Clinical features and management of gamma-hydroxybutyrate (GHB) withdrawal: a review

AIM

To examine the clinical course of gamma-hydroxybutyrate (GHB) withdrawal and generate management guidelines.

DESIGN

Review and analysis of all published reports of GHB or GHB precursor withdrawal identified from electronic searches.

FINDINGS

In total, 38 cases of GHB (n = 28) or GHB precursor (n = 10) withdrawal were identified, 36 of which were from the US. A rapidly deteriorating course into delirium (53% of cases) was typical for heavily dependent users. Symptoms were broadly similar to alcohol withdrawal but often occurred earlier in usage with delirium being associated with severe dependence as determined by more frequent ingestion. High dose benzodiazepines were effective in pharmacological management of GHB withdrawal. In benzodiazepine refractory cases withdrawal responded to other sedative agents, mainly pentobarbital or chloral hydrate. No withdrawal seizures but one death was recorded.

CONCLUSIONS

GHB withdrawal is potentially life threatening and requires vigorous clinical management, preferably as an inpatient for severe cases. A management algorithm is proposed.

Club drugs: MDMA, gamma-hydroxybutyrate (GHB), Rohypnol, and ketamine

Club drugs are substances commonly used at nightclubs, music festivals, raves, and dance parties to enhance social intimacy and sensory stimulation. The most widely used club drugs are 3,4-methylenedioxymethamphetamine (MDMA), also known as ecstasy; gamma-hydroxybutyrate (GHB); flunitrazepam (Rohypnol); and ketamine (Ketalar). These drugs are popular because of their low cost and convenient distribution as small pills, powders, or liquids. Club drugs usually are taken orally and may be taken in combination with each other, with alcohol, or with other drugs. Club drugs often are adulterated or misrepresented. Any club drug overdose should therefore be suspected as polydrug use with the actual substance and dose unknown. Persons who have adverse reactions to these club drugs are likely to consult a family physician. Toxicologic screening generally is not available for club drugs. The primary management is supportive care, with symptomatic control of excess central nervous system stimulation or depression. There are no specific antidotes except for flunitrazepam, a benzodiazepine that responds to flumazenil. Special care must be taken for immediate control of hyperthermia, hypertension, rhabdomyolysis, and serotonin syndrome. Severe drug reactions can occur even with a small dose and may require critical care. Club drug over-dose usually resolves with full recovery within seven hours. Education of the patient and family is essential.

Use of GHB Compounds by HIV-Positive Individuals

Gamma hydroxybutyrate (GHB) has been used by body-builders to enhance performance and by young adults in rave parties. Warnings have been posted about its addictive potential. The use of these dietary compounds is currently banned by the Food and Drug Administration, but they are widely available through the Internet and in certain communities. The purpose of the study was to examine the use of these compounds by HIV-positive individuals and to investigate their knowledge of the addictive potential of GHB and its related dietary compounds. One hundred HIV-positive individuals from the UCSD outpatient HIV clinic responded to an anonymous survey that inquired about their knowledge, use, and effects produced by GHB containing dietary compounds. The most common reported dietary compound beside GHB was Growth Hormone Release Extract (GHRE). Fifty-two percent of individuals reported using at least one GHB containing dietary compound. Gay subjects reported the highest use of GHB compounds (76.9%; p < or = 0.001). The most common effect reported by users was increased energy (71%). Only 24% of the total responders knew about GHB's addictive potential. Among reported users of GHB containing compounds, fourteen (27%) knew about its addictive potential and nine (17%) knew that the compound is illegal. This study shows that HIV-positive gay individuals attending our clinic are using GHB compounds. Reported GHB users have limited knowledge about its addictive potential and serious adverse effects. More controlled studies are needed to evaluate long-term effects of dietary compounds containing GHB, especially among HIV-positive individuals who are actively receiving antiretroviral treatment.

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.

Medical problems related to recreational drug use at nocturnal dance parties

During 'I love techno' (edition 2001), an indoor rave party attended by 37 000 people, data about medical problems (especially drug-related problems) were collected. To place these data in a wider perspective, a similar registration was done during 'De Nacht', a traditional New Year's Eve dance party held at the same location and attended by 12 000 people. Furthermore, a prospective study on the time course of the level of consciousness (Glasgow Coma Score) and blood concentrations of illicit drugs, especially gamma-hydroxybutyrate was set up. The results revealed that during 'I love techno' the incidence of medical problems was high (66.5/10 000 attendees), but not higher than during 'De Nacht' (70.0/10 000 attendees). At 'I love techno', however, mainly illicit drugs were used, more frequently leading to severe drug-related medical problems. The observations in patients with a drug-related medical problem who had taken gamma-hydroxybutyrate showed that for a given level of consciousness the gamma-hydroxybutyrate concentrations may show important differences, that the transition from coma (Glasgow Coma Score < or =7) to full recovery (Glasgow Coma Score 15) takes only 30-60 min (and only a small decrease in gamma-hydroxybutyrate concentrations), and that the time it takes before a comatose patient reaches the above-mentioned 'transition area' may be a few hours.

From Club Drug to Orphan Drug: Sodium Oxybate (Xyrem) for the Treatment of Cataplexy

Narcolepsy, a rare disease with a prevalence of 0.05% in the general population, affects an estimated 140,000 patients in the United States. Patients have been able to lead fuller personal and professional lives since the Food and Drug Administration approved sodium oxybate (Xyrem) in 2002 for treatment of cataplexy in patients with narcolepsy. Previously, gamma-hydroxybutyrate (GHB), the active ingredient of sodium oxybate, had been a substance of abuse, most notoriously as a date-rape drug. Public Law 106-172, the date-rape prohibition act enacted in 2000, was modified to allow the drug to be legally administered for medical purposes. Because of the apprehension regarding the risk of possible drug diversion after the approval of sodium oxybate and concerns about safety, the Xyrem Risk Management Program was created. This program has been successful in satisfying the needs of patients and physicians while ensuring responsible distribution of the drug.

Gamma-hydroxybutyric acid tolerance and withdrawal in a rat model

Long-term daily use of gamma-hydroxybutyrate (GHB) and related compounds has recently been associated with a withdrawal syndrome. To the best of the authors' knowledge, there are currently no animal models of GHB withdrawal.

OBJECTIVES

The authors studied and described the effect of chronic dosing of GHB (3-6 days) on tolerance and withdrawal in a rat model.

METHODS

Rats were administered GHB every three hours via intraperitoneal catheter. Groups of rats (2 per group) were dosed with GHB for either 3 (24 doses), 4 (32 doses), 5 (40 doses), or 6 (48 doses) days. The GHB dose was 0.25 g/kg for doses 1-8, 0.75 g/kg for doses 9-12, 1 g/kg for doses 13-16, 1.25 g/kg for doses 17-24, 1.5 g/kg for doses 25-32, 1.75 g/kg for doses 33-40, and 2 g/kg for doses 41-48. Following the last dose of GHB, the rats were scored using a 16-point ethanol intoxication-withdrawal scale rating spontaneous behaviors, response to handling, grooming, and neurological signs. Lower scores indicate intoxication, while higher scores indicate withdrawal. Scores were recorded at hours 0, 1, 2, 3, 4, 5, 6, 9, 12, and 24.

RESULTS

Tolerance: Rats dosed with GHB for more days were less intoxicated one hour after their last GHB dose despite receiving higher doses. WITHDRAWAL: The scores for all rats dosed with GHB increased at hours 4 (p = 0.028), 5 (p = 0.037), 6 (p = 0.007), and 9 (p = 0.024) after the last dose, indicating withdrawal. The scores demonstrated a linear increase dependent upon the number of days of GHB dosing at hours 3 (p < 0.000), 4 (p = 0.004), 5 (p = 0.002), and 12 (p = 0.039) as well as prior to the last dose at hour 0 (p = 0.000). No rats developed seizures.

CONCLUSIONS

Tolerance and mild withdrawal in rats can be induced by administering intraperitoneal GHB every three hours for 3-6 days. More prolonged dosing and higher doses of GHB may be necessary to induce severe withdrawal.

Gamma-hydroxybutyrate serum levels and clinical syndrome after severe overdose

STUDY OBJECTIVE

We discuss a prospective case series of patients who present with a severe gamma-hydroxybutyrate intoxication with confirmatory serum and urine gamma-hydroxybutyrate levels.

METHODS

Patients with a clinical suspicion of gamma-hydroxybutyrate-like drug overdoses and a Glasgow Coma Scale score of 8 or lower were identified from July 1998 through January 1999. Serial serum specimens and a single urine specimen were collected. The levels of gamma-hydroxybutyrate were performed by gas chromatography-mass spectrometry.

RESULTS

All 16 suspected severe gamma-hydroxybutyrate overdose patients had significant serum or urine levels of gamma-hydroxybutyrate. Serum levels ranged from 45 to 295 mg/L, with a median of 180 mg/L (interquartile range [IQR] 235 to 118 mg/L). Patients who developed a Glasgow Coma Scale score of 3 had serum levels that ranged from 72 to 300 mg/L, with a median of 193 mg/L (IQR 242 to 124 mg/L). The time of awakening ranged from 30 minutes to 190 minutes, with a median of 120 minutes (IQR 150 to 83 minutes). Quantitative serum gamma-hydroxybutyrate levels did not correlate with the degree of coma or the time to awakening. Urine levels ranged from 432 to 2,407 mg/L, with a median of 1,263 mg/L (IQR 1,550 to 796 mg/L). Mild transitory hypoventilation occurred in 5 of the 16 patients.

CONCLUSION

All of our patients with clinically suspected severe gamma-hydroxybutyrate overdose were confirmed to have significant serum and urine levels of exogenous gamma-hydroxybutyrate. They presented with severe coma that lasted 1 to 2 hours. Transient hypoventilation occurred in one third of these patients.

The abrupt cessation of therapeutically administered sodium oxybate (GHB) does not cause withdrawal symptoms

Sodium oxybate (gamma-hydroxybutyrate; GHB) has demonstrated efficacy for the treatment of narcolepsy. However, there are reports of withdrawal following chronic abuse of illicit GHB which involve escalating both doses and dosing frequency. The present trial afforded an opportunity to test the hypothesis that chronic daily therapeutic dosing of sodium oxybate in narcoleptics does not cause withdrawal following abrupt cessation. Fifty-five narcoleptic patients, taking sodium oxybate (dose range 3-9 gm/night) for 7-44 months (mean 21 months), were randomized into a 2-week double-blind period: 29 patients received placebo and 26 continued to receive sodium oxybate. During this 2-week trial period, the following symptoms were reported in patients receiving placebo (N): anxiety (2), dizziness (1), insomnia (1) and somnolence (1). While these symptoms may represent possible symptoms of mild GHB withdrawal, they are also highly consistent with the returning symptoms of narcolepsy. We conclude there is minimal evidence of withdrawal symptoms following abrupt cessation of chronic sodium oxybate dosing in the therapeutic range.

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

Many psychiatric professionals are unfamiliar with gamma-hydroxybutyrate (GHB), an increasingly popular drug of abuse. GHB withdrawal can lead to psychosis and agitation, and patients may present to psychiatric facilities for treatment. Withdrawal may progress to delirium, with the potential for severe or even fatal medical complications. Therefore, it is imperative for psychiatric professionals to understand how to treat these patients. In this article, we describe two cases of severe GHB withdrawal syndrome that were treated in our inpatient psychiatric unit. These are among the most severe cases reported. Pertinent literature is reviewed and suggestions for treatment are discussed.

Gamma-hydroxybutyrate versus chlorprothixene/phenobarbital sedation in children undergoing MRI studies

BACKGROUND

Few clinical studies have assessed gamma-hydroxybutyrate and chlorprothixene/phenobarbital sedation in children. This prospective trial compared the two regimes in children, in particular concerning differences in recovery time.

METHODS

28 pediatric oncology patients undergoing elective MRI studies at a university hospital were randomly assigned to either receive gamma-hydroxybutyrate or chlorprothixene/phenobarbital sedation. Time to induce deep sedation (Ramsay score of 5) and recovery time, the incidence of failure of sedation, the frequency of side effects, the need for therapeutic interventions, and the number of patients receiving additional midazolam were recorded. Analysis of hemodynamic parameters was performed at five defined time points.

RESULTS

All 28 MRI studies were successfully completed. Recovery time was significantly shorter with gamma-hydroxybutyrate (p < 0.01). There were more side effects with chlorprothixene/phenobarbital, in particular tachycardia and hyperexcitation. Vomiting was the side effect most often seen in gamma-hydroxybutyrate sedation. Therapeutic interventions were not required in any patient. Additional midazolam was necessary to maintain satisfactory sedation in six children receiving gamma-hydroxybutyrate and four receiving chlorprothixene/phenobarbital.

CONCLUSIONS

Due to its significantly shorter recovery time, gamma-hydroxybutyrate is a reasonable sedative drug for children undergoing non-invasive diagnostic procedures, and is superior to chlorprothixene/phenobarbital. In pediatric oncology patients gamma-hydroxybutyrate appears to be associated more often with vomiting. The long recovery time and its great variability make chlorprothixene/phenobarbital a less valuable alternative.

The influence of gender and food on the pharmacokinetics of sodium oxybate oral solution in healthy subjects

Sodium oxybate (Xyrem; gamma-hydroxybutyrate) oral solution was recently approved in the United States for the treatment of cataplexy in patients with narcolepsy. Two single-center, randomized, open-label studies in healthy volunteers receiving single oral 4.5-g doses of sodium oxybate evaluated effects of (1) gender on oxybate pharmacokinetics and (2) food on its oral bioavailability. In the latter study, one dose was administered after an overnight fast, another after a high-fat meal; 1 week separated treatments. Sodium oxybate pharmacokinetics was not significantly different between sexes. However, food significantly altered the bioavailability of oxybate by decreasing mean peak plasma concentration, increasing median time-to-peak concentration, and decreasing the area under the plasma concentration-time curve. Food did not affect elimination and urinary excretion of unchanged drug. No dose adjustment of sodium oxybate based on sex is indicated. Although significant food effects were observed, these are minimized in patients by the nocturnal dosing of sodium oxybate hours after the evening meal at a consistent time interval following food ingestion.

What are club drugs? Here's a quick look

The National Institute on Drug Abuse in Bethesda, MD, provides a brief overview on the most common designer drugs and how they are used, how they affect users, and what their dangers are.

Trends in illicit drug emergencies: the emerging role of gamma-hydroxybutyrate

BACKGROUND

Previously used as a general anesthetic, gamma-hydroxybutyrate is now used as a recreational drug. Not surprisingly, an increasing number of acute overdose cases requiring emergency medical care have been reported and described, especially in the United States.

OBJECTIVES

To determine the number and percentage of gamma-hydroxybutyrate overdoses over a 15-month period and to describe the clinical hallmarks and course of this new drug in overdose.

METHODS

All toxicological emergencies, including those caused by illicit drug consumption, were recorded for 15 months in an urban public hospital emergency department. Accurate toxicological history was obtained from the patients and, if gamma-hydroxybutyrate was suspected, confirmation was performed by urine mass spectrometry. The study data were compared with data recorded in the same emergency department in 1989.

RESULTS

The total number of toxicological emergencies attended in our emergency department have remained unchanged during the last decade, with a significant decrease in number of opiate overdoses and an increase in the number of cocaine, amphetamine, and gamma-hydroxybutyrate overdoses. During the study period, 104 gamma-hydroxybutyrate overdoses presented to the emergency department (3.1% of all toxicological emergencies), ranking second in illicit drugs requiring emergency consultation. The profile of a patient with gamma-hydroxybutyrate intoxication is well defined: a young individual (23 +/- 5 years), male (64%), emergency department presentation on weekends (90%), with simultaneous ethanol consumption (73%) and ingestion of additional illicit drugs (86%), decrease of consciousness being the main complaint in all cases [16% with Glasgow Coma Scale (GCS) = 3]. Complete recovery without sequelae occurred in all cases.

CONCLUSION

Health authorities must be aware of the hazards of recreational gamma-hydroxybutyrate, and physicians must be cognizant of this recent cause of coma among youths presenting to the emergency departments.

Gamma hydroxybutyric acid (GHB) intoxication

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. In the past decade it has become very popular as a dietary supplement and recreational drug. Acute overdose leads to profound alteration of mental status and variable amounts of respiratory depression. With proper management, most patients recover fully within six hours. However, respiratory arrest and death have been reported in severe GHB intoxication. In addition to acute overdose, there is a GHB withdrawal syndrome that is similar to sedative/hypnotic and ethanol withdrawal. Recently several congeners of GHB, gamma butyrolactone and 1,4-butanediol, have emerged as drugs of abuse and show toxidromes similar to GHB. Emergency physicians should be familiar with the presentation and management of GHB-related emergencies.