology: acute intoxication, concentrations in blood and urine in forensic cases and treatment of the withdrawal syndrome

The illicit recreational drug of abuse, γ-hydroxybutyrate (GHB) is a potent central nervous system depressant and is often encountered during forensic investigations of living and deceased persons. The sodium salt of GHB is registered as a therapeutic agent (Xyrem®), approved in some countries for the treatment of narcolepsy-associated cataplexy and (Alcover®) is an adjuvant medication for detoxification and withdrawal in alcoholics. Trace amounts of GHB are produced endogenously (0.5-1.0 mg/L) in various tissues, including the brain, where it functions as both a precursor and a metabolite of the major inhibitory neurotransmitter γ-aminobutyric acid (GABA). Available information indicates that GHB serves as a neurotransmitter or neuromodulator in the GABAergic system, especially via binding to the GABA-B receptor subtype. Although GHB is listed as a controlled substance in many countries abuse still continues, owing to the availability of precursor drugs, γ-butyrolactone (GBL) and 1,4-butanediol (BD), which are not regulated. After ingestion both GBL and BD are rapidly converted into GHB (t½ ~1 min). The Cmax occurs after 20-40 min and GHB is then eliminated from plasma with a half-life of 30-50 min. Only about 1-5% of the dose of GHB is recoverable in urine and the window of detection is relatively short (3-10 h). This calls for expeditious sampling when evidence of drug use and/or abuse is required in forensic casework. The recreational dose of GHB is not easy to estimate and a concentration in plasma of ~100 mg/L produces euphoria and disinhibition, whereas 500 mg/L might cause death from cardiorespiratory depression. Effective antidotes to reverse the sedative and intoxicating effects of GHB do not exist. The poisoned patients require supportive care, vital signs should be monitored and the airways kept clear in case of emesis. After prolonged regular use of GHB tolerance and dependence develop and abrupt cessation of drug use leads to unpleasant withdrawal symptoms. There is no evidence-based protocol available to deal with GHB withdrawal, apart from administering benzodiazepines.

Withdrawal from gamma-hydroxybutyrate, 1,4-butanediol and gamma-butyrolactone: a case report and systematic review

1,4-Butanediol (1,4-BD) is an industrial solvent that is metabolized to gamma-hydroxybutyrate (GHB), a gamma-aminobutyric acid agonist and central nervous system depressant. GHB and its analogues are popular drugs of abuse. Withdrawal from these agents is characterized by autonomic instability and altered mental status. We report a case of withdrawal from 1,4-BD lasting 6 days and complicated by new onset of seizures and rhabdomyolysis. In addition, we conducted a systematic review of the English literature pertaining to withdrawal from GHB, 1,4-BD and gamma-butyrolactone (GBL). Data collected from source articles included last use prior to symptom onset, clinical features on presentation, duration of symptoms and outcome. Twenty-seven studies with 57 episodes of withdrawal were included. Thirty-six cases (63%) involved GHB, 3 cases (5%) involved 1,4-BD and 18 (32%) involved GBL. The most common patient symptoms were tremor (67%), hallucinations (63%), tachycardia (63%) and insomnia (58%). Seizures and rhabdomyolysis each occurred in 7% of cases, but only 1 death occurred. Emergency physicians must consider withdrawal from these agents when patients present with clinical features suggestive of a sedative-hypnotic withdrawal syndrome.

Management and treatment of gamma butyrolactone withdrawal syndrome: a case report and review

Gamma butyrolactone (GBL) is an increasingly popular drug of abuse that is readily available in most countries, and it is often purchased over the Internet. In addition to the acute hazards of intoxication and overdose, users who are dependent on GBL can also experience severe withdrawal reactions, including hallucinations, agitation, confusion, delusions, delirium, rhabdomyolysis, and seizures. Most of the existing literature suggests the use of a high-dose benzodiazepine as a first-line treatment for GBL withdrawal. However, several cases of resistance to benzodiazepines have been observed, which likely reflect some pharmacological differences between benzodiazepines and GBL. Specifically, the effects of benzodiazepines are primarily mediated by gamma-aminobutyric acid (GABA)-A receptors, while GBL and its analogues act mainly at GABA-B receptors, with possible additional effects via the ionotropic GABA-A receptors. In this regard, recent studies have found that GBL and its analogues possess a high affinity for a specific form of extrasynaptic GABA-A receptors that are strongly activated by barbiturates, such as phenobarbital, but that are insensitive to benzodiazepines. Taken together, these findings suggest that barbiturates could be evaluated as first-choice agents for the treatment of GBL/gamma hydroxybutyrate (GHB) withdrawal instead of benzodiazepines. In support of this view, we describe a clinical case of difficult to manage GBL withdrawal symptoms in a 42-year-old male. We also review the literature on treatment options for GBL/GHB withdrawal, including benzodiazepine-resistant withdrawal.

Nurse's perspectives on care provided for patients with gamma-hydroxybutyric acid and gamma-butyrolactone abuse

AIMS AND OBJECTIVES

To describe registered nurses' views and experiences providing care for gamma-hydroxybutyric acid and gamma-butyrolactone abuse inpatients in a psychiatric unit.

BACKGROUND

Gamma-hydroxybutyric acid and gamma-butyrolactone are illegal drugs with potentially fatal outcomes that are entering wider use in Scandinavia. Gamma-hydroxybutyric acid-dependent persons with withdrawal symptoms often require forceful withdrawal treatment provided in psychiatric units.

DESIGN

A qualitative study with a purposive sample including interviews from registered nurses.

METHODS

Data were collected from interviews with 15 registered nurses working in specialised dependency units in psychiatric wards. The data collected were analysed through a descriptive, qualitative analysis.

RESULTS

The registered nurses' narratives revealed four main areas of convergence: feelings of anxiety and despair, preparation for unpredictable and precarious situations, striving for good relationship and striving to optimise and develop nursing care. The interviews revealed that registered nurses reflect on and discuss their feelings about their patients' situations with colleagues; prepare themselves for potential aggressiveness and unpredictable situations; improve their care through conscious attitude adjustment and relationship-forming behaviours; and strive to increase their personal knowledge, maintain a hopeful outlook and exhibit a positive approach. These themes were found in all nine categories and sixteen subcategories.

DISCUSSION

The findings based on the registered nurses' narratives indicated that the registered nurses experienced their work situation when caring for these patients to be very complex and demanding.

CONCLUSION

The study revealed that registered nurses worked extensively to craft their approach and attitude towards their patients. It is clear that registered nurses use themselves as tools or instruments for the creation of good relationships, thus providing the best care possible.

RELEVANCE TO CLINICAL PRACTICE

Registered nurses should be given more education, clearer guidelines and better guidance to assist them in facing such challenging and often problematic situations. One-on-one shadowing provides the possibility to create and develop relationship.

Physical dependence on gamma-hydroxybutrate (GHB) prodrug 1,4-butanediol (1,4-BD): time course and severity of withdrawal in baboons

BACKGROUND

1,4-Butanediol (1,4-BD) is a gamma-hydroxybutyrate (GHB) pro-drug, with multiple commercial uses, and a drug of abuse. Although there are case reports of a withdrawal syndrome following 1,4-BD use, no studies have evaluated the physical dependence potential of 1,4-BD and characterized the time course of withdrawal.

METHODS

Vehicle and then 1,4-BD were administered continuously 24 h/day via intragastric catheters in male baboons (Papio anubis, n=3). Dosing was initiated at 100 mg/kg and increased by 100mg/kg/day to 400mg/kg. After a stabilization period, doses of 500 and then 600 mg/kg/day were each maintained for 3-4 weeks. Plasma levels of 1,4-BD and GHB were determined for each dose condition. Physical dependence was assessed via administration of a GABA-B antagonist (precipitated withdrawal test) during administration of the 600 mg/kg dose and via abrupt termination of chronic 1,4-BD administration (spontaneous withdrawal test). Outcome measures included the number of food pellets earned, performance on a fine-motor task, observed behaviors, and plasma levels of GHB and 1,4-BD.

RESULTS

Following maintenance of 1,4-BD 600 mg/kg for 3 weeks, the number of food pellets earned was significantly decreased. At the end of chronic 1,4-BD dosing, the levels of GHB in plasma ranged from 1290 to 2300 μmol/L and levels of 1,4-BD in plasma ranged from 13.1 to 37.9 μmol/L. Signs of physical dependence were observed following precipitated and spontaneous withdrawal tests. Seizures were not observed.

CONCLUSIONS

These data indicate chronic 1,4-BD produced physical dependence in baboons and the withdrawal syndrome can be characterized as mild to intermediate.

The clinical toxicology of γ-hydroxybutyrate, γ-butyrolactone and 1,4-butanediol

INTRODUCTION

Gamma-hydroxybutyrate (GHB) and its precursors, gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD), are drugs of abuse which act primarily as central nervous system (CNS) depressants. In recent years, the rising recreational use of these drugs has led to an increasing burden upon health care providers. Understanding their toxicity is therefore essential for the successful management of intoxicated patients. We review the epidemiology, mechanisms of toxicity, toxicokinetics, clinical features, diagnosis, and management of poisoning due to GHB and its analogs and discuss the features and management of GHB withdrawal.

METHODS

OVID MEDLINE and ISI Web of Science databases were searched using the terms "GHB," "gamma-hydroxybutyrate," "gamma-hydroxybutyric acid," "4-hydroxybutanoic acid," "sodium oxybate," "gamma-butyrolactone," "GBL," "1,4-butanediol," and "1,4-BD" alone and in combination with the keywords "pharmacokinetics," "kinetics," "poisoning," "poison," "toxicity," "ingestion," "adverse effects," "overdose," and "intoxication." In addition, bibliographies of identified articles were screened for additional relevant studies including nonindexed reports. Non-peer-reviewed sources were also included: books, relevant newspaper reports, and applicable Internet resources. These searches produced 2059 nonduplicate citations of which 219 were considered relevant.

EPIDEMIOLOGY

There is limited information regarding statistical trends on world-wide use of GHB and its analogs. European data suggests that the use of GHB is generally low; however, there is some evidence of higher use among some sub-populations, settings, and geographical areas. In the United States of America, poison control center data have shown that enquiries regarding GHB have decreased between 2002 and 2010 suggesting a decline in use over this timeframe.

MECHANISMS OF ACTION

GHB is an endogenous neurotransmitter synthesized from glutamate with a high affinity for GHB-receptors, present on both on pre- and postsynaptic neurons, thereby inhibiting GABA release. In overdose, GHB acts both directly as a partial GABA(b) receptor agonist and indirectly through its metabolism to form GABA.

TOXICOKINETICS

GHB is rapidly absorbed by the oral route with peak blood concentrations typically occurring within 1 hour. It has a relatively small volume of distribution and is rapidly distributed across the blood-brain barrier. GHB is metabolized primarily in the liver and is eliminated rapidly with a reported 20-60 minute half-life. The majority of a dose is eliminated completely within 4-8 hours. The related chemicals, 1,4-butanediol and gamma butyrolactone, are metabolized endogenously to GHB. CLINICAL FEATURES OF POISONING: GHB produces CNS and respiratory depression of relatively short duration. Other commonly reported features include gastrointestinal upset, bradycardia, myoclonus, and hypothermia. Fatalities have been reported. MANAGEMENT OF POISONING: Supportive care is the mainstay of management with primary emphasis on respiratory and cardiovascular support. Airway protection, intubation, and/or assisted ventilation may be indicated for severe respiratory depression. Gastrointestinal decontamination is unlikely to be beneficial. Pharmacological intervention is rarely required for bradycardia; however, atropine administration may occasionally be warranted. WITHDRAWAL SYNDROME: Abstinence after chronic use may result in a withdrawal syndrome, which may persist for days in severe cases. Features include auditory and visual hallucinations, tremors, tachycardia, hypertension, sweating, anxiety, agitation, paranoia, insomnia, disorientation, confusion, and aggression/combativeness. Benzodiazepine administration appears to be the treatment of choice, with barbiturates, baclofen, or propofol as second line management options.

CONCLUSIONS

GHB poisoning can cause potentially life-threatening CNS and respiratory depression, requiring appropriate, symptom-directed supportive care to ensure complete recovery. Withdrawal from GHB may continue for up to 21 days and can be life-threatening, though treatment with benzodiazepines is usually effective.

[Abuse of γ-hydroxybutyrate]

BACKGROUND

Gamma-hydroxybutyrate (GHB) is naturally present in the human body, but may also be used as an intoxicating drug. Information from several sources has suggested its increased availability and use in Norway. There have also been reports of an increasing use of the chemical precursor gamma-butyrolactone (GBL).There is currently a need for knowledge on symptoms, addictiveness and overdoses, as well as targeted preventive measures.

MATERIAL AND METHODS

The article is based on a discretionary selection of articles resulting from a literature search in PubMed, as well as reports from Norwegian and European authorities and research institutions.

RESULTS

An intake of small amounts of GHB produces an intoxicating effect, whereas higher doses can result in poisoning. Deaths have been reported. The effect may be variable, due to a steep dose-response curve and interaction with alcohol and other intoxicants. Treatment of poisoning is symptomatic and supportive. Treatment of abstinence is also supportive, while delirium may be treated as delirium tremens.

INTERPRETATION

Preventive measures should be tailored specifically to potential user-groups.

Acute toxicity and withdrawal syndromes related to γ-hydroxybutyrate (GHB) and its analogues γ-butyrolactone (GBL) and 1,4-butanediol (1,4-BD)

Gamma-hydroxybutyrate (GHB) has been used as a recreational drug since the 1990s and over the last few years there has been increasing use of its analogues gamma-butyrolactone (GBL) and to a lesser extent 1,4-butanediol (1,4BD). This review will summarize the literature on the pharmacology of these compounds; the patterns and management of acute toxicity associated with their use; and the clinical patterns of presentation and management of chronic dependency associated with GHB and its analogues.

γ Hydroxybutyrate use: exploring the influence of outcome expectancies through memory modeling

Gamma hydroxybutyrate (GHB) has been linked to overdose, criminal surreptitious administration, the need for emergency medical care, and fatalities worldwide. To begin to identify and understand the motivational factors that lead to the use of GHB, the present investigation utilized methods that have been successful in identifying potential expectancy targets and have been incorporated into prevention and intervention strategies successful in reducing high-risk alcohol use. In the present investigation, GHB expectancies were elicited from 926 voluntary participants aged 18-60 at a university in the southeastern United States to develop the GHB Expectancy Questionnaire (GHBEQ). The GHBEQ was subsequently administered to a different sample of 1,373 participants aged 18-55 in order to empirically derive the possible organization of GHB expectancies in memory, including likely paths of GHB expectancy activation. Findings suggest differences in GHB expectancies based on use history and sex. These results can be used to understand differences in GHB use for men and women, and to develop expectancy-based prevention and intervention programming to prevent and reduce its use in high-risk populations. 

[Withdrawal syndrome after abuse of GHB (Gamma-Hydroxybutyrate) and its physiological precursors - its relevance for child and adolescent psychiatrists]

BACKGROUND

The chronic abuse of Gamma-Hydroxybutyrate (GHB) as a designer drug as well as it's physiological precursors Gamma-Butyrolactone (GBL) and 1,4-Butandiole (1,4-BD) confronts child and adolescent psychiatrists with new challenges. The acute withdrawal of GHB with its cardiovascular and delirant symptoms is of particular importance for child and adolescent psychiatrists.

METHODS

In the present paper theoretical and biological aspects of acute GHB-/GBL-/1,4-BD-withdrawal syndrome are presented, and selected cases are discussed as regards potential treatment.

RESULTS

High dose treatment with benzodiazepines was successful in some cases of acute GHB-/GBL-/1,4-BD-withdrawal syndrome. Complications were severe dystonia under neuroleptic treatment, and also side-effects of treatment with benzodiazepines. Further problems were vegetative symptoms, electrocardiographic changes, rhabdomyolysis, acute renal failure, and death.

CONCLUSION

Acute GHB-withdrawal syndrome is a life-threatening condition which requires immediate intensive care treatment along with continuous monitoring of vital parameters. As acute GHB-withdrawal syndrome can present with symptoms close to psychotic episodes or acute alcohol withdrawal this condition is relevant for child and adolescent psychiatrists.

Gamma-hydroxybutyrate withdrawal syndrome: dangerous but not well-known

Gamma-hydroxybutyrate (GHB) is an endogenous inhibitory neurotransmitter and anesthetic agent that is being abused as a 'club drug.' Withdrawal symptoms after cessation of GHB use are common and depend on the intensity of use. However, GHB withdrawal syndrome and delirium are unfamiliar to most psychiatrists, probably due to the fact that neither textbooks nor guidelines cover the subject. The GHB withdrawal syndrome may have a fulminant course that progresses to delirium. In those severe cases, admission to a general hospital and involvement of a psychiatrist become necessary. We present two cases of severe GHB withdrawal delirium, provide an overview of the literature and conclude with treatment recommendations.

Gamma-hydroxybutyrate withdrawal syndrome: a case report

Introduction

To raise awareness among health care workers of the risk of withdrawal symptoms after longstanding and intense abuse of gamma-hydroxybutyric acid.

Case presentation

A 23 year old Caucasian woman presented with gamma-hydroxybutyric addiction and withdrawal syndrome. The symptoms of gamma-hydroxybutyric withdrawal in this patient initially went unrecognized, upon which her situation deteriorated in such a way that she needed to be admitted to the Intensive Care Unit for airway protection and mechanical ventilation. Treatment with high doses of benzodiazepines led to liberation of the ventilator and further recovery.

Conclusion

Withdrawal symptoms of gamma-hydroxybutyric addiction are often not well recognized and the responsible physicians at Emergency Department, Intensive Care Unit and the Psychiatry ward need better understanding of diagnose and treatment. Gamma-hydroxybutyric acid withdrawal is potentially life threatening and its management may require a multidisciplinary approach. Early recognition of gamma-hydroxybutyric acid withdrawal may lead to better management of these patients.

Chronic intragastric administration of gamma-butyrolactone produces physical dependence in baboons

RATIONALE

Abuse of gamma-hydroxybutyrate (GHB) and its precursors is a public health concern. Gamma-butyrolactone (GBL) is found in commercially available products and, when ingested, is metabolized to GHB.

OBJECTIVE

The goal was to evaluate the physical dependence potential and behavioral effects of GBL.

METHODS

Vehicle and then GBL were administered continuously (24 h per da y) in baboons (Papio anubis, n=5) via intragastric catheters. GBL dosing was initiated at 100 mg/kg/day and then progressively increased stepwise by increments of 100 mg/kg to a final dose of 600 mg/kg. The number of food pellets earned, fine-motor task performance, and observed behaviors were used as dependent measures. Precipitated withdrawal was evaluated after administration of GABA-B and benzodiazepine receptor antagonists during chronic GBL dosing (400-600 mg/kg). Spontaneous withdrawal was evaluated after discontinuation of chronic GBL 600 mg/kg. Blood GHB levels were determined during chronic dosing of each GBL dose by isotope dilution assay.

RESULTS

Chronic GBL dose-dependently decreased food-maintained behavior, disrupted performance on the fine-motor task, and produced signs of sedation and muscle relaxation. The GABA-B antagonist SGS742 [56 mg/kg, intramuscular (IM)] precipitated a withdrawal syndrome, whereas the benzodiazepine antagonist flumazenil (5 mg/kg, IM) produced little or no effect. Signs of physical dependence were also demonstrated when chronic GBL dosing was discontinued. Analysis of plasma indicated GBL was metabolized to GHB; levels were 825 to 1,690 micromol l(-1) GHB and 2,430 to 3,785 micromol l(-1) GHB after week 1 of 400 and 600 mg/kg/day, respectively.

CONCLUSIONS

These data indicate that, like GHB, chronic GBL dosing produced physical dependence that likely involved the GABA-B receptor.

Immunohistochemical localization of a GHB receptor-like protein isolated from rat brain

Gamma-hydroxybutyrate (GHB) is a substance derived from the metabolism of GABA and is heterogeneously distributed in various regions of the brain. This compound possesses a neuromodulatory role on several types of synapses, particularly those using GABA as a neurotransmitter. At physiological concentrations, this effect of GHB is mediated via specific receptors that induce neuronal hyperpolarization and bind radioactive GHB with a specific distribution, ontogenesis, kinetics, and pharmacology. A membrane protein that possesses six to seven transmembrane domains and which binds and is activated by micromolar amounts of GHB was recently cloned from rat brain hippocampus. In order to study the regional and cellular distribution of this receptor in rat brain, we selected several specific peptides belonging to the extracellular domains of the receptor to be used as specific immunogens to raise polyclonal antibodies in the rabbit. Among the antisera obtained, one of them gave particularly good results in terms of specificity and reactivity at high dilution. Immunohistochemical analyses, both at the confocal and electron microscopic level, showed receptor protein distribution closely resembling the distribution of GHB high-affinity binding sites, except for cerebellum, where GHB receptor(s) of lower affinity exist(s). In all regions studied the GHB receptor-like protein labeling appears to be distributed specifically in neurons and not in glial cells. At the cellular level the antibody specifically labels dendrites, and no immunoreactivity was detected in presynaptic endings or in axons. Accordingly, electron microscopy reveals strong labeling of postsynaptic densities and of neuronal cytosol.

Spontaneous and precipitated withdrawal after chronic intragastric administration of gamma-hydroxybutyrate (GHB) in baboons

RATIONALE

gamma-Hydroxybuyrate (GHB) is a current drug of abuse that may produce physical dependence.

OBJECTIVES

The present study characterized the behavioral effects of chronic GHB in baboons (n = 4), and evaluated whether signs of withdrawal occurred (1) after administration of the GABA-B antagonist CGP36742 during chronic GHB administration (precipitated withdrawal) and (2) following discontinuation of chronic GHB administration (spontaneous withdrawal).

METHODS

Water (vehicle) and then GHB was continuously infused via intragastric (IG) catheters. GHB administration was initiated at 350 mg/kg per day, and the dose was increased by 100 mg/kg over 4 days to 750 mg/kg per day. Food pellets were available 20 h/day under a fixed ratio (FR5 or 10) schedule of reinforcement. Observation sessions and a 2-min fine motor task were conducted during vehicle and GHB administration. CGP36742 (32 and 56 mg/kg, IM) was administered during vehicle and chronic GHB administration. After a total of 32-36 days GHB administration was abruptly discontinued. Blood samples were collected during all interventions and analyzed for GHB content.

RESULTS

Chronic GHB decreased food-maintained behavior, disrupted performance of the fine motor task, and produced ataxia, muscle relaxation, tremors and jerks. At the end of GHB administration, plasma levels of GHB ranged from 486 to 2080 micromol/L. Administration of CGP36742 during chronic GHB administration produced increases in aggression, self-directed behaviors, vomit/retch, tremors and/or jerks, which is consistent with a precipitated withdrawal syndrome. Similar signs were observed when GHB administration was discontinued. Seizures were not observed.

CONCLUSIONS

These data indicate that chronic GHB administration produced physical dependence and that activation of the GABA-B receptor may be important for GHB physical dependence.

The ??-Hydroxybutyrate Withdrawal Syndrome

gamma-Hydroxybutyrate (GHB) is endogenous inhibitory transmitter that, when administered in pharmacological doses, has sedative-hypnotic properties. It is used in anaesthesia for the treatment of narcolepsy/catalepsy and in alcohol/opioid detoxification treatment regimens. Based on its purported anabolic effects, GHB use became established among bodybuilders. As the euphorigenic effects of GHB became publicised, attendees at dance clubs and rave parties began to use it alone or in combination with other psychoactive drugs. Following the ban of GHB in 1990, several precursor products (e.g. gamma-butyrolactone, butanediol) became widely used as replacement drugs until their ultimate proscription from lawful use in 2000. GHB and its precursors, like most sedative-hypnotic agents, can induce tolerance and produce dependence. Although many GHB users will experience a mild withdrawal syndrome upon drug discontinuation, those with chronic heavy GHB use can experience severe withdrawal. This syndrome clinically resembles the withdrawal syndrome noted from alcohol and other sedative-hypnotic drugs (e.g. benzodiazepines). Distinct clinical features of GHB withdrawal are its relatively mild and brief autonomic instability with prolonged psychotic symptoms. Patients with fulminant GHB withdrawal require aggressive treatment with cross-tolerant sedative hypnotics, such as benzodiazepines.