Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0917801 (insomnia)
 10,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A recent report showed that zolpidem (CAS 82626-48-0) can lead to the arousal of a semi-comatosed patient. Zolpidem is clinically used for the treatment of insomnia. It belongs to the imidazopyridine chemical class and is a non benzodiazepine drug. It illicits its pharmacological action via the GABA receptor system through stimulation of particularly the omega 1 receptors. In this study, the effect of zolpidem on brain perfusion was examined by 99mTc hexamethyl-propylene amine oxime (HMPAO) split dose brain SPECT on four normal baboons and in one baboon with abnormal neurological behaviour. The global and regional brain perfusion was not significantly affected in the normal brains. In some regions of the abnormal baboon brain, however, there was a disproportionate increase in perfusion after zolpidem.
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PMID:Measurement of cerebral perfusion after zolpidem administration in the baboon model. 1155 20

GABA is the main inhibitory neurotransmitter of the CNS. It is well established that activation of GABA(A) receptors favors sleep. Three generations of hypnotics are based on these GABA(A) receptor-mediated inhibitory processes. The first and second generation of hypnotics (barbiturates and benzodiazepines respectively) decrease waking, increase slow-wave sleep and enhance the intermediate stage situated between slow-wave sleep and paradoxical sleep, at the expense of this last sleep stage. The third generation of hypnotics (imidazopyridines and cyclopyrrolones) act similarly on waking and slow-wave sleep but the slight decrease of paradoxical sleep during the first hours does not result from an increase of the intermediate stage. It has been shown that GABA(B) receptor antagonists increase brain-activated behavioral states (waking and paradoxical sleep: dreaming stage). Recently, a specific GABA(C) receptor antagonist was synthesized and found by i.c.v. infusion to increase waking at the expense of slow-wave sleep and paradoxical sleep. Since the sensitivity of GABA(C) receptors for GABA is higher than that of GABA(A) and GABA(B) receptors, GABA(C) receptor agonists and antagonists, when available for clinical practice, could open up a new era for therapy of troubles such as insomnia, epilepsy and narcolepsy. They could possibly act at lower doses, with fewer side effects than currently used drugs. This paper reviews the influence of different kinds of molecules that affect sleep and waking by acting on GABA receptors.
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PMID:GABA mechanisms and sleep. 1198 10

Synthesised by Justin Liebig in 1832 chloral hydrate is one of the oldest synthetic agents. Since 1869 it has been in use for hypnotic or sedative purposes. Chloral hydrate was used a lot from the end of the 19th century to the middle of the 20th century. Since then chloral hydrate has been less frequently in use as a hypnotic. In the 1990's, the principal use of chloral hydrate in pediatrics was the sedation of children for minor surgery during dental or diagnostic procedures. In general practice, it is an analgesia found in topical preparations. It was known as safe and easy to use. Now it is shown to be potentially dangerous (risk of death in case of intoxication) and there is doubt about genotoxicity and carcinogenecity. The pharmacological property was known in 1948 when Butler discovered the principal active metabolite, trichloroethanol. The gastro-intestinal tract rapidly absorbs chloral hydrate after oral or rectal use. The sedative and hypnotic effects appear in 20 to 60 minutes. The main metabolites [trichloroethanol (TCE) and trichloroacetic acid (TCA)] are formed by hepatocytes and erythrocytes. The half-life of chloral hydrate is short (a few minutes), the half lives of the metabolics are longer, 8 to 12 hours for TCE and 67 hours for TCA. The affinity for lipids is high. It is eliminated principally by the kidneys. Its mechanism of action is unknown. It is a depressor of the SNC, and the sedation is attributed to chloral hydrate and the hypnotic effect to TCE. The interactions appear with: alcohol, anticoagulants, amitriptyline and furosemide. The use of flumazenil (a gaba antagonist), in case of intoxication, indicates a possible action of GABA. The posology is usually between 0.5 to 2 g per day. Chloral hydrate is taken during meals to prevent gastric irritation. The main side effects are digestive, cardiologic (risk of rhythm disorder), dermatologic, neuropsychiatric (withdrawn, delusions, hallucination, dependence) and ophthalmologic. Death occurs after absorption of doses of around 10 g of hydrate chloral, some cases were reported with 5 g. The use of hydrate chloral is contra-indicated in cases of gastric ulcers, hepatic insufficiency, porphyry, respiratory insufficiency, association with anticoagulants and hyper sensibility. Nowadays should we be using chloral hydrate in cases of insomnia in adult and older people? A recent preclinical working group of the French Agency for evaluation of medicinal products reassessed the benefit/risk ratio of chloral hydrate. Many references are found about genotoxicity and carcinogenicity in recent literature. In France, since the end of 2000, chloral hydrate has been withdrawn from many medications for external use in dermatology and in stomatology. Chloral hydrate can be used as a pediatric sedative only once in a lifetime. The psychiatric indication for insomnia is no longer justified and especially in older people.
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PMID:[Chloral hydrate: a hypnotic best forgotten?]. 1209 79

We screened 124 individuals for single nucleotide polymorphisms of the alpha1, beta3 and gamma2 genes of the GABA(A) receptor in the regions corresponding to the ligand-binding domains on the protein level. In a patient with chronic insomnia, a missense mutation was found in the gene of the beta3 subunit. This mutation results in the substitution of the amino acid residue arginine for histidine in position 192 (beta3(R192H)). The patient was found to be heterozygous for this mutation. Functional analysis of human alpha1beta3(R192H)gamma2S GABA(A) receptors using ultra fast perfusion techniques revealed a slower rate of the fast phase of desensitization compared with alpha1beta3gamma2S GABA(A) receptors. Additionally, current deactivation [a major determinant of inhibitory postsynaptic current (IPSC) duration] was faster in the mutated receptors. This raises the possibility of decreased GABAergic inhibition contributing to insomnia, as some members of the patient's family also suffer from insomnia. The mutation beta3(R192H) might, therefore, be linked to this condition. The intron/exon boundaries of the alpha1 subunit gene were also established and three additional variants were found in the alpha1 and beta3 genes.
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PMID:Functional characterization of the new human GABA(A) receptor mutation beta3(R192H). 1218 88

gamma-Aminobutyric acid(A) (GABA(A)) receptors are ligand-gated ion channels that mediate the majority of fast synaptic inhibition in the brain and that are also important drug targets for benzodiazepines, barbiturates, and neurosteriods. These receptors are pentameric hetero-oligomers that can be assembled from 7 subunit classes with multiple members: alpha(1-6), beta(1-3), gamma(1-3), delta, epsilon, theta, and pi. Most receptor subtypes in the brain, however, are believed to be composed of alpha-, beta-, and gamma-subunits. Modifications of GABA(A) receptor function are continually implicated in a range of pathologies, including epilepsy, anxiety, insomnia, and substance abuse. Moreover, changes in the efficacy of synaptic inhibition mediated by GABA(A) receptors are believed to be play central roles in certain forms of synaptic plasticity, including rebound potentiation in the cerebellum, and hippocampal long-term potentiation. Given the critical role that GABA(A) receptors play as mediators of synaptic transmission, it is of fundamental importance to understand the endogenous mechanisms used by neurones to control the function of these receptors. This review will focus on the dynamic regulation of GABA(A) receptor phosphorylation state and channel function as mechanisms involved in determining the efficacy of synaptic inhibition. In addition, the possible role of GABA(A) receptor phosphorylation in controlling receptor internalization and recycling will also be explored.
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PMID:Multiple roles of protein kinases in the modulation of gamma-aminobutyric acid(A) receptor function and cell surface expression. 1219 97

Treatment resistance remains a relatively common problem in panic disorder (PD) despite the success of the selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioral therapy (CBT) as first-line agents. Factors contributing to medication treatment resistance include inadequacy of trial duration, improper dosage, poor tolerability, noncompliance, and medical and psychiatric comorbidity. Poor tolerability to the SSRIs can frequently be addressed by judicious lowering of the initial dose, with a gradual upward titration. For patients who have not responded to one or more adequate trials of SSRIs, options include combination treatment with a benzodiazepine or tricyclic antidepressant (TCA), augmentation with pindolol, or switching to a different class of medication. The newer antidepressants, particularly venlafaxine XR, seem promising as alternatives, and might be beneficial for the refractory patient with a comorbid mood disorder. Anticonvulsants and olanzapine might be particularly beneficial for the refractory patient with hypomania, irritability, and insomnia, who also has demonstrated acute SSRI hypersensitivity. Experimental therapeutics in refractory panic probably will continue to examine the role of corticotropin releasing factor and glutamate/GABA systems. The role of CBT in the medication refractory patient has been explored, with preliminary suggestions of efficacy.
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PMID:Management of treatment-refractory panic disorder. 1239 90

The challenge in developing hypnotic agents for the treatment of insomnia is to balance the sedative effect needed at bedtime with the residual sedation on awakening. Zaleplon is a novel pyrazolopyrimidine hypnotic agent that acts as a selective agonist to the brain omega(1) receptor situated on the alpha(1) subunit of the GABA(A) receptor complex. Zaleplon was proven to be an effective hypnotic drug as it consistently and significantly reduced latency to persistent sleep in insomniac patients for doses of 10 mg and above in polysomnography studies. The pharmacodynamic profile of zaleplon on psychomotor performance, actual driving and cognitive function, including memory, was assessed in several randomized, double-blind, placebo-controlled studies in healthy young subjects as well as insomniac patients by using various positive controls (zolpidem, zopiclone, triazolam and flurazepam). The recommended hypnotic dose of zaleplon in young adults (10 mg) produced minimal or no impairment of psychomotor and memory performance even when administered during the night as little as 1 h before waking. No impairment of actual driving was observed when zaleplon 10 mg was administered either at bedtime or in the middle of the night as little as 4 h before waking. Zaleplon 20 mg, twice the recommended dose, generally produced significant impairment of performance and cognitive functions when these functions were measured at the time of peak plasma concentration, i.e. 1 h after dose administration, and no impairment of driving abilities was observed 4 h after a middle-of-the-night administration. In contrast, consistent detrimental residual effects on various aspects of psychomotor and cognitive functions were observed with the therapeutic doses of the various commonly prescribed hypnotic agents used as comparators, e.g. zolpidem 10 mg up to 5 h after dose administration, zopiclone 7.5 mg up to 10 h after, flurazepam 30 mg up to 14 h after and triazolam 0.25 mg up to 6 h after. Also, zolpidem 10 mg and zopiclone 7.5 mg were also shown to significantly impair driving ability the next morning when this was measured 4 h and up to 10 h after dose administration, respectively. The present review shows that zaleplon 10 mg has little or no residual effect when administered in the middle of the night, as late as 1 h before waking, and is devoid of impairment of driving abilities as assessed by actual driving 4 h after dose administration. The lack of clinically significant or minimally statistically significant residual effects of zaleplon even at its peak concentration may be explained by its unique pharmacokinetic (rapid elimination half-life) and pharmacodynamic (low affinity, and specific binding profile to various subunits of the GABA(A)receptor) profiles. These properties allow zaleplon to be used for treatment of symptoms only when they occur, either at bedtime or later in the night, without incurring significant risk of developing next-day impairment of psychomotor and cognitive functioning. Copyright 2001 John Wiley & Sons, Ltd.
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PMID:Pharmacodynamic profile of Zaleplon, a new non-benzodiazepine hypnotic agent. 1240 58

Zolpidem is a short-acting imidazopyridine hypnotic that is an agonist at the gamma-aminobutyric acid A type (GABAA) receptor. It has been suggested that it acts selectively on alpha1 subunit-containing GABAA benzodiazepine (BZ1) receptors presenting (contrary to classic benzodiazepines) low or no affinity for other subtypes. Therefore, it has been proposed that it lacks the benzodiazepines-like side-effects, having minimal abuse and dependence potential. Nevertheless, there is a considerable number of zolpidem dependence case reports in the literature. We present eight cases of zolpidem abuse and dependence without criminal record, without history of substance abuse (except for one alcohol abuser), with minor psychiatric disorders, who took zolpidem after physicians prescription in order to deal with their insomnia. However, they became zolpidem abusers not craving its sedative, but its anxiolytic and stimulating action, which helped them to cope with everyday activities. It is possible that, in the high doses that our patients used, zolpidem abandons its selectivity for BZ1 receptors and demonstrates all the actions of classic benzodiazepines. Molecular biology, via possible mutations on GABA receptors, may provide some answers as to why our eight patients (who did not differ much from the thousands of insomniacs who use zolpidem) and other zolpidem abusers, raised the dose progressively, and sought something from the drug other than hypnotic action.
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PMID:Zolpidem dependence case series: possible neurobiological mechanisms and clinical management. 1268 Jul 51

Because of strong association between epilepsy mechanisms and sleep disturbances, the latter may deteriorate the disease course and the patient's quality of life. Thirty eight patients with epilepsy (19 men and 19 women, mean age 25.6 +/- 11.4 years, age at onset 19.1 +/- 13.3 years, the disease duration 7.2 +/- 6.9 years) have been examined. The control group included 10 healthy individuals. The comparative group comprised 17 patients with physiological insomnia. All the patients had sleep disturbances of different level and were given hypnotic drug ivadal, which was compared to anticonvulsant depakine chrono, directly influencing GABA-ergic brain system. After sleep corrections, positive clinical and electroencephalographic trends in epileptic patients were detected. Comparing to depakine chrono, ivadal was suggested to up-regulate GABA-ergic brain systems during sleep due to rehabilitation of physiological brain characteristics.
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PMID:[Influence of ivadal and depakene chrono on sleep structure in patients with epilepsy]. 1283 May 2

Benzodiazepines have historically been the mainstay of treatment for sleeping disorders, yet they have many shortcomings. A new group of sedative hypnotic agents has been developed for this purpose. Similar to the benzodiazepines, zaleplon, zolpidem and zopiclone have activity at the GABA receptor complex, yet they appear to have more selectivity for certain subunits of the GABA receptor. This produces a clinical profile that is more efficacious with fewer side effects. Zaleplon, zolpidem and zopiclone are structurally distinct. Due to variation in binding to the GABA receptor subunits, these three compounds show subtle differences in their effect on sleep stages, and as antiepileptics, anxiolytics and amnestics. The duration of action of zaleplon, zolpidem and zopiclone can be related to their individual pharmacokinetic profile, which subsequently determines the time course of drug effect. Each of these compounds has a unique pharmacokinetic profile with different bioavailability, volume of distribution and elimination half-lives. Zaleplon has a rapid elimination so there are fewer residual side effects after taking a single dose at bedtime. By comparison, zolpidem and zopiclone have a more delayed elimination so there may be a prolonged drug effect. This can result in residual sedation and side effects but may be useful for sustained treatment of insomnia with less waking during the night. There are also differences in potency based on plasma concentrations suggesting that there are differences in binding to the GABA receptor complex. Although zaleplon has a much lower bioavailability (30%), the treatment dose is similar to zolpidem and zopiclone (bioavilaibility of 70%) because of the increased potency of zaleplon. The pharmacokinetics and pharmacodynamics of zaleplon, zolpidem and zopiclone are significantly different from benzodiazepines. The new drugs are sufficiently unique from each other to allow customisation of treatment for various types of insomnia. While zaleplon may be best indicated for the delayed onset of sleep, zolpidem and zopiclone may be better indicated for maintaining a complete night's sleep. Only the patient's symptoms and response to treatment will dictate the best course of treatment.
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PMID:Comparative pharmacokinetics and pharmacodynamics of short-acting hypnosedatives: zaleplon, zolpidem and zopiclone. 1500 37


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