NICE: The National Institute of Clinical Excellence -- or Eccentricity? Reflections on the Z-drugs as hypnotics

The role of the GABAergic system on insomnia

Sleep is an essential activity for the survival of mammals. Good sleep quality helps promote the performance of daily functions. In contrast, insufficient sleep reduces the efficiency of daily activities, causes various chronic diseases like Alzheimer's disease, and increases the risk of having accidents. The GABAergic system is the primary inhibitory neurotransmitter system in the central nervous system. It transits the gamma-aminobutyric acid (GABA) neurotransmitter via GABAA and GABAB receptors to counterbalance excitatory neurotransmitters, such as glutamate, noradrenaline, serotonin, acetylcholine, orexin, and dopamine, which release and increase arousal activities during sleep. Several studies emphasized that dysfunction of the GABAergic system is related to insomnia, the most prevalent sleep-related disorder. The GABAergic system comprises the GABA neurotransmitter, GABA receptors, GABA synthesis, and degradation. Many studies have demonstrated that GABA levels correlate with sleep quality, suggesting that modulating the GABAergic system may be a promising therapeutic approach for insomnia. In this article, we highlight the significance of sleep, the classification and pathology of insomnia, and the impact of the GABAergic system changes on sleep. In addition, we also review the medications that target the GABAergic systems for insomnia, including benzodiazepines (BZDs), non-BZDs, barbiturates, GABA supplements, and Chinese herbal medicines.

BDZs, designer BDZs, and Z-drugs: pharmacology and misuse insights

Benzodiazepines (BZDs) are a widely prescribed class of sedative-hypnotics compounds for the treatment of a broad range of conditions as anxiety and obsessive-compulsive disorders, phobias, sleep related problems associated with insomnia and for the management of alcohol and GHB withdrawal. Zolpidem, zopiclone and zaleplon, commonly known as Z-drugs are non-benzodiazepine hypnotic drug with pharmacology similar to BDZs. Despite their usefulness, BDZs and Z-drugs present a potential for abuse and dependence. Moreover, the non-medical use of BDZs is a well-known phenomenon and represents an increasingly widespread public health problem since is associated with an elevated risk of serious health consequences or fatal overdose, especially among specific group of users. The spectrum of BDZs and Z-drugs misuse is extended by new synthetic BDZs, which may pose high risks to users, since the majority have never undergone clinical trials or tests and consequently their pharmacology and toxicology is largely unknown.

British Association for Psychopharmacology consensus statement on evidence-based treatment of insomnia, parasomnias and circadian rhythm disorders: An update

This British Association for Psychopharmacology guideline replaces the original version published in 2010, and contains updated information and recommendations. A consensus meeting was held in London in October 2017 attended by recognised experts and advocates in the field. They were asked to provide a review of the literature and identification of the standard of evidence in their area, with an emphasis on meta-analyses, systematic reviews and randomised controlled trials where available, plus updates on current clinical practice. Each presentation was followed by discussion, aiming to reach consensus where the evidence and/or clinical experience was considered adequate, or otherwise to flag the area as a direction for future research. A draft of the proceedings was circulated to all speakers for comments, which were incorporated into the final statement.

British Association for Psychopharmacology consensus statement on evidence-based treatment of insomnia, parasomnias and circadian rhythm disorders

Sleep disorders are common in the general population and even more so in clinical practice, yet are relatively poorly understood by doctors and other health care practitioners. These British Association for Psychopharmacology guidelines are designed to address this problem by providing an accessible up-to-date and evidence-based outline of the major issues, especially those relating to reliable diagnosis and appropriate treatment. A consensus meeting was held in London in May 2009. Those invited to attend included BAP members, representative clinicians with a strong interest in sleep disorders and recognized experts and advocates in the field, including a representative from mainland Europe and the USA. Presenters were asked to provide a review of the literature and identification of the standard of evidence in their area, with an emphasis on meta-analyses, systematic reviews and randomized controlled trials where available, plus updates on current clinical practice. Each presentation was followed by discussion, aimed to reach consensus where the evidence and/or clinical experience was considered adequate or otherwise to flag the area as a direction for future research. A draft of the proceedings was then circulated to all participants for comment. Key subsequent publications were added by the writer and speakers at draft stage. All comments were incorporated as far as possible in the final document, which represents the views of all participants although the authors take final responsibility for the document.

Emerging therapies for sleep disorders

There has been an upsurge in interest in treatments for sleep disorders recently, as new discoveries in the physiology of sleep-related brain neurotransmitter systems have been made. New targets for therapies have been identified in the field of insomnia, and these will be described in this article.

The treatments of chronic insomnia: a review of benzodiazepine receptor agonists and psychological and behavioral therapies

The present review provides an assessment of the efficacy and safety of benzodiazepine receptor agonists (BZRAs) and psychological and behavioral interventions for insomnia. These methods include relaxation techniques, sleep hygiene rules, stimulus control, sleep restriction and cognitive techniques, often also referred to as cognitive-behavioral therapy (CBT) when encompassing cognitive strategies and at least one kind of behavioral intervention. In order to provide a comprehensive assessment of the literature regarding the efficacy and safety of these standard treatments for insomnia, an integrative synthesis of the existing meta-analytic studies for each of the various treatment modalities was conducted. Where meta-analytic studies were not available, data from double-blind placebo-controlled randomized controlled trials (RCTs) were included. The summary findings from this review are (1) BZRAs and psychological and behavioral methods are effective to treat insomnia in the short-term and the latter have significantly more durable effects when active treatment is discontinued; and (2) there is only very limited evidence that BZRAs retain their efficacy during long-term treatment. The present review underscores the need for further research regarding the comparative efficacy and safety of these treatments for insomnia, how this varies with age and comorbidity, and how the various treatment modalities impact (1) daytime functioning, (2) quality of life, (3) health care utilization; and (4) pharmacoeconomics. Finally, it is particularly important that studies be conducted to determine if successful insomnia treatment influences the clinical course of the diseases that often occur co-morbidly with sleep continuity disturbance.

Management of insomnia: treatments and mechanismsi

Management of insomnia is an interesting subject at present. New drug treatments are now becoming available after a relatively static period since the development of the Z-drugs in the 1990s. Moreover, more evidence is coming to light about the length of drug treatment and the effectiveness of psychological therapies. This article briefly describes current treatments, both evidence-based and common practice, and goes on to describe some emerging approaches.