Low-dose doxepin: in the treatment of insomnia

Doxepin is more effective than zolpidem in improving executive function in patients with insomnia disorder

BACKGROUND : Insomnia disorder is associated with an impairment in cognitive performance. Doxepin and zolpidem have been found to be effective in improving sleep. In this study, we aimed to compare the effects of doxepin and zolpidem on sleep structure and executive function in patients with insomnia disorder.

METHODS

Patients with primary insomnia were randomly assigned to receive doxepin 6 mg/day orally or zolpidem 5-10 mg/day orally. Polysomnography (PSG) and the Pittsburgh Sleep Quality Index (PSQI) were used at baseline and after the 8-week treatment to compare clinical efficacy in the two groups. Safety was assessed using the Treatment Emergent Symptom Scale (TESS). Executive function was evaluated using the Wisconsin sorting card test (WSCT).

RESULTS

Of 120 patients enrolled in the study, 60 participants were assigned to each group. A total of 109 participants (53 in the doxepin group and 56 in the zolpidem group) completed the study. After treatment, the wake after sleep onset (WASO) and total sleep time (TST) values in the doxepin group were 80.3 ± 21.4 min and 378.9 ± 21.9 min, respectively, which were significantly better than those in the zolpidem group (132.9 ± 26.5 min and 333.2 ± 24.2 min, respectively; (P < 0.05)). The sleep onset latency (SOL) value in the zolpidem group (20.3 ± 4.7 min) was significantly better than that in the doxepin group (28.2 ± 5.6 min; P < 0.05). The sleep efficiency (SE) in the doxepin group was 77.8 ± 4.2%, which was significantly better than that in the zolpidem group (68.6 ± 5.0%; P < 0.05). The PSQI score of the doxepin group was 6.1 ± 1.1, which was significantly lower than that in the zolpidem group (7.9 ± 1.9; P < 0.05). The treatment adverse events in the doxepin group was 23.3%, which was significantly higher than that in the zolpidem group (13.3%; P < 0.05). The WSCT showed a significant improvement in persistent errors (PE), random errors (RE), and categories in the two groups after 8-week treatment, and the improvement in RE and the categories was more obvious in the doxepin group (P < 0.05).

CONCLUSIONS

Both doxepin and zolpidem were found to be effective in improving sleep quality, but the effects exhibited different patterns. Doxepin improved executive function more effectively than zolpidem in patients with insomnia disorder.

Medications Used for Pediatric Insomnia

Pediatric insomnia can affect physical and mental health and cause cognitive deficits, social deficits and decrease quality of life. There are no Food and Drug Administration approved medications approved for pediatric insomnia. Pharmacologic interventions derive mostly from adult data or pediatric case reports. This review focuses on Food and Drug Administration approved prescription drugs (in adults), over-the-counter drugs, and off-label pediatric insomnia drugs. This review helps the clinician learn general principles, practice guidelines, and pharmacologic considerations for medication selection in the pediatric population. Pharmacologic management should be considered in combination with behavior therapy, which is proven to have long-lasting outcomes.

Metabolic bioactivation of antidepressants: advance and underlying hepatotoxicity

Many drugs that serve as first-line medications for the treatment of depression are associated with severe side effects, including liver injury. Of the 34 antidepressants discussed in this review, four have been withdrawn from the market due to severe hepatotoxicity, and others carry boxed warnings for idiosyncratic liver toxicity. The clinical and economic implications of antidepressant-induced liver injury are substantial, but the underlying mechanisms remain elusive. Drug-induced liver injury may involve the host immune system, the parent drug, or its metabolites, and reactive drug metabolites are one of the most commonly referenced risk factors. Although the precise mechanism by which toxicity is induced may be difficult to determine, identifying reactive metabolites that cause toxicity can offer valuable insights for decreasing the bioactivation potential of candidates during the drug discovery process. A comprehensive understanding of drug metabolic pathways can mitigate adverse drug-drug interactions that may be caused by elevated formation of reactive metabolites. This review provides a comprehensive overview of the current state of knowledge on antidepressant bioactivation, the metabolizing enzymes responsible for the formation of reactive metabolites, and their potential implication in hepatotoxicity. This information can be a valuable resource for medicinal chemists, toxicologists, and clinicians engaged in the fields of antidepressant development, toxicity, and depression treatment.

Sleep and Circadian Disturbances in Children With Neurodevelopmental Disorders

Sleep problems are highly prevalent in those with neurodevelopmental disorders (NDDs). We propose this is secondary to multiple factors that directly and indirectly negatively impact sleep and circadian processes in those with NDDs, which in turn, further perturbs development, resulting in a "developmental and sleep/circadian-related encephalopathy." In this review, we discuss select NDDs with known or suspected sleep and circadian phenotypes. We also highlight important considerations when evaluating and treating sleep and circadian disorders in these populations.

Molecular dynamics and free energy calculations of clozapine bound to D2 and H1 receptors reveal a cardiometabolic mitigated derivative

Most atypical antipsychotics derive from a high dropout of drug treatments due to adverse cardiometabolic side effects. These side effects are caused, in part, by the H1 receptor blockade. The current work sought a clozapine derivative with a reduced affinity for the H1 receptor while maintaining its therapeutic effect linked to D2 receptor binding. Explicit molecular dynamics simulations and end-point free energy calculations of clozapine in complex with the D2 and H1 receptors embedded in cholesterol-rich lipid bilayers were performed to analyze the intermolecular interactions and address the relevance of clozapine-functional groups. Based on that, free energy perturbation calculations were performed to measure the change in free energy of clozapine structural modifications. Our results indicate the best clozapine derivative is the iodine atom substitution for chlorine. The latter is mainly due to electrostatic interaction loss for the H1 receptor, while the halogen orientation out of the D2 active site reduces the impact on the affinity.Communicated by Ramaswamy H. Sarma.

Evergreening of Psychiatric Medications: A Systemic Literature Review of Strategies, Case Examples, and the Implications of Cost

Evergreening consists of multiple ways that pharmaceutical companies extend patent protection and prolong profitability of brand name drugs past patent expiration. In psychotropic medications, these strategies do not necessarily make more effective drugs, and often increase drug prices, which can result in lower access and utilization. There has not been a systematic literature review of evergreening strategies for psychiatric medications. Based on such a review, 11 strategies were identified and relevant examples were provided. Four case examples of commonly used psychiatric medications indicated evergreen prices 3 to 211 times the cost of the original medication, and the evergreen costs ranging from $132.00 to $10,125.24 higher than the original cost on an annual basis. The higher cost of evergreening medications can create inefficiencies and waste in healthcare resulting in lower-quality patient care. Healthcare providers, patient advocates, health insurance companies, and policy-makers should be aware of these practices to improve healthcare systems.

Inhibition of Microglial Activation by Amitriptyline and Doxepin in Interferon-β Pre-Treated Astrocyte–Microglia Co-Culture Model of Inflammation

Depression may occur in patients with multiple sclerosis, especially during interferon-β (IFN-β) treatment, and therapy with antidepressants may be necessary. Interactions of IFN-β with antidepressants concerning glia-mediated inflammation have not yet been studied. Primary rat co-cultures of astrocytes containing 5% (M5, consistent with “physiological” conditions) or 30% (M30, consistent with “pathological, inflammatory” conditions) of microglia were incubated with 10 ng/mL amitriptyline or doxepin for 2 h, or with 2000 U/mL IFN-β for 22 h. To investigate the effects of antidepressants on IFN-β treatment, amitriptyline or doxepin was added to IFN-β pre-treated co-cultures. An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was performed to measure the glial cell viability, immunocytochemistry was performed to evaluate the microglial activation state, and ELISA was performed to measure pro-inflammatory TNF-α and IL-6 cytokine concentrations. Incubation of inflammatory astrocyte–microglia co-cultures with amitriptyline, doxepin or IFN-β alone, or co-incubation of IFN-β pre-treated co-cultures with both antidepressants, significantly reduced the extent of inflammation, with the inhibition of microglial activation. TNF-α and IL-6 levels were not affected. Accordingly, the two antidepressants did not interfere with the anti-inflammatory effect of IFN-β on astrocytes and microglia. Furthermore, no cytotoxic effects on glial cells were observed. This is the first in vitro study offering novel perspectives in IFN-β treatment and accompanying depression regarding glia.

Odevixibat: A Review of a Bioactive Compound for the Treatment of Pruritus Approved by the FDA

Odevixibat is synthesized through chemical modification of Benzothiazepine's structure. It is a tiny chemical that inhibits the ileal bile acid transporter and is used to treat a variety of cholestatic illnesses, including progressive familial intrahepatic cholestasis (PFIC). For cholestatic pruritus and liver disease development, bile acid transporter inhibition is a unique treatment strategy. Odevixibat reduces enteric bile acid reuptake. Oral odevixibat was also studied in children with cholestatic liver disease. Odevixibat received its first approval in the European Union (EU) in July 2021 for the treatment of PFIC in patients aged 6 months, followed by approval in the USA in August 2021 for the treatment of pruritus in PFIC patients aged 3 months. Bile acids in the distal ileum can be reabsorbed by the ileal sodium/bile acid cotransporter, a transport glycoprotein. Odevixibat is a sodium/bile acid co-transporter reversible inhibitor. An average 3 mg once-daily dose of odevixibat for a week resulted in a 56% reduction in the area under the curve of bile acid. A daily dose of 1.5 mg resulted in a 43% decrease in the area under the curve for bile acid. Odevixibat is also being evaluated in many countries for the treatment of other cholestatic illnesses, including Alagille syndrome and biliary atresia. This article reviews the updated information on odevixibat with respect to its clinical pharmacology, mechanism of action, pharmacokinetics, pharmacodynamics, metabolism, drug-drug interactions, pre-clinical studies, and clinical trials.

Clinical efficacy and safety of low-dose doxepin in Chinese patients with generalized anxiety disorder: A before-after study

Clinical and animal studies have reported that low-dose doxepin may have positive effects on generalized anxiety disorder (GAD); however, its effectiveness and clinical safety are less well understood. This study is a before-after study and aims to investigate the effectiveness and side effects of low-dose doxepin by evaluating Hamilton Anxiety Scale (HAMA) scores, hormones, blood glucose, serum lipids, body weight, and body mass index (BMI) in patients with GAD. Forty-nine patients (20 males and 29 females) with GAD were randomly assigned to receive low-dose doxepin (6.25 mg-12.5 mg per day) for 12 weeks between February 2015 and March 2016. HAMA scores, fasting blood glucose (FBG) body weight, BMI, and some serum biochemical indexes, such as adrenocorticotropic hormone (ACTH), free triiodothyronine (FT3), total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDLC), and FBG, were assessed during pretreatment and post-treatment. Mean scores of HAMA decreased from 19.50 ± 1.22 to 8.50 ± 3.61 after low-dose doxepin treatment (P < .01). The serum levels of ACTH (4.33 ± 2.14 vs 6.12 ± 3.02 pmol/L), FT3 (4.78 ± 0.51 vs 5.15 ± 0.52 pg/mL), TC (4.55 ± 1.01 vs 5.93 ± 1.66 mmol/L), TG (1.69 ± 1.51 vs 3.39 ± 2.86 mmol/L), and LDLC (2.43 ± 0.88 vs 3.76 ± 1.25 mmol/L), and FBG (5.06 ± 0.43 vs 5.78 ± 0.81 mmol/L) were higher than that pretreatment with a significant difference (P < .01). Bodyweight (62.00 ± 7.45 vs 64.00 ± 6.44 kg, P = .23) and BMI (23.70 ± 2.35 vs 24.48 ± 2.11 kg/m2, P = .14) had no difference after treatment. These results suggest that low-dose doxepin has beneficial clinical efficacy and safety. Low-dose doxepin can ameliorate anxiety in GAD patients and has some effects on neuroendocrine systems and the metabolic activity of serum glucose and lipid.

A novel solid phase extraction sample preparation method for sensitively determining doxepin and N-nordoxepin in human plasma and its application in a bioequivalence study in healthy Chinese volunteers

Doxepin, a tricyclic antidepressant (TCA), is widely used in the treatment of depressive disorder and anxiety. There are some liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods that have been reported for detecting doxepin, but inadequacies in recovery and cumbersome sample preparation obstruct the pharmacokinetics study. Therefore, we aimed to develop and validate a rapid sample preparation method based on solid-phase extraction (SPE) for the precise quantification of doxepin and its metabolites. Chromatography separation was performed on a Waters ACQUITY UPLC BEH C18 column (2.1 × 100 mm, 1.7 μm) and a mobile phase consisting of 70% of mobile phase A (0.1% formic acid and 10 mM ammonium formate) and 30% mobile phase B (0.1% formic acid in acetonitrile) at a flow rate of 0.4 mL min^-1 in the step gradient elution conditions. The lower limits of quantification for doxepin and N-nordoxepin were 4 pg mL^-1 and 2 pg mL^-1, respectively. This method was validated with satisfactory results including good precision and accuracy. A rapid, sensitive, and specific LC-MS/MS method was developed and validated for the determination of doxepin in human plasma. This method could be applied for determining doxepin and N-nordoxepin concentrations in plasma that could be useful for bioequivalence study of 3 mg doxepin.

Impact of Pharmacotherapy on Insomnia in Patients with Alzheimer's Disease

Insomnia is a pervasive sleep disorder affecting numerous patients across diverse demographical populations and comorbid disease states. Contributing factors are often a complex interaction of biological, psychological, and social components, requiring a multifaceted approach in terms of both diagnosis and management. In the setting of Alzheimer’s disease, insomnia is an even more complicated issue, with a higher overall prevalence than in the general population, greater complexity of contributing etiologies, and differences in diagnosis (at times based on caregiver observation of sleep disruption rather than subjective complaints by the individual with the disorder), and requiring more discretion in terms of treatment, particularly in regard to adverse effect profile concerns. There also is growing evidence of the bidirectional nature of sleep disruption and Alzheimer’s disease, with insomnia potentially contributing to disease progression, making the condition even more paramount to address. The objective of this review was to provide the clinician with an overview of treatment strategies that may have value in the treatment of disturbed sleep in Alzheimer’s disease. Nonpharmacological approaches to treatment should be exhausted foremost; however, pharmacotherapy may be needed in certain clinical scenarios, which can be a challenge for clinicians given the paucity of evidence and guidelines for treatment in the subpopulation of Alzheimer’s disease. Agents such as sedating antidepressants, melatonin, and site-specific γ-aminobutyric acid agonists are often employed based on historical usage but are not necessarily supported by high-quality trials. Newer agents such as dual orexin receptor antagonists have demonstrated some promise but still need further evaluation.

Comparative efficacy and safety of hypnotics for insomnia in older adults: a systematic review and network meta-analysis

STUDY OBJECTIVES

To compare the efficacy and safety of various hypnotics for identifying the best treatments for insomnia in older adults.

METHODS

We searched the EMBASE, PubMed, ClinicalTrials.gov, and ProQuest Dissertations and Theses A&I databases from the inception to September 12, 2020. Only randomized controlled trials comparing hypnotics with either another hypnotic or placebo for insomnia treatment in elderly people were included. Sleep outcomes, including total sleep time, sleep onset latency, wake after sleep onset, sleep efficiency, were derived from polysomnography, valid questionnaires, or sleep diaries.

RESULTS

We identified 24 articles with 5917 older adults. Eszopiclone and low-dose doxepin were ranked the optimal therapy for prolonging objective and subjective total sleep time (26.69 and 28.19 min), respectively, compared to placebo. Zaleplon was the most effective therapy in reducing objective and subjective sleep onset latency (-21.63 and -15.86 min) compared with control. Temazepam was the best treatment for objective and subjective wake after sleep onset (-25.29 and -22.25 min) compared with control. Low-dose doxepin appeared to be the effective treatment for increasing objective sleep efficiency (6.08%) Triazolam showed the higher risk of overall adverse events (odds ratio, 1.96, 95% confidence interval 1.03-3.74) when compared to zaleplon.

CONCLUSIONS

Considering study quality and the potential adverse effects of benzodiazepines and nonbenzodiazepines, low-dose doxepin seems to be the optimal pharmacotherapy for the improvements in total sleep time and sleep efficiency. Future RCTs investigating the treatment effects of hypnotics, particularly low-dose doxepin, on insomnia in older adults are warranted. PROSPERO Registration number: CRD42016046301.

Medications Used for Pediatric Insomnia

Pediatric insomnia can affect physical and mental health and cause cognitive deficits, social deficits and decrease quality of life. There are no Food and Drug Administration approved medications approved for pediatric insomnia. Pharmacologic interventions derive mostly from adult data or pediatric case reports. This review focuses on Food and Drug Administration approved prescription drugs (in adults), over-the-counter drugs, and off-label pediatric insomnia drugs. This review helps the clinician learn general principles, practice guidelines, and pharmacologic considerations for medication selection in the pediatric population. Pharmacologic management should be considered in combination with behavior therapy, which is proven to have long-lasting outcomes.

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.

Off-label uses of drugs for depression

The prescription of drugs for depression is rising rapidly. One of the reasons for this trend is their many off-label uses. Up to one third of all prescriptions are for non-indicated use, which in addition to drug repurposing includes different dosing or duration than those recommended. In this review, we elaborate on what antidepressants can treat besides depression. The five classes of drugs for depression are introduced, and their mechanisms of action and serious side effects are described. The most common off-label uses of antidepressants are discussed, with a special focus on treating eating disorders, sleep problems, smoking cessation and managing chronic pain. Depression is often a comorbidity when antidepressants are chosen as therapy, but good therapeutic effects have been observed for other conditions also when depression is not involved. Finally, a new type of antidepressant developed from the hallucinogenic "party drug" ketamine is briefly introduced. This recent development suggests that antidepressants will keep playing a central role in medicine for years to come.

Construction of molecularly imprinted nanoparticles by employing ultrasound waves for selective determination of doxepin from human plasma samples: Modeling and optimization

In this work, molecularly imprinted nanoparticles (MINPs) were applied as selective adsorbent for ultrasound-assisted micro-solid-phase extraction (UAMSPE) of doxepin (DP) from human plasma samples, which was then cleaned up, pre-concentrated and subjected to HPLC. The MINPs were synthesized based on a non-covalent approach by precipitation polymerization utilizing methacrylic acid and styrene as functional monomers, DP as template, ethylene glycol dimethacrylate as cross-linker and 2,2-azobisisobutyronitrile (AIBN) as initiator. The obtained MINPs were characterized by Fourier transform-infrared and field emission scanning electron microscopy. Factors influencing the efficiency of UAMSPE such as sonication time, volume of eluent solvent and amount of sorbent were investigated using a central composite design and the optimal points were identified as 4 min of sonication time, 380 μL of eluent solvent and 30 mg of sorbent. Under optimized conditions, the proposed method has linear responses in the range of 0.2-2000 ng mL^-1 , with a satisfactory limit of detection of 0.04 ng mL^-1 and limit of quantification of 0.11 ng mL^-1 .

Doxepin Mitigates Noise-induced Neuronal Damage in Primary Auditory Cortex of Mice via Suppression of Acid Sphingomyelinase/Ceramide Pathway

Neuronal damage in primary auditory cortex (A1) underlies complex manifestations of noise exposure, prevention of which is critical for health maintenance. Acid sphingomyelinase (ASM) catalyzes generation of ceramide (Cer) which if over-activated mediates neuronal disorders in various diseases. Tricyclic antidepressants (TCAs), by restraining ASM/Cer, benefits multiple neuronal anomalies, so we aimed to elucidate the effect of TCA on noise induced hearing loss and auditory cortex derangement, unraveling mechanism involved. The mice were exposed to noise with frequencies of 20-20 KHz and intensity of 95 dB. Doxepin hydrochloride (DOX), a kind of TCAs, was given intragastrically by 5 mg kg^-1  days^-1 . Morphology of neurons was examined using hematoxylin-eosin (HE) and Nissl staining. Apoptosis was assayed through transferase-mediated dUTP nick end labeling (TUNEL). The content of ASM, Cer or acid ceramidase (AC) was detected by western blot and immunohistochemistry analysis. We demonstrated intense, broad band noise caused upward shift of auditory brainstem response (ABR) threshold to sound over frequencies 4-32 KHz, with prominent morphologic changes and enhanced apoptosis in neurons of primary auditory cortex (A1) (P < 0.05). DOX partly restored noise-caused hearing loss alleviating morphologic changes or apoptosis remarkably (P < 0.05). Both ASM and Cer abundance were elevated significantly by noise which was reversed upon DOX treatment (P < 0.05), but neither noise nor DOX altered AC content. DOX had no influence on hearing, neuronal morphology or ASM/Cer in control mice. Our result suggests DOX palliates noise induced hearing loss and neuronal damage in auditory cortex by correcting over-activation of ASM/Cer without hampering intrinsic behavior of it. Anat Rec, 300:2220-2232, 2017. © 2017 Wiley Periodicals, Inc.

Understanding sleep-wake mechanisms and drug discovery

INTRODUCTION

Although not discernible at first glance, sleep is a highly active and regulated brain state. Although we spend practically one third of our lifetimes in this stage, its importance is often taken for granted. Sleep loss can lead to disease, error and economic loss. Our understanding of how sleep is achieved has greatly advanced in recent years, and with that, the management of sleep disorders has improved. There is still room for improvement and recently many new compounds have reached clinical trials with a few being approved for commercial use. Areas covered: In this review, the authors make the case of sleep disorders as a matter of public health. The mechanisms of sleep transition are discussed emphasizing the wake and sleep promoting interaction of different brain regions. Finally, advances in pharmacotherapy are examined in the context of chronic insomnia and narcolepsy. Expert opinion: The orexinergic system is an example of a breakthrough in sleep medicine that has catalyzed drug development. Nevertheless, sleep is a topic still with many unanswered questions. That being said, the melanin-concentrating hormone system is becoming increasingly relevant and we speculate it will be the next target of sleep medication.

Doxepin inhibits GPVI-dependent platelet Ca2+ signaling and collagen-dependent thrombus formation

Platelet adhesion, activation, and aggregation are essential for primary hemostasis, but are also critically involved in the development of acute arterial thrombotic occlusion. Stimulation of the collagen receptor glycoprotein VI (GPVI) leads to phospholipase Cγ2-dependent inositol triphosphate (IP₃) production with subsequent platelet activation, due to increased intracellular Ca²⁺ concentration ([Ca²⁺]_i). Although tricyclic antidepressants have been shown to potentially impair platelet activation, nothing is hitherto known about potential effects of the tricyclic antidepressant doxepin on platelet Ca²⁺ signaling and thrombus formation. As shown in the present study, doxepin significantly diminished the stimulatory effect of GPVI agonist collagen-related peptide (CRP) on intracellular Ca²⁺ release as well as subsequent extracellular Ca²⁺ influx. Doxepin was partially effective by impairment of CRP-dependent IP₃ production. Moreover, doxepin abrogated CRP-induced platelet degranulation and integrin α_IIbβ₃ activation and aggregation. Finally, doxepin markedly blunted in vitro platelet adhesion to collagen and thrombus formation under high arterial shear rates (1,700^-s). In conclusion, doxepin is a powerful inhibitor of GPVI-dependent platelet Ca²⁺ signaling, platelet activation, and thrombus formation.

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.

Efficacy and safety evaluation of citalopram and doxepin on sleep quality in comorbid insomnia and anxiety disorders

Anxiety disorders are frequently comorbid with insomnia, and sleep disturbance in patients with anxiety disorders is the most common complaint. Antidepressants can affect sleep quality; however, their effect in patients with comorbid insomnia and anxiety disorders is unclear. The aim of the present study was to comprehensively evaluate the dose, treatment duration, treatment efficacy and safety of clinical citalopram and doxepin application in patients with comorbid insomnia and anxiety disorders. It was found that both citalopram (20 mg/day) and low-dose doxepin (12.5 mg/day) significantly improved sleep latency, duration and disturbances, as well as daytime dysfunction and the global Pittsburgh Sleep Quality Index during the 12-week treatment period. Notably, low-dose doxepin significantly improved sleep latency in patients after treatment for 8 and 12 weeks as compared with citalopram. It was further observed that both citalopram and low-dose doxepin improved anxiety. A significant and positive correlation was found between the improvement in the sleep quality and anxiety in the two treatment groups. Citalopram and low-dose doxepin both showed good efficacy and a low adverse reaction rate in the treated patients. These data support a potential application of citalopram and low-dose doxepin in the treatment of patients with comorbid insomnia and anxiety disorders.

Pharmacokinetic and pharmacodynamic evaluation of ramelteon : an insomnia therapy

INTRODUCTION

Ramelteon , a selective melatonin receptor agonist, is the first member of a novel class of hypnotics. It is approved for the treatment of insomnia characterized by sleep onset difficulties in the US and Japan, but not in Europe.

AREAS COVERED

The main clinical properties as well as safety issues of ramelteon are described. Relevant publications reporting ramelteon characteristics and its use in insomnia disorder were identified using PubMed and SciFinder databases up to January 2015. Additional information was collected from the US clinical trials database and from Takeda website.

EXPERT OPINION

Despite its high prevalence and economic burden, insomnia disorder remains mostly untreated. Ramelteon has demonstrated sleep-promoting effects in clinical trials and clinical practice, and it is not associated with the adverse effects typical of other class of hypnotics. Its efficacy appears to be relatively modest compared to current insomnia therapeutics, and its use seems restricted to patients with sleep onset difficulties. Assessment of ramelteon effects on sleep quality and maintenance, daytime function and of improvements in comorbid insomnia conditions deserves further studies. The potential application of ramelteon in other pathological conditions could open the way to novel therapeutic approaches as well as to new market opportunities.

Major depressive disorder: mechanism-based prescribing for personalized medicine

Individual patients with depression present with unique symptom clusters - before, during, and even after treatment. The prevalence of persistent, unresolved symptoms and their contribution to patient functioning and disease progression emphasize the importance of finding the right treatment choice at the onset and the utility of switching medications based on suboptimal responses. Our primary goal as clinicians is to improve patient function and quality of life. In fact, feelings of well-being and the return to premorbid levels of functioning are frequently rated by patients as being more important than symptom relief. However, functional improvements often lag behind resolution of mood, attributed in large part to persistent and functionally impairing symptoms - namely, fatigue, sleep/wake disturbance, and cognitive dysfunction. Thus, patient outcomes can be optimized by deconstructing each patient's depressive profile to its component symptoms and specifically targeting those domains that differentially limit patient function. This article will provide an evidence-based framework within which clinicians may tailor pharmacotherapy to patient symptomatology for improved treatment outcomes.

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.

Orexin receptor antagonists as therapeutic agents for insomnia

Insomnia is a common clinical condition characterized by difficulty initiating or maintaining sleep, or non-restorative sleep with impairment of daytime functioning. Currently, treatment for insomnia involves a combination of cognitive behavioral therapy (CBTi) and pharmacological therapy. Among pharmacological interventions, the most evidence exists for benzodiazepine (BZD) receptor agonist drugs (GABAA receptor), although concerns persist regarding their safety and their limited efficacy. The use of these hypnotic medications must be carefully monitored for adverse effects. Orexin (hypocretin) neuropeptides have been shown to regulate transitions between wakefulness and sleep by promoting cholinergic/monoaminergic neural pathways. This has led to the development of a new class of pharmacological agents that antagonize the physiological effects of orexin. The development of these agents may lead to novel therapies for insomnia without the side effect profile of hypnotics (e.g., impaired cognition, disturbed arousal, and motor balance difficulties). However, antagonizing a system that regulates the sleep-wake cycle may create an entirely different side effect profile. In this review, we discuss the role of orexin and its receptors on the sleep-wake cycle and that of orexin antagonists in the treatment of insomnia.

Antidepressant drugs

Therapeutic Reviews aim to provide essential independent information for health professionals about drugs used in palliative and hospice care. Additional content is available on www.palliativedrugs.com. Country-specific books (Hospice and Palliative Care Formulary USA, and Palliative Care Formulary, British and Canadian editions) are also available and can be ordered from www.palliativedrugs.com. The series editors welcome feedback on the articles (hq@palliativedrugs.com).

What is the role of sedating antidepressants, antipsychotics, and anticonvulsants in the management of insomnia?

Psychiatric medications such as antidepressants, antipsychotics, and anticonvulsants are commonly prescribed by physicians for the off-label use of improving sleep. Reasons for preferential prescription of these medications over FDA-approved insomnia drugs may include a desire to treat concurrent sleep problems and psychiatric illness with a single medication, and/or an attempt to avoid hypnotic drugs due to their publicized side effects. However, there have been few large studies demonstrating the efficacy and safety of most off-label medications prescribed to treat insomnia. In addition, many of these medications have significant known side effect profiles themselves. Here we review the pertinent research studies published in recent years on antidepressant, antipsychotic, and anticonvulsant medications frequently prescribed for sleep difficulties. Although there have been few large-scale studies for most of these medications, some may be appropriate in the treatment of sleep issues in specific well-defined populations.