Zolpidem for insomnia

The interactive walkway provides fit-for-purpose fall-risk biomarkers in the elderly: Comparison of zolpidem and suvorexant

Dynamic balance assessments such as walking adaptability may yield a more realistic prediction of drug-induced falls compared with postural stability measurements, as falls often result from limited gait adjustments when walking. The Interactive Walkway (IWW) measures walking adaptability but sensitivity to medication effects is unknown. If proven sensitive and specific, IWW could serve as a biomarker for targeted fall-risk assessments in early clinical drug development. In this three-way crossover study, 18 healthy elderly (age: 65-80 years) subjects received 5 mg zolpidem, 10 mg suvorexant, or placebo in the morning. Assessments were performed pre-dose and approximately hourly until 9 h post-dose. IWW assessments included an 8-meter walking test, goal-directed stepping, obstacle-avoidance, and tandem-walking. Other pharmacodynamic measurements were the Timed-Up-and-Go (TUG) test at a comfortable and fast pace, adaptive tracking, and body sway. A decline in performance was observed for zolpidem compared with placebo for 3 h post-dose in IWW walking adaptability outcome measures, TUG, adaptive tracking, and body sway. For the IWW tasks, a decrease in walking speed (among others) was observed. IWW parameters were not affected by suvorexant compared with placebo at any timepoint. However, an increase of 9.8% (95%CI: 1.8%, 18.5%) in body sway was observed for suvorexant compared with placebo up to 3 h post-dose. The IWW successfully quantified drug effects of two hypnotic drugs and distinguished between zolpidem and suvorexant regarding their effects on walking. As a biomarker, the IWW demonstrated sensitivity in assessing dynamic balance and potential fall risk in early phase clinical drug development.

Sleep Pathologies and Eating Disorders: A Crossroad for Neurology, Psychiatry and Nutrition

The intricate connection between eating behaviors and sleep habits is often overlooked in clinical practice, despite their profound interdependence. Sleep plays a key role in modulating psychological, hormonal and metabolic balance and exerting an influence on food choices. Conversely, various eating disorders may affect sleep continuity, sometimes promoting the development of sleep pathologies. Neurologists, nutritionists and psychiatrists tend to focus on these issues separately, resulting in a failure to recognize the full extent of the clinical conditions. This detrimental separation can lead to underestimation, misdiagnosis and inappropriate therapeutic interventions. In this review, we aim to provide a comprehensive understanding of the tangled relationship between sleep, sleep pathologies and eating disorders, by incorporating the perspective of sleep experts, psychologists and psychiatrists. Our goal is to identify a practical crossroad integrating the expertise of all the involved specialists.

2023 Guidelines on the Diagnosis and Treatment of Insomnia in Adults - Brazilian Sleep Association

Chronic insomnia disorder (simplified in this document as insomnia) is an increasingly common clinical condition in society and a frequent complaint at the offices of different areas of health practice (particularly Medicine and Psychology). This scenario has been accompanied by a significant evolution in treatment, as well as challenges in approaching patients in an appropriately way. This clinical guideline, coordinated by the Brazilian Sleep Association and the Brazilian Association of Sleep Medicine and counting on the active participation of various specialists in the area, encompasses an update on the diagnosis and treatment of insomnia in adults. To this end, it followed a structured methodology. Topics of interest related to diagnosis were written based on theoretical framework, evidence in the literature, and professional experience. As for the topics related to the treatment of insomnia, a series of questions were developed based on the PICO acronym (P - Patient, problem, or population; I - Intervention; C - Comparison, control, or comparator; O - Outcome). The work groups defined the eligible options within each of these parameters. Regarding pharmacological interventions, only the ones currently available in Brazil or possibly becoming available in the upcoming years were considered eligible. Systematic reviews were conducted to help prepare the texts and define the level of evidence for each intervention. The final result is an objective and practical document providing recommendations with the best scientific support available to professionals involved in the management of insomnia.

Making a 'sex-difference fact': Ambien dosing at the interface of policy, regulation, women's health, and biology

The U.S. Food and Drug Administration's (FDA) 2013 decision to lower recommended Ambien dosing for women has been widely cited as a hallmark example of the importance of sex differences in biomedicine. Using regulatory documents, scientific publications, and media coverage, this article analyzes the making of this highly influential and mobile 'sex-difference fact'. As we show, the FDA's decision was a contingent outcome of the drug approval process. Attending to how a contested sex-difference fact came to anchor elite women's health advocacy, this article excavates the role of regulatory processes, advocacy groups, and the media in producing perceptions of scientific agreement while foreclosing ongoing debate, ultimately enabling the stabilization of a binary, biological sex-difference fact and the distancing of this fact from its conditions of construction.

Designer benzodiazepines: an update

INTRODUCTION

Designer benzodiazepines (DBs) are a subclass of novel psychoactive substances (NPS). DBs mimic the properties of approved and prescribed benzodiazepines.

AREA COVERED

A systematic search of literature on DB classification, structure-activity relationships, pharmacologic properties, and adverse effects.

EXPERT OPINION

The prevalence of DB use has increased substantially over the last decade. All DBs are full-agonist ligands at the gamma-aminobutyric acid type A-benzodiazepine (GABA_A-BZ) receptor system. This is not surprising, since DBs largely represent either minor structural modifications, or well-recognized active metabolites, of existing approved benzodiazepines. As such, the pharmacologic profile and associated risks and hazards of DBs are similar or identical to clinically approved and legitimately prescribed benzodiazepines, most of which have been in use for decades. Concurrent use of DBs along with other abusable or recreational drugs (alcohol, opioids, cocaine, stimulants, hallucinogens, other sedative-hypnotics) represents the principal public health risk. The increasing illicit availability and use of DBs is of concern and requires regulatory attention, but DBs do not rank highly among designer psychotropic agents in terms of health risk to humans.

Imidazopyridine, a promising scaffold with potential medicinal applications and structural activity relationship (SAR): recent advances

Imidazopyridine scaffold has gained tremendous importance over the past few decades. Imidazopyridines have been expeditiously used for the rationale design and development of novel synthetic analogs for various therapeutic disorders. A wide variety of imidazopyridine derivatives have been developed as potential anti-cancer, anti-diabetic, anti-tubercular, anti-microbial, anti-viral, anti-inflammatory, central nervous system (CNS) agents besides other chemotherapeutic agents. Imidazopyridine heterocyclic system acts as a key pharmacophore motif for the identification and optimization of lead structures to increase medicinal chemistry toolbox. The present review highlights the medicinal significances of imidazopyridines for their rationale development as lead molecules with improved therapeutic efficacies. This review further emphasis on the structure-activity relationships (SARs) of the various designed imidazopyridines to establish a relationship between the key structural features versus the biological activities.Communicated by Ramaswamy H. Sarma.

Zolpidem use and risk of suicide: A systematic review and meta-analysis

INTRODUCTION

Zolpidem is one of the most commonly prescribed nonbenzodiazepine hypnotic drugs for insomnia. Published epidemiological studies linked zolpidem with the risk of suicide. However, to date, no meta-analysis investigated this association. Hence, we systematically reviewed and meta-analysed the current evidence from real-world studies reporting the risk of suicide with the use of zolpidem.

METHODS

Medline (Ovid), Embase (Ovid), and PsycINFO databases were searched from inception till June 2021 for real-world evidence studies reporting the risk of suicide with the use of zolpidem. The quality assessment of included studies was assessed using the New-Castle Ottawa Scale (NOS). Random-effect meta-analysis was performed using a generic inverse variance method.

RESULTS

This meta-analysis was based on four studies with 344,753 participants, of which 42,279 were zolpidem users. The methodological quality of all the included studies was of high quality. A significantly increased risk of suicide or suicide attempt was found in zolpidem users compared to non-users, with a pooled relative risk of 1.88 (95% CI: 1.54 - 2.30). Furthermore, an increased risk of suicidal death was observed in zolpidem users compared to non-users, with a pooled relative risk of 1.82 (95% CI: 1.43 - 2.30). Dose-response analysis also revealed a significantly increased risk of suicide in patients receiving ≥ 180cDDD (cumulative defined daily doses) of zolpidem (124 times), followed by 90-179cDDD (113 times) and <90cDDD (93 times) of zolpidem compared to non-users.

CONCLUSION

In conclusion, zolpidem use was associated with an increased risk of suicide or suicide attempt and suicidal death. Therefore, careful prescribing practices must be followed by considering the risk-benefit profile.

Impact of Hypnotic Drug Zolpidem Tartrate on the Development of Forensic Fly Sarcophaga ruficornis (Diptera: Sarcophagidae)

The flesh fly Sarcophaga ruficornis (Fabricius) is one of the fly species of significant medical and forensic importance since it is one of the most common flesh flies used in forensic investigations. Zolpidem tartrate is a sedative-hypnotic drug used for the short-term treatment of insomnia in adults and its use has been implicated in many suicide cases worldwide. Fresh chopped liver of buffalo Bubalus bubalis (Artiodactyla: Bovidae) containing different concentrations of Zolpidem tartrate was given to S. ruficornis larvae to evaluate the effect of Zolpidem tartrate on the developmental rate of the different stages, life cycle duration, and the morphological parameters. The findings have shown significant variation in the time required for the different developmental stages and total life cycle duration, which correlated positively with the Zolpidem tartrate concentration in different cultures. Compared to the control, the morphological parameters were negatively correlated with the concentration of Zolpidem tartrate in the treated cultures. The obtained results indicate that the Zolpidem tartrate retards larval development and alters the estimation of the total developmental duration. Thus, when Zolpidem tartrate may be the cause of death, the entomological evidence needs to be analyzed so it takes zolpidem-related changes to the mPMI into account.

Association of Zolpidem With Increased Mortality in Patients With Brain Cancer: A Retrospective Cohort Study Based on the National Health Insurance Service Database

Background and Purpose

Zolpidem is one of the most common hypnotics prescribed to treat insomnia worldwide. However, there are numerous reports of a positive association between zolpidem and mortality, including an association with increased cancer-specific mortality found in a Taiwanese cohort study. This study aimed to determine the association between zolpidem use and brain-cancer-specific mortality in patients with brain cancer.

Methods

This population-based, retrospective cohort study analyzed data in the National Health Insurance Service database. All incident cases of brain cancer at an age of ≥18 years at the time of brain cancer diagnosis over a 15-year period (2003–2017) were included. A multivariate Cox regression analysis after adjustment for covariables was performed to evaluate the associations of zolpidem exposure with brain-cancer-specific and all-cause mortality.

Results

This study identified 38,037 incident cases of brain cancer, among whom 11,823 (31.1%) patients were exposed to zolpidem. In the multivariate Cox regression model, the brain-cancer-specific mortality rate was significantly higher in patients who were prescribed zolpidem than in those with no zolpidem prescription (adjusted hazard ratio [HR]=1.14, 95% confidence interval [CI]=1.08–1.21, p<0.001). Zolpidem exposure was significantly associated with increased brain-cancer-specific mortality after adjustment in younger adults (age 18–64 years; adjusted HR=1.37, 95% CI=1.27–1.49) but not in older adults (age ≥65 years; adjusted HR=0.94, 95% CI=0.86–1.02).

Conclusions

Zolpidem exposure was significantly associated with increased brain-cancer-specific mortality in patients with brain cancer aged 18–64 years. Further prospective studies are warranted to understand the mechanism underlying the effect of zolpidem on mortality in patients with brain cancer.

The efficacy and safety of zolpidem and zopiclone to treat insomnia in Alzheimer's disease: a randomized, triple-blind, placebo-controlled trial

No prior studies have evaluated the efficacy and safety of zolpidem and zopiclone to treat insomnia of demented patients. This randomized, triple-blind, placebo-controlled clinical trial used these drugs to treat patients with probable, late onset Alzheimer's dementia (AD) (DSM V and NINCDS-ADRDA criteria) exhibiting insomnia (DSM V criteria and nocturnal NPI scores ≥ 2). Actigraphic records were performed for 7 days at baseline and for 14 days during the treatment period in 62 patients aged 80.5 years in average and randomized at a 1:1:1 ratio for administration of zolpidem 10 mg/day, zopiclone 7.5 mg/day or placebo. Primary endpoint was the main nocturnal sleep duration (MNSD), whereas secondary outcomes were the proportion of the night time slept, awake time after sleep onset (WASO), nocturnal awakenings, total daytime sleep time and daytime naps. Cognitive and functional domains were tested before and after drug/placebo use. Three participants under zopiclone use had intervention interrupted due to intense daytime sedation and worsened agitation with wandering. Zopiclone produced an 81 min increase in MNSD (95% confidence interval (CI): -0.8, 163.2), a 26 min reduction in WASO (95% CI: -56.2, 4.8) and a 2-episode decrease in awakening per night (95% CI: -4.0, 0.4) in average compared to placebo. Zolpidem yielded no significant difference in MNSD despite a significant 22 min reduction in WASO (95% CI: -52.5, 8.3) and a reduction of 1 awakening each night (95% CI: -3.4, 1.2) in relation to placebo. There was a 1-point reduction in mean performance in the symbols search test among zolpidem users (95% CI: -4.1, 1.5) and an almost eight-point reduction in average scores in the digit-symbol coding test among zopiclone users (95% CI: -21.7, 6.2). In summary, short-term use of zolpidem or zopiclone by older insomniacs with AD appears to be clinically helpful, even though safety and tolerance remain issues to be personalized in healthcare settings and further investigated in subsequent trials. This trial was registered in ClinicalTrials.gov Identifier: NCT03075241.

Efficacy of the triple-combination SM-1 in a 5-h phase advance transient insomnia model

Thomas Dahl, PO Box 404, Guilford, CT 06437 USA. Email: tadahl@outlook.com. The objectives of the study were to demonstrate the efficacy and safety of SM-1 in a circadian challenge model of transient insomnia. Randomized, double-blind, placebo-controlled cross-over study utilizing a 5-h phase advance model of transient insomnia. Subjects were 85 healthy adults reporting a history of transient insomnia, with an average age of 38.9 years. Both SM-1 and placebo were administered to all subjects in a randomly assigned sequence, with at least 1 week between treatments. The primary endpoint was total sleep time determined by polysomnography. Secondary endpoints included wakefulness after sleep onset, latency to persistent sleep, number of awakenings, subjective total sleep time and subjective sleep onset latency, total sleep time by quarters of the night, subjective number of awakenings, and sleep quality. Safety endpoints included adverse events, Karolinska Sleepiness Scale, Digit Symbol Substitution Test, and predischarge evaluation (tandem gait and Romberg tests). SM-1 provided an increase of 94.4 min in total sleep time over placebo (p < 0.0001). Wakefulness after sleep onset, subjective total sleep time, subjective sleep onset latency, and total sleep time in the first quarter of the night also showed significant improvement. SM-1 was well-tolerated with both type and frequency of adverse events being comparable to placebo, and no residual sleepiness upon awakening (i.e., after 8 h). SM-1 provided a robust and statistically significant increase in total sleep time compared to placebo in a circadian model of transient insomnia, without evidence of next-day impairment.

Efficacy and safety of Zolpidem in the treatment of insomnia disorder for one month: a meta-analysis of a randomized controlled trial

SUBJECT

A meta-analysis of a randomized placebo-controlled trial was used to evaluate the effectiveness and safety of Zolpidem in the treatment of insomnia disorder for one month.

METHOD

Searched from PubMed, EMBASE, MEDLINE, PsycINFO, Cochrane Central Register of Controlled Trials and web of science from inception to May 13, 2021. In addition, we also searched ClinicalTrials.gov trials register to obtain relevant research and related data. Include all randomized controlled trials that meet the criteria. The primary efficacy outcome were total sleep time and sleep latency. The secondary outcome was wake-time after sleep onset. And to evaluate the safety of Zolpidem in the treatment of insomnia.

RESULTS

Total of 6 randomized placebo-controlled trials involving 1068 patients with insomnia disorder were included in our study. Our analysis results showed that compared with placebo, zolpidem treatment for one month was more effective in increasing the total sleep time of patients with insomnia disorder, reducing sleep latency and improving sleep quality. There was no significant statistical difference between the two groups in the amount of change in the wake after sleep onset. Meanwhile, there was no significant statistical difference in adverse events between Zolpidem and placebo after one month of treatment.

CONCLUSION

Our meta-analysis showed that zolpidem is an effective and safe therapy option to treat insomnia disorder for one month. However, when using zolpidem to treat insomnia, its effect on sleep structure should be considered. In the future, large-scale clinical trials are needed to compare the effectiveness and safety of zolpidem in the treatment of insomnia from subjective and objective indicators combined with zolpidem on sleep structure.

Catalyst-free, visible-light-induced direct radical cross-coupling perfluoroalkylation of the imidazo[1,2-a]pyridines with perfluoroalkyl iodides

A mild and eco-friendly visible-light-induced direct radical cross-coupling perfluoroalkylation of the imidazo[1,2-a]pyridines with perfluoroalkyl iodides was established.

Relationship between plasma exposure of zolpidem and CYP2D6 genotype in healthy Korean subjects

Zolpidem, a widely prescribed hypnotic agent, is extensively metabolized by cytochrome P450 (CYP) 3A4, and CYP2C9, CYP1A2 and CYP2D6 are also involved in the metabolism of zolpidem. The aim of the study was to investigate the effects of CYP2D6 genotypes on the exposure of zolpidem. The healthy male volunteers were divided into three different genotype groups (CYP2D6*wt/*wt [*wt = *1 or *2], CYP2D6*wt/*10, and CYP2D6*10/*10). Each subject received a single oral dose of zolpidem 5 mg with or without a steady-state concentration of clarithromycin (a potent inhibitor of CYP3A4), and plasma concentrations of zolpidem were measured up to 12 h after zolpidem dosing by using liquid chromatography-tandem mass spectrometry method. When zolpidem was administered alone, the exposure of zolpidem (the total areas under the curve and the mean peak plasma concentrations) was not significantly different among three different genotype groups. Even with the steady-state concentration of clarithromycin, a potent CYP3A4 inhibitor, there were no significant differences in the exposure of zolpidem in relation to CYP2D6 genotypes.

More than a quarter century of the most prescribed sleeping pill: Systematic review of zolpidem use by older adults

Zolpidem is widely used to treat insomnia of older adults despite that few randomized controlled studies were conducted in this group. We systematically reviewed the relevant literature on efficacy/effectiveness and safety of zolpidem use by elderly individuals in relevant databases completed with a manual search of key journals. Studies were required to include individuals aged ≥60 years under intervention with zolpidem compared to placebo or other hypnosedatives. Outcomes were either objectively- or subjectively-assessed improvements in specific sleep parameters and safety for clinical use. The 31 reports selected for review were mostly of low-quality. The evidence suggests that zolpidem is useful typically by reducing sleep latency and episodes of wake after sleep onset, and increasing total sleep time and sleep efficiency. Regarding safety and tolerability, analyses suggest a low risk of daytime sleepiness and of deleterious effects on memory or psychomotor performance, provided that recommended dosage and precautions are followed. Few retrospective studies associate zolpidem use with risk of falls, fractures, dementia, cancer, and stroke. Zolpidem appears effective at lower doses and for short-term treatment among the elderly. Rigorous, new clinical trials are warranted to further document the specific effects of zolpidem in older individuals.

Temporal association between zolpidem medication and the risk of suicide: A 12-year population-based, retrospective cohort study

There have been concerns about abuse and unnecessary chronic administration of zolpidem, and zolpidem's relation to suicide risk. To investigate the temporal association of zolpidem with the risk of suicide, we conducted a 12-year, population-based, retrospective cohort study on the National Health Insurance Service-National Sample Cohort (NHIS-NSC), South Korea. Data were collected from 2002 to 2013 from the NHIS-NSC, and data cleaning was performed for 1,125,691 subjects. Cox proportional hazards regression analysis was used to investigate the correlation over time between zolpidem medication and suicide. Over intervals commencing after 80 months of observation, the adjusted hazard ratio of suicides associated with the use of the zolpidem was 2.01 (95% CI: 1.58-2.56; p < 0.001). The mean cumulative number of days of zolpidem prescription was significantly longer in the suicide group than in the non-suicide group after log-transformation (p = 0.005). Cases of chronic use of zolpidem (over six months or one year) were significantly more common in the suicide group compared to the non-suicide group (p = 0.002 and 0.005, respectively). Subjects who received zolpidem medication had a significantly higher risk of suicide after at least 80 months of observation, suggesting a long-term increased suicide risk associated with insomnia exposed to zolpidem medication.

Sublingual and oral zolpidem for insomnia disorder: a 3-month randomized trial

Objective:

To evaluate the safety and efficacy of a 5 mg sublingual dose of zolpidem, compared to a 10 mg oral dose, at bedtime and “as needed” following middle-of-the-night awakenings.

Methods:

Participants were randomized into an oral group (oral zolpidem 10 mg and sublingual placebo at bedtime and “as-needed”) and a sublingual group (oral placebo and sublingual zolpidem 5 mg at bedtime and “as-needed”). Participants underwent medical evaluation, polysomnography, the psychomotor vigilance test, and completed questionnaires.

Results:

Of 85 patients, 67 met the criteria for insomnia (48±10 years; 79% women) and were randomized. Of these, 46 completed 92±5 days of treatment. Mild-to-moderate adverse events were reported by 25% of the participants, including headache, sleepiness, and dizziness. Both treatments decreased middle-of-the-night awakenings by an average of -3.1±2.3 days/week and increased total sleep time by 1.5 hours. Changes in sleep quality and insomnia severity scores were also favorable and comparable between groups: variation depended on continuation of treatment. Regarding PSG findings, sleep latency decreased more in the sublingual group than the oral group (-14±42 vs. 10±29 min; p = 0.03). The psychomotor vigilance test showed minor residual effects 30 minutes after awakening, which reversed after 2 hours.

Conclusions:

The safety and efficacy of both zolpidem formulations are comparable. The sublingual 5 mg dose induced sleep more rapidly.

Clinical trial registration:

NCT01896336

Efficacy of SM-1 in a transient insomnia model

OBJECTIVES

The objectives of this study were primarily to assess the efficacy and safety of SM-1 in a circadian challenge model of transient insomnia and secondarily, to assess the contribution of diphenhydramine to the combination.

METHODS

Randomized, double-blind, placebo-controlled three-way cross-over study with a 5-hr phase advance. Subjects were 39 healthy adults reporting a history of transient insomnia. All treatments (SM-1, SM-1 without diphenhydramine, or placebo) were administered to all subjects in a randomly assigned sequence, with at least 1 week between treatments. The primary endpoint was total sleep time (TST) determined by polysomnography. Secondary endpoints included wakefulness after sleep onset (WASO), latency to persistent sleep, number of awakenings (NAW), subjective TST (sTST) and sleep latency (sSL), TST, and NAW by quarters of the night and sleep quality. Safety endpoints included adverse events, Karolinska Sleepiness Scale digit symbol substitution test, and subject-reported alertness level.

RESULTS

SM-1 provided an increase of 126.7 min in TST over placebo (p < .001). WASO, sTST, sleep quality, and sSL also showed significant improvement. Diphenhydramine demonstrated a significant (p = .014) contribution of 43.7 min to TST. SM-1 was well-tolerated with type and frequency of adverse events comparable with placebo, and no residual sleepiness upon awakening after 8 hr.

CONCLUSIONS

SM-1 provided a robust and statistically significant increase in TST compared with placebo in a circadian model of transient insomnia, without evidence of next-day impairment. Diphenhydramine contributed to the effect.

Pharmacodynamic and pharmacokinetic profile of SM-1, a triple-drug combination to increase total sleep time

OBJECTIVE

The primary objective was to characterize the pharmacokinetics and pharmacodynamics of SM-1 after administration of a single oral dose to healthy volunteers in a placebo-controlled double-blind trial of daytime sedation. Secondary objectives were to determine the onset, duration, and offset of the sedative effects using subjective and objective measures of sedation. Safety and tolerability of SM-1 were also investigated.

METHODS

Males and females 18-45 years of age received SM-1, a combination drug product comprised of diphenhydramine, zolpidem (delayed release), and lorazepam (delayed release). The pharmacokinetic profile of each drug was determined from blood samples. Sedative effects were assessed by visual analog scale, digit symbol substitution test, memory test, and quantitative electroencephalography.

RESULTS

Similar number and severity of adverse events were observed following administration of SM-1 and placebo. Onset of sedation, as determined by subjective, performance, and electroencephalography measures, occurred 0.5-1 hr postdose, lasting about 7-7.5 hr. Plasma concentration curves for the two delayed-release components were altered compared with published data for unmodified drugs. Exposure values obtained with the combination product were in good agreement with published values of the drugs given individually.

CONCLUSIONS

SM-1 was well tolerated and has pharmacologic activity starting within an hour of ingestion, lasting approximately 7-8 hr. Sedative activity was seen with subjective, psychomotor, and electroencephalography assays.

GABA Receptors and the Pharmacology of Sleep

Current GABAergic sleep-promoting medications were developed pragmatically, without making use of the immense diversity of GABA_A receptors. Pharmacogenetic experiments are leading to an understanding of the circuit mechanisms in the hypothalamus by which zolpidem and similar compounds induce sleep at α2βγ2-type GABA_A receptors. Drugs acting at more selective receptor types, for example, at receptors containing the α2 and/or α3 subunits expressed in hypothalamic and brain stem areas, could in principle be useful as hypnotics/anxiolytics. A highly promising sleep-promoting drug, gaboxadol, which activates αβδ-type receptors failed in clinical trials. Thus, for the time being, drugs such as zolpidem, which work as positive allosteric modulators at GABA_A receptors, continue to be some of the most effective compounds to treat primary insomnia.

Sleep modulating agents

Sleep and wake are two fundamental states of human existence. Conditions such as insomnia and hypersomnia can have profound negative effects on human health. Many pharmacological interventions impacting sleep and wake are available or are under development. This brief digest surveys early approaches to sleep modulation and highlights recent developments in sleep modulating agents.

Zolpidem and Gender: Are Women Really At Risk?

BACKGROUND

In 2013 the Food and Drug Administration (FDA) claimed the existence of new data showing women to be at risk for excessive daytime sedation and impaired driving proficiency following bedtime doses of zolpidem. The putative explanation was the reduced metabolic clearance of zolpidem and higher morning blood concentrations in women compared to men. The FDA acted to reduce the recommended dosage for women down to 50% of the dose for men. No other regulatory agency worldwide has taken similar action.

METHODS

Gender effects on zolpidem pharmacokinetics, pharmacodynamics, adverse effects, clinical efficacy, and driving performance were evaluated through a further analysis of data from a previous study, together with a literature review.

RESULTS

Women had on average 35% lower apparent clearance of zolpidem than men (236 vs 364 mL/min, P < 0.001). This difference was not explained by body weight. In some laboratory studies, women had greater functional impairment than men taking the same dose, but in all studies active drug was not distinguishable from placebo at 8 hours after oral dosage. On-the-road driving studies likewise showed no evidence of driving impairment in men or women at 8 hours after 10 mg of oral immediate-release zolpidem. No clinical trial demonstrated a gender-related difference in clinical efficacy or adverse reactions, and there was no evidence of a particular risk to women.

CONCLUSIONS

Dosage reduction in women is not supported by available scientific evidence, and may in fact lead to underdosing and the consequent hazard of inadequately treated insomnia.

Comparative single-dose bioavailability study of two 10 mg Zolpidem tablet formulations in healthy volunteers

Zolpidem is a hypnotic agent with a chemical structure unrelated to benzodiazepines, barbiturates, pyrrolopyrazines, pyrazolopyrimidines or other drugs with known hypnotic properties. Zolpidem as conventional tablets is used as a hypnotic agent in the short-term management of insomnia, generally for periods not exceeding 7–10 days in duration. The objective of this study was to evaluate and compare the relative bioavailability, and therefore the bioequivalence of Zolpidem 10 mg test formulation versus a reference Zolpidem 10 mg formulation, following a single dose administration under fasting conditions The study was a single center, open, single dose, randomized, two - way crossover study in healthy male volunteers with a wash - out period of one week between study periods. Twenty-eight male healthy volunteers, aged 20-49 years were included into study. Blood samples for determination of zolpidem plasma concentrations were withdraw at 0 (pre-drug administration), 0.33, 0.66, 1, 1.33, 1.66, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 12, 16 and 24 hours post-drug. The zolpidem concentrations in plasma were determined with HPLC, using fluorescence detection. The test formulation of zolpidem, dosed at 10 mg is bioequivalent for primary zolpidem parameters (Cmax, AUC0-t and AUC0-∞) to the reference formulation after a single oral administration of 10 mg zolpidem. Both medications are well tolerated with no serious adverse events. Thus, in view of the clinical use, both formulations are exchangeable without restrictions. Keywords: Zolpidem, bioavailability, bioequivalence study, single-dose

The influences of CYP2C9*1/*3 genotype on the pharmacokinetics of zolpidem

Zolpidem is predominantly metabolized by CYP3A4, and to a lesser extent by CYP2C9, CYP1A2, CYP2D6 and CYP2C19. The aim of this study was to identify the effects of CYP2C9*3 allele on the pharmacokinetics of zolpidem. Healthy male subjects were divided into two genotype groups, CYP2C9*1/*1 and CYP2C9*1/*3. They received a single oral dose of 5 mg zolpidem, and the plasma concentrations of zolpidem were determined up to 12 h after drug administration. In addition, since zolpidem is metabolized at a high rate by CYP3A4, the effect of CYP2C9*3 allele on the pharmacokinetics of zolpidem was also observed in the condition where CYP3A4 was sufficiently inhibited by the steady-state concentration of clarithromycin, a potent CYP3A4 inhibitor. For this, clarithromycin 500 mg was administered twice daily for 5 days. Plasma concentrations of zolpidem were determined using liquid chromatography-tandem mass spectrometry method. The overall pharmacokinetic parameters of zolpidem were not significantly different between two CYP2C9 genotypes. Even with the potent CYP3A4 inhibitor clarithromycin present at steady-state concentrations, there were no significant differences in the exposure of zolpidem, except for elimination half-life (t_1/2). In conclusion, our study suggests that CYP2C9*1/*3 genotype does not affect the plasma exposure of zolpidem.

Effects of genetic polymorphisms of CYP2C19 on the pharmacokinetics of zolpidem

Zolpidem is indicated for the short-term treatment of insomnia and it is predominantly metabolized by CYP3A4, and to a lesser extent by CYP2C19, CYP1A2, and CYP2C9. Therefore, we evaluated the effects of CYP2C19 genetic polymorphisms on the pharmacokinetics of zolpidem in healthy male subjects. Thirty-two male subjects were recruited and all subjects were classified into three groups according to their genotypes: CYP2C19EM (CYP2C19*1/*1, n = 12), CYP2C19IM (CYP2C19*1/*2 or *1/*3, n = 10), and CYP2C19PM (CYP2C19*2/*2, *2/*3 or *3/*3, n = 10). The pharmacokinetic parameters of zolpidem were compared in three CYP2C19 genotype groups after zolpidem administration with or without a CYP3A4 inhibitor at steady-state concentration. Plasma concentrations of zolpidem were determined up to 12 h after drug administration by liquid chromatography-tandem mass spectrometry method. The maximum plasma concentration (C_max) differed, but mean total area under the plasma concentration-time curve (AUC_inf), half-life (t_1/2), and apparent oral clearance (CL/F) of zolpidem administered alone did not significantly differ among the three different CYP2C19 genotype groups. Furthermore, when zolpidem was administered with a CYP3A4 inhibitor at steady-state concentration, there were no significant differences in any of the pharmacokinetic parameters of zolpidem in relation to CYP2C19 genotypes. In conclusion, we did not find any evidence for the impact of CYP2C19 genetic polymorphisms on the pharmacokinetic parameters of zolpidem.

Neuroprotective effect of zolpidem against glutamate-induced toxicity is mediated via the PI3K/Akt pathway and inhibited by PK11195

Excitotoxicity is a pathological process in which neuronal dysfunction and death are induced by excessive glutamate stimulation, the major fast excitatory neurotransmitter in the mammalian brain. Excitotoxicity-induced neurodegeneration is a contributing factor in ischemia-induced brain damage, traumatic brain injury, and various neurodegenerative diseases. It is triggered by calcium overload due to prolonged over-activation of ionotropic N-methyl-d-aspartate (NMDA) receptors. Enhanced Ca²⁺ release results in neuronal vulnerability through several intertwined mechanisms, including activation of proteolytic enzymes, increased production of reactive oxygen species (ROS), mitochondrial dysfunction and modulation of intracellular signalling pathways. We investigated the neuroprotective effect of hypnotic zolpidem, a drug that exerts its central effects at the GABA_A receptor complex, against glutamate-induced toxicity in P19 neurons. Zolpidem prevented death of P19 neurons exposed to glutamate, and abolished the glutamate-induced increase in ROS production, p53 and Bax expression, and caspase-3/7 activity. Zolpidem effects were mediated by marked over-activation of Akt kinase. The pro-survival effect, as well as the pAkt induction, were prevented in the presence of wortmannin, an inhibitor of phosphatidylinositol-3-kinase (PI3K) that functions upstream of Akt. The beneficial effect of zolpidem on neuronal survival was not prevented by flumazenil, a GABA_A receptor antagonist. PK11195, a drug that modulates the mitochondrial translocator protein 18 kDa (TSPO) and F₀F₁-ATPase, prevented the beneficial effect of zolpidem, indicating that the mechanism of zolpidem action involves preservation of mitochondrial function and integrity. Zolpidem effects were further mediated by prevention of glutamate-induced increase in the expression of the NR2B subunit of NMDA receptor. The obtained results suggest the promising therapeutic potential of zolpidem against excitotoxic insults and highlight the importance of mitochondria and the Akt pathway as valuable targets for therapeutic interventions in glutamate-mediated neuropathological conditions.

Sleep and Sedative States Induced by Targeting the Histamine and Noradrenergic Systems

Sedatives target just a handful of receptors and ion channels. But we have no satisfying explanation for how activating these receptors produces sedation. In particular, do sedatives act at restricted brain locations and circuitries or more widely? Two prominent sedative drugs in clinical use are zolpidem, a GABA_A receptor positive allosteric modulator, and dexmedetomidine (DEX), a selective α2 adrenergic receptor agonist. By targeting hypothalamic neuromodulatory systems both drugs induce a sleep-like state, but in different ways: zolpidem primarily reduces the latency to NREM sleep, and is a controlled substance taken by many people to help them sleep; DEX produces prominent slow wave activity in the electroencephalogram (EEG) resembling stage 2 NREM sleep, but with complications of hypothermia and lowered blood pressure—it is used for long term sedation in hospital intensive care units—under DEX-induced sedation patients are arousable and responsive, and this drug reduces the risk of delirium. DEX, and another α2 adrenergic agonist xylazine, are also widely used in veterinary clinics to sedate animals. Here we review how these two different classes of sedatives, zolpidem and dexmedetomideine, can selectively interact with some nodal points of the circuitry that promote wakefulness allowing the transition to NREM sleep. Zolpidem enhances GABAergic transmission onto histamine neurons in the hypothalamic tuberomammillary nucleus (TMN) to hasten the transition to NREM sleep, and DEX interacts with neurons in the preoptic hypothalamic area that induce sleep and body cooling. This knowledge may aid the design of more precise acting sedatives, and at the same time, reveal more about the natural sleep-wake circuitry.

The Association Between the Use of Zolpidem and the Risk of Alzheimer's Disease Among Older People

OBJECTIVES

To evaluate the association between zolpidem use and the risk of Alzheimer's disease among older people.

DESIGN

A retrospective cohort study using data from 2001 to 2011 from the National Health Insurance Research Database.

SETTING

Taiwan.

PARTICIPANTS

A total of 6,922 patients aged 65 years or older enrolled from January 2002 to December 2004 (the enrollment period).

INTERVENTION (EXPOSURE)

Zolpidem users were identified as patients who used zolpidem during the enrollment period. The index date was the date of the first zolpidem prescription. Dosage of zolpidem use was defined using cumulative defined daily dose (cDDD) based on the cumulative dosage that patients took within one year after the index date (grouped as: less than 28, 28-90, 91-180, and more than 180 cDDD).

MEASUREMENTS

The occurrence of Alzheimer's disease was defined as the time period from the end of one year after the index date to the date of the Alzheimer's disease diagnosis. The propensity score was used to adjust the measured confounders of Alzheimer's disease. Cox proportional hazards models were used to evaluate the association between zolpidem use and the incidence of Alzheimer's disease.

RESULTS

Zolpidem users with a high cumulative dose (>180 cDDD) in the first year after initiation had a significantly greater risk of Alzheimer's disease than non-zolpidem users (HR = 2.97, 95% CI = 1.61-5.49) and low cumulative dose (<28 cDDD) users (HR = 4.18, 95% CI = 1.77-9.86).

CONCLUSION

We found the use of a high cumulative dose of zolpidem was associated with an increased risk of Alzheimer's disease among older people living in Taiwan. It is advised to use caution when considering long-term use of zolpidem in older patients.

Orexin OX2 Receptor Antagonists as Sleep Aids

The discovery of the orexin system represents the single major progress in the sleep field of the last three to four decades. The two orexin peptides and their two receptors play a major role in arousal and sleep/wake cycles. Defects in the orexin system lead to narcolepsy with cataplexy in humans and dogs and can be experimentally reproduced in rodents. At least six orexin receptor antagonists have reached Phase II or Phase III clinical trials in insomnia, five of which are dual orexin receptor antagonists (DORAs) that target both OX1 and OX2 receptors (OX2Rs). All clinically tested DORAs induce and maintain sleep: suvorexant, recently registered in the USA and Japan for insomnia, represents the first hypnotic principle that acts in a completely different manner from the current standard medications. It is clear, however, that in the clinic, all DORAs promote sleep primarily by increasing rapid eye movement (REM) and are almost devoid of effects on slow-wave (SWS) sleep. At present, there is no consensus on whether the sole promotion of REM sleep has a negative impact in patients suffering from insomnia. However, sleep onset REM (SOREM), which has been documented with DORAs, is clearly an undesirable effect, especially for narcoleptic patients and also in fragile populations (e.g. elderly patients) where REM-associated loss of muscle tone may promote an elevated risk of falls. Debate thus remains as to the ideal orexin agent to achieve a balanced increase in REM and non-rapid eye movement (NREM) sleep. Here, we review the evidence that an OX2R antagonist should be at least equivalent, or perhaps superior, to a DORA for the treatment of insomnia. An OX2R antagonist may produce more balanced sleep than a DORA. Rodent sleep experiments show that the OX2R is the primary target of orexin receptor antagonists in sleep modulation. Furthermore, an OX2R antagonist should, in theory, have a lower narcoleptic/cataplexic potential. In the clinic, the situation remains equivocal, since OX2R antagonists are in early stages: MK-1064 has completed Phase I, and MIN202 is currently in clinical Phase II/III trials. However, data from insomnia patients have not yet been released. Promotional material suggests that balanced sleep is indeed induced by MIN-202, whereas in volunteers MK-1064 has been reported to act similarly to DORAs.

Effect of zolpidem on functional recovery in a rat model of ischemic stroke

Objective

To evaluate the effects of zolpidem on functional recovery in a rat model of acute ischemic stroke.

Methods

Following ischemic stroke procedures, 42 rats (six in each group) were randomly assigned to receive zolpidem (0.1, 0.25, 0.5, 1.0, 2.0 or 4.0 mg/kg) or normal saline administer intraperitoneally once daily for two weeks. Motor behavioural index (MBI) scores, radial 8-arm maze (RAM) test times and brain MRI scans were obtained 24 hours (Day 1) and two weeks (Day 14) post-procedure. Immunohistochemistry was performed on Day 14.

Results

By comparison with the normal saline group, the 0.5 and 1.0 mg/kg zolpidem groups showed statistically significant improvements in MBI scores and increased numbers of brain-derived neurotrophic factor (BDNF) stained cells over the two week dosing period. By contrast, the 4.0 mg/kg zolpidem group had statistically significantly impaired MBI scores compared with the control group. No differences among groups were found in RAM times or infarction volumes.

Conclusions

This study in a rat model showed that 0.5–1.0 mg/kg of zolpidem had beneficial effects on behavioural recovery by enhancing neural plasticity without causing any memory impairment in acute ischemic stroke.

Sex in Context: Limitations of Animal Studies for Addressing Human Sex/Gender Neurobehavioral Health Disparities

Many brain and behavioral disorders differentially affect men and women. The new National Institutes of Health requirement to include both male and female animals in preclinical studies aims to address such health disparities, but we argue that the mandate is not the best solution to this problem. Sex differences are highly species-specific, tied to the mating system and social ecology of a given species or even strain of animal. In many cases, animals poorly replicate male-female differences in brain-related human diseases. Sex/gender disparities in human health have a strong sociocultural component that is intimately entangled with biological sex and challenging to model in animals. We support research that investigates sex-related variables in hypothesis-driven studies of animal brains and behavior. However, institutional policies that require sex analysis and give it special salience over other sources of biological variance can distort research. We caution that the costly imposition of sex analysis on nearly all animal research entrenches the presumption that human brain and behavioral differences are largely biological in origin and overlooks the potentially more powerful social, psychological, and cultural contributors to male-female neurobehavioral health gaps.

Bottom-Up versus Top-Down Induction of Sleep by Zolpidem Acting on Histaminergic and Neocortex Neurons

Zolpidem, a GABA_A receptor-positive modulator, is the gold-standard drug for treating insomnia. Zolpidem prolongs IPSCs to decrease sleep latency and increase sleep time, effects that depend on α2 and/or α3 subunit-containing receptors. Compared with natural NREM sleep, zolpidem also decreases the EEG power, an effect that depends on α1 subunit-containing receptors, and which may make zolpidem-induced sleep less optimal. In this paper, we investigate whether zolpidem needs to potentiate only particular GABAergic pathways to induce sleep without reducing EEG power. Mice with a knock-in F77I mutation in the GABA_A receptor γ2 subunit gene are zolpidem-insensitive. Using these mice, GABA_A receptors in the frontal motor neocortex and hypothalamic (tuberomammillary nucleus) histaminergic-neurons of γ2I77 mice were made selectively sensitive to zolpidem by genetically swapping the γ2I77 subunits with γ2F77 subunits. When histamine neurons were made selectively zolpidem-sensitive, systemic administration of zolpidem shortened sleep latency and increased sleep time. But in contrast to the effect of zolpidem on wild-type mice, the power in the EEG spectra of NREM sleep was not decreased, suggesting that these EEG power-reducing effects of zolpidem do not depend on reduced histamine release. Selective potentiation of GABA_A receptors in the frontal cortex by systemic zolpidem administration also reduced sleep latency, but less so than for histamine neurons. These results could help with the design of new sedatives that induce a more natural sleep.

SIGNIFICANCE STATEMENT

Many people who find it hard to get to sleep take sedatives. Zolpidem (Ambien) is the most widely prescribed "sleeping pill." It makes the inhibitory neurotransmitter GABA work better at its receptors throughout the brain. The sleep induced by zolpidem does not resemble natural sleep because it produces a lower power in the brain waves that occur while we are sleeping. We show using mouse genetics that zolpidem only needs to work on specific parts and cell types of the brain, including histamine neurons in the hypothalamus, to induce sleep but without reducing the power of the sleep. This knowledge could help in the design of sleeping pills that induce a more natural sleep.

Zolpidem prescribing practices before and after Food and Drug Administration required product labeling changes

Background:

Women have higher morning serum zolpidem concentrations than men after taking an evening dose, potentially leading to increased risk of harm. On 19 April 2013, the United States Food and Drug Administration required labeling changes for zolpidem, recommending an initial dose of no greater than 5 mg (immediate release) or 6.25 mg (controlled release) per night in women.

Objectives:

The primary objective of this study was to compare prescribing practices before and after the 2013 zolpidem labeling change. A secondary objective was to evaluate serious adverse events potentially related to zolpidem.

Methods:

Electronic medical records of adults receiving care through the University of Colorado Health system were accessed for study inclusion if patients were provided a first-time prescription for zolpidem either prior to or after the Food and Drug Administration labeling change. Patients were randomly chosen from eight strata based on age, gender, and date of zolpidem initiation (before/after the labeling change). Demographic and zolpidem prescribing data were collected. Low-dose zolpidem was considered 5 mg (immediate release) or 6.25 mg (controlled release) daily or less. Documentation of potentially related serious adverse events within the patients’ records was also evaluated.

Results:

A total of 400 patients were included in the study. The overall percentage of patients prescribed low-dose zolpidem increased from 44% to 58% after the labeling change (p = 0.0020). In a pre-specified subgroup analysis, the percentage of patients prescribed low-dose zolpidem increased in all groups, including young men (38%–50%, p = 0.23), elderly men (34%–40%, p = 0.53), and elderly women (60%–74%, p = 0.14), but the change was only significant in young women (42%–70%, p = 0.0045).

Conclusion:

After Food and Drug Administration–mandated labeling changes for zolpidem in 2013, the percentage of overall patients in our health system, and specifically young women, with initial prescriptions for low-dose zolpidem significantly increased as compared to before the labeling change.

Zolpidem's use for insomnia

Zolpidem is a short-acting non-benzodiazepine hypnotic drug that belongs to the imidazopyridine class. In addition to immediate-release (IR) and extended-release (ER) formulations, the new delivery forms including two sublingual tablets [standard dose (SD) and low dose (LD)], and an oral spray form have been recently developed which bypass the gastrointestinal tract. So far, Zolpidem has been studied in several clinical populations: cases poor sleepers, transient insomnia, elderly and non-elderly patients with chronic primary insomnia, and in comorbid insomnia. Peak plasma concentration (Tmax) of zolpidem-IR occurs in 45 to 60min, with the terminal elimination half-life (t½) equating to 2.4h. The extended-release formulation results in a higher concentration over a period of more than 6h. Peak plasma concentration is somewhat shorter for the sublingual forms and the oral spray, while their t½ is comparable to that of zolpidem-IR. Zolpidem-IR reduces sleep latency (SL) at recommended doses of 5mg and 10mg in elderly and non-elderly patients, respectively. Zolpidem-ER at doses of 6.25mg and 12.5mg, improves sleep maintenance in elderly and non-elderly patients, respectively, 4h after its administration. Sublingual zolpidem-LD (5mg) and zolpidem oral spray are indicated for middle-of-the-night (MOTN) wakefulness and difficulty returning to sleep, while sublingual zolpidem-SD (10mg) is marketed for difficulty falling asleep. With their array of therapeutic uses and their popularity among physicians and patients; this review describes the clinical pharmacology, indications and uses, identifying withdrawal symptoms, abuse and dependence potentials, and adverse drug reactions are discussed.

Safety analysis of zolpidem in elderly subjects 80 years of age or older: adverse event monitoring in Japanese subjects

OBJECTIVES

Prescriptions of non-benzodiazepine sedative hypnotics, e.g. zolpidem, for insomnia in elderly subjects 80 years of age or older have markedly increased in the USA. However, a meta-analysis of the risks and benefits of hypnotics in older people reported the benefits associated with hypnotics use are outweighed by the risks. This study aimed to investigate the safety of zolpidem administration in extremely old elderly.

METHODS

The prevalence of adverse reactions to zolpidem was investigated in a subpopulation of participants in the Drug Event Monitoring project of the Japan Pharmaceutical Association. A total of 1011 (316 males and 695 females) zolpidem users, including 261 (25.8%) subjects 80 years of age or older without cognitive or mental complications, were eligible for the analysis.

RESULTS

The elderly and female patients were prescribed significantly lower doses of zolpidem than their counterparts. Adverse symptoms after the last prescription were reported by 60 (5.9%) subjects. The most common symptoms were impaired balance and/or falls (1.8%) and morning drowsiness (1.3%). The multiple logistic regression analyses showed that subjects 80 years of age or older were at lower risk of adverse symptoms (odds ratio 0.39, 95% confidence intervals: 0.17-0.88).

CONCLUSION

Our findings in a real-world clinical setting suggest that low-dose zolpidem can be safely prescribed to subjects 80 years of age or older without cognitive or mental complications.

Pharmacokinetics of a Novel Zolpidem Nasal Spray for Rapid Management of Insomnia: First Trial in Humans

STUDY OBJECTIVES

The present single-dose, parallel-group, randomized, double-blind, placebo-controlled study is to evaluate the pharmacokinetics, tolerability and safety of zolpidem tartrate nasal spray (ZNS) as compared to placebo in healthy subjects.

METHODS

Thirty-six healthy subjects participated in this study, with 19 male and 17 female subjects in 3 cohorts (12 subjects per cohort), who were randomly assigned to receive either an intranasal dose of ZNS 1.75 mg, 3.5 mg, 5.0 mg (n = 10 per dose), or an intranasal placebo (n = 2). Multiple venous blood samples were collected for pharmacokinetic analyses.

RESULTS

Plasma zolpidem concentrations rapidly increased after intranasal ZNS 1.75, 3.5, and 5.0 mg with mean T_max of 0.42, 0.76 and 0.50 h, respectively, followed by rapid decreases at all three doses. C_max, AUC_0-t, and AUC_0-∞ were found to increase in a dose-proportional manner. Female subjects had generally higher AUC_0-t, AUC_0-∞, and lower weight-normalized clearance rate (CL/F) than male subjects. In this study, ZNS was safe and well tolerated over the evaluated dose range. There were no serious adverse events.

CONCLUSIONS

Zolpidem was rapidly absorbed and eliminated after intranasal administration of ZNS. Dose proportionality was found at the doses ranged from 1.75 mg to 5.0 mg. Intranasal exposure of zolpidem was generally higher in female subjects than that in male subjects. It could be concluded that ZNS is safe and well tolerated over the evaluated range of intranasal doses.

Zolpidem use and risk of fractures: a systematic review and meta-analysis

Zolpidem is a representative of non-benzodiazepine hypnotics. Recent epidemiologic studies have reported increased fracture risk in patients taking zolpidem, but the results have been inconsistent. The present meta-analysis shows that the use of zolpidem is associated with an increased risk of fractures.

PURPOSE

Previous studies have reported inconsistent findings regarding the association between the use of zolpidem and the risk of fractures. We performed a systematic literature review and meta-analysis to assess the association.

METHODS

We identified relevant studies by searching MEDLINE, EMBASE, Cochrane Library, and PsycINFO without language restrictions (until August 2014). Methodological quality was assessed based on the Newcastle-Ottawa Scale (NOS).

RESULTS

A total of 1,092,925 participants (129,148 fracture cases) were included from 9 studies (4 cohort, 4 case-control, and 1 case-crossover study). Overall, the use of zolpidem was associated with an increased risk of fracture (relative risk [RR] 1.92, 95 % CI 1.65-2.24; I (2) = 50.9 %). High-quality subgroups (cohort studies, high NOS score, adjusted for any confounder, or adjusted for osteoporosis) had higher RRs than the corresponding low-quality subgroups (high quality, 1.94-2.76; low quality, 1.55-1.79). Of note, the risk for hip fracture was higher than that for fracture at any site (hip fracture, RR 2.80, 95 % CI 2.19-3.58; fracture at any site, RR 1.84, 95 % CI 1.67-2.03; P < 0.001).

CONCLUSIONS

The use of zolpidem may increase the risk of fractures. Clinicians should be cautious when prescribing zolpidem for patients at high risk of fracture.

Fluorination methods in drug discovery

Fluorination reactions of medicinal and biologically-active compounds will be discussed. Late stage fluorination strategies of medicinal targets have recently attracted considerable attention on account of the influence that a fluorine atom can impart to targets of medicinal importance, such as modulation of lipophilicity, electronegativity, basicity and bioavailability, the latter as a consequence of membrane permeability. Therefore, the recourse to late-stage fluorine substitution on compounds with already known and relevant biological activity can provide the pharmaceutical industry with new leads with improved medicinal properties. The fluorination strategies will take into account different fluorinating reagents, either of nucleophilic or electrophilic, and of radical nature. Diverse families of organic compounds such as (hetero)aromatic rings, and aliphatic substrates (sp(3), sp(2), and sp carbon atoms) will be studied in late-stage fluorination reaction strategies.

Learning and Memory Deficits in Male Adult Mice Treated with a Benzodiazepine Sleep-Inducing Drug during the Juvenile Period

Gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the mammalian central nervous system, is also known to be important for brain development. Therefore, disturbances of GABA receptor (GABA-R) mediated signaling (GABA-R signal) during brain development may influence normal brain maturation and cause late-onset brain malfunctions. In this study, we examined whether the stimulation of the GABA-R signal during brain development induces late-onset adverse effects on the brain in adult male mice. To stimulate the GABA-R signal, we used either the benzodiazepine sleep-inducing drug triazolam (TZ) or the non-benzodiazepine drug zolpidem (ZP). We detected learning and memory deficits in mice treated with TZ during the juvenile period, as seen in the fear conditioning test. On the other hand, ZP administration during the juvenile period had little effect. In addition, decreased protein expression of GluR1 and GluR4, which are excitatory neurotransmitter receptors, was detected in the hippocampi of mice treated with TZ during the juvenile period. We measured mRNA expression of the immediate early genes (IEGs), which are neuronal activity markers, in the hippocampus shortly after the administration of TZ or ZP to juvenile mice. Decreased IEG expression was detected in mice with juvenile TZ administration, but not in mice with juvenile ZP administration. Our findings demonstrate that TZ administration during the juvenile period can induce irreversible learning and memory deficits in adult mice. It may need to take an extra care for the prescription of benzodiazepine sleep-inducing drugs to juveniles because it might cause learning and memory deficits.