Off-Label Treatment of Severe Childhood Narcolepsy-Cataplexy With Sodium Oxybate

STUDY OBJECTIVES

To evaluate the efficacy and side-effect profile of off-label sodium oxybate (gamma hydroxy butyrate) therapy in severe childhood narcolepsy-cataplexy.

DESIGN

Retrospective; chart review.

SETTING

A multidisciplinary tertiary sleep center.

PATIENTS

A group of eight children with severe narcolepsy-cataplexy diagnosed on the basis of clinical history, nocturnal polysomnography and the multiple sleep latency test were studied. A modified Epworth Sleepiness Scale and an arbitrary cataplexy severity scale (1 = minimal weakness, 2 = voluntarily preventable falls, 3 = falls to the ground) were utilized.

INTERVENTIONS

Sodium oxybate therapy; concurrent medications were maintained.

MEASUREMENTS AND RESULTS

Before sodium oxybate therapy, all subjects had suboptimally controlled sleepiness and cataplexy. Following treatment with sodium oxybate, 7/8 subjects (88%) improved. Cataplexy frequency decreased from a median of 38.5 to 4.5/ week (p = 0.0078). Cataplexy severity decreased from 2.75 to 1.75 (p = 0.06). The Epworth Sleepiness Scores improved from a median of 19 to 12.5 (p = 0.02). Suicidal ideation, dissociative episodes, tremor and constipation occurred in one subject each and terminal insomnia in two. Three of the 8 (38%) discontinued therapy. Two stopped the drug owing to side effects and one due to problems with postal delivery of the medication.

CONCLUSIONS

This is the first report on sodium oxybate therapy in childhood narcolepsy-cataplexy. Our finding of improvement in cataplexy and sleepiness suggests that this medication is effective in treating severe childhood narcolepsy-cataplexy.

La soumission chimique: une revue de la littérature

The aim of this review is to describe the present knowledge about chemical submission. The number of scientific publications on this phenomenon has increased over the last 10 years. Perpetrators choose drugs which act rapidly, produce desinhibition, sedation, and anterograde amnesia during the abuse. Ethanol and benzodiazepines are the most frequently used. A few drugs, including flunitrazepam and gamma-hydroxybutyric acid (GHB), have received widespread media coverage. Toxicological investigations on blood, urine or hair samples allow to detect the substance used. Every effort should be made to collect appropriate specimens as quickly as possible. Gas chromatography-mass spectrometry is at present the most appropriate analytical method to detect these drugs in a biological specimen.

A pilot tolerability and efficacy trial of sodium oxybate in ethanol-responsive movement disorders

Sodium oxybate is currently approved in the United States exclusively for the treatment of cataplexy in narcoleptic patients. In a prior article published in this journal, we reported a patient with severe posthypoxic myoclonus whose myoclonus improved with ethanol and also with treatment with sodium oxybate. We extend this preliminary observation to five other patients with ethanol-responsive movement disorders in an open-label, dose-titration, add-on, 8-week trial. All five patients (one with severe alcohol-responsive posthypoxic myoclonus, two with epsilon-sarcoglycan-linked myoclonus-dystonia, and two with essential tremor) experienced improvement from baseline of 50% or greater as measured by blinded videotape review. Tolerability was satisfactory, with dose-dependent sedation as the most common side effect. Further studies of this drug in hyperkinetic movement disorders are warranted.

Further evidence supporting the use of sodium oxybate for the treatment of cataplexy: a double-blind, placebo-controlled study in 228 patients

BACKGROUND AND PURPOSE

To measure the effect of the nocturnal administration of sodium oxybate on cataplexy in patients with narcolepsy.

PATIENTS AND METHODS

This trial was conducted with 228 adult narcolepsy/cataplexy patients in 42 sleep clinics. Patients using anticataplectic medications were weaned from these medications, then randomized to receive 4.5, 6 or 9 g sodium oxybate nightly or placebo for 8 weeks. Patients receiving 6 and 9 g doses were titrated to their final dose in weekly 1.5 g increments. Placebo patients underwent a randomized mock dose-titration schedule. The effect of sodium oxybate on weekly cataplexy attacks was measured using patient daily diaries.

RESULTS

Compared to placebo, nightly doses of 4.5, 6 and 9 g sodium oxybate for 8 weeks resulted in statistically significant median decreases in weekly cataplexy attacks of 57.0, 65.0 and 84.7%, respectively. The decrease in cataplexy at the 4.5 g dose represents a novel finding. The weekly increase in sodium oxybate dose was associated with fewer adverse events than previously reported in double-blind sodium oxybate trials using fixed doses. Some adverse events reported demonstrated a clear dose-response relationship.

CONCLUSIONS

In the largest study of its kind, sodium oxybate was highly effective for the treatment of cataplexy. The improvements in cataplexy are dependent on the dosage of sodium oxybate as well on the duration of treatment. Weekly dose titration appears to be well-tolerated.

A single-blind, open-label trial of sodium oxybate for myoclonus and essential tremor

The authors performed an open-label, rater-blinded, add-on study of sodium oxybate in 20 patients with ethanol-responsive myoclonus or essential tremor. Blinded ratings of videotaped examinations showed improvements in myoclonus at rest, stimulus-sensitive myoclonus, action myoclonus, functional performance, and postural and kinetic tremor. Tolerability was acceptable, and more than half of the patients chose to continue treatment after the trial. Double-blind placebo-controlled studies in these disorders are warranted.

Dilated cardiomyopathy and acute liver injury associated with combined use of ephedra, gamma-hydroxybutyrate, and anabolic steroids

Anabolic-androgenic steroids are synthetic derivatives of testosterone that some athletes have used to enhance muscle mass and improve their athletic performance. Ephedrine is a potent sympathomimetic agent that can lead to cardiomyopathy similar to that seen with catecholamine excess. Adverse cardiovascular events attributed to anabolic steroid and ephedra use, such as arrhythmias, myocardial infarction, cardiomyopathy, and sudden death, are rarely reported. Bodybuilders have used gamma-hydroxybutyrate, a potent secretagogue of growth hormone, to promote muscle development. Although dilated cardiomyopathy is a known complication of excess growth hormone levels, it has not been associated with use of gamma-hydroxybutyrate. A healthy 40-year-old man was admitted to our hospital for new-onset congestive heart failure and severe acute hepatitis that developed several months after he began using anabolic-androgenic steroids, ephedra, and gamma-hydroxybutyrate supplements. Analysis with an objective causality assessment scale revealed a probable adverse drug reaction between the patient's use of anabolic steroids, ephedra, and gamma-hydroxybutyrate and the development of his cardiomyopathy and acute liver injury.

γ-Hydroxybuttersäure — Neurotransmitter, Medikament und Droge

Gamma-hydroxybutyrate (GHB) is a short fatty acid and physiologic neurotransmitter. Initially, it was synthesized as a GABA agonist and used as a narcotic agent, because it rapidly induces sleep without major cardiovascular or respiratory side effects. Recently, a specific GHB receptor was identified, but while the clinical use of GHB as an anaesthetic was reduced due to putative pro-convulsive effects, it now is used to treat alcohol withdrawal and sleep disorders. Furthermore, GHB was postulated to be a regulator of energy metabolism, and tissue-protective effects were demonstrated in different animal models. Besides its clinical use, GHB (also called "liquid ecstasy") is increasingly consumed in the disco scene because of its mild sedative and euphoric effects. Intoxication from GHB is common with GHB users. For this reason and because GHB is not easy to detect, it is important to be aware of the symptoms of GHB intoxication. Moreover, some recent case reports document the danger of GHB dependence.

Club drugs: reasons for and consequences of use

This preliminary descriptive study was designed to assess the reasons, primary contexts, and consequences (physical, psychological, lifestyle) of club drug use in a sample of young adults in a mid-size U.S. city. Fifty young adults (18 to 30 years old) reported on their use of club drugs (Ecstasy, GHB, ketamine, Rohypnol, methamphetamine, LSD) in face-to-face interviews that included quantitative and qualitative measures. Ecstasy was the most frequently used club drug followed by ketamine, LSD and methamphetamine. All of the participants reported using club drugs to "experiment" and most reported using these drugs to feel good and enhance social activities. Club drugs were frequently used at raves, in bars or clubs, and at home with friends. An average of 16 negative physical, psychological, and lifestyle consequences were reported for club drug use. Despite substantial negative consequences, participants perceived several positive consequences of regular recreational club drug use. These findings corroborate descriptions of club drug use in other countries (e.g., Australia, United Kingdom) and provide additional information on perceived positive consequences that users experience with club drug use. Further exploration of the reasons and positive consequences that are associated with use of each of the club drugs may provide important information on the growing trend in use of these drugs.

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.

Emerging drugs for narcolepsy

Narcolepsy is characterised by excessive daytime sleepiness, usually associated with cataplexy, hypnagogic hallucinations, sleep paralysis and fragmented nocturnal sleep. Although uncommon, it results in significant disability. Most cases occur sporadically, but genetic factors probably form a susceptibility background on which unknown environmental triggers act. The hypocretin system is strongly implicated in the development of narcolepsy. Cerebrospinal fluid levels of hypocretin-1 are significantly reduced in narcoleptic subjects with cataplexy. Despite the advances in our understanding of narcolepsy, current therapy is primarily symptomatic. Stimulants (standard and novel) combat excessive daytime sleepiness. Antidepressants (tricyclics, dual-action or selective serotonin re-uptake inhibitors) and sodium oxybate are anticataplexy agents. Hypnagogic hallucinations and sleep paralysis respond to antidepressants. Sodium oxybate consolidates sleep. Novel and experimental treatments include histamine antagonists, hypocretin agonists, slow-wave sleep enhancers, intravenous gamma-globulin, tramadol and corticosteroids.

Within-patient variability in clinical presentation of gamma-hydroxybutyrate withdrawal: a case report

The emergence of gamma-hydroxybutyrate (GHB) dependence in the UK is described, with specific reference to a case study of serial episodes of GHB withdrawal. Symptoms are broadly similar to those for alcohol withdrawal, and rapid deterioration into delirium is common in severe dependence. This case report reflects the variability in clinical presentation of GHB withdrawal and response to treatment, even within the same patient. It is concluded that GHB withdrawal requires vigorous clinical management, preferably on an elective basis, in an inpatient setting if dependence is severe.

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.

Pharmacotherapy for cataplexy

A variety of medications representing several major drug classes improve cataplexy in patients with narcolepsy. These include aminergic reuptake inhibitors such as venlafaxine and clomipramine as well as sodium oxybate. This review is intended to familiarize readers with the safety and efficacy of these medications, thus enabling clinicians to optimize their management of cataplexy.

Self-extraction of teeth involving gamma-hydroxybutyric acid

A case involving self-extraction of teeth linked to the abuse of gamma-hydroxybutyric acid (GHB) is reported. A 28-year-old woman and her 29-year-old boyfriend were discovered by paramedics following an extensive period of GHB use. The paramedics were alerted by a neighbor who had heard screaming from the house. On presentation to the accident and emergency department, it was noted that the female had 18 fresh extraction sockets visible intra-orally. At the scene, a mirror, a pair of pliers, and a bowl containing human teeth were found. Charges of assault were taken to the courts against the boyfriend who was subsequently acquitted. Odontological evidence centered on whether or not it was possible to self-extract the teeth using the pliers found. This case is the first to describe possible oral self-mutilation under the influence of GHB and odontologists should always consider self-injury as an explanation for intra- and perio-oral injuries of unknown origin.

[Is GHB use in Switzerland on the rise?]

Vermutlich ist der Konsum von GHB (Gammahydroxybutyrat) und vor allem von dessen eng strukturverwandten Analoga GBL (Gamma-Butyrolactone) und BDO (1,4-Butandiol) auch in der Schweiz ansteigend. In der Psychiatrischen Universitätsklinik Zürich häuften sich in den letzten Wochen Fälle solcher Intoxikationen, die eine ärztliche Intervention notwendig machten. Der Zweck dieser Mini-Review ist es deshalb, Kolleginnen und Kollegen mit dieser wenig bekannten Substanzgruppe vertraut zu machen. Dazu wird kurz auf die Geschichte, die erwünschten und unerwünschten Wirkungen, die Nachweismöglichkeit sowie die (Akut-)Therapie eingegangen.