Advances in Z-drug detection

The use of Z-drugs (zolpidem, zaleplon, zopiclone, and eszopiclone) has increased in recent years, leading to a growing need for analytical methods to accurately and reliably detect these compounds in biological samples. This review comprehensively presents the latest developments in the analysis of Z-drugs in biological samples, examining methods such as LC-MS/MS, GC-MS/MS, and HPLC. These methods have been thoroughly evaluated in biological matrices (such as blood, plasma, serum, urine, and hair), with specific attention given to characteristics like sample preparation technique, calibration range, LLOQ, analysis time, mobile phase, and column. Recent studies have shown that these methods are effective in routine toxicological analysis and forensic detection of drug abuse. This review aims to provide a valuable resource for researchers and practitioners involved in the detection and analysis of Z-drugs, contributing to a better understanding and management of both therapeutic and illicit use of these compounds.

Rebound effect, discontinuation, and withdrawal syndromes associated with drugs used in psychiatric and neurological disorders

Sudden cessation of the drug can cause withdrawal syndrome, discontinuation syndrome, or rebound effect. The common feature of these phenomena is a quick onset, usually limited duration depending on the drug's half-life and remission after restarting the therapy. They are characterized by varying clusters of somatic, autonomic, and psychiatric symptoms. Originally withdrawal syndrome was described for drugs with addictive properties such as barbiturates or benzodiazepines. On the other hand sudden abrupt of antidepressants or antipsychotics may cause discontinuation symptoms including movement or sensory disturbances, sleep disturbances, and hyperarousal but generally of less severity comparing to withdrawal syndrome. The aforementioned syndromes are physiologically based on the predominance of cellular counter-regulations as an effect of the sudden abrupt of a regularly taken medication. Classically the pathogenesis of withdrawal syndrome, based on physical dependence, results in life-threatening, long-lasting manifestations such as, seizures and delirium, different from the treated disease. In turn, these symptoms are not typical for discontinuation syndrome which is not considered as serious and usually spontaneously resolving. In turn, the rebound effect is clinically characterized by the relapse of the disease symptoms that are controlled by medication, but of greater severity than those before treatment.In the current review, we describe withdrawal and discontinuation syndromes associated with selected drugs used in psychiatry and neurology, risk factors, and recommendations for diminishing syndrome occurrence. Knowledge of their pathogenesis and symptoms resulting from drug discontinuation may be helpful in syndrome management and expectantly reduces the risk of diagnostic and therapeutic errors.

An evaluation of the adequacy of Indian national and state essential medicines lists (EMLs) for palliative care medical needs-a comparative analysis

Objectives

Essential medicines lists (EMLs) guide the public sector procurement and supply of medications to impact access to adequate and appropriate palliative care drugs. This study evaluates the adequacy of India's national and sub-national EMLs that can directly impact palliative care for 5.4 million patients.

Methods

In this qualitative document review, we compared Indian national, and state EMLs acquired from official government websites with the International Association for Hospice and Palliative Care (IAHPC) EML recommendations. We analysed data on the indication and formulation of drugs under the different categories of formulations present (all, some and no), and drugs absent. Literature review and inputs from palliative care experts provided alternatives of absent medications to assess the adequacy of lists in managing the symptoms listed by IAPHC.

Results

We analysed 3 national and 27 state lists for 33 recommended drugs. The Central Government Health Services list had the maximum availability of all formulations of drugs (16 [48%]) nationally. Among states and union territories, the Delhi EML was the closest to IAHPC with 17 (52%) drugs with all formulations present. Karnataka had the most incomplete EML with only 3 (9%) drugs with all formulations present. No EML had all the recommended formulations of morphine. In one national and seventeen state EMLs, oral morphine was absent.

Conclusion

While Indian EMLs lack drugs for palliative care when compared with the IAHPC EML, symptom management is adequate. There is a need for countries with limited resources to modify the IAPHC list for their settings.

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.

Late-Stage Halogenation of Peptides, Drugs and (Hetero)aromatic Compounds with a Nucleophilic Hydrazide Catalyst

Unlike its other halogen atom siblings, chlorination of a bioactive compound can change its physiological characteristics, improve its pharmacological profile, and function as a point of diversification through cross-coupling reactions. As a result, it has been a crucial strategy for drug discovery and development. However, functional groups such as amines, amides, hydroxy groups, or carboxylic acids trap the Cl+ , severely limiting the reactivity and making direct chlorination far too difficult to be practical. Herein, we introduce a nucleophilic sulfonohydrazide catalyst for late-stage halogenation of peptides and drugs. This direct, mild and metal-free protocol shows high functional-group tolerance and is compatible with a range of structurally diverse peptides, drugs and aromatic compounds. Furthermore, DFT studies indicate that the reaction most likely proceeds via a cationic transition state. The gram-scale synthesis, high stability and efficiency of the catalyst provide a facile route for late-stage functionalization and intermediates for further derivatization.

Pharmacotherapeutic management of insomnia and effects on sleep processes, neural plasticity, and brain systems modulating stress: A narrative review

Introduction

Insomnia is a stress-related sleep disorder, may favor a state of allostatic overload impairing brain neuroplasticity, stress immune and endocrine pathways, and may contribute to mental and physical disorders. In this framework, assessing and targeting insomnia is of importance.

Aim

Since maladaptive neuroplasticity and allostatic overload are hypothesized to be related to GABAergic alterations, compounds targeting GABA may play a key role. Accordingly, the aim of this review was to discuss the effect of GABAA receptor agonists, short-medium acting hypnotic benzodiazepines and the so called Z-drugs, at a molecular level.

Method

Literature searches were done according to PRISMA guidelines. Several combinations of terms were used such as “hypnotic benzodiazepines” or “brotizolam,” or “lormetazepam” or “temazepam” or “triazolam” or “zolpidem” or “zopiclone” or “zaleplon” or “eszopiclone” and “insomnia” and “effects on sleep” and “effect on brain plasticity” and “effect on stress system”. Given the complexity and heterogeneity of existing literature, we ended up with a narrative review.

Results

Among short-medium acting compounds, triazolam has been the most studied and may regulate the stress system at central and peripheral levels. Among Z-drugs eszopiclone may regulate the stress system. Some compounds may produce more “physiological” sleep such as brotizolam, triazolam, and eszopiclone and probably may not impair sleep processes and related neural plasticity. In particular, triazolam, eszopiclone, and zaleplon studied in vivo in animal models did not alter neuroplasticity.

Conclusion

Current models of insomnia may lead us to revise the way in which we use hypnotic compounds in clinical practice. Specifically, compounds should target sleep processes, the stress system, and sustain neural plasticity. In this framework, among the short/medium acting hypnotic benzodiazepines, triazolam has been the most studied compound while among the Z-drugs eszopiclone has demonstrated interesting effects. Both offer potential new insight for treating insomnia.

New Axially Chiral Molecular Scaffolds with Antibacterial Activities against Xanthomonas oryzae pv. oryzae for Protection of Rice

A new class of axially chiral thiazine molecules were constructed and showed promising antibacterial activities against the plant pathogen Xanthomonas oryzae pv. oryzae (Xoo). The axial chiralities of these compounds (R- or S-atropisomer) showed clear impacts on the in vitro inhibitory activities against Xoo. An optimal molecule of this class with the (S)-axially chiral configuration was identified to exhibit inhibitory activity against Xoo with an EC₅₀ value of 4.18 μg/mL. This inhibition efficiency is superior to that of two commercial antibacterial agrochemicals, thiodiazole-copper and bismerthiazol, as the positive controls. This hit compound also performed better than the controls in our in vivo studies. Preliminary mechanistic studies via scanning electron microscopy images showed that our hit compound at a concentration of 10 μg/mL destroyed the bacterial integrity of Xoo. Label-free quantitative proteomics analysis indicated that a total of 366 differentially expressed proteins of the rice plants were significantly influenced in the presence of our hit molecule.

Acute and Persistent Withdrawal Syndromes Following Discontinuation of Psychotropic Medications

Studies on psychotropic medications decrease, discontinuation, or switch have uncovered withdrawal syndromes. The present overview aimed at analyzing the literature to illustrate withdrawal after decrease, discontinuation, or switch of psychotropic medications based on the drug class (i.e., benzodiazepines, nonbenzodiazepine benzodiazepine receptor agonists, antidepressants, ketamine, antipsychotics, lithium, mood stabilizers) according to the diagnostic criteria of Chouinard and Chouinard [Psychother Psychosom. 2015;84(2):63-71], which encompass new withdrawal symptoms, rebound symptoms, and persistent post-withdrawal disorders. All these drugs may induce withdrawal syndromes and rebound upon discontinuation, even with slow tapering. However, only selective serotonin reuptake inhibitors, serotonin noradrenaline reuptake inhibitors, and antipsychotics were consistently also associated with persistent post-withdrawal disorders and potential high severity of symptoms, including alterations of clinical course, whereas the distress associated with benzodiazepines discontinuation appears to be short-lived. As a result, the common belief that benzodiazepines should be substituted by medications that cause less dependence such as antidepressants and antipsychotics runs counter the available literature. Ketamine, and probably its derivatives, may be classified as at high risk for dependence and addiction. Because of the lag phase that has taken place between the introduction of a drug into the market and the description of withdrawal symptoms, caution is needed with the use of newer antidepressants and antipsychotics. Within medication classes, alprazolam, lorazepam, triazolam, paroxetine, venlafaxine, fluphenazine, perphenazine, clozapine, and quetiapine are more likely to induce withdrawal. The likelihood of withdrawal manifestations that may be severe and persistent should thus be taken into account in clinical practice and also in children and adolescents.

Electrophilic chloro(ω-alkoxy)lation of alkenes employing 1-chloro-1,2-benziodoxol-3-one: facile synthesis of β-chloroethers

A four-component reaction for electrophilic chloro(ω-alkoxy)lation of alkenes has been described. The stable chloro-iodine(iii) reagent and SOCl2 were used as electrophilic and nucleophilic chlorine sources, respectively. This approach provides a straightforward way to synthesize various useful β-chloro ω-chloroalkyl ethers from a wide range of alkenes, including electron-deficient, aromatic and unactivated alkenes. The synthetic applications of this approach were also explored in some useful transformations.

Selectfluor-promoted regioselective chlorination/bromination of 2-aminopyridines and 2-aminodiazines using LiCl/LiBr

Using LiCl/LiBr, Selectfluor-promoted chlorination/bromination of 2-aminopyridines and 2-aminodiazines is established, producing the corresponding products with high regioselectivity.

Eszopiclone for insomnia

BACKGROUND

Insomnia is a major public health issue affecting between 6% to 10% of the adult population in Western countries. Eszopiclone is a hypnotic drug belonging to a newer group of hypnotic agents, known as new generation hypnotics, which was marketed as being just as effective as benzodiazepines for this condition, while being safer and having a lower risk for abuse and dependence. It is the aim of the review to integrate evidence from randomised controlled trials and to draw conclusions on eszopiclone's efficacy and safety profile, while taking methodological features and bias risks into consideration.

OBJECTIVES

To assess the efficacy and safety of eszopiclone for the treatment of insomnia compared to placebo or active control.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled trials (CENTRAL), MEDLINE, Embase, PsycINFO, PSYNDEX and registry databases (WHO trials portal, ClinicalTrials.gov) with results incorporated from searches to 10 February 2016. To identify trials not registered in electronic databases, we contacted key informants and searched reference lists of identified studies. We ran an update search (21 February 2018) and have placed studies of interest in awaiting classification/ongoing studies. These will be incorporated into the next version of the review, as appropriate.

SELECTION CRITERIA

Parallel group randomised controlled trials (RCTs) comparing eszopiclone with either placebo or active control were included in the review. Participants were adults with insomnia, as diagnosed with a standardised diagnostic system, including primary insomnia and comorbid insomnia.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted outcome data; one reviewer assessed trial quality and the second author cross-checked it.

MAIN RESULTS

A total of 14 RCTs, with 4732 participants, were included in this review covering short-term (≤ 4 weeks; 6 studies), medium-term (> 4 weeks ≤ 6 months; 6 studies) and long-term treatment (> 6 months; 2 studies) with eszopiclone. Most RCTs included in the review included participants aged between 18 and 64 years, three RCTs only included elderly participants (64 to 85 years) and one RCT included participants with a broader age range (35 to 85 years). Seven studies considered primary insomnia; the remaining studies considered secondary insomnia comorbid with depression (2), generalised anxiety (1), back pain (1), Parkinson's disease (1), rheumatoid arthritis (1) and menopausal transition (1).Meta-analytic integrations of participant-reported data on sleep efficacy outcomes demonstrated better results for eszopiclone compared to placebo: a 12-minute decrease of sleep onset latency (mean difference (MD) -11.94 min, 95% confidence interval (CI) -16.03 to -7.86; 9 studies, 2890 participants, moderate quality evidence), a 17-minute decrease of wake time after sleep onset (MD -17.02 min, 95% CI -24.89 to -9.15; 8 studies, 2295 participants, moderate quality evidence) and a 28-minute increase of total sleep time (MD 27.70 min, 95% CI 20.30 to 35.09; 10 studies, 2965 participants, moderate quality evidence). There were no significant changes from baseline to the first three nights after drug discontinuation for sleep onset latency (MD 17.00 min, 95% CI -4.29 to 38.29; 1 study, 291 participants, low quality evidence) and wake time after sleep onset (MD -6.71 min, 95% CI -21.25 to 7.83; 1 study, 291 participants, low quality evidence). Adverse events during treatment that were documented more frequently under eszopiclone compared to placebo included unpleasant taste (risk difference (RD) 0.18, 95% CI 0.14 to 0.21; 9 studies, 3787 participants), dry mouth (RD 0.04, 95% CI 0.02 to 0.06; 6 studies, 2802 participants), somnolence (RD 0.04, 95% CI 0.02 to 0.06; 8 studies, 3532 participants) and dizziness (RD 0.03, 95% CI 0.01 to 0.05; 7 studies, 2933 participants). According to the GRADE criteria, evidence was rated as being of moderate quality for sleep efficacy outcomes and adverse events and of low quality for rebound effects and next-day functioning.

AUTHORS' CONCLUSIONS

Eszopiclone appears to be an efficient drug with moderate effects on sleep onset and maintenance. There was no or little evidence of harm if taken as recommended. However, as certain patient subgroups were underrepresented in RCTs included in the review, findings might not have displayed the entire spectrum of possible adverse events. Further, increased caution is required in elderly individuals with cognitive and motor impairments and individuals who are at increased risk of using eszopiclone in a non-recommended way.

Transition-Metal-Free Decarboxylative Iodination: New Routes for Decarboxylative Oxidative Cross-Couplings

Constructing products of high synthetic value from inexpensive and abundant starting materials is of great importance. Aryl iodides are essential building blocks for the synthesis of functional molecules, and efficient methods for their synthesis from chemical feedstocks are highly sought after. Here we report a low-cost decarboxylative iodination that occurs simply from readily available benzoic acids and I₂. The reaction is scalable and the scope and robustness of the reaction is thoroughly examined. Mechanistic studies suggest that this reaction does not proceed via a radical mechanism, which is in contrast to classical Hunsdiecker-type decarboxylative halogenations. In addition, DFT studies allow comparisons to be made between our procedure and current transition-metal-catalyzed decarboxylations. The utility of this procedure is demonstrated in its application to oxidative cross-couplings of aromatics via decarboxylative/C–H or double decarboxylative activations that use I₂ as the terminal oxidant. This strategy allows the preparation of biaryls previously inaccessible via decarboxylative methods and holds other advantages over existing decarboxylative oxidative couplings, as stoichiometric transition metals are avoided.

A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids leading to chlorinated arenes

A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids with NCS for the synthesis of aryl chlorides has been described.

Story of an Age-Old Reagent: An Electrophilic Chlorination of Arenes and Heterocycles by 1-Chloro-1,2-benziodoxol-3-one

By the use of 1-chloro-1,2-benziodoxol-3-one, an age-old reagent, the practical and efficient chlorination method is achieved. This hypervalent iodine reagent is amenable not only to the chlorination of nitrogen-containing heterocycles but also to selected classes of arenes, BODIPY dyes, and pharmaceuticals. In addition, the advantages, such as easy preparation and recyclable, air- and moisture-stable, in combination with the success in a gram-scale experiment grant this reagent great potential for industrial application.

Effect of Inhaled Lavender and Sleep Hygiene on Self-Reported Sleep Issues: A Randomized Controlled Trial

OBJECTIVES

To compare the effectiveness of lavender (Lavandula angustifolia) and sleep hygiene versus sleep hygiene alone on sleep quantity and sleep quality and to determine sustained effect at two-week follow-up.

DESIGN

A randomized controlled trial with investigator blinding and steps taken to blind the participants.

SETTING

Participants' usual sleep setting.

SUBJECTS

Seventy-nine college students with self-reported sleep issues.

INTERVENTIONS

The intervention took place over five nights with baseline, postintervention, and two-week follow-up assessments. Both groups practiced good sleep hygiene and wore an inhalation patch on their chest at night. One group wore a patch with 55 μl of lavender essential oil and the other group wore a blank patch.

OUTCOME MEASURES

Sleep quantity was measured using a Fitbit(®) tracker and a sleep diary, and sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI) and the NIH Patient-Reported Outcomes Measurement Information System (PROMIS) sleep disturbance short form.

RESULTS

The lavender and sleep hygiene group demonstrated better sleep quality at postintervention and two-week follow-up (PSQI p=0 .01, <0.001 and PROMIS p=0.04, 0.007, respectively). The sleep-hygiene-only group also demonstrated better sleep quality but to a lesser extent (PSQI p=0.02, 0.06 and PROMIS p=0.03, 0.03, respectively). Additionally, a clinical effect was found for the lavender group at postintervention, along with a significant finding for waking feeling refreshed (p=0.01). Sleep quantity did not differ between groups.

CONCLUSIONS

Lavender and sleep hygiene together, and sleep hygiene alone to a lesser degree, improved sleep quality for college students with self-reported sleep issues, with an effect remaining at follow-up.

Base-promoted coupling of carbon dioxide, amines, and N-tosylhydrazones: a novel and versatile approach to carbamates

A base-promoted three-component coupling of carbon dioxide, amines, and N-tosylhydrazones has been developed. The reaction is suggested to proceed via a carbocation intermediate and constitutes an efficient and versatile approach for the synthesis of a wide range of organic carbamates. The advantages of this method include the use of readily available substrates, excellent functional group tolerance, wide substrate scope, and a facile work-up procedure.

Palau'chlor: a practical and reactive chlorinating reagent

Unlike its other halogen atom siblings, the utility of chlorinated arenes and (hetero)arenes are twofold: they are useful in tuning electronic structure as well as acting as points for diversification via cross-coupling. Herein we report the invention of a new guanidine-based chlorinating reagent, CBMG or "Palau'chlor", inspired by a key chlorospirocyclization en route to pyrrole imidazole alkaloids. This direct, mild, operationally simple, and safe chlorinating method is compatible with a range of nitrogen-containing heterocycles as well as select classes of arenes, conjugated π-systems, sulfonamides, and silyl enol ethers. Comparisons with other known chlorinating reagents revealed CBMG to be the premier reagent.

Sleep aid toxicosis in dogs: 317 cases (2004-2010)

OBJECTIVE

To summarize the signalment, clinical signs observed, time to onset of clinical signs, duration of clinical signs, and the outcome in a large case series of nonbenzodiazepine sleep aid ingestions in dogs, including 2 sleep aids that have not been previously described in the veterinary literature.

DESIGN

Retrospective study conducted between 2004 and 2010.

SETTING

An animal poison control center based out of Bloomington, MN.

ANIMALS

During this time frame, 453 cases were identified involving 467 dogs. Of these cases, 150 cases were excluded due to incomplete medical records, multipet households, or the inability to calculate a dose exposure. A total of 317 dogs with presumed sleep aid medication toxicosis were included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Records of dogs with sleep aid medication toxicosis identified by a review of an animal poison control center electronic database were evaluated. The most common sleep aid medications ingested were zolpidem (240/317 [75.7%]), eszopiclone (62/317 [19.5%]), and zaleplon (15/317 [4.7%]). Overall, clinical signs developed in 36% of patients (115/317), while 64% (202/317) remained asymptomatic. The most common organ systems affected and clinical signs seen involved the central nervous system (eg, agitation, sedation) and gastrointestinal tract (eg, anorexia, hypersalivation, vomiting).

CONCLUSIONS

Overall, the prognosis for dogs with sleep aid medication toxicosis was excellent, and no fatalities were reported in this clinical population. As significant clinical signs can still be seen with ingestion, appropriate decontamination is warranted in asymptomatic patients via emesis or gastric lavage, followed by activated charcoal administration. Symptomatic patients should be hospitalized for monitoring and supportive care for a minimum of 12 hours or until clinical signs resolve.

Melatonin and its analogs in insomnia and depression

Benzodiazepine sedative-hypnotic drugs are widely used for the treatment of insomnia. Nevertheless, their adverse effects, such as next-day hangover, dependence and impairment of memory, make them unsuitable for long-term treatment. Melatonin has been used for improving sleep in patients with insomnia mainly because it does not cause hangover or show any addictive potential. However, there is a lack of consistency on its therapeutic value (partly because of its short half-life and the small quantities of melatonin employed). Thus, attention has been focused either on the development of more potent melatonin analogs with prolonged effects or on the design of slow release melatonin preparations. The MT(1) and MT(2) melatonergic receptor ramelteon was effective in increasing total sleep time and sleep efficiency, as well as in reducing sleep latency, in insomnia patients. The melatonergic antidepressant agomelatine, displaying potent MT(1) and MT(2) melatonergic agonism and relatively weak serotonin 5HT(2C) receptor antagonism, was found effective in the treatment of depressed patients. However, long-term safety studies are lacking for both melatonin agonists, particularly considering the pharmacological activity of their metabolites. In view of the higher binding affinities, longest half-life and relative higher potencies of the different melatonin agonists, studies using 2 or 3mg/day of melatonin are probably unsuitable to give appropriate comparison of the effects of the natural compound. Hence, clinical trials employing melatonin doses in the range of 50-100mg/day are warranted before the relative merits of the melatonin analogs versus melatonin can be settled.

Melatonin agonists in primary insomnia and depression-associated insomnia: are they superior to sedative-hypnotics?

Current pharmacological treatment of insomnia involves the use of sedative-hypnotic benzodiazepine and non-benzodiazepine drugs. Although benzodiazepines improve sleep, their multiple adverse effects hamper their application. Adverse effects include impairment of memory and cognitive functions, next-day hangover and dependence. Non-benzodiazepines are effective for initiating sleep but are not as effective as benzodiazepines for improving sleep quality or efficiency. Furthermore, their prolonged use produces adverse effects similar to those observed with benzodiazepines. Inasmuch as insomnia may be associated with decreased nocturnal melatonin, administration of melatonin is a strategy that has been increasingly used for treating insomnia. Melatonin can be effective for improving sleep quality without the adverse effects associated with hypnotic-sedatives. Ramelteon, a synthetic analog of melatonin which has a longer half life and a stronger affinity for MT1 and MT2 melatonergic receptors, has been reportedly effective for initiating and improving sleep in both adult and elderly insomniacs without showing hangover, dependence, or cognitive impairment. Insomnia is also a major complaint among patients suffering from depressive disorders and is often aggravated by conventional antidepressants especially the specific serotonin reuptake inhibitors. The novel antidepressant agomelatine, a dual action agent with affinity for melatonin MT1 and MT2 receptors and 5-HT2c antagonistic properties, constitutes a new approach to the treatment of major depressive disorders. Agomelatine ameliorates the symptoms of depression and improves the quality and efficiency of sleep. Taken together, the evidence indicates that MT1/MT2 receptor agonists like ramelteon or agomelatine may be valuable pharmacological tools for insomnia and for depression-associated insomnia.

Potentiating effect of eszopiclone on GABA(A) receptor-mediated responses in pedunculopontine neurons

The pedunculopontine nucleus (PPN) is part of the cholinergic arm of the reticular activating system, which is mostly active during waking and REM sleep. GABAergic modulation of this area appears to regulate sleep-wake cycles. Eszopiclone (ESZ), a nonbenzodiazepine hypnotic agent, appears to modulate GABAergic receptors. However, the action site of ESZ in the brain is still unresolved. We tested the hypothesis that ESZ acts by potentiating GABA(A) receptors on PPN neurons. Wholecell voltage clamp recordings were performed on PPN neurons in 7-15 day rat brainstem slices, and the potentiating effects of ESZ on the responses to the GABA(A) receptor agonist isoguvacine (IGV), and on GABA(A) receptor-mediated inhibitory post-synaptic currents (IPSCs), were determined. In the presence of tetrodotoxin, ESZ (1) increased the amplitude of the outward current induced by IGV, (2) increased its duration, and (3) enhanced the IGV-induced decrease in input resistance (Rin). The GABA(A) receptor antagonist gabazine (GBZ) blocked these effects. ESZ alone did not induce detectable currents or change Rin at a holding potential of -60 mV, but when held at 0 mV, ESZ induced an outward current in 13/21 PPN cells, an effect blocked by GBZ. ESZ also increased the amplitude (n = 18/21), duration (n = 17/21), and frequency (n = 13/15) of IPSCs. ESZ may potentiate GABA(A) inhibition in the PPN via pre- and post-synaptic modulation, which may underlie the hypnotic effects of ESZ. The differential effects of ESZ on both pre- and post-synaptic sites may partially explain why it has less significant side effects compared to other hypnotic agents.

Spotlight on eszopiclone in insomnia

Eszopiclone (Lunesta), the S-enantiomer of racemic zopiclone, is a nonbenzodiazepine hypnotic agent that is approved in the US as an oral, once-nightly therapy for insomnia in adults; eszopiclone is also currently under review by the European Medicines Agency.Eszopiclone is rapidly absorbed after oral administration without any next-day clinical residual effects being detected. Large, well designed trials of up to 6 months' duration have shown that eszopiclone significantly improves both sleep onset and sleep maintenance compared with placebo in adult and elderly patients with primary insomnia. Eszopiclone for 4-8 weeks also significantly improved sleep parameters compared with placebo in patients with insomnia coexisting with other conditions that also disturb sleep (co-morbid insomnia), and improved certain measures of the co-morbid conditions to a greater extent than the standard therapies alone. Short-term eszopiclone produced improvements in daytime functioning in patients with co-morbid insomnia. Six months' therapy in adults with primary insomnia improved daytime functioning and health-related quality of life. Eszopiclone was generally well tolerated. There was no evidence of tolerance during 12 months of treatment with this agent. On discontinuation of eszopiclone, there was no rebound insomnia or serious withdrawal effects. Well designed, comparative trials with other nonbenzodiazepine hypnotics are needed to determine its relative efficacy and tolerability. A cost-utility analysis suggested that eszopiclone is cost effective for the treatment of primary insomnia in the US. Therefore, eszopiclone is a useful therapeutic option in the management of adult and elderly patients with primary or co-morbid insomnia. Unlike most other hypnotics, eszopiclone is not limited to short-term use.