Clinical pharmacokinetics and pharmacodynamics of zolpidem. Therapeutic implications

Preferential Synaptic Type of GABA-A Receptor Ligands Enhancing Neuronal Survival and Facilitating Functional Recovery After Ischemic Stroke

Selective enhancement of synaptic GABA signaling mediated by GABA-A receptors has been previously reported to promote functional recovery after ischemic stroke, while tonic GABA signaling has been detrimental. To identify agents that enhance synaptic signaling, we synthesized GABA-A ligands based on three chemotypes with affinity values pKi= 6.44-8.32. Representative compounds showed a preference in functional responses toward synaptic type of GABA-A receptors, compared to the extrasynaptic ones. In a cellular ischemia model (OGD), selected compounds showed the potential to improve neuronal recovery. The selected lead, compound 4, demonstrated the ability to reduce mitochondrial dysfunction, regulate intracellular calcium levels, decrease caspase 3 levels, and promote neurite outgrowth in in vitro assays. In an animal model, compound 4 enhanced motor recovery and showed neuroprotective activity by reducing infarct volume and decreasing poststroke acidosis. These findings underscore the value of selective ligands modulating synaptic GABA-A receptors in promoting recovery from ischemic stroke.

Case report: Additional grounds for tighter regulation? A case series of five women with zolpidem dependence from a Brazilian women-specific substance use disorder outpatient service

Objective

This study presents a case series of five women with zolpidem dependence treated at the Drug Dependent Women Treatment Center (PROMUD), one of the first women-specific substance use disorder outpatient services in Latin America.

Methods

This was an retrospective review of medical records of patients with a diagnosis of zolpidem dependence at the Institute of Psychiatry of Clinics Hospital of University of São Paulo between December 2021 and December 2023. Description of the cases followed the Case Report Statement, Checklist and Guidelines (CARE). The weekly zolpidem intake, comprising prescribed amounts and relapse episodes, was totaled to compute a mean daily dose. This was graphically illustrated to bring clinical insights.

Results

The patients, aged 25-45 years, displayed escalating oral zolpidem doses (range: 60-900 mg/day), with adverse effects such as memory and social impairment, falls, seizures. Commonalities among cases included initiating zolpidem use for primary insomnia and withdrawal symptoms, including rebound insomnia, social impairment, and craving. History of physical and psychological abuse were reported. Comorbid psychiatric conditions, particularly eating disorders (n=3), recurrent depression (n=1), borderline personality disorder traits (n=1), and attention deficit hyperactivity disorder (n=1), were identified. Although zolpidem abuse often correlates with the concurrent abuse of other substances, none of the reported cases in this study exhibited other substance use disorders. Concurrent use of sedatives, especially benzodiazepines and levomepromazine, was observed (n=2).

Conclusion

The surge in zolpidem prescriptions, driven by its perceived safety and low abuse potential compared to benzodiazepines, may lead to a global health issue of dependence. The medical community faces the challenge of managing this without standardized treatment protocols. Our case series underscores the effectiveness of the PROMUD program, which employs a multidisciplinary, women-specific approach with tailored group therapies and weekly psychiatric appointments to address and prevent relapse.

PBBM Considerations for Base Models, Model Validation, and Application Steps: Workshop Summary Report

The proceedings from the 30th August 2023 (Day 2) of the workshop "Physiologically Based Biopharmaceutics Models (PBBM) Best Practices for Drug Product Quality: Regulatory and Industry Perspectives" are provided herein. Day 2 covered PBBM case studies from six regulatory authorities which provided considerations for model verification, validation, and application based on the context of use (COU) of the model. PBBM case studies to define critical material attribute (CMA) specification settings, such as active pharmaceutical ingredient (API) particle size distributions (PSDs) were shared. PBBM case studies to define critical quality attributes (CQAs) such as the dissolution specification setting or to define the bioequivalence safe space were also discussed. Examples of PBBM using the credibility assessment framework, COU and model risk assessment, as well as scientific learnings from PBBM case studies are provided. Breakout session discussions highlighted current trends and barriers to application of PBBMs including: (a) PBBM credibility assessment framework and level of validation, (b) use of disposition parameters in PBBM and points to consider when iv data are not available, (c) conducting virtual bioequivalence trials and dealing with variability, (d) model acceptance criteria, and (e) application of PBBMs for establishing safe space and failure edges.

Zolpidem-triggered atrial fibrillation in a patient with cardiomyopathy: a case report

BACKGROUND

Zolpidem is a non-benzodiazepine hypnotic widely used to manage insomnia. Zolpidem-triggered atrial fibrillation (AF) in patients with cardiomyopathy has never been reported before.

CASE PRESENTATION

A 40-year-old man with Duchenne muscular dystrophy-related cardiomyopathy attempted suicide and developed new-onset AF after zolpidem overdose. One year before admission, the patient visited our clinic due to chest discomfort and fatigue after daily walks for 1 month; both electrocardiography (ECG) and 24-hour Holter ECG results did not detect AF. After administration of cardiac medication (digoxin 0.125 mg/day, spironolactone 40 mg/day, furosemide 20 mg/day, bisoprolol 5 mg/day, sacubitril/valsartan 12/13 mg/day), he felt better. AF had never been observed before this admission via continuous monitoring during follow-up. Sixteen days before admission, the patient saw a sleep specialist and started zolpidem tartrate tablets (10 mg/day) due to insomnia for 6 months; ECG results revealed no significant change. The night before admission, the patient attempted suicide by overdosing on 40 mg of zolpidem after an argument, which resulted in severe lethargy. Upon admission, his ECG revealed new-onset AF, necessitating immediate cessation of zolpidem. Nine hours into admission, AF spontaneously terminated into normal sinus rhythm. Results from the ECG on the following days and the 24-hour Holter ECG at 1-month follow-up showed that AF was not detected.

CONCLUSIONS

This study provides valuable clinical evidence indicating that zolpidem overdose may induce AF in patients with cardiomyopathy. It serves as a critical warning for clinicians when prescribing zolpidem, particularly for patients with existing heart conditions. Further large-scale studies are needed to validate this finding and to explore the mechanisms between zolpidem and AF.

Development of a Web Application for Simulating Plasma Drug Concentrations in Patients with Zolpidem Intoxication

Zolpidem is a widely prescribed hypnotic Z-drug used to treat short-term insomnia. However, a growing number of individuals intentionally overdose on these drugs. This study aimed to develop a predictive tool for physicians to assess patients with zolpidem overdose. A population pharmacokinetic (PK) model was established using digitized data obtained from twenty-three healthy volunteers after a single oral administration of zolpidem. Based on the final PK model, a web application was developed using open-source R packages such as rxode2, nonmem2rx, and shiny. The final model was a one-compartment model with first-order absorption and elimination with PK parameters, including clearance (CL, 16.9 L/h), absorption rate constant (Ka, 5.41 h-1), volume of distribution (Vd, 61.7 L), and lag time (ALAG, 0.394 h). Using the established population PK model in the current study, we developed a web application that enables users to simulate plasma zolpidem concentrations and visualize their profiles. This user-friendly web application may provide essential clinical information to physicians, ultimately helping in the management of patients with zolpidem intoxication.

Alleviating sleep disturbances and modulating neuronal activity after ischemia: Evidence for the benefits of zolpidem in stroke recovery

AIMS

Sleep disorders are prevalent among stroke survivors and impede stroke recovery, yet they are still insufficiently considered in the management of stroke patients, and the mechanisms by which they occur remain unclear. There is evidence that boosting phasic GABA signaling with zolpidem during the repair phase improves stroke recovery by enhancing neural plasticity; however, as a non-benzodiazepine hypnotic, the effects of zolpidem on post-stroke sleep disorders remain unclear.

METHOD

Transient ischemic stroke in male rats was induced with a 30-minute middle cerebral artery occlusion. Zolpidem or vehicle was intraperitoneally delivered once daily from 2 to 7 days after the stroke, and the electroencephalogram and electromyogram were recorded simultaneously. At 24 h after ischemia, c-Fos immunostaining was used to assess the effect of transient ischemic stroke and acute zolpidem treatment on neuronal activity.

RESULTS

In addition to the effects on reducing brain damage and mitigating behavioral deficits, repeated zolpidem treatment during the subacute phase of stroke quickly ameliorated circadian rhythm disruption, alleviated sleep fragmentation, and increased sleep depth in ischemic rats. Immunohistochemical staining showed that in contrast to robust activation in para-infarct and some remote areas by 24 h after the onset of focal ischemia, the activity of the ipsilateral suprachiasmatic nucleus, the biological rhythm center, was strongly suppressed. A single dose of zolpidem significantly upregulated c-Fos expression in the ipsilateral suprachiasmatic nucleus to levels comparable to the contralateral side.

CONCLUSION

Stroke leads to suprachiasmatic nucleus dysfunction. Zolpidem restores suprachiasmatic nucleus activity and effectively alleviates post-stroke sleep disturbances, indicating its potential to promote stroke recovery.

Electroencephalogram changes over time in zolpidem withdrawal seizure: A case study

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Abusive use of Zolpidem as a Result of COVID-19 and Perspectives of Continuity of the Problem in the Post-Pandemic Period

Zolpidem is a non-benzodiazepine hypnotic drug that works as a positive modulator of Gamma-Amino Butyric Acid-A (GABA-A) receptors, with high selectivity for α1 subunits. Given this selective binding, the drug has a strong hypnotic activity. Social isolation during the SARS-CoV-2 pandemic has contributed to increased rates of anxiety, depression, and insomnia. As a result, studies have pointed to a possible increase in the indiscriminate use of drugs with sedative effects, such as Zolpidem, during the pandemic. The aim of this work was to present prospective evidence that warns of the possibility of the abusive use of Zolpidem even after the pandemic. High rates of addiction to this drug have been reported around the world after the emergence of the coronavirus. Data from the National Survey on Drug Use and Health and from Medicaid support the continuing growth in prescription and indiscriminate use of Zolpidem during the pandemic and afterward. Therefore, there is enough evidence to support the indiscriminate use of this drug since the beginning of the pandemic. Rates of indiscriminate use of sedatives may continue to increase in the post-pandemic period, especially if strict control measures are not taken by health authorities.

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.

Case report: Hyperactive delirium after a single dose of zolpidem administered additionally to psychopharmacotherapy including clozapine

The non-benzodiazepine hypnotic zolpidem is frequently administered as a short term psychopharmacotherapy for insomnia. Although it is well-established in a broad clinical routine and often well-tolerated, severe delirium and complex sleep behavior were reported in rare cases. Hereby, it remains unclear whether zolpidem's potential for delirium might be enhanced when combined with further psychopharmacotherapeutics. The present case report portrays a young male Caucasian inpatient with schizoaffective disorder, who was admitted due to severe hyperactive delirium after a single dose of zolpidem 10 mg that was administered in addition to already established psychopharmacotherapy including clozapine 200 mg/day, aripiprazole 15 mg/day and cariprazine 4.5 mg/day. In detail, disorientation, agitation, confabulations, bizarre behavior, and anterograde amnesia occurred shortly after ingestion of zolpidem and gained in intensity within a couple of hours. Once zolpidem was discontinued, the abovementioned symptoms subsided completely and did not reoccur. Since a clear temporal association could be drawn between the intake of zolpidem and the onset of hyperactive delirium, the present clinical experience should serve as a cautionary note for combining potent sedative-hypnotics and substances with anticholinergic properties, even in young adults in a good general condition. Moreover, our case argues for the necessity of further research into the pathomechanism of the interaction potential of non-benzodiazepines as zolpidem, especially with substances exerting anticholinergic properties, which are known for their potential to precipitate delirium. Therefore, the metabolic pathways of the concurrently administered substances should be further taken into account.

Efficacy and tolerability of pharmacological treatments for insomnia in adults: A systematic review and network meta-analysis

Insomnia is one of the most common and burdensome disorders in adults. We compared and ranked insomnia medication on the basis of their efficacy and tolerability. We performed a systematic review and network meta-analysis of placebo-controlled or head-to-head randomized controlled trials for primary insomnia in adults comparing 20 drugs. We searched eight databases and seven trial registers from inception to March 1st, 2022. Primary outcomes included sleep latency (SL), awake time after sleep onset (WASO) and discontinuation for adverse events (AED), and secondary outcomes included total sleep time (TST), sleep efficiency (SE), sleep quality (SQ) and adverse events (ADE). Pooled standardized mean differences or odds ratios with 95% credible intervals were estimated using pairwise and network meta-analysis with random-effects. Differences among trial findings were explored in subgroup and sensitivity analyses. Confidence in evidence was assessed using GRADE. The PROSPERO registered number is CRD42020182144. We identified 22,538 records and included 69 studies (17,319 patients). Orexin receptor antagonists (ORAs) are more efficacious than benzodiazepine-like drugs (Z-drugs) and placebo for WASO and SE, and better than melatonin receptor agonists (MRAs) for SL, WASO and SE. ORAs ranked the best in SL (SUCRA value: 0.84), WASO (0.93), TST (0.86) and SE (0.96). Lemborexant and daridorexant (two ORAs) showed greater efficacy than placebo for SL, WASO, and TST, with good tolerability. Z-drugs were more efficacious than placebo for SL, WASO, TST and SE, but with higher risk to safety. Zaleplon and eszopiclone had better efficacy than placebo for TST and SQ respectively. MRAs may also be efficacious for sleep-onset insomnia with good safety. However, the long-term adverse effects of all medications are unclear. Insomnia medications differ in their efficacy and tolerability. ORAs have superior efficacy and tolerability. These findings should aid clinicians in matching risk/benefits of drugs available in their countries to insomnia symptoms.

Voltage-clamp evidence of GABAA receptor subunit-specific effects: pharmacodynamic fingerprint of chlornordiazepam, the major active metabolite of mexazolam, as compared to alprazolam, bromazepam, and zolpidem

BACKGROUND

Anxiolytic benzodiazepines, due to their clinical effectiveness, are one of the most prescribed drugs worldwide, despite being associated with sedative effects and impaired psychomotor and cognitive performance. Not every GABA_A receptor functions in the same manner. Those containing α1 subunits are associated with sleep regulation and have a greater effect on the sedative-hypnotic benzodiazepines, whereas those containing α2 and/or α3 subunits are associated with anxiety phenomena and have a greater effect on the anxiolytic benzodiazepines. Therefore, characterization of the selectivity profile of anxiolytic drugs could translate into a significant clinical impact.

METHODS

The present study pharmacodynamically evaluated chlornordiazepam, the main active metabolite of mexazolam, upon GABA_A receptors containing α2 and/or α3, anxiety-related, and those containing an α1 subunit, associated with sleep modulation.

RESULTS

As shown by whole-cell patch-clamp data, chlornordiazepam potentiated GABA-evoked current amplitude in α2 and α3 containing receptors without changing the current amplitude in α1 containing receptors. However, current decay time increased, particularly in GABA_A receptors containing α1 subunits. In contrast, other anxiolytic benzodiazepines such as alprazolam, bromazepam, and zolpidem, all increased currents associated with GABA_A receptors containing the α1 subunit.

CONCLUSIONS

This novel evidence demonstrates that mexazolam (through its main metabolite chlornordiazepam) has a "pharmacodynamic fingerprint" that correlates better with an anxiolytic profile and fewer sedative effects, when compared to alprazolam, bromazepam and zolpidem, explaining clinical trial outcomes with these drugs. This also highlights the relevance of the pharmacological selectivity over GABA_A receptor subtypes in the selection of benzodiazepines, in addition to their clinical performance and pharmacokinetic characteristics.

Euphoric effect induced by zolpidem: a case study of magnetoencephalography

Initially, zolpidem, a non-benzodiazepine hypnotic agent, was considered to have fewer adverse reactions than traditional benzodiazepines. However, after zolpidem was approved for medical use, an increasing number of case reports have described abuse or dependence complications. We were especially interested in the cases of dependence that presented a paradoxical ‘euphoric’ effect of zolpidem. This article reports the case of a female zolpidem-dependent patient who presented with 6 years of daily use of 400–1400 mg of zolpidem. She reported subjective effects of euphoria, intense craving and the inability to stop drug ingestion. Her diagnoses were zolpidem dependence and a depressive episode induced by substance abuse. To explore the neural mechanisms of the euphoric effect caused by high-dose zolpidem, we performed repeated magnetoencephalography (MEG) recordings. Before undergoing detoxification, her MEG results indicated that cerebellar electrical signal activation increased when taking high zolpidem doses. However, the prefrontal and parietal lobes’ electrical signal activity showed a tendency to recover to a normal state as the withdrawal time progressed to completion. This case suggests that the cerebellum plays a role in the euphoria induced by high zolpidem doses and provides clues for further research.

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.

Case report: Chronological symptom profile after cessation of overdose zolpidem in a patient with comorbid bipolar disorder-from anxiety, craving, paresthesia and influenza-like symptoms to seizures and hallucinations

INTRODUCTION

Insomnia is a major public health problem that determines the quality of life. Among the many causes of insomnia, psychological factors have an important influence on the process, duration of insomnia, help-seeking behavior, and treatment choice. Regarding medical treatment, zolpidem is always chosen to treat acute and transient insomnia due to its few side effects. Although some randomized controlled trials have verified its safety, zolpidem abuse and withdrawal reactions have been reported in recent years.

CASE REPORT

A 25-year-old unmarried man with a college degree who worked as a graphic designer was referred and admitted to the inpatient ward for a chief complaint of "alternative episodes of lowering and elevation of mood for 10 years, overdosage use of zolpidem for two years." He underwent a time-dependent withdrawal reaction after admission. It was characterized by rebound insomnia, anxiety, craving, skin paresthesia, influenza-like symptoms, tonic-clonic-type seizures, and hallucinations. At the 1-year follow-up, he did not exhibit any remaining withdrawal symptoms.

DISCUSSION

The acute cessation of overdosage zolpidem use causes a series of withdrawal symptoms that manifest in chronological order. Additionally, long-term benzodiazepine exposure has potential influences on zolpidem dependence/tolerance. However, patients with a history of abuse or dependence, or mental disorders seem to be at risk of drug abuse. Clinicians should be alert to the potential for zolpidem dependence and addiction. Once the acute cessation of overdosage zolpidem use occurs, the potential of the withdrawal reaction needs to be considered and addressed properly.

Zolpidem withdrawal seizure in an Iranian young woman: A case presentation

Background

Zolpidem is a non-benzodiazepine drug, approved by FDA for sleep induction. Zolpidem is thought to be a safer drug than benzodiazepines (BZD) because of no evidence of abuse or dependence potential, but several case reports of zolpidem abuse and dependence have been published along with a small number of cases demonstrating seizures after sudden zolpidem withdrawal.

Case presentation

A 32-year-old unmarried woman suffering from major depressive disorder had been taking zolpidem for insomnia for more than 1 year. She began to take zolpidem alone without mixing other kinds of hypnotics, and 50 mg of zolpidem used to be initially effective in treating her insomnia. In some days the dose increased up to 100 mg per day. In the end, she had to discontinue zolpidem abruptly because she could not afford it anymore. After 2 days, she suddenly showed facial spasm, mouth opening, tonic-clonic seizure, and loss of consciousness for about 1-2 minutes. Post-ictal confusion with clouded consciousness, psycho-motor retardation, persisted in 1 day. EEG in wakefulness revealed intermittent, generalized, diffused alpha wave and diffused sharp waves, and suggested seizure waves in the patient.

Conclusion

Our case suggested that the potential of zolpidem dependence and withdrawal seizure are also present in the Iranian population. The female-gender, high dosage and long-term use of zolpidem might be risk factors for the development of adverse effects.

Zolpidem: Efficacy and Side Effects for Insomnia

Purpose of Review

Insomnia is a common type of sleep disorder defined by an ongoing difficulty initiating or maintaining sleep or nonrestorative sleep with subsequent daytime impairment. The sleep disturbances in insomnia usually manifest as difficulty in falling asleep, maintaining the continuity of sleep, or waking up too early in the morning well before the desired time, irrespective of the adequate circumstances to sleep every night. Insomnia can significantly impact daytime functioning resulting in decreased workplace productivity, proneness to errors and accidents, inability to concentrate, frequent daytime naps, and poor quality of life.The treatment of insomnia should involve a multi-disciplinary approach, focusing on implementing behavioral interventions, improving sleep hygiene, managing psychological stressors, hypnotic treatment, and pharmacological therapy. The most effective therapies utilize cognitive behavioral therapy in conjunction with pharmacotherapy to minimize the needed dose and any resulting side effects. Non-benzodiazepine hypnotics such as zolpidem, eszopiclone, zaleplon are the most used as adjunctive treatment. One of the most used of these hypnotics is zolpidem. However, zolpidem has a wide variety of adverse effects and has some special considerations noted in the literature.

Recent Findings

Zolpidem has been associated with an increased risk of falls in hospitalized patients with an OR of 4.28 (P <0.001) when prescribed short-term for insomnia. The relative risk (RR) for hip fractures in patients taking zolpidem was described as 1.92 (95% CI 1.65-2.24; P<0.001), with hip fractures being the most commonly seen. A case series of 119 inpatients aged 50 or older demonstrated that a majority (80.8%) of ADRs were central nervous system (CNS)-related such as confusion, dizziness, and daytime sleepiness. A systematic review of 24 previous studies of sleepwalking associated with zolpidem demonstrated that the association was not dependent on age, dose, medical history, or even a history of sleepwalking at any time before zolpidem use. Suicide attempts and completion have been successfully linked with zolpidem use (OR 2.08; 95% CI 1.83-2.63) in patients regardless of the presence of comorbid psychiatric illness. There have been multiple cases reported of seizures following the withdrawal of zolpidem. Most cases have demonstrated that withdrawal seizures occurred in patients taking daily dosages of around 450-600mg/day, but some reported them as low as 160mg/day. Rebound insomnia has been a concern to prescribers of zolpidem. Sleep onset latency has been demonstrated to be significantly increased on the first night after stopping zolpidem (13.0 minutes; 95% CI 4.3-21.7; P<0.01). Women had a non-significantly higher mean plasma concentration than men after 8 hours for the 10mg IR (28 vs. 20 ng/mL) and the 12.5mg MR (33 vs. 28ng/mL). The FDA has classified zolpidem as a category C drug based on adverse outcomes seen in animal fetal development. In the mothers exposed to zolpidem, there was an increased incidence of low birth weight (OR = 1.39; P<0.001), preterm delivery (OR 1.49; P<0.001), small for gestational age (SGA) babies (OR = 1.34; P<0.001), and cesarean deliveries (OR =1.74; P<0.001). The rate of congenital abnormalities was not significantly increased with zolpidem (0.48 vs 0.65%; P = 0.329).

Summary

Insomnia is linked to fatigue, distractibility, mood instability, decreased satisfaction, and overall decreased quality of life. Optimal therapy can aid patients in returning to baseline and increase their quality of life. Zolpidem is a helpful drug for the treatment of insomnia in conjunction with cognitive-behavioral therapy. When prescribed to elderly patients, the dose should be adjusted to account for their slower drug metabolism. Still, zolpidem is considered a reasonable choice of therapy because it has a lower incidence of residual daytime sleepiness and risk of falls when compared to other drugs. The most concerning adverse effects, which are often the most publicized, include the complex behaviors that have been seen in patients taking Zolpidem, such as sleeping, hallucinations, increased suicidality, driving cars while asleep, and even a few cases of committing homicide. Even so, zolpidem could be a suitable pharmacological treatment for insomnia. Decisions for whether or not to prescribe it and the dosage should be made on a case-by-case basis, considering both the psychical and psychiatric risks posed to the patient with insomnia versus if the patient were to take zolpidem to treat their condition.

Cognitive and balance dysfunctions due to the use of zolpidem in the elderly: a systematic review

Zolpidem is one of the most widely prescribed hypnotic (non-benzodiazepine) agents for sleep disorder. Recently, an increase in the demand for this drug has been observed, mainly in the elderly population.

Objective

This study aims to analyze the acute effect of zolpidem on cognitive and balance dysfunctions in the elderly population.

Methods

A study was conducted by two independent researchers in four virtual scientific information bases and included randomized controlled trials. The studies evaluated elderly patients using zolpidem. Cognitive and balance dysfunctions were analyzed.

Results

Six articles were included. The mean age of the participants in the studies was 69 years. The following zolpidem dosages were evaluated: 5, 6.25, 10, and 12.5 mg. Comparing zolpidem and placebo, relating to the cognitive dysfunctions, there is no statistically significant difference between the groups. However, in relation to balance dysfunctions, there is a statistically significant difference between the intervention and the comparison, favoring placebo.

Conclusions

Zolpidem, even in usual doses (5 mg and 10 mg), has shown to increase the risk for balance dysfunctions. However, this does not occur in relation to cognitive changes.

Effect of CYP3A4 metabolism on sex differences in the pharmacokinetics and pharmacodynamics of zolpidem

To investigate pharmacokinetic and pharmacodynamic differences of zolpidem between males and females and their causes, including CYP3A4 activity. A single oral dose of zolpidem (10 mg) was administered to 15 male and 15 female healthy subjects. Blood samples were collected up to 12 h post-dose to determine plasma zolpidem concentrations. Pharmacokinetic parameters were obtained using non-compartmental analysis. Digit symbol substitution test, choice reaction time, and visual analog scale of sleepiness were used to evaluate pharmacodynamics. We measured CYP3A4 activity using 4β-hydroxycholesterol, an endogenous metabolite. Mean maximum plasma concentration and area under the plasma concentration–time curve were higher for females than for males (9.9% and 32.5%, respectively); other pharmacokinetic parameters showed no significant differences. Pharmacodynamic scores for females showed delayed recovery compared with that for males. CYP3A4 activity was higher in females than in males (p = 0.030). There was no serious adverse event, and adverse event incidence was not different between the sexes. Zolpidem exposure was about 30% higher in females than in males. Delayed pharmacodynamic score recovery in females could be related to higher zolpidem concentrations. Although apparent clearance was lower in females, systemic clearance might not be the cause of the different exposures to zolpidem.

Zolpidem for Insomnia: A Double-Edged Sword. A Systematic Literature Review on Zolpidem-Induced Complex Sleep Behaviors

BACKGROUND

Being a nonbenzodiazepine, zolpidem is believed to have a favorable side-effect profile and is widely prescribed for insomnia. However, in the past few years, numerous neuropsychiatric adverse reactions, particularly complex sleep behaviors (CSBs), have been reported with zolpidem.

OBJECTIVE

To conduct a systematic review of zolpidem-associated CSBs.

DATA SOURCES

An electronic search was conducted using MEDLINE, Embase, PubMed, and Cochrane database of systematic reviews to extract relevant articles till July 2020.

STUDY ELIGIBILITY CRITERIA

Any type of literature article (case report, case series, and observational or interventional study) reporting CSBs associated with zolpidem.

RESULTS

In this review, we present aggregate summarized data from 148 patients presenting with zolpidem-induced CSBs (79 patients from 23 case reports and 5 case series; 69 patients out of 1454 taking zolpidem [4.7%] from three observational clinical studies). Various types of CSBs associated with zolpidem were reported, most common being sleepwalking/somnambulism and sleep-related eating disorder. On causality assessment, around 88% of cases were found to have a probable association with zolpidem.

LIMITATIONS

Extraction of data from observational studies and spontaneous reports, due to nonavailability of any randomized controlled trials relevant to the study objective.

CONCLUSION AND IMPLICATION OF KEY FINDINGS

Zolpidem-induced CSBs, although not very common, may develop when the drug is used at therapeutic doses for insomnia. Doctors need to be alert to monitor such adverse effects of zolpidem and exercise caution while prescribing it.

An explorative approach to understanding individual differences in driving performance and neurocognition in long-term benzodiazepine users

OBJECTIVE

Previous research reported cognitive and psychomotor impairments in long-term users of benzodiazepine receptor agonists (BZRAs). This article explores the role of acute intoxication and clinical complaints.

METHODS

Neurocognitive and on-road driving performance of 19 long-term (≥6 months) regular (≥twice weekly) BZRA users with estimated plasma concentrations, based on self-reported use, exceeding the therapeutic threshold (C_BZRA +), and 31 long-term regular BZRA users below (C_BZRA -), was compared to that of 76 controls.

RESULTS

BZRA users performed worse on tasks of response speed, processing speed, and sustained attention. Age, but not C_BZRA or self-reported clinical complaints, was a significant covariate. Road-tracking performance was explained by C_BZRA only. The C_BZRA  + group exhibited increased mean standard deviation of lateral position comparable to that at blood-alcohol concentrations of 0.5 g/L.

CONCLUSIONS

Functional impairments in long-term BZRA users are not attributable to self-reported clinical complaints or estimated BZRA concentrations, except for road-tracking, which was impaired in CBZRA + users. Limitations to address are the lack of assessment of objective clinical complaints, acute task related stress, and actual BZRA plasma concentrations. In conclusion, the results confirm previous findings that demonstrate inferior performance across several psychomotor and neurocognitive domains in long-term BZRA users.

Perspectives on the pharmacological management of dystonia

Introduction: Treatment of dystonia is particularly complex due to various etiologies and heterogeneous clinical manifestation, as well as different degrees of disability. In absence of causative treatment, all symptomatic therapy should be predominantly tailored to ameliorate those symptoms (motor and non/motor) that mostly affect patients' daily life and regular activities. Many different treatment options, including oral medications, neurosurgical interventions, physical and occupational therapy are available in treatment of dystonia.Areas covered: The aim of this perspective is to point out different possibilities in pharmacological management of dystonic movements. Due to pure clinical presentation, the authors concentrate mainly on the isolated dystonias, which are presented solely as dystonic movements. Combined and complex dystonias are not instructive due to compound clinical presentation and consequently, complicated treatment. The article is based on a literature search from sources including PubMed, the Cochrane Library, Web of Science, PiCarta, and PsycINFO.Expert opinion: Although dystonia therapy should be adapted according to the individual needs, severity, age, type, symptoms distribution and acceptable side-effect profile, certain principles should be followed to reach the optimal result. Furthermore, the authors believe that a better understanding of the pathophysiology of dystonia will bring with it the development of new and improved treatment approaches and medications.

LC-MS/MS method for determining picogram-level of zolpidem and its main metabolites in hair using a zirconia-based sorbent

Although urine and blood samples have been conventionally used for testing zolpidem (ZPD), a sedative-hypnotic, these matrices have limited application because they have a relatively short detection period and can be used only in case of recent drug exposure. Therefore, it is necessary to use an alternative biological sample to obtain the evidence of ZPD misuse. Herein, a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of ZPD and its metabolites, zolpidem phenyl-4-carboxylic acid (ZPCA) and zolpidem 6-carboxylic acid (ZCA), in hair to resolve the above-mentioned problems. Mechanical pulverization of hair, methanol extraction with sonication, and the zirconia-based hybrid solid-phase extraction technique were used for obtaining improved extraction efficiency and effective sample purification. The treated hair sample was analyzed using the LC-MS/MS method with the electrospray ionization source in positive and multiple-reaction monitoring modes. The target analytes were separated and detected within 8 min using an Xselect HSS T3 column. Gradient elution was performed using 5 mM ammonium formate and acetonitrile. The lower limit of quantification of ZPD, ZPCA, and ZCA were 1.0, 0.5, and 1.0 pg mg^-1, respectively. The calibration ranges were 1.0-1000.0 pg mg^-1 for ZPD, 0.5-200.0 pg mg^-1 for ZPCA, and 1.0-200.0 pg mg^-1 for ZCA, with the determination coefficients (r² ≥ 0.9986). The intraday accuracy and precision ranged from -7.1 to 9.0% and within 6.5%, respectively, and the interday accuracy and precision ranged from -6.1 to 7.9% and within 5.4%, respectively. The recovery, matrix effect, and process efficiency were 65.2-96.6%, 64.6-106.5%, and 44.3-100.5%, respectively, with the relative standard deviation of 4.0-5.0%. The developed method was successfully applied to analyze 13 forensic hair samples of ZPD abusers, and the concentration ratios of ZPD and its two main metabolites (ZPCA and ZCA) in the ZPD-positive samples were also presented. These results revealed that ZPCA and ZCA were not easily incorporated into hair, and demonstrated that their analysis in hair samples requires the employed method to have picogram-level sensitivity. Therefore, the developed method was suitable for simultaneous analysis of ZPD, ZPCA, and ZCA in hair samples, and it could provide clear evidence for illegal ZPD administration, including ZPD-facilitated sexual assault.

The Effect of Zolpidem on Language Function of Patients With Nonfluent Variant of Frontotemporal Dementia: A Pilot Study

OBJECTIVE

Primary progressive aphasia (PPA), as the language variant of frontotemporal dementia, is a neurodegenerative disease with an insidious course that has no appropriate treatment yet. The present study evaluated the effect of zolpidem on improving language function in patients with nonfluent variant PPA (nfv-PPA).

METHODS

In this interventional pilot study, patients diagnosed with nfv-PPA were evaluated for language function through the Persian Aphasia Test. Patients were then treated with zolpidem with a maximum dose of 10 mg twice daily and reevaluated after 6 weeks using the Persian Aphasia Test. Data were compared by paired samples t test. Values of P ≤ 0.05 were considered significant.

RESULTS

Thirteen (8 men) patients completed the study. The mean age of the patients was 58.5 ± 4.5 years. Changes were statistically significant in none of the 6 subtests including spontaneous speech content, speech fluency, auditory comprehension, sequential command comprehension, repetition, and naming.

CONCLUSION

The study showed that zolpidem did not affect the improvement of language function in patients with nfv-PPA. Thus, traditional language structures do not seem to be sensitive to the modulatory effects of zolpidem. Studies with larger sample sizes will help support this hypothesis.

Determination of zolpidem phenyl-4-carboxylic acid and zolpidem 6-carboxylic acid in hair using gas chromatography-electron ionization-tandem mass spectrometry

A gas chromatography-electron ionization-tandem mass spectrometric (GC-EI-MS/MS) method was developed and validated for determination of the major metabolites of zolpidem, zolpidem phenyl-4-carboxylic acid (ZPCA) and zolpidem 6-carboxylic acid (ZCA) in human hair. The sample preparation procedure involves decontamination, mechanical pulverization, incubation, extraction and purification prior to instrumental analysis. The extracts were derivatized using hexafluoroisopropanol and heptafluorobutyric anhydride and analyzed by GC-EI-MS/MS. The linear ranges were 8-100 pg/mg for ZPCA and 16-200 pg/mg for ZCA, with the correlation coefficients >0.997. The limits of detection were 1.8 pg/mg for ZPCA and 1.7 pg/mg for ZCA. The recoveries ranged from 77.6 to 111.7%. The intra- and inter-day precisions were within 16.9 and 11.7%, while intra- and inter-day accuracies were -7.0-8.7 and -2.8-7.8%, respectively. The developed method was applied for the analysis of forensic hair samples obtained from suspected zolpidem abusers and the following concentration ranges were monitored: ZPCA 11.9-35.9 pg/mg and ZCA 16.6-21.8 pg/mg. The method proved to be suitable for picogram-level determination of ZPCA and ZCA in human hair.

Improving Medication-Related Outcomes in Chronic Liver Disease

Patients with chronic liver disease (CLD) are becoming increasingly complex due to the rising prevalence of multimorbidity and polypharmacy. Medications are often essential to manage the underlying liver disease, complications of cirrhosis and portal hypertension, and comorbidities. However, medication-related problems (MRPs) have been associated with adverse patient outcomes, including hospitalization and mortality. Factors that can contribute to MRPs in people with CLD are variable and often entwined. This narrative literature review discusses key barriers and opportunities to modify risk factors and improve medication-related outcomes for people with CLD.

[Association Suvorexant and Ramelteon Use with the Risk of Falling: A Retrospective Case-control Study]

Sedative hypnotics are among the classes of drugs reported to influence falls. However, the effects of the sedative hypnotic drugs, suvorexant and ramelteon, on falls are not well known. Therefore, we conducted this retrospective case-control study to examine the association of the use of these two sedative hypnotics with the risk of falls. Conducted at the Sapporo Medical University Hospital in Japan, our study included 360 patients with fall incidents and 819 randomly selected control patients. Patients in the fall group were significantly older with a lower body mass index, and had a history of falls, disabilities in activities of daily living, cognitive impairment, and delirium. Monovariate analysis revealed that patients in the fall group frequently used ramelteon [odds ratio (OR) 2.38, 95% confidence interval (CI): 1.49-3.81, p<0.001], but rarely used suvorexant (OR 0.66, 95% CI: 0.29-1.39, p=0.317), compared with control patients. Furthermore, multivariate analysis revealed that ramelteon use did not increase the risk of falls (adjusted OR 1.43, 95% CI: 0.82-2.48, p=0.207), whereas suvorexant use significantly decreased the risk of falls (adjusted OR 0.32, 95% CI: 0.13-0.76, p=0.009). Although ramelteon tends to be used in patients at a high risk of falls, it may not increase the risk of falls. In contrast, the use of suvorexant may reduce the risk of falls.

Effects of steady-state clarithromycin on the pharmacokinetics of zolpidem in healthy subjects

Zolpidem is extensively metabolized by CYP3A4, CYP2C9 and CYP1A2. Previous studies demonstrated that pharmacokinetics of zolpidem was affected by CYP inhibitors, but not by short-term treatment of clarithromycin. The objective of this study was to investigate the effects of steady-state clarithromycin on the pharmacokinetics of zolpidem in healthy subjects. In the control phase, 33 subjects received a single dose of zolpidem (5 mg). One week later, in the clarithromycin phase, the subjects received clarithromycin (500 mg) twice daily for 5 days to reach steady state concentrations, followed by zolpidem (5 mg) and clarithromycin (500 mg). In each phase, plasma concentrations of zolpidem were evaluated up to 12 h after drug administration by using liquid chromatography-tandem mass spectrometry method. In the clarithromycin phase, mean total area under the curve of zolpidem (AUC_inf) was 1.62-fold higher and the time to reach peak plasma concentration of zolpidem (t_max) was prolonged by 1.95-fold compared to the control phase. In addition, elimination half-life (t_1/2) of zolpidem was 1.40-fold longer during co-administration with clarithromycin and its apparent oral clearance (CL/F) was 36.2% lower with clarithromycin administration. The experimental data demonstrate the significant pharmacokinetic interaction between zolpidem and clarithromycin at steady-state.

3-Carene, a Phytoncide from Pine Tree Has a Sleep-enhancing Effect by Targeting the GABAA-benzodiazepine Receptors

3-Carene, a bicyclic monoterpene, is one of the major components of the pine tree essential oils. It has been reported that, in addition to its known properties as a phytoncide, 3-carene has anti-inflammatory, antimicrobial, and anxiolytic effects. We have previously demonstrated that α-pinene, the major component of pine tree, has a hypnotic effect through GABA_A-benzodiazepine (BZD) receptors. However, a hypnotic effect of 3-carene has not been studied yet. Here, we report that oral administration of 3-carene increases the sleep duration and reduces sleep latency in pentobarbital- induced sleep test. 3-Carene potentiates the GABA_A receptor-mediated synaptic responses by prolonging the decay time constant of inhibitory synaptic responses. These enhancing effects of 3-carene are reproduced by zolpidem, a modulator for GABA_A-BZD receptor, and fully inhibited by flumazenil, an antagonist for GABA_A-BZD receptor. The molecular docking of 3-carene to the BZD site of GABA_A protein structure, suggests that 3-carene binds to the BZD site of α1 and ϒ2 subunits of GABA_A-BZD receptor. These results indicate that, similar to α-pinene, 3-carene shows a sleep-enhancing effect by acting as a positive modulator for GABA_A-BZD receptor.

In-vitro–in-silico investigation of the negative food effect of zolpidem when administered as immediate-release tablets

Objectives

The main objective of the present work was to combine in-vitro and in-silico tools to better understand the in-vivo behavior of the immediate release (IR) formulation of zolpidem in the fasted and fed states.

Methods

The dissolution of zolpidem was evaluated using biorelevant media simulating the gastric and intestinal environment in the fasted and fed states. Additionally, the influence of high viscosity and high fat content on the release of zolpidem under fed state conditions was investigated. The in-vitro results were combined with a physiologically based pharmacokinetic (PBPK) model constructed with Simcyp® to simulate the zolpidem pharmacokinetic profile in both prandial states.

Key findings

In vitro biorelevant dissolution experiments representing the fasted and fed states, combinedwith PBPKmodelling, were able to simulate the plasma profiles from the clinical food effect studies well. Experiments reflecting the pH and fat content of themeal led to a good prediction of the zolpidem plasma profile in the fed state, whereas increasing the viscosity of the gastricmedia led to an under-prediction.

Conclusions

This work demonstrates that the combination of biorelevant dissolution testing and PBPK modelling is very useful for understanding the in-vivo behavior of zolpidem in the fasted and fed states. This approach could be implemented in the development of other drugs exhibiting negative food effects, saving resources and bringing new drug products to the market faster.

Zolpidem for the Treatment of Dystonia

Background and Purpose: There are recent reports of zolpidem being effective for the treatment of a variety of movement disorders, due to its action on the gamma-aminobutyric acid A receptors in the thalamus, subthalamic nucleus, and globus pallidus, hence facilitating inhibitory pathways in the basal ganglia motor loop. Its beneficial effects have been described for Parkinson's disease and other related disorders. The objective of this study was to assess the therapeutic effects of zolpidem for various types of dystonia.

Methods: We conducted a literature search using MEDLINE via PubMed, Cochrane Library, EMBASE, Scopus, and Google Scholar.

Results: There were no randomized controlled trials. The literature included 6 case reports, 4 case series, and 1 non-randomized, non-controlled interventional trial. Overall, 49 adult participants (range 1–34 participants) with a mean age of 49.5 years were treated. Regardless of the dystonia subtype, a single dose of zolpidem at 10 mg causes improvement of symptoms for a mean duration of 3.4 h until patient returns to baseline. The main adverse effect noted was drowsiness, which was dose-dependent.

Conclusion: While the current available literature suggests that zolpidem may be an effective pharmacologic option for treating dystonia, however the quality of evidence remains limited. Larger sample size, methodological consistency, and randomized controlled trials with long-term patient follow-ups are necessary to come up with definitive conclusion.

Comorbid Zolpidem Dependence and Over-the-Counter Compound Analgesic Abuse

Zolpidem is a commonly prescribed hypnotic used to treat insomnia. However, its potential for abuse and dependence has recently become controversial. Although over-the-counter (OTC) medications are widely used, their abuse potential has not received much research attention. We report a case of comorbid zolpidem and OTC compound analgesic abuse. OTC analgesics may serve as gateway drugs, and physicians must be cautious about this issue, especially when prescribing hypnotics or benzodiazepines.

The contribution of contextual fear in the anxiolytic effect of chlordiazepoxide in the fear-potentiated startle test

This study evaluated the extent to which a reduction in contextual fear contributes to the anxiolytic effect of benzodiazepines in the fear-potentiated startle response. To this end, chlordiazepoxide, an anxiolytic often used as positive control in preclinical drug studies, and zolpidem, known to have sedative properties and to be devoid of anxiolytic effects, were tested in two contexts: the same context as training had taken place and an alternative context. In addition, the level of muscle relaxation was assessed in a grip strength test. Chlordiazepoxide (2.5-10 mg/kg) decreased the fear-potentiated startle response, confirming its anxiolytic activity. In addition, it dose-dependently decreased the overall startle response in the same, but not the alternative context, and did not affect grip strength, indicating that chlordiazepoxide inhibits contextual fear in the absence of non-specific drug effects. Zolpidem (1.0-10 mg/kg) reduced the overall startle response in both contexts equally and decreased grip strength, indicating that its effects on fear-potentiated startle are due to non-specific drug effects, and not anxiolytic effects. The present findings show that chlordiazepoxide reduces contextual conditioned fear in the absence of non-specific drug effects. In addition, they show that training and testing rats in different contexts makes it possible to distinguish between cued, contextual and non-specific drug effects. As exaggerated contextual fear conditioning contributes to the fear generalization processes implicated in pathological anxiety, focus in screening of anxiolytic effects could be directed more towards the suppression of contextual fear and, therefore, this approach would be a valuable addition to standard preclinical screening.

Tardive Myoclonic Dyskinesia Responsive to Sodium Oxybate

Hyperkinetic movement disorders may be difficult to treat, but cases where patients respond to alcohol and/or drugs with similar effects have been described. We report the case of a 64-year-old man with tardive dyskinesia characterized by severe uncontrolled dystonic and myoclonic jerks of the face, shoulders, and arm and forearm muscles, which improved with oral sodium oxybate. Our case suggests the possibility to test sodium oxybate in patients with severe, drug-resistant hyperkinetic syndromes, especially when they are known to improve with alcohol.

Conversion factors for assessment of driving impairment after exposure to multiple benzodiazepines/z-hypnotics or opioids

AIMS

Norway has introduced legal concentration limits in blood for 28 non-alcohol drugs in driving under the influence cases. As of 2016 this legislation also regulates the assessment of combined effects of multiple benzodiazepines and opioids. We herein describe the employed methodology for the equivalence tables for concentrations of benzodiazepines/z-hypnotics and opioids implemented in the Norwegian Road Traffic Act.

METHODS

Legislative limits corresponding to impairment at blood alcohol concentrations (BAC) of 0.02%, 0.05% and 0.12% were established for 15 different benzodiazepines and opioids. This was based on a concept of a linear relationship between blood drug concentration and impairment in drug naïve users. Concentration ratios between these drugs were used to establish conversion factors and calculate net impairment using diazepam and morphine equivalents.

RESULTS

Conversion factors were established for 14 benzodiazepines/z-hypnotics (alprazolam, bromazepam, clobazam, clonazepam, etizolam, flunitrazepam, lorazepam, nitrazepam, nordiazepam, oxazepam, phenazepam, temazepam, zolpidem and zopiclone) and two opioids (methadone and oxycodone).

CONCLUSIONS

Conversion factors to calculate diazepam and morphine equivalents for benzodiazepines/z-hypnotics and selected opioids, respectively, have been operative in the Norwegian Road Traffic Act as of February 2016. Calculated equivalents can be applied by the courts to meter out sanctions.

Potential benefits of zolpidem in disorders of consciousness

INTRODUCTION

It has been suggested that zolpidem may arouse patients with decreased level of consciousness. Zolpidem may partially or even completely reverse abnormal cell metabolism following brain damage. In this article, available evidences regarding effects of zolpidem on disorders of consciousness were reviewed. Areas covered: A literature review was conducted using PubMed, Scopus, Medline, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Google Scholar as online databases. Search Keywords were 'vegetative state', 'minimally conscious state', 'semi-comatose', 'arousal', 'zolpidem', 'wakefulness', 'awareness', and 'loss of consciousness'. All English language studies that evaluated the effects of zolpidem on disorders of consciousness as a main surrogate endpoint were included. Finally 21 articles within this subject were included. Expert commentary: Zolpidem showed positive effects in several conditions with decreased level of consciousness. However, benefits of zolpidem were not detected in all patients with disorders of consciousness. Patients with post-anoxic encephalopathy or traumatic brain injury did not experience benefits of zolpidem. Available evidences support positive effects of zolpidem on brain functions in patients with non-brain stem injuries.

Improved Arousal and Motor Function Using Zolpidem in a Patient With Space-Occupying Intracranial Lesions: A Case Report

Patients with disorders of consciousness (DOC) have profound functional limitations with few treatment options for improving arousal and quality of life. Zolpidem is a nonbenzodiazepine hypnotic used to treat insomnia that has also been observed to paradoxically improve arousal in those with DOC, such as the vegetative or minimally conscious states. Little information exists on its use in patients with DOC who have intracranial space-occupying lesions. We present a case of a 24-year-old man in a minimally conscious state due to central nervous system lymphoma who was observed to have increased arousal and improved motor function after the administration of zolpidem.

LEVEL OF EVIDENCE

V.

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.

Benzodiazepine Use During Hospitalization: Automated Identification of Potential Medication Errors and Systematic Assessment of Preventable Adverse Events

Objective

Benzodiazepines and “Z-drug” GABA-receptor modulators (BDZ) are among the most frequently used drugs in hospitals. Adverse drug events (ADE) associated with BDZ can be the result of preventable medication errors (ME) related to dosing, drug interactions and comorbidities. The present study evaluated inpatient use of BDZ and related ME and ADE.

Methods

We conducted an observational study within a pharmacoepidemiological database derived from the clinical information system of a tertiary care hospital. We developed algorithms that identified dosing errors and interacting comedication for all administered BDZ. Associated ADE and risk factors were validated in medical records.

Results

Among 53,081 patients contributing 495,813 patient-days BDZ were administered to 25,626 patients (48.3%) on 115,150 patient-days (23.2%). We identified 3,372 patient-days (2.9%) with comedication that inhibits BDZ metabolism, and 1,197 (1.0%) with lorazepam administration in severe renal impairment. After validation we classified 134, 56, 12, and 3 cases involving lorazepam, zolpidem, midazolam and triazolam, respectively, as clinically relevant ME. Among those there were 23 cases with associated adverse drug events, including severe CNS-depression, falls with subsequent injuries and severe dyspnea. Causality for BDZ was formally assessed as ‘possible’ or ‘probable’ in 20 of those cases. Four cases with ME and associated severe ADE required administration of the BDZ antagonist flumazenil.

Conclusions

BDZ use was remarkably high in the studied setting, frequently involved potential ME related to dosing, co-medication and comorbidities, and rarely cases with associated ADE. We propose the implementation of automated ME screening and validation for the prevention of BDZ-related ADE.

Worsening Hepatic Encephalopathy Secondary to Zolpidem

Objective:

To report a case of worsening hepatic encephalopathy secondary to ingestion of Zolpidem.

Case Summary:

A 41-year-old white man had postoperative complications 11 months after liver transplantation. Complications included narrowing of the choledochal anastomosis site, cyclosporine nephrotoxicity, and recurrent hepatitis C. Approximately seven months after transplantation, the patient experienced elevations in liver enzyme concentrations, lethargy, ascites, fever, chills, and nausea. Examination of a biopsy sample revealed recurrent hepatitis C. The patient's condition did not resolve despite administration of interferon alfa-2b, and his mental status began to deteriorate secondary to hepatic encephalopathy. One day before admission, the patient was given Zolpidem 5 mg for sleep; one hour after taking Zolpidem, he awoke in a stupor and was not oriented to place or time. When he became increasingly incoherent and verbally abusive, family members brought him to the emergency department. Although the patient exhibited mental status deterioration before receiving Zolpidem, considering the strong temporal relationship, his rapidly worsening state may be attributable to the drug. The patient subsequently required a second liver transplant in addition to a kidney transplant as a result of cyclosporine nephrotoxicity. The patient was not rechallenged with Zolpidem nor given flumazenil.

Discussion:

One pathophysiologic explanation for hepatic encephalopathy implicates endogenously produced benzodiazepine agonists. In patients with portal-systemic shunting, psychoactive compounds escape metabolism and are subsequently free to cross the blood-brain barrier. This mechanism is supported by reports of successful treatment of patients who have encephalopathy with flumazenil, a benzodiazepine antagonist. Hence, it follows that a benzodiazepine agonist could potentially exacerbate encephalopathic symptomatology. Zolpidem, although structurally unrelated to benzodiazepines, is a benzodiazepine agonist that binds preferentially to the benzodiazepine1 ω1 subtype of the γ-aminobutyric acid (GABAA) receptor complex. Therefore, administration of Zolpidem to patients with encephalopathy may worsen the condition by contributing to the accumulation of benzodiazepine agonists within the central nervous system.

Conclusions:

Although this patient's worsening mental status could be explained by a naturally evolving encephalopathic state, it is possible that Zolpidem exacerbated his decline. Existing evidence supports this view. First, an endogenously produced, benzodiazepine-related mechanism of hepatic encephalopathy is described in the literature. Second, benzodiazepine-like substances have been detected in the serum of patients with encephalopathy who have not received benzodiazepine therapy. Finally, clinical evidence supports the use of flumazenil in encephalopathic patients. Thus, it is likely that administration of Zolpidem hastened the mental decline of this patient.