"Grievous bodily harm:" gamma hydroxybutyrate abuse leading to a Wernicke-Korsakoff syndrome

Toxicological Characterization of GHB as a Performance-Enhancing Drug

Performance-enhancing drugs (PEDs) are represented by several compounds used to ameliorate the image, the appearance, or an athletic or non-athletic performance. Gamma-hydroxybutyrate (GHB) is an endogenous molecule first used as anesthetic and then marketed as a nutritional supplement with a wide diffusion in the bodybuilding community. The aim of the present work is to provide a toxicological characterization of the use of GHB as a PED, including the scientific basis for its use, the patterns of use/abuse, and the health risks arising from its consumption in this peculiar recreative setting. A literature search was performed on multiple databases including experimental studies on humans and animals as well as epidemiological reports and forensic case reports/series. Experimental studies demonstrated that the use of GHB as a PED is motivated by the release of growth hormone and the induction of sleep. However, the panel of desired performance-related effects was much wider in real cases and epidemiological studies. Even though the use of GHB among bodybuilders has decreased, its use to enhance some kind of performance, particularly sexual ones or social-communicative ones, as well as means to increase mood and perceived energy, is still common.

Toxin-Induced Coma and Central Nervous System Depression

Many medications and toxins may induce central nervous system (CNS) depression. Even when the intention is to induce CNS depression, other nervous system adverse effects may occur, such as with anesthetics. Pain medications produce characteristic CNS toxicities. Sedative hypnotics may induce altered mentation among systemic toxicities. Stimulants may mimic coma when discontinued abruptly. Acute and chronic carbon monoxide poisoning can lead to altered mental status and prolonged cognitive difficulties. Some medications and environmental toxins can mimic brain death. High clinical suspicion and early recognition of these effects is vital to treatment, most of which is supportive.

Illicit drugs: Effects on eye

There is a myriad of changes that can be produced in the eye by toxic drugs ranging from mild/no symptoms to severe loss of vision from endophthalmitis. The routes of administration include oral ingestion, smoking, nasal inhalation, intravenous injection, topical application or application to other mucosal surfaces. It is important to recognize certain clinical signs and symptoms in the eye produced by these toxins. This article describes in brief some of the ocular effects of commonly abused drugs. For identification of a particular poisoning, in addition to the clinical presentation, pulse, blood pressure, respiration and body temperature, pupillary size, pupillary reaction to light, ocular convergence and nystagmus can be useful indicators of the type of drug the patient is exposed to. Unmasking these features help the clinician in an early and accurate diagnosis of the offending drug as well as timely management.

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.

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.

GHB acid: A rage or reprive

Gamma-hydroxybutyric acid (GHB) is a naturally occurring analog of gamma-aminobutyric acid (GABA) that has been used in research and clinical medicine for many years. GHB was used clinically as an anesthetic in the 1960s but was withdrawn due to side effects that included seizures and coma. GHB has been implicated in a number of crime types; most notably in drug-facilitated sexual assault. GHB is abused by three main groups of users: Body builders who use the substance believing that it stimulated the release of growth hormone; sexual predators who covertly administer the drug for its sedative and amnesic effects and club-goers (rave parties) who take the drug for its euphoric effects. The short-lived hypnotic effects, relative safety and widespread availability of the drug have made it particularly well suited to this role. The drug has an addictive potential if used for long term. The primary effects of GHB use are those of a CNS depressant and therefore range from relaxation, to euphoria, confusion, amnesia, hallucinations, and coma. Despite the increased regulation, GHB remains widely available through the Internet where one can easily purchase the necessary reagents as well as recipes for home production. There are reports of patients being unresponsive to painful stimuli and cases of oral self-mutilations linked to the abuse of GHB, though quiet rare. Such cases should remind odontologists that intra-oral lesions may be the result of self-mutilation either due to mental illness or altered states caused by the use of prescription or non-prescription drugs.

Withdrawal delirium with dance drug ‘liquid ecstasy’ (GHB)

We wish to describe a case of gamma hydroxyl butyrate (GHB) withdrawal, including seizure activity in a 34 year old male, who had been taking the substance over a two year period. The syndrome has many aspects in common with alcohol withdrawal (delirium tremens) and benzodiazepine withdrawal (long duration of symptoms), however detoxification presents many challenges for clinicians.

GHB acid: A rage or reprive

Gamma-hydroxybutyric acid (GHB) is a naturally occurring analog of gamma-aminobutyric acid (GABA) that has been used in research and clinical medicine for many years. GHB was used clinically as an anesthetic in the 1960s but was withdrawn due to side effects that included seizures and coma. GHB has been implicated in a number of crime types; most notably in drug-facilitated sexual assault. GHB is abused by three main groups of users: Body builders who use the substance believing that it stimulated the release of growth hormone; sexual predators who covertly administer the drug for its sedative and amnesic effects and club-goers (rave parties) who take the drug for its euphoric effects. The short-lived hypnotic effects, relative safety and widespread availability of the drug have made it particularly well suited to this role. The drug has an addictive potential if used for long term. The primary effects of GHB use are those of a CNS depressant and therefore range from relaxation, to euphoria, confusion, amnesia, hallucinations, and coma. Despite the increased regulation, GHB remains widely available through the Internet where one can easily purchase the necessary reagents as well as recipes for home production. There are reports of patients being unresponsive to painful stimuli and cases of oral self-mutilations linked to the abuse of GHB, though quiet rare. Such cases should remind odontologists that intra-oral lesions may be the result of self-mutilation either due to mental illness or altered states caused by the use of prescription or non-prescription drugs.

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.

Possible long-term effects of γ-hydroxybutyric acid (GHB) due to neurotoxicity and overdose

In several countries, including the Netherlands, the use of GHB seems to be rising. GHB is regarded by recreational users as an innocent drug without any side effects. Recently, the number of patients in treatment due to GHB addiction sharply increased. In addition, various studies report incidents following risky GHB use or GHB overdosing. Other sedative drugs, like ketamine and alcohol have been shown to result in unintended neurotoxic harm at the level of memory and cognitive function. As outlined in the present review, GHB and ketamine have a common mode of action, which suggests that GHB may also lead to similar neurotoxicity as ketamine. GHB overdosing, as well as binge drinking (and high ketamine doses), induce profound coma which is probably neurotoxic for the brain especially in the maturing brain of young adults. It is therefore advocated to investigate possible long-term neurotoxic effects in recreational GHB users e.g. by studying the residual effects on cognition and memory.

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.

Evaluation for the withdrawal syndrome from gamma-hydroxybutyric acid (GHB), gamma-butyrolactone (GBL), and 1,4-butanediol (1,4-BD) in different rat lines

A severe and life-threatening gamma-hydroxybutyric acid (GHB) withdrawal syndrome, clinically similar to the alcohol withdrawal syndrome, is increasingly being reported in GHB addicts. We investigated for the occurrence of withdrawal in Wistar and Sprague-Dawley rats, and in the selectively bred lines of GHB-sensitive (GHB-S) and Sardinian alcohol-preferring (sP) rats, following chronic administration of GHB, gamma-butyrolactone (GBL), and/or 1,4-butanediol (1,4-BD). Using validated rodent alcohol withdrawal scoring scales, little to no spontaneous or pharmacologically precipitated withdrawal effects were observed in Wistar, Sprague-Dawley, or GHB-S rats. Conversely, sP rats displayed both spontaneous and precipitated audiogenic seizures following abrupt cessation of chronic GHB or 1,4-BD administration and following pharmacological challenge with the GABA(B) receptor-selective antagonist, SCH 50911, respectively.

Effects of combining ethanol (EtOH) with gamma-hydroxybutyrate (GHB) on the discriminative stimulus, locomotor, and motor-impairing functions of GHB in mice

RATIONALE

Gamma-hydroxybutyrate (GHB) is a drug of abuse that is often coabused with ethanol (EtOH) and has been implicated as a date rape agent in conjunction with EtOH. Much information is lacking regarding the manner in which GHB interacts with EtOH.

OBJECTIVE

This study was designed to further characterize the behavioral effects of GHB alone and in combination with EtOH in male Swiss-Webster mice.

METHODS

The effects of GHB (0.1-1.0 g/kg) and EtOH (2.0-5.0 g/kg) alone, as well as the effects of GHB in combination with EtOH, were examined using an automated locomotor activity procedure, a functional observational battery (FOB) and a GHB drug discrimination procedure.

RESULTS

GHB decreased, whereas EtOH had little effect on locomotor activity. In the FOB, EtOH dose-dependently decreased activity in combination with 0.3 g/kg GHB. Alone, each drug had little effect on the righting reflex, but combining ineffective doses of GHB and EtOH significantly impaired righting. GHB and EtOH decreased forelimb grip strength. Combinations of ineffective doses of GHB and EtOH decreased forelimb grip strength when given together. GHB and EtOH impaired inverted screen performance, and EtOH increased the impairing effects of low, but not high, doses of GHB. GHB and EtOH increased hind limb splay, and EtOH increased the effects of 0.1 and 0.3 g/kg GHB on splay. GHB and EtOH decreased body temperature, and EtOH augmented the temperature-decreasing effects of GHB. EtOH produced less than 50% GHB-like discriminative stimulus effects, and GHB failed to alter the GHB-like discriminative stimulus effects of EtOH.

CONCLUSIONS

Overall, EtOH increased the effects of GHB on several gross measures of behavior and only partially occasioned the discriminative stimulus properties of GHB.

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.

Gamma hydroxy butyrate abuse and dependency

The recreational use of gamma hydroxy butyrate (GHB) has gained popularity over the last decade. GHB was initially sold as a safe body building and fat burning compound. It is now also widely abused by body builders and young ravers. GHB attracts young people due the euphoria that it initially produces, and the claimed increase in sociability and sexual function (it is also known as liquid Ecstasy). Over the last few years, there has been an increase in the number of cases of GHB intoxication, dependence and severe withdrawal, as reported in medical literature. The situation is complicated by the use of GHB analogues, other toxic chemicals that are easily converted into GHB. GHB has recently been classified as a class 'C' drug in the UK, but no provisions were made in relation to GHB analogues. GHB has been increasingly used in rape cases due to its capacity to produce intoxication and amnesia. The management of patients dependent on GHB is rather complicated due to the high doses of medication that they require to control withdrawal symptoms.

Recent trends in the use of "club drugs": an Australian review

The use of "club drugs" such as MDMA, ketamine, and GHB appears to have increased in Western countries over the last 20 years, and Australia is no exception to that trend. While levels of use appear to be relatively low in the general population, among users of these drugs a number of adverse health and psychological problems, including dependence, have been reported. MDMA or ecstasy is the third most commonly used illicit drug in Australia, and relatively more information is available on its use in Australia than of drugs such as GHB or ketamine. Although there are no population level data available, levels of ketamine use in the general population appear to be lower than those of MDMA. In addition, the harms reported by recreational users are not excessive and the mortality rate is low. At the individual level, many of those who experiment find the effects aversive and do not persist. The harms that require further investigation are the association between ketamine and unsafe sex and injecting behaviors, the neurotoxic effects, and use in situations where there is a heightened risk of accidental death when the user's cognition is grossly impaired. In contrast, while least is known of the epidemiology of GHB use, there is mounting evidence suggesting significant acute and long-term risks associated with the use of this drug. This suggests an urgent need for international research on the patterns of use, health, and psychosocial consequences of GHB use. In order to address public health issues associated with a range of club drug use, there is a need for research to identify the trends in population prevalence of these drugs. This could be most easily achieved by the inclusion of MDMA, ketamine, and GHB in household surveys that are currently collected routinely in a number of countries.

A brief overview of the clinical pharmacology of "club drugs"

Four different "club drugs" are reviewed: MDMA (methylenedioxymethamphetamine, "Ecstasy"), GHB (gamma-hydroxybutyrate), ketamine, and Rohypnol (flunitrazepam). The neurobiology, clinical pharmacology, and treatment issues for each are discussed.

Mechanisms Underlying the Sympathomimetic Cardiovascular Responses Elicited by γ-Hydroxybutyrate

Gamma-hydroxybutyrate (GHB) is generally thought to be a central nervous system depressant; however, GHB also has sympathomimetic cardiovascular actions. Radio telemetry was used to record the cardiovascular responses elicited by GHB (180-1000 mg/kg IV) in conscious rats. GHB elicited increases in mean arterial pressure (MAP) (24 +/- 3 to 60 +/- 5 mm Hg) lasting from 28 +/- 8 to 227 +/- 37 minutes. GHB (560 and 1000 mg/kg IV) also elicited a prolonged tachycardic response (85 +/- 23 and 95 +/- 22 bpm). The hypertension and tachycardia elicited by GHB (560 mg/kg) were reversed by the intravenous and intracerebroventricular administration of the GABAb receptor antagonist CGP 35348. CGP 35348 also reversed GHB-mediated increases in renal sympathetic nerve activity (RSNA). Administration of the purported GHB receptor antagonist NCS-382 reversed the increase in heart rate but not the pressor response elicited by GHB in telemetered rats. These data indicate that the intravenous administration of GHB markedly increases MAP, heart rate, and RSNA in conscious rats via activation of central GABAb receptors. In addition, GHB receptors appear to selectively mediate the increase in heart rate elicited by large doses of GHB.

GHB ameliorates naloxone-induced conditioned place aversion and physical aspects of morphine withdrawal in mice

RATIONALE

Gamma-hydroxybutyric acid (GHB) is a naturally occurring substance in the brain, the administration of which has proved useful in the treatment of the opiate withdrawal symptoms in humans.

OBJECTIVES

The aim of the present work was to validate this beneficial effect on the physical and motivational aspects of morphine withdrawal in mice.

METHODS

In a first experiment, animals rendered morphine-dependent were conditioned to develop a place aversion (CPA) to the compartment paired with naloxone administration in a two-chamber apparatus. The conditioning phase consisted of three pairings of either naloxone (0.250 mg/kg) or vehicle in one compartment, both with similar time allotments during the preconditioning test. During the testing phase, mice were again allowed to explore the entire apparatus. GHB (6, 12.5, 25, and 50 mg/kg) was administered during either the acquisition or expression phase of this conditioning. In a second experiment, the capacity of GHB to ameliorate the intensity of physical signs of morphine withdrawal was evaluated.

RESULTS

GHB blocked CPA in both phases: administered during acquisition (from 12.5 mg/kg and higher) as well as in the expression phase (from 6 mg/kg, except for 25 mg/kg). It also decreased the intensity of physical signs of morphine withdrawal to near control levels measured by the modified Gellert-Holtzman scale (25 mg/kg and higher). Decreases in jumping, body shakes, and paw tremor were also observed.

CONCLUSIONS

Our results support the idea that GHB ameliorates both aspects of morphine withdrawal, physical as well as motivational signs.

Interaction between 1,4-butanediol and ethanol on operant responding and the cardiovascular system

The current studies characterized the rate-decreasing and cardiovascular responses produced by 1,4-butanediol administered alone and in combination with ethanol to test the hypothesis that these effects resulted from the degradation of 1,4-butanediol to gamma-hydroxybutyrate. One group of rats responded under a fixed-ratio 20 schedule of food presentation; ethanol and 1,4-butanediol dose-dependently decreased response rates. Ethanol administered in combination with 1,4-butanediol attenuated the rate-decreasing effects of 1,4-butanediol without altering the potency of ethanol. In separate groups of conscious rats, radio telemetry was used to record mean arterial pressure and heart rate. In contrast to its depressant effects on schedule-controlled responding, 1,4-butanediol increased mean arterial pressure and heart rate; these increases were attenuated by ethanol. Thus, the behavioral and cardiovascular actions of 1,4-butanediol are similar to those elicited by gamma-hydroxybutyrate. The ability of ethanol to attenuate the behavioral and cardiovascular effects of 1,4-butanediol indicates that these effects require the conversion of 1,4-butanediol to gamma-hydroxybutyrate.

Cloning and characterization of a rat brain receptor that binds the endogenous neuromodulator gamma-hydroxybutyrate (GHB)

Gamma-hydroxybutyrate (GHB) is an endogenous neuromodulator with therapeutical applications in anesthesia, sleep disorders, and drug addiction. We report the cloning of a GHB receptor from a rat hippocampal cDNA library. This receptor has a molecular mass of 56 kDa and belongs to the seven-transmembrane receptor family. The peptidic sequence has no significant homology with any known receptor, including GABA(B) receptors. Its mRNA is restricted to the brain and is particularly abundant in the hippocampus, cortex, striatum, thalamus, olfactory bulbs, and cerebellum, matching the distribution of GHB binding sites in rat brain. Southern blot revealed the presence of homologous sequences in several species including the human. Binding assays on transfected CHO cells showed a dissociation constant (Kd) of 426 nM for GHB and no affinity for GABA, baclofen, or glutamate. In patch-clamp experiments, transfected CHO cells revealed a functional G-protein-coupled receptor as demonstrated by GTP-gamma-S-induced irreversible activation. Application of 0.1-15 microM GHB specifically induced an inward current at negative membrane potentials that was not reproduced by application of baclofen (10 microM). CGP-55845, a GABA(B) receptor antagonist, did not inhibit the GHB-induced response nor did the GHB receptor antagonist NCS-382, suggesting that the GHB receptor system includes several subtypes.

The prevalence and correlates of gamma-hydroxybutyrate (GHB) overdose among Australian users

AIM

The aim of this study was to examine the correlates, context and risk perceptions regarding gamma-hydroxybutyrate (GHB) overdose among a sample of recreational GHB users in Australia.

DESIGN

A cross-sectional survey of 76 GHB users who were administered a structured interview on GHB use. They were asked a series of questions regarding whether they had ever experienced a GHB overdose, the context of their most recent GHB overdose, and about their perceptions of the risks of GHB overdose.

FINDINGS

This sample of GHB users had not had a long or extensive experience with GHB use; despite this, half (53%) had experienced a GHB overdose. This sample of GHB users appeared to be well-educated, employed and a history of either drug treatment or incarceration was uncommon. There were no differences between those who had or had not overdosed in terms of socio-demographic characteristics, extent of other drug use or typical patterns of other drug use when using GHB. However, those who had overdosed on GHB had used it more times during their life-time, and had been using it for a longer period of time.

CONCLUSIONS

GHB-related overdoses were common among a sample of GHB users who had only recently begun using the drug. The only apparent distinguishing factor between those who had and had not overdosed on GHB was the amount of experience with GHB use.

GHB use among Australians: characteristics, use patterns and associated harm

The aim of this study was to examine the characteristics of gamma-hydroxybutyrate (GHB) users, their GHB and other drug use patterns, and the harms associated with GHB use. Seventy-six GHB users were recruited and administered a structured interview on GHB use and related harms. GHB users appeared to be a stable, highly educated and well-functioning group. They had had extensive experience with a range of drugs, and GHB was typically used in conjunction with other drugs. Despite the fact that most GHB users had not had a long or extensive experience with GHB use, the proportion reporting significant negative side effects when using GHB was high (99% reported at least one), and the mean number of side effects ever experienced was 6.5. Notably, half (52%) reported becoming unconscious, 53% reported vomiting, 58% reported profuse sweating, and 8% reported having a fit or seizure. The high rate of problems reported by a group with limited use of this drug suggests that in a context of polydrug use, GHB use is associated with significant risks to users.

A comprehensive review of MDMA and GHB: two common club drugs

"Club drugs" have become alarmingly popular. The use of 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy) and gamma-hydroxybutyrate (GHB), in particular, has increased dramatically from 1997-1999. The pharmacokinetics of MDMA and GHB appear to be nonlinear, making it difficult to estimate a dose-response relationship. The drug MDMA is an amphetamine analog with sympathomimetic properties, whereas GHB is a gamma-aminobutyric acid analog with sedative properties. Symptoms of an MDMA toxic reaction include tachycardia, sweating, and hyperthermia. Occasional severe sequelae include disseminated intravascular coagulation, rhabdomyolysis, and acute renal failure. Treatment includes lowering the body temperature and maintaining adequate hydration. Symptoms of GHB intoxication include coma, respiratory depression, unusual movements, confusion, amnesia, and vomiting. Treatment includes cardiac and respiratory support. Because of the popularity of these agents and their potentially dangerous effects, health care professionals must be familiar with these substances and the treatment options for patients who present with symptoms of a toxic reaction.

gamma-Hydroxybutyrate modulation of glutamate levels in the hippocampus: an in vivo and in vitro study

The effect of gamma-hydroxybutyric acid on extracellular glutamate levels in the hippocampus was studied by microdialysis in freely moving rats and in isolated hippocampal synaptosomes. Intra-hippocampal (CA1) perfusion with gamma-hydroxybutyric acid (10 nM-1 mM) concentration-dependently influenced glutamate levels: gamma-hydroxybutyric acid (100 and 500 nM) increased glutamate levels; 100 and 300 microM concentrations were ineffective; whereas the highest 1 mM concentration reduced local glutamate levels. The stimulant effect of gamma-hydroxybutyric acid (100 nM) was suppressed by the locally co-perfused gamma-hydroxybutyric acid receptor antagonist NCS-382 (10 microM) but not by the GABA(B) receptor antagonist CGP-35348 (500 microM). Furthermore, the gamma-hydroxybutyric acid (1 mM)-induced reduction in CA1 glutamate levels was counteracted by NCS-382 (10 microM), and it was also reversed into an increase by CGP-35348. Given alone, neither NCS-382 nor CGP-35348 modified glutamate levels. In hippocampal synaptosomes, gamma-hydroxybutyric acid (50 and 100 nM) enhanced both the spontaneous and K(+)-evoked glutamate efflux, respectively, both effects being counteracted by NCS-382 (100 nM), but not by CGP-35348 (100 microM). These findings indicate that gamma-hydroxybutyric acid exerts a concentration-dependent regulation of hippocampal glutamate transmission via two opposing mechanisms, whereby a direct gamma-hydroxybutyric acid receptor mediated facilitation is observed at nanomolar gamma-hydroxybutyric acid concentrations, and an indirect GABA(B) receptor mediated inhibition predominates at millimolar concentrations.

Discrimination of gamma-hydroxybutyrate and ethanol administered separately and as a mixture in rats

The physiological effects of gamma-hydroxybutyrate (GHB) are complex and not yet clearly defined. GHB has been labeled as a recreational drug and is reported to be frequently coabused with ethanol (ETH). Other studies have yielded discrepant results as to the interaction between GHB and ETH. Thus, the present study investigated extensively the discriminative stimulus of GHB and ETH and a mixture of the two compounds. Thirty male Long-Evans rats were divided into three groups and trained to discriminate doses of either 300 mg/kg GHB, 1000 mg/kg ETH, or a mixture (MIX: 150 mg/kg GHB+500 mg/kg ETH) from vehicle on a two-lever fixed-ratio (FR) 10 schedule of food reinforcement. Dose-response curves were attained in each group with its respective training drugs. GHB and ETH did not cross-generalize in the ETH- and GHB-trained rats, respectively. However, when the effects of the MIX were tested in the GHB- and ETH-trained rats, a greater than additive response was observed. Testing also revealed that the MIX-trained rats did not perceive a novel stimulus but a near-equal contribution from GHB and ETH. This study provides evidence of a complex relationship between GHB and ETH and opposes previous work reporting cross-generalization between GHB and ETH.

A case of withdrawal from the GHB precursors gamma-butyrolactone and 1,4-butanediol

We describe a case of withdrawal from the gamma hydroxybutyric acid (GHB) precursors gamma butyrolactone and 1,4-butanediol. Symptoms included visual hallucinations, tachycardia, tremor, nystagmus, and diaphoresis. Administration of benzodiazepines and phenobarbital successfully treated the withdrawal symptoms. As predicted from the metabolism of gamma butyrolactone and 1,4-butanediol to GHB, the symptoms were nearly identical to those reported from GHB withdrawal. Because GHB is now illegal in the United States, individuals have begun abusing the legal and easier to acquire GHB precursors. More frequent cases of both abuse and withdrawal from these GHB precursors can be expected.

GHB: a new and novel drug of abuse

There has been increasing attention in the United States to problems of abuse of gamma-hydroxybutyrate (GHB), with some evidence for problems in other parts of the world as well. In vitro and animal research show that, while GHB shares some properties with abused central nervous system depressant drugs, it has unique aspects of its pharmacology as well, including actions at a specific neural receptor which probably mediates many of its effects. Abuse potential assessment of GHB using standard animal models has not yielded a picture of a highly abusable substance, but little human testing has yet been done. Very little systematic data exist on tolerance and dependence with GHB, but both have been seen in human users. Quantitative data on the prevalence of GHB abuse is incomplete, but various qualitative measures indicate that a mini-epidemic of abuse began in the late 1980s and continues to the present. GHB is often included with the group of 'club drugs', and can be used as an intoxicant. It also has been used as a growth promoter and sleep aid and has been implicated in cases of 'date rape', usually in combination with alcohol. Undoubtedly the easy availability of GHB and some of its precursors has contributed to its popularity. Recent changes in the control status of GHB in the US may reduce its availability with as yet unknown consequences for the scope of the public health problem. Drug abuse experts need to familiarize themselves with GHB as possibly representing a new type of drug abuse problem with some unique properties.

Gamma hydroxybutyrate (GHB) and gamma butyrolactone (GBL) withdrawal: five case studies

There is little medical information available about gamma-hydroxybutyrate (GHB) or gamma-butyrolactone (GBL) dependence or withdrawal. In this study the authors treated and reviewed multiple cases of GHB and GBL withdrawal in high-dose users. Five patients during nine hospitalizations were treated for GHB or GBL withdrawal. The authors describe a spectrum of GHB or GBL withdrawal from mild to severe and discuss medications used for treatment. They conclude that patients with GHB or GBL withdrawal may present with agitated psychosis, delirium, and autonomic instability. In this sample, relapse to GHB or GBL use occurred soon after treatment of withdrawal.

Successful management of prolonged gamma-hydroxybutyrate and alcohol withdrawal

A 27-year-old man was admitted with tremulousness, diaphoresis, tachypnea (28 breaths/min), full-body rigidity, irritability, paranoia, and auditory and visual hallucinations 2 days after stopping long-term gamma-hydroxybutyrate (GHB) and 8 hours after stopping alcohol intake. He received intravenous fluids and tapering dosages of lorazepam to control agitation and rigidity, and recovered with no significant sequelae after 8 days. Abrupt cessation of GHB after high-dosage abuse can precipitate a clinically significant withdrawal syndrome. Lorazepam should be considered for treatment of GHB withdrawal. Concomitant alcohol abuse may mask early GHB withdrawal symptoms and exacerbate withdrawal.

Gamma-hydroxybutyric acid in alcohol preference, dependence and withdrawal

Gamma-hydroxybutyric acid (GHB) is an endogenous constituent of the mammalian brain, where it likely functions as a neurotransmitter or a neuromodulator. Its exogenous administration exerts a number of pharmacological effects, including reduction of intensity of alcohol withdrawal syndrome and alcohol consumption in both laboratory animals and human alcoholics.The clinical studies conducted to date, although often testing samples of limited size, feature GHB as an effective, well-tolerated and safe drug for the treatment of alcohol dependence. Behavioural data in rats suggest that GHB may produce alcohol-like effects. This similarity may explain why GHB produces positively reinforcing properties, being subsequently self-administered by rodents and sometimes abused by humans (although episodes of self-directed intake of GHB appear to be a limited phenomenon in alcoholics); in addition it provides support to the hypothesis that GHB constitutes for alcoholism a replacement therapy similar to methadone in heroin addiction.

Substance abuse and withdrawal in the intensive care unit. Contemporary issues

Because 36% of intentional injury victims are drug dependent, the association between drug abuse and violence, especially in urban settings, is high. Withdrawal syndromes in ICU patients confuse their clinical management, may be extremely difficult to diagnose, are often lethal, need to be suspected, and should be prophylaxed against; therefore, all ICU patients should be considered to be at high risk for drug or alcohol dependence, should be tested for evidence of such drugs, and should be interviewed (together with their family members) for the presence of drug dependence traits. Appropriate patients should be referred for formal evaluation and treatment. Withdrawal syndromes must be promptly recognized, differentiated from traumatic or metabolic deterioration, and immediately treated. As patients are unique, so is their drug dependence. Individualized withdrawal therapy, not a "one method fits all" approach, works best. The mainstay of most withdrawal therapy is supportive care and benzodiazepine therapy. Also, considering the high rate of multiple intoxicants present in trauma patients, withdrawal can occur from multiple agents in a single patient, further compounding these difficulties. Withdrawal from unusual substances, such as GHB, or from therapeutic interventions (e.g., prolonged opioid or benzodiazepine administration) also must be considered.

Safety and tolerability of gamma-hydroxybutyric acid in the treatment of alcohol-dependent patients

Gamma-hydroxybutyric acid (GHB) has been in clinical use in Italy since 1991 for treatment of alcohol dependence. Results of phase III and phase IV studies have shown that the drug is effective and well tolerated in the treatment of alcohol withdrawal syndrome and in reducing alcohol consumption and alcohol craving. Pharmacosurveillance indicates that abuse of gamma-hydroxybutyric acid is a limited phenomenon in clinical settings when the drug is dispensed under strict medical surveillance and entrusted to a referring familiar member of the patient.

Abuse and therapeutic potential of gamma-hydroxybutyric acid

Gamma-hydroxbutyric acid is a compound found in mammalian brain that is structurally related to the neurotransmitters gamma-aminobutyric acid and glutamic acid. Gamma-hydroxybutyric acid effects dopaminergic systems in the brain and may be a neurotransmitter. Gamma-hydroxybutyric acid was first reported as a drug of abuse in 1990 and continues to be abused by bodybuilders, participants of "rave" dance parties, and polydrug abusers. Physical dependence can develop after prolonged, high-dose use, and overdoses have been widely reported. Its use in sexual assaults as a "date rape" drug and availability on the internet have recently emerged. Gamma-hydroxybutyric acid has established efficacy as an anesthetic agent, and preliminary evidence supports its utility in the treatment of alcohol dependence, opiate dependence, and narcolepsy.

Gamma-hydroxybutyric acid and alcohol-related syndromes

We report on the effectiveness and safety of gamma-hydroxybutyric acid in the therapy of overt alcohol withdrawal syndromes, their prevention, and the prevention of relapses in formerly detoxified alcoholics. We studied 321 patients (236 men, 85 women), divided into two open-study groups for the treatment and prevention of alcohol withdrawal syndromes and one double-blind study group to evaluate the effects of gamma-hydroxybutyric acid versus placebo on alcoholic craving and relapses in detoxified patients. Gamma-hydroxybutyric acid treatment promptly reduced withdrawal symptoms in all patients and prevented alcohol withdrawal syndromes in 55% of cases. The attenuation of craving in detoxified patients was significantly greater in the gamma-hydroxybutyric acid-treated group in comparison with the placebo-treated group. The therapeutic use of gamma-hydroxybutyric acid was not accompanied by serious side effects. Gamma-hydroxybutyric acid diversion was poorly represented: gamma-hydroxybutyric acid-induced abuse was reported in 4 (1.1%) of 345 treated patients, and only 9 cases of gamma-hydroxybutyric acid acute poisoning were reported in the years 1992-1995. Our results suggest that gamma-hydroxybutyric acid, with a favorable risk/benefit ratio, is a clinically useful drug in the treatment of alcohol dependence.

Severe gamma-hydroxybutyrate withdrawal: a case report and literature review

We report a case of gamma-hydroxybutyrate (GHB) withdrawal resulting in severe agitation, mental status changes, elevated blood pressure, and tachycardia hours after stopping chronic use of GHB. The patient admitted to substantial GHB abuse on a daily basis for 2.5 years. Previous attempts at cessation reportedly resulted in diaphoresis, tremors, and agitation. The patient's symptoms, negative polypharmacy history, and negative urine and blood toxicological analysis for alcohol, benzodiazepines, sedative-hypnotics, or other substances suggested the diagnosis of GHB withdrawal. Later analysis of a patient drug sample confirmed the presence of GHB. The patient required 507 mg of lorazepam and 120 mg of diazepam over 90 h to control agitation. This is one of the few reported cases of GHB withdrawal and one of the most severe. Given the increasing use of GHB, more cases of severe GHB withdrawal should be anticipated.

A sudden awakening from a near coma after combined intake of gamma-hydroxybutyric acid (GHB) and ethanol

OBJECTIVE

A case of a sudden awakening from a near coma after combined intake or gamma-hydroxybutyric acid (GHB) (125 micrograms/mL), ethanol (134 mg/dL), and cannabinoids is described.

METHODS

GHB was determined by gas chromatography-mass spectrometry after acetonitrile precipitation and derivation with N-methyl-N-trimethylsilyltrifluoroacetamide, using valproic acid as the internal standard.

CONCLUSION

The described case illustrates the consequences of GHB overdose. GHB overdose should be considered in every case of unexplained sudden coma, i.e., without any evidence of head injury, intake of coma-inducing drugs, or increasing intracranial pressure. GHB overdose will be missed by routine toxicological screening.

Simultaneous stimulation of slow-wave sleep and growth hormone secretion by gamma-hydroxybutyrate in normal young Men

The aim of this study was to investigate, in normal young men, whether gamma-hydroxybutyrate (GHB), a reliable stimulant of slow-wave (SW) sleep in normal subjects, would simultaneously enhance sleep related growth hormone (GH) secretion. Eight healthy young men participated each in four experiments involving bedtime oral administration of placebo, 2.5, 3.0, and 3.5 g of GHB. Polygraphic sleep recordings were performed every night, and blood samples were obtained at 15-min intervals from 2000 to 0800. GHB effects were mainly observed during the first 2 h after sleep onset. There was a doubling of GH secretion, resulting from an increase of the amplitude and the duration of the first GH pulse after sleep onset. This stimulation of GH secretion was significantly correlated to a simultaneous increase in the amount of sleep stage IV. Abrupt but transient elevations of prolactin and cortisol were also observed, but did not appear to be associated with the concomitant stimulation of SW sleep. Thyrotropin and melatonin profiles were not altered by GHB administration. These data suggest that pharmacological agents that reliably stimulate SW sleep, such as GHB, may represent a novel class of powerful GH secretagogues.

The emerging role of clozapine in the treatment of movement disorders

Clozapine, the only commercially available atypical neuroleptic, is approved for the treatment of schizophrenic patients who are unresponsive to or intolerant of typical neuroleptics. It has an unusual pharmacologic profile compared with standard neuroleptics, and it follows that clinical response to this drug is also different. It has shattered the notion that a drug must be capable of inducing or worsening parkinsonism to be a potent antipsychotic. Based on these findings, it is being used increasingly by neurologists for psychiatric and nonpsychiatric problems in patients with movement disorders. The most common use for clozapine among neurologists is in the management of drug-induced psychosis in Parkinson's disease (PD). This problem has been a source of increased morbidity and mortality in PD because of a lack of adequate therapeutic intervention. At this time, because of success in numerous open trials, with improvement of > 80% of patients, clozapine therapy for psychosis in PD is becoming the standard of care. It also appears to be of value in the management of some motor features of PD, including tremors and dyskinesia and possibly even sensory symptoms such as akathisia and pain. The literature also suggests that clozapine may be of potential benefit in hyperkinetic movement disorders including essential tremor, Huntington's disease, and tardive dyskinesia. We review the current data concerning the use of clozapine in patients with these movement disorders and others.