Efficacy and safety of doxepin 1 mg, 3 mg, and 6 mg in adults with primary insomnia

[Pharmacological treatment of posttraumatic stress disorder]

In addition to trauma-focussed psychotherapy, pharmacological treatment is often unavoidable, especially in patients with severe posttraumatic stress disorder (PTSD). As long as comorbid disorders do not dictate the pharmacotherapy approach, sertraline and paroxetine, along with other off-label prescribable substances approved in Germany, can be used for the treatment of PTSD. Venlafaxine, in particular, has shown good effectiveness in studies, whereas risperidone has shown lower effectiveness in augmentation. Overall, only a small to medium effect size is to be expected for all substances. Psychopharmacotherapy plays an important role in addressing sleep disorders, which are highly prevalent in PTSD. Treatment of trauma-related nightmares can be attempted with doxazosin or clonidine. In contrast, there are limited empirical data available for sleep disorders associated with PTSD, but the pharmacological treatment of insomnia can provide some guidance.

Effectiveness of Exercise, Cognitive Behavioral Therapy, and Pharmacotherapy on Improving Sleep in Adults with Chronic Insomnia: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

Despite the well-established treatment effectiveness of exercise, cognitive behavioral therapy for insomnia (CBT-I), and pharmacotherapy on improving sleep, there have been no studies to compare their long-term effectiveness, which is of clinical importance for sustainable management of chronic insomnia. This study compared the long-term effectiveness of these three interventions on improving sleep in adults with chronic insomnia. MEDLINE, PsycINFO, Embase, and SPORTDiscus were searched for eligible reports. Trials that investigated the long-term effectiveness of these three interventions on improving sleep were included. The post-intervention follow-up of the trial had to be ≥6 months to be eligible. The primary outcome was the long-term effectiveness of the three interventions on improving sleep. Treatment effectiveness was the secondary outcome. A random-effects network meta-analysis was carried out using a frequentist approach. Thirteen trials were included in the study. After an average post-intervention follow-up period of 10.3 months, both exercise (SMD, -0.29; 95% CI, -0.57 to -0.01) and CBT-I (-0.48; -0.68 to -0.28) showed superior long-term effectiveness on improving sleep compared with control. Temazepam was the only included pharmacotherapy, which demonstrated superior treatment effectiveness (-0.80; -1.25 to -0.36) but not long-term effectiveness (0.19; -0.32 to 0.69) compared with control. The findings support the use of both exercise and CBT-I for long-term management of chronic insomnia, while temazepam may be used for short-term treatment.

Connecting insufficient sleep and insomnia with metabolic dysfunction

The global epidemic of obesity and type 2 diabetes parallels the rampant state of sleep deprivation in our society. Epidemiological studies consistently show an association between insufficient sleep and metabolic dysfunction. Mechanistically, sleep and circadian rhythm exert considerable influences on hormones involved in appetite regulation and energy metabolism. As such, data from experimental sleep deprivation in humans demonstrate that insufficient sleep induces a positive energy balance with resultant weight gain, due to increased energy intake that far exceeds the additional energy expenditure of nocturnal wakefulness, and adversely impacts glucose metabolism. Conversely, animal models have found that sleep loss-induced energy expenditure exceeds caloric intake resulting in net weight loss. However, animal models have significant limitations, which may diminish the clinical relevance of their metabolic findings. Clinically, insomnia disorder and insomnia symptoms are associated with adverse glucose outcomes, though it remains challenging to isolate the effects of insomnia on metabolic outcomes independent of comorbidities and insufficient sleep durations. Furthermore, both pharmacological and behavioral interventions for insomnia may have direct metabolic effects. The goal of this review is to establish an updated framework for the causal links between insufficient sleep and insomnia and risks for type 2 diabetes and obesity.

Sleep Dysfunction in Huntington's Disease: Impacts of Current Medications and Prospects for Treatment

Sleep dysfunction is highly prevalent in Huntington's disease (HD). Increasing evidence suggests that such dysfunction not only impairs quality of life and exacerbates symptoms but may even accelerate the underlying disease process. Despite this, current HD treatment approaches neither consider the impact of commonly used medications on sleep, nor directly tackle sleep dysfunction. In this review, we discuss approaches to these two areas, evaluating not only literature from clinical studies in HD, but also that from parallel neurodegenerative conditions and preclinical models of HD. We conclude by summarizing a hierarchical framework of current medications with regard to their impact on sleep, and by outlining key emerging sleep therapies.

Drug-Induced Insomnia and Excessive Sleepiness

Undesirable side effects of insomnia and/or sleepiness may occur with many prescribed drugs, psychotropics as well as non-psychotropics. These central nervous system effects can be explained by the interactions of the drug with any of the numerous neurotransmitters and receptors that are involved in sleep and wakefulness. Also a close - sometimes bidirectional - relationship between disease and (disturbed) sleep/wakefulness is often present e.g. in chronic pain; drug effects may lead this vicious circle in both ways. Besides the importance for health and quality of life, effects on sleep or waking function can be a potential source of non-compliance.

Changes in histaminergic system in neuropsychiatric disorders and the potential treatment consequences

In contrast to that of other monoamine neurotransmitters, the association of the histaminergic system with neuropsychiatric disorders is not well documented. In the last two decades, several clinical studies involved in the development of drugs targeting the histaminergic system have been reported. These include the H3R-antagonist/inverse agonist, pitolisant, used for the treatment of excessive sleepiness in narcolepsy, and the H1R antagonist, doxepin, used to alleviate symptoms of insomnia. The current review summarizes reports from animal models, including genetic and neuroimaging studies, as well as human brain samples and cerebrospinal fluid measurements from clinical trials, on the possible role of the histaminergic system in neuropsychiatric disorders. These studies will potentially pave the way for novel histamine-related therapeutic strategies.

Histamine receptors, agonists, and antagonists in health and disease

Histamine in the brain is produced by a group of tuberomamillary neurons in the posterior hypothalamus and a limited number of mast cells in different parts of the brain. Four G-protein-coupled receptors mediate the effects of histamine. Two of these receptors, H3 and H4 receptors, are high-affinity receptors in the brain and immune system, respectively. The two classic histamine receptors, H1 receptor and H2 receptor, are well known as drug targets for allergy and gastric ulcer, respectively. These receptors have lower affinity for histamine than the more recently discovered H3 and H4 receptors. The H1 and H2 receptors are important postsynaptic receptors in the brain, and they mediate many of the central effects of histamine on, e.g., alertness and wakefulness. H3 receptor is a pre- and postsynaptic receptor, which regulates release of histamine and several other neurotransmitters, including serotonin, GABA, and glutamate. H4 receptor is found in cerebral blood vessels and microglia, but its expression in neurons is not yet well established. Pitolisant, a H3 receptor antagonist, is used to treat narcolepsy and hypersomnia. H1 receptor antagonists have been used to treat insomnia, but its use requires precautions due to potential side effects. H2 receptor antagonists have shown efficacy in treatment of schizophrenia, but they are not in widespread clinical use. H4 receptor ligands may in the future be tested for neuroimmunological disorders and potentially neurodegenerative disorders in which inflammation plays a role, but clinical tests have not yet been initiated.

Repurposing Doxepin to Ameliorate Steatosis and Hyperglycemia by Activating FAM3A Signaling Pathway

Mitochondrial protein FAM3A suppresses hepatic gluconeogenesis and lipogenesis. This study aimed to screen drug(s) that activates FAM3A expression and evaluate its effect(s) on hyperglycemia and steatosis. Drug-repurposing methodology predicted that antidepressive drug doxepin was among the drugs that potentially activated FAM3A expression. Doxepin was further validated to stimulate the translocation of transcription factor HNF4α from the cytoplasm into the nucleus, where it promoted FAM3A transcription to enhance ATP synthesis, suppress gluconeogenesis, and reduce lipid deposition in hepatocytes. HNF4α antagonism or FAM3A deficiency blunted doxepin-induced suppression on gluconeogenesis and lipid deposition in hepatocytes. Doxepin administration attenuated hyperglycemia, steatosis, and obesity in obese diabetic mice with upregulated FAM3A expression in liver and brown adipose tissues (BAT). Notably, doxepin failed to correct dysregulated glucose and lipid metabolism in FAM3A-deficient mice fed on high-fat diet. Doxepin's effects on ATP production, Akt activation, gluconeogenesis, and lipogenesis repression were also blunted in FAM3A-deficient mouse livers. In conclusion, FAM3A is a therapeutic target for diabetes and steatosis. Antidepressive drug doxepin activates FAM3A signaling pathways in liver and BAT to improve hyperglycemia and steatosis of obese diabetic mice. Doxepin might be preferentially recommended as an antidepressive drug in potential treatment of patients with diabetes complicated with depression.

Doxepin in children and adolescents with symptoms of insomnia: a single-center experience

STUDY OBJECTIVES

Pediatric insomnia is a widespread problem and especially difficult to manage in children with neurodevelopmental disorders. There are currently no US Food and Drug Administration-approved medications to use once first-line therapy fails. The objective of this study was to evaluate the efficacy and tolerability of doxepin in pediatric patients.

METHODS

This is a retrospective single-center chart review of children and adolescents (2-17 years of age) whose sleep failed to improve with behavioral intervention and melatonin who were then trialed on doxepin. Treatment was initiated at a median starting dose of 2 mg and slowly escalated to a median maintenance dose of 10 mg. Improvement in sleep was recorded using a 4-point Likert scale reported by parents on follow-up visits.

RESULTS

A total of 29 patients were included in the analysis. Mean follow-up duration was 6.5 ± 3.5 months. Of 29 patients, 4 (13.8%) patients discontinued doxepin because of lack of efficacy or side effects. Eight (27.6%) patients showed significant improvement of their insomnia, 8 (27.6%) showed moderate improvement, 10 (34.5%) showed mild improvement, and 3 (10.3%) showed minimal to no improvement on treatment with doxepin (P < .05) Only 2 patients (6.9%) experienced adverse effects in the form of behavioral side effects (aggression) and enuresis.

CONCLUSIONS

Results of our studies suggest that low-dose doxepin is both effective and well tolerated in pediatric patients with insomnia.

Sleep, insomnia, and depression

Since ancient times it is known that melancholia and sleep disturbances co-occur. The introduction of polysomnography into psychiatric research confirmed a disturbance of sleep continuity in patients with depression, revealing not only a decrease in Slow Wave Sleep, but also a disinhibition of REM (rapid eye movement) sleep, demonstrated as a shortening of REM latency, an increase of REM density, as well as total REM sleep time. Initial hopes that these abnormalities of REM sleep may serve as differential-diagnostic markers for subtypes of depression were not fulfilled. Almost all antidepressant agents suppress REM sleep and a time-and-dose-response relationship between total REM sleep suppression and therapeutic response to treatment seemed apparent. The so-called Cholinergic REM Induction Test revealed that REM sleep abnormalities can be mimicked by administration of cholinomimetic agents. Another important research avenue is the study of chrono-medical timing of sleep deprivation and light exposure for their positive effects on mood in depression. Present day research takes the view on insomnia, i.e., prolonged sleep latency, problems to maintain sleep, and early morning awakening, as a transdiagnostic symptom for many mental disorders, being most closely related to depression. Studying insomnia from different angles as a transdiagnostic phenotype has opened many new perspectives for research into mechanisms but also for clinical practice. Thus, the question is: can the early and adequate treatment of insomnia prevent depression? This article will link current understanding about sleep regulatory mechanisms with knowledge about changes in physiology due to depression. The review aims to draw the attention to current and future strategies in research and clinical practice to the benefits of sleep and depression therapeutics.

The assessment and management of insomnia: an update

Insomnia poses significant challenges to public health. It is a common condition associated with marked impairment in function and quality of life, psychiatric and physical morbidity, and accidents. As such, it is important that effective treatment is provided in clinical practice. To this end, this paper reviews critical aspects of the assessment of insomnia and the available treatment options. These options include both non-medication treatments, most notably cognitive behavioral therapy for insomnia, and a variety of pharmacologic therapies such as benzodiazepines, "z-drugs", melatonin receptor agonists, selective histamine H1 antagonists, orexin antagonists, antidepressants, antipsychotics, anticonvulsants, and non-selective antihistamines. A review of the available research indicates that rigorous double-blind, randomized, controlled trials are lacking for some of the most commonly administered insomnia therapies. However, there are an array of interventions which have been demonstrated to have therapeutic effects in insomnia in trials with the above features, and whose risk/benefit profiles have been well characterized. These interventions can form the basis for systematic, evidence-based treatment of insomnia in clinical practice. We review this evidence base and highlight areas where more studies are needed, with the aim of providing a resource for improving the clinical management of the many patients with insomnia.

Drugs for Insomnia beyond Benzodiazepines: Pharmacology, Clinical Applications, and Discovery

Although the GABAergic benzodiazepines (BZDs) and Z-drugs (zolpidem, zopiclone, and zaleplon) are FDA-approved for insomnia disorders with a strong evidence base, they have many side effects, including cognitive impairment, tolerance, rebound insomnia upon discontinuation, car accidents/falls, abuse, and dependence liability. Consequently, the clinical use of off-label drugs and novel drugs that do not target the GABAergic system is increasing. The purpose of this review is to analyze the neurobiological and clinical evidence of pharmacological treatments of insomnia, excluding the BZDs and Z-drugs. We analyzed the melatonergic agonist drugs, agomelatine, prolonged-release melatonin, ramelteon, and tasimelteon; the dual orexin receptor antagonist suvorexant; the modulators of the α₂δ subunit of voltage-sensitive calcium channels, gabapentin and pregabalin; the H₁ antagonist, low-dose doxepin; and the histamine and serotonin receptor antagonists, amitriptyline, mirtazapine, trazodone, olanzapine, and quetiapine. The pharmacology and mechanism of action of these treatments and the evidence-base for the use of these drugs in clinical practice is outlined along with novel pipelines. There is evidence to recommend suvorexant and low-dose doxepin for sleep maintenance insomnia; there is also sufficient evidence to recommend ramelteon for sleep onset insomnia. Although there is limited evidence for the use of the quetiapine, trazodone, mirtazapine, amitriptyline, pregabalin, gabapentin, agomelatine, and olanzapine as treatments for insomnia disorder, these drugs may improve sleep while successfully treating comorbid disorders, with a different side effect profile than the BZDs and Z-drugs. The unique mechanism of action of each drug allows for a more personalized and targeted medical management of insomnia.

Role of optimum diagnosis and treatment of insomnia in patients with hypertension and diabetes: A review

Sleep plays a pivotal role in regulation and function of the central nervous system (CNS) and other physiological functions of the body such as regulation of body temperature, metabolism, catabolism, learning, and memory consolidation. Therefore, sleep is not a mere passive state, but it is a highly organized interaction of neural networks and neurotransmitters of the CNS which maintain active neurobehavioral state. However, in insomnia normal physiological function is disturbed which results in several comorbidities such as depression, cardiovascular disorders, hypertension, diabetes mellitus, breathing difficulties, chronic pain, and gastrointestinal problems which affect the quality of life. Diagnosis of insomnia requires a comprehensive assessment of patient's medical history, physical examination, and sleeping pattern using various screen tools. There are several options available for the treatment of insomnia such as non-pharmacological and pharmacological that increase our understanding of the involvement of neurophysiological, neurobehavioral, neurochemical, neurocognitive, and neuroendocrine factors associated with insomnia. The pharmacological agents that are currently in use for the treatment of insomnia include benzodiazepines (BZDs), non-BZD hypnotics, and ramelteon as well as antidepressants such as doxepin. However, due to adverse events and addiction potential, use of BZDs is obsolete. Among non-BZD, zolpidem is the highly prescribed drug for the treatment of insomnia, globally. This review article focuses on prevalence, pathophysiology, diagnosis, and treatment of insomnia in patients with hypertension and diabetes. In addition, it also discusses the role of zolpidem in comparison to BZDs in the management of insomnia.

Antidepressants for insomnia in adults

BACKGROUND

Insomnia disorder is a subjective condition of unsatisfactory sleep (e.g. sleep onset, maintenance, early waking, impairment of daytime functioning). Insomnia disorder impairs quality of life and is associated with an increased risk of physical and mental health problems including anxiety, depression, drug and alcohol abuse, and increased health service use. hypnotic medications (e.g. benzodiazepines and 'Z' drugs) are licensed for sleep promotion, but can induce tolerance and dependence, although many people remain on long-term treatment. Antidepressant use for insomnia is widespread, but none is licensed for insomnia and the evidence for their efficacy is unclear. This use of unlicensed medications may be driven by concern over longer-term use of hypnotics and the limited availability of psychological treatments.

OBJECTIVES

To assess the effectiveness, safety and tolerability of antidepressants for insomnia in adults.

SEARCH METHODS

This review incorporated the results of searches to July 2015 conducted on electronic bibliographic databases: the Cochrane Central Register of Controlled Trials (CENTRAL, 2015, Issue 6), MEDLINE (1950 to 2015), Embase (1980 to 2015) and PsycINFO (1806 to 2015). We updated the searches to December 2017, but these results have not yet been incorporated into the review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of adults (aged 18 years or older) with a primary diagnosis of insomnia and all participant types including people with comorbidities. Any antidepressant as monotherapy at any dose whether compared with placebo, other medications for insomnia (e.g. benzodiazepines and 'Z' drugs), a different antidepressant, waiting list control or treatment as usual.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for eligibility and extracted data using a data extraction form. A third review author resolved disagreements on inclusion or data extraction.

MAIN RESULTS

The search identified 23 RCTs (2806 participants).Selective serotonin reuptake inhibitors (SSRIs) compared with placebo: three studies (135 participants) compared SSRIs with placebo. Combining results was not possible. Two paroxetine studies showed significant improvements in subjective sleep measures at six (60 participants, P = 0.03) and 12 weeks (27 participants, P < 0.001). There was no difference in the fluoxetine study (low quality evidence).There were either no adverse events or they were not reported (very low quality evidence).Tricyclic antidepressants (TCA) compared with placebo: six studies (812 participants) compared TCA with placebo; five used doxepin and one used trimipramine. We found no studies of amitriptyline. Four studies (518 participants) could be pooled, showing a moderate improvement in subjective sleep quality over placebo (standardised mean difference (SMD) -0.39, 95% confidence interval (CI) -0.56 to -0.21) (moderate quality evidence). Moderate quality evidence suggested that TCAs possibly improved sleep efficiency (mean difference (MD) 6.29 percentage points, 95% CI 3.17 to 9.41; 4 studies; 510 participants) and increased sleep time (MD 22.88 minutes, 95% CI 13.17 to 32.59; 4 studies; 510 participants). There may have been little or no impact on sleep latency (MD -4.27 minutes, 95% CI -9.01 to 0.48; 4 studies; 510 participants).There may have been little or no difference in adverse events between TCAs and placebo (risk ratio (RR) 1.02, 95% CI 0.86 to 1.21; 6 studies; 812 participants) (low quality evidence).'Other' antidepressants with placebo: eight studies compared other antidepressants with placebo (one used mianserin and seven used trazodone). Three studies (370 participants) of trazodone could be pooled, indicating a moderate improvement in subjective sleep outcomes over placebo (SMD -0.34, 95% CI -0.66 to -0.02). Two studies of trazodone measured polysomnography and found little or no difference in sleep efficiency (MD 1.38 percentage points, 95% CI -2.87 to 5.63; 169 participants) (low quality evidence).There was low quality evidence from two studies of more adverse effects with trazodone than placebo (i.e. morning grogginess, increased dry mouth and thirst).

AUTHORS' CONCLUSIONS

We identified relatively few, mostly small studies with short-term follow-up and design limitations. The effects of SSRIs compared with placebo are uncertain with too few studies to draw clear conclusions. There may be a small improvement in sleep quality with short-term use of low-dose doxepin and trazodone compared with placebo. The tolerability and safety of antidepressants for insomnia is uncertain due to limited reporting of adverse events. There was no evidence for amitriptyline (despite common use in clinical practice) or for long-term antidepressant use for insomnia. High-quality trials of antidepressants for insomnia are needed.

Perceived fatigue and energy are independent unipolar states: Supporting evidence

Persistent fatigue is a common problem (∼20-45% of U.S. population), with higher prevalence and severity in people with medical conditions such as cancer, depression, fibromyalgia, heart failure, sleep apnea and multiple sclerosis. There are few FDA-approved treatments for fatigue and great disagreement on how to measure fatigue, with over 250 instruments used in research. Many instruments define fatigue as "a lack of energy", thus viewing energy and fatigue states as opposites on a single bipolar continuum. In this paper, we hypothesize that energy and fatigue are distinct perceptual states, should be measured using separate unipolar scales, have different mechanisms, and deficits should be treated using tailored therapies. Energy and fatigue independence has been found in both exploratory and confirmatory factor analysis studies. Experiments in various fields, including behavioral pharmacology and exercise science, often find changes in energy and not fatigue, or vice versa. If the hypothesis that energy and fatigue are independent is correct, there are likely different mechanisms that drive energy and fatigue changes. Energy could be increased by elevated dopamine and norepinephrine transmission and binding. Fatigue could be increased by elevated brain serotonin and inflammatory cytokines and reduced histamine binding. The hypothesis could be tested by an experiment that attempts to produce simultaneously high ratings of energy and fatigue (such as with two drugs using a randomized, double-blind, placebo-controlled design), which would offer strong evidence against the common viewpoint of a bipolar continuum. If the hypothesis is correct, prior literature using bipolar instruments will be limited, and research on the prevalence, mechanisms, and treatment of low energy and elevated fatigue as separate conditions will be needed. In the immediate future, measuring both energy and fatigue using unipolar measurement tools may improve our understanding of these states and improve therapeutic outcomes.

Arousability and Fall Risk During Forced Awakenings From Nocturnal Sleep Among Healthy Males Following Administration of Zolpidem 10 mg and Doxepin 6 mg: A Randomized, Placebo-Controlled, Four-Way Crossover Trial

Study Objectives

To examine and compare the arousability threshold and fall risk upon awakening of doxepin (6 mg) versus zolpidem (10 mg).

Methods

A total of 52 healthy adult males were included in a double-blind, placebo-controlled, four-way crossover study. The experimental procedure included four nights with polysomnography in the lab (zolpidem, doxepin, and their respective placebo conditions). Arousability was measured using an auditory awakening threshold delivered at the peak-plasma concentration for the active hypnotics and at matched times for the respective placebo conditions. Fall risk during the night was measured following awakening using the Berg Balance Scale and the Tandem Walk Task.

Results

Both arousability and fall risk were lower in the doxepin condition compared to the zolpidem condition. Furthermore, arousability and fall risk for doxepin did not differ significantly from the placebo conditions. A significantly greater proportion of participants in the zolpidem condition (63.5%) did not wake until receiving the loudest tone (110 dB) as compared to the doxepin (17.6%) and placebo conditions (17.3%, 5.8%).

Conclusions

Results suggest that zolpidem has greater risks for balance and awakening threshold compared with low-dose doxepin. Future prospective studies should extend results to clinical samples with population-level risk of injury and arousability.

Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia in Adults: An American Academy of Sleep Medicine Clinical Practice Guideline

INTRODUCTION

The purpose of this guideline is to establish clinical practice recommendations for the pharmacologic treatment of chronic insomnia in adults, when such treatment is clinically indicated. Unlike previous meta-analyses, which focused on broad classes of drugs, this guideline focuses on individual drugs commonly used to treat insomnia. It includes drugs that are FDA-approved for the treatment of insomnia, as well as several drugs commonly used to treat insomnia without an FDA indication for this condition. This guideline should be used in conjunction with other AASM guidelines on the evaluation and treatment of chronic insomnia in adults.

METHODS

The American Academy of Sleep Medicine commissioned a task force of four experts in sleep medicine. A systematic review was conducted to identify randomized controlled trials, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence. The task force developed recommendations and assigned strengths based on the quality of evidence, the balance of benefits and harms, and patient values and preferences. Literature reviews are provided for those pharmacologic agents for which sufficient evidence was available to establish recommendations. The AASM Board of Directors approved the final recommendations.

RECOMMENDATIONS

The following recommendations are intended as a guideline for clinicians in choosing a specific pharmacological agent for treatment of chronic insomnia in adults, when such treatment is indicated. Under GRADE, a STRONG recommendation is one that clinicians should, under most circumstances, follow. A WEAK recommendation reflects a lower degree of certainty in the outcome and appropriateness of the patient-care strategy for all patients, but should not be construed as an indication of ineffectiveness. GRADE recommendation strengths do not refer to the magnitude of treatment effects in a particular patient, but rather, to the strength of evidence in published data. Downgrading the quality of evidence for these treatments is predictable in GRADE, due to the funding source for most pharmacological clinical trials and the attendant risk of publication bias; the relatively small number of eligible trials for each individual agent; and the observed heterogeneity in the data. The ultimate judgment regarding propriety of any specific care must be made by the clinician in light of the individual circumstances presented by the patient, available diagnostic tools, accessible treatment options, and resources. We suggest that clinicians use suvorexant as a treatment for sleep maintenance insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians use eszopiclone as a treatment for sleep onset and sleep maintenance insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians use zaleplon as a treatment for sleep onset insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians use zolpidem as a treatment for sleep onset and sleep maintenance insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians use triazolam as a treatment for sleep onset insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians use temazepam as a treatment for sleep onset and sleep maintenance insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians use ramelteon as a treatment for sleep onset insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians use doxepin as a treatment for sleep maintenance insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians not use trazodone as a treatment for sleep onset or sleep maintenance insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians not use tiagabine as a treatment for sleep onset or sleep maintenance insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians not use diphenhydramine as a treatment for sleep onset and sleep maintenance insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians not use melatonin as a treatment for sleep onset or sleep maintenance insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians not use tryptophan as a treatment for sleep onset or sleep maintenance insomnia (versus no treatment) in adults. (WEAK). We suggest that clinicians not use valerian as a treatment for sleep onset or sleep maintenance insomnia (versus no treatment) in adults. (WEAK).

Changes in Histidine Decarboxylase, Histamine N-Methyltransferase and Histamine Receptors in Neuropsychiatric Disorders

Compared to other monoamine neurotransmitters, information on the association between the histaminergic system and neuropsychiatric disorders is scarce, resulting in a lack of histamine-related treatment for these disorders. The current chapter tries to combine information obtained from genetic studies, neuroimaging, post-mortem human brain studies and cerebrospinal fluid measurements with data from recent clinical trials on histamine receptor agonists and antagonists, with a view to determining the possible role of the histaminergic system in neuropsychiatric disorders and to pave the way for novel histamine-related therapeutic strategies.

Clinical Sleep-Wake Disorders II: Focus on Insomnia and Circadian Rhythm Sleep Disorders

Insomnia and circadian rhythm sleep disorders affect large proportions of the population and have pronounced effects on quality of life and daytime performance. While the neurobiology of insomnia is not yet fully understood, circadian rhythm sleep disorders are assumed to be caused by a mismatch between the individual circadian phase position and the desired sleep-wake schedule. Benzodiazepines and non-benzodiazepine positive allosteric GABA_A receptor modulators improve sleep onset and maintenance in the short-term treatment of insomnia. However, tolerance and dependence are important side effects. Sedating antidepressants are frequently prescribed for insomnia, however, only few randomised controlled trials have been published so far. Melatonin and melatonin receptor agonists are considered to be an option for the treatment of insomnia especially because of their minimal abuse potential and safety. First data on orexin (aka hypocretin) receptor antagonists are promising, however, the risk-benefit ratio needs to be further evaluated. With respect to circadian rhythm sleep disorders, there is solid evidence from meta-analyses supporting the use of melatonin in jet lag disorder to accelerate entrainment to the new time zone, and in delayed sleep phase disorder to advance sleep-wake rhythms. In addition to that, there is evidence supporting the use of melatonin in patients with shift work disorder in order to promote daytime sleep after night shifts.

Adverse Effects of Psychotropic Medications on Sleep

Psychotropic medications such as antidepressants, antipsychotics, stimulants, and benzodiazepines are widely prescribed. Most of these medications are thought to exert their effects through modulation of various monoamines as well as interactions with receptors such as histamine and muscarinic cholinergic receptors. Through these interactions, psychotropics can also have a significant impact on sleep physiology, resulting in both beneficial and adverse effects on sleep.

Computational Analysis of Structure-Based Interactions for Novel H₁-Antihistamines

As a chronic disorder, insomnia affects approximately 10% of the population at some time during their lives, and its treatment is often challenging. Since the antagonists of the H₁ receptor, a protein prevalent in human central nervous system, have been proven as effective therapeutic agents for treating insomnia, the H₁ receptor is quite possibly a promising target for developing potent anti-insomnia drugs. For the purpose of understanding the structural actors affecting the antagonism potency, presently a theoretical research of molecular interactions between 129 molecules and the H₁ receptor is performed through three-dimensional quantitative structure-activity relationship (3D-QSAR) techniques. The ligand-based comparative molecular similarity indices analysis (CoMSIA) model (Q² = 0.525, R²ncv = 0.891, R²pred = 0.807) has good quality for predicting the bioactivities of new chemicals. The cross-validated result suggests that the developed models have excellent internal and external predictability and consistency. The obtained contour maps were appraised for affinity trends for the investigated compounds, which provides significantly useful information in the rational drug design of novel anti-insomnia agents. Molecular docking was also performed to investigate the mode of interaction between the ligand and the active site of the receptor. Furthermore, as a supplementary tool to study the docking conformation of the antagonists in the H₁ receptor binding pocket, molecular dynamics simulation was also applied, providing insights into the changes in the structure. All of the models and the derived information would, we hope, be of help for developing novel potent histamine H₁ receptor antagonists, as well as exploring the H₁-antihistamines interaction mechanism.

Occupational Sleep Medicine

Sleep and circadian rhythms significantly impact almost all aspects of human behavior and are therefore relevant to occupational sleep medicine, which is focused predominantly around workplace productivity, safety, and health. In this article, 5 main factors that influence occupational functioning are reviewed: (1) sleep deprivation, (2) disordered sleep, (3) circadian rhythms, (4) common medical illnesses that affect sleep and sleepiness, and (5) medications that affect sleep and sleepiness. Consequences of disturbed sleep and sleepiness are also reviewed, including cognitive, emotional, and psychomotor functioning and drowsy driving.

New Developments in Insomnia Medications of Relevance to Mental Health Disorders

Many insomnia medications with high specificity have become available recently. They provide a window into the clinical effects of modulating specific brain systems and establish a new guiding principal for conceptualizing insomnia medications: "mechanism matters." A new paradigm for insomnia therapy in which specific drugs are selected to target the specific type of sleep difficulty for each patient includes administering specific treatments for patients with insomnia comorbid with particular psychiatric disorders. This article reviews insomnia medications and discusses the implications for optimizing the treatment of insomnia occurring comorbid with psychiatric conditions.

The effect of histamine on changes in mental energy and fatigue after a single bout of exercise

The purpose of this research was to determine if histamine, acting on brain H1 receptors, influences changes in feelings of energy and fatigue or cognitive test performance after acute exercise. Women (n=20) with low vigor and high fatigue were administered the H1 antagonist drug doxepin hydrocholoride (6 mg) in tomato juice and tomato juice alone (placebo) in a randomized, double-blinded, cross-over experiment before performing 30 min of light intensity cycling exercise and completing energy, fatigue, sleepiness, and motivation scales, and cognitive tasks. After exercise, mental fatigue increased for the doxepin condition (p=0.014) but not placebo (p=0.700), while mental energy decreased for both PLA and DOX (p<0.001) and cognitive task performance was unaffected. It is inferred that histamine binding to H1 receptors in the brain has a role in exercise-induced reductions in mental fatigue, but not increases in energy.

Interactions of the histamine and hypocretin systems in CNS disorders

Histamine and hypocretin neurons are localized to the hypothalamus, a brain area critical to autonomic function and sleep. Narcolepsy type 1, also known as narcolepsy with cataplexy, is a neurological disorder characterized by excessive daytime sleepiness, impaired night-time sleep, cataplexy, sleep paralysis and short latency to rapid eye movement (REM) sleep after sleep onset. In narcolepsy, 90% of hypocretin neurons are lost; in addition, two groups reported in 2014 that the number of histamine neurons is increased by 64% or more in human patients with narcolepsy, suggesting involvement of histamine in the aetiology of this disorder. Here, we review the role of the histamine and hypocretin systems in sleep-wake modulation. Furthermore, we summarize the neuropathological changes to these two systems in narcolepsy and discuss the possibility that narcolepsy-associated histamine abnormalities could mediate or result from the same processes that cause the hypocretin cell loss. We also review the changes in the hypocretin and histamine systems, and the associated sleep disruptions, in Parkinson disease, Alzheimer disease, Huntington disease and Tourette syndrome. Finally, we discuss novel therapeutic approaches for manipulation of the histamine system.

Sleep disorders in chronic obstructive pulmonary disease: etiology, impact, and management

ABSTRACT

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality and may frequently be complicated by sleep disorders. Insomnia and obstructive sleep apnea are commonly encountered in patients with COPD. Nocturnal hypoxemia is also prevalent in COPD may occur despite adequate awake oxygenation and can be especially severe in rapid eye movement sleep. Additionally, several factors--some of them unique to COPD--can contribute to sleep-related hypoventilation. Recognition of hypoventilation can be vital as supplemental oxygen therapy itself can acutely worsen hypoventilation and lead to disastrous consequences. Finally, accruing data establish an association between restless leg syndrome and COPD--an association that may be driven by hypoxemia and/or hypercapnia. Comorbid sleep disorders portend worse sleep quality, diminished quality of life, and multifarious other adverse consequences. The awareness and knowledge regarding sleep comorbidities in COPD has continued to evolve over past many years. There are still several lacunae, however, in our understanding of the etiologies, impact, and therapies of sleep disorders, specifically in patients with COPD. This review summarizes the latest concepts in prevalence, pathogenesis, diagnosis, and management of diverse sleep disorders in COPD.

Treatment of Insomnia, Insomnia Symptoms, and Obstructive Sleep Apnea During and After Menopause: Therapeutic Approaches

Understanding sleep complaints among menopausal women is an emerging area of clinical and research interest. Several recent reviews have focused on mechanisms of menopausal insomnia and symptoms. In this review, we present a discussion on the most relevant and recent publications on the treatment of sleep disorders for menopausal women, with a focus on menopause-related insomnia, insomnia symptoms, and obstructive sleep apnea. We discuss both nonpharmacological and pharmacological treatments, including cognitive-behavioral therapy for insomnia (CBT-I), complementary and alternative medicine, hormone replacement therapy, sedative hypnotics, antidepressants, and continuous positive airway pressure. In addition, we briefly discuss methods and considerations of assessment of sleep disorders in menopausal women.

Pharmacological treatment of sleep disorders and its relationship with neuroplasticity

Sleep and wakefulness are regulated by complex brain circuits located in the brain stem, thalamus, subthalamus, hypothalamus, basal forebrain, and cerebral cortex. Wakefulness and NREM and REM sleep are modulated by the interactions between neurotransmitters that promote arousal and neurotransmitters that promote sleep. Various lines of evidence suggest that sleep disorders may negatively affect neuronal plasticity and cognitive function. Pharmacological treatments may alleviate these effects but may also have adverse side effects by themselves. This chapter discusses the relationship between sleep disorders, pharmacological treatments, and brain plasticity, including the treatment of insomnia, hypersomnias such as narcolepsy, restless legs syndrome (RLS), obstructive sleep apnea (OSA), and parasomnias.

Current Phase II investigational therapies for insomnia

INTRODUCTION

Insomnia is typified by a difficulty in sleep initiation, maintenance and/or quality (non-restorative sleep) resulting in significant daytime distress.

AREAS COVERED

This review summarizes the available efficacy and safety data for drugs currently in the pipeline for treating insomnia. Specifically, the authors performed MEDLINE and internet searches using the keywords 'Phase II' and 'insomnia'. The drugs covered target GABAA (zaleplon-CR, lorediplon, EVT-201), orexin (filorexant, MIN-202), histamine-H1 (LY2624803), serotonin 5-HT2A (ITI-007), melatonin/serotonin5-HT1A (piromelatine) and melatonin (indication expansions of prolonged-release melatonin and tasimelteon for pediatric sleep and circadian rhythm disorders) receptors.

EXPERT OPINION

Low-priced generic environments and high development costs limit the further development of drugs that treat insomnia. However, the bidirectional link between sleep and certain comorbidities may encourage development of specific drugs for comorbid insomnia. New insomnia therapies will most likely move away from GABAAR receptors' modulation to more subtle neurological pathways that regulate the sleep-wake cycle.

Use of ultra-low-dose (≤6 mg) doxepin for treatment of insomnia in older people

BACKGROUND

Insomnia is one of the most frequent complaints encountered in primary care practice, one that results in significant clinical consequences and cost burden to the public health system. It is more common in elderly adults (≥65 years of age), with frequent complaints regarding sleep maintenance and early morning wakening. Current treatment options have limitations. This review was conducted to evaluate the evidence behind ultra-low-dose doxepin in insomnia and to discuss its potential advantages, its place in therapy and its implications in practice in the treatment of older patients.

METHODS

A systematic literature search was conducted of MEDLINE via Ovid, PubMed and EMBASE using the MeSH and key terms "doxepin," "sleep initiation and maintenance disorders," "insomnia," and "low dose." Only randomized controlled trials comparing 3 mg and/or 6 mg of doxepin to placebo and involving participants diagnosed with primary insomnia were included. Primary outcomes for this review were objective sleep study parameters.

RESULTS

Five studies were identified, 3 of which (n = 571) were conducted in older adults. Doxepin 3 mg and 6 mg significantly reduced waking after sleep onset and increased total sleep time. There was no significant difference between the 2 doses of doxepin. Latency to persistent sleep did not differ significantly compared with placebo for any doses of doxepin. The most frequent adverse events reported were somnolence and headache. Adverse events did not appear to be dose-related, and studies reported the incidence of adverse effects to be comparable to placebo.

CONCLUSION

Doxepin 3 mg and 6 mg significantly improved and sustained sleep maintenance and sleep duration into the last third of the night but did not significantly affect sleep onset. Sleep benefits were achieved without next-day residual or discontinuation effects. Doxepin appears to be well suited for managing insomnia in older people.

Medication effects on sleep and breathing

Sleep respiration is regulated by circadian, endocrine, mechanical and chemical factors, and characterized by diminished ventilatory drive and changes in Pao2 and Paco2 thresholds. Hypoxemia and hypercapnia are more pronounced during rapid eye movement. Breathing is influenced by sleep stage and airway muscle tone. Patient factors include medical comorbidities and body habitus. Medications partially improve obstructive sleep apnea and stabilize periodic breathing at altitude. Potential adverse consequences of medications include precipitation or worsening of disorders. Risk factors for adverse medication effects include aging, medical disorders, and use of multiple medications that affect respiration.

Advances in the management of insomnia

Insomnia is highly prevalent and associated with considerable morbidity. Several very efficacious treatments, both pharmacologic and non-pharmacologic, exist for the management of insomnia. New modes of delivery and new formulations of existing sedative-hypnotic medications have been introduced. Novel agents are still being developed and tested to arrive at a hypnotic that has limited side effects while still being efficacious. Innovations with respect to behavioral interventions, which are drastically under-utilized, have focused mainly on making these interventions more widely available through dissemination efforts, briefer formats and more accessible platforms.

New and emerging pharmacotherapeutic approaches for insomnia

Advances in understanding the neurochemistry of sleep and waking have stimulated new pharmacological directions in the treatment of insomnia. While the sedation of historic insomnia medications was discovered serendipitously, now compounds can be developed for specific molecular targets with known sleep-related actions. Numerous investigational compounds, including some entirely novel approaches, are being evaluated currently as possible insomnia treatments. In recent years the US Federal Drug Administration (FDA) has approved medications with new pharmacodynamic and pharmacokinetic properties thereby extending the options for personalized pharmacotherapy. The FDA is reviewing new applications for innovative sleep-promoting medications currently, including suvorexant and tasimelteon. Presently the FDA-approved insomnia treatment medications include benzodiazepine receptor agonists available in immediate-release, extended-release, and alternative delivery oral absorption formulations; a melatonin receptor agonist; and a histamine receptor antagonist. Clinical indications include insomnia associated with difficulty with sleep onset, sleep maintenance, and middle-of-the-night awakenings. Alternative approaches to treating insomnia have included prescription medications employed on an off-label basis for insomnia, over-the-counter sleep aids, and assorted unregulated substances marketed to enhance sleep.

Antidepressant management of insomnia disorder in the absence of a mood disorder

Insomnia is the most common sleep disorder, and antidepressants are increasingly being used for its management. This article reviews the existing data concerning the use of antidepressants in the treatment of primary insomnia.

Efficacy and safety of low-dose doxepin in depressed patients suffering from insomnia: a retrospective, naturalistic case series analysis

OBJECTIVE

Low-dose doxepin has produced favorable results in healthy adults and elderly persons with chronic or transient insomnia, while exhibiting an amenable adverse event profile. The aim of this article is to investigate the efficacy and safety of low-dose doxepin for insomnia in depressed patients.

METHOD

In this retrospective case series analysis, the files of 17 inpatients diagnosed with major depressive disorder (MDD) and comorbid insomnia between January 1, 2011, and October 1, 2012 who had received a course of off-label doxepin (< 25 mg/d) were analyzed with regard to dose, efficacy, and safety for up to 4 weeks of treatment. Hamilton Depression Rating Scale (HDRS) sleep item scores were used to estimate efficacy.

RESULTS

Our results showed no improvement in sleep onset and sleep maintenance insomnia in patients with MDD during the 4 weeks of treatment. We found a significant improvement in insomnia between baseline and week 3 when considering all 3 HDRS sleep items (P = .058).

CONCLUSION

Contrasting previous results in healthy subjects, low-dose doxepin does not seem to improve sleep onset or maintenance in patients with MDD. Further research, preferably placebo-controlled, double-blind sleep laboratory trials, is necessary to determine whether low-dose doxepin may be beneficial in this important patient subgroup.

Weight considerations in psychotropic drug prescribing and switching

Our review describes potential weight-altering effects of psychotropic medications (antipsychotics, antidepressants, anti-anxiety medications, mood stabilizers, sedative-hypnotics, medications for attention-deficit/hyperactivity disorder, and other psychotropic medications) and offers guidance on switching a medication if its weight-altering effect becomes problematic. For second-generation antipsychotics, the risk of weight gain is high with clozapine and olanzapine, low with amisulpride, aripiprazole, and ziprasidone, and medium with other second-generation antipsychotics. Switching from a high-risk antipsychotic to a low-risk antipsychotic usually mitigates or reverses weight gain. For second-generation antidepressants, there may be modest weight loss with bupropion and modest weight gain with mirtazapine and paroxetine. Other second-generation antidepressants are weight neutral but individual variations can occur. If significant change in weight occurs, switching to or adding a low-risk second-generation antidepressant should be considered. Mood stabilizers include lithium, valproate, carbamazepine, lamotrigine, oxcarbazepine, and most second-generation antipsychotics. Risk of weight gain is high with lithium and valproate and low with carbamazepine, lamotrigine, and oxcarbazepine. Given the complexity of bipolar disorder and its management, a switch of a mood stabilizer would be best done by a psychiatrist. Benzodiazepines, non-benzodiazepine and melatonergic hypnotics, doxepin, and trazodone are weight neutral. Diphenhydramine may cause weight-gain and can be switched to a weight-neutral hypnotic if needed. Stimulants can cause varying degrees of weight loss and switching to atomoxetine or bupropion may reverse this problem. If that fails, switching to clonidine or guanfacine can be tried. Switching must be evidence-based and take into account status of the condition being treated, efficacy, side effect profile, potential drug-drug interactions, required laboratory monitoring and cost of the drug(s) being considered, and patient's pregnancy status or plan. Non-pharmacological interventions both for mental disorders and overweight/obesity must be fully availed.

Optimizing the Pharmacologic Treatment of Insomnia: Current Status and Future Horizons

A number of medications are available for treating patients with insomnia. These medications include agents approved as insomnia therapies by the U.S. Food and Drug Administration (FDA), agents approved by the FDA for another condition that are used "off-label" to treat insomnia, and agents available "over-the-counter" that are taken by individuals with insomnia. These agents differ in their properties, their safety and efficacy when used for different insomnia patient subtypes, and the available data on their efficacy and safety in these subtypes. As a result, optimizing the medication treatment of insomnia for a given patient requires that the clinician select an agent for use which has characteristics that make it most likely to effectively and safely address the type of sleep difficulty experienced by that individual. This article is intended to assist clinicians and researchers in carrying out this optimization. It begins by reviewing the basic characteristics of the medications used to treat insomnia. This is followed by a review of the fundamental ways that individuals with insomnia may differ and affect the choice of medication therapy. This review includes discussions that illustrate how to best choose a medication based on the characteristics of the available medications, the key differences among insomnia patients, and the available research literature. Lastly, we discuss future directions for the optimizing pharmacologic management of insomnia. It is hoped that the treatment tailoring methods discussed herein serve as a means of improving the clinical management of insomnia and, thus, improve the lives of the many patients who suffer from this common and impairing condition.

Effects of different doses of doxepin on passive avoidance learning in rats

BACKGROUND

Studies have shown that Doxepin has anti-inflammatory effects and reduces oxidative stress. Due to the fact that other tricyclic antidepressants have been shown to have neuroprotective effects, this study aimed to investigate the effects of different doses of doxepin on passive avoidance learning in rats.

MATERIALS AND METHODS

Old male Wistar rats were used in this study. Doxepin was administered intraperitoneally (1, 5 and 10 mg/kg) for 21 days. Passive avoidance learning test was used for evaluation of learning and memory. Rats received foot electrical shock on fifteen day, and step through latencies were evaluated one week after the electrical shock in retention phase.

RESULTS

Administration of Doxepin considerably increased the step through latencies in the rats that received the doses of 1 and 5 mg/kg (P < 0.05). However, in the dose of 10 mg/kg, there wasn't any significant change comparing to control group.

CONCLUSION

These results indicate that Doxepin has desirable effects on cognitive functions in low doses. Therefore, Doxepin can be considered as memory enhancers that understanding the underling mechanisms need further investigation.