Residual effects of zopiclone 7.5 mg on highway driving performance in insomnia patients and healthy controls: a placebo controlled crossover study

Residual next-day effects of alprazolam on psychomotor performance and simulated driving in healthy normal adults

The prevalence of drugged driving has increased in the United States. Some drugged driving may be unintentional as prescription medications used as sleeping aids, like zolpidem, cause impairment after the predicted duration of therapeutic action has elapsed. The aim of this study was to determine if nighttime administration of alprazolam, a drug commonly prescribed off-label as a sleeping aid, impacts driving performance the following day. Participants were healthy adults (n = 15) who completed a double-blind, double-dummy, within-subjects inpatient study examining the effects of nighttime administration of alprazolam (0.5, 1, and 2 mg), zolpidem (10 mg), and placebo on driving performance the following day. Alprazolam (1 mg; morning) and zolpidem (nighttime) both served as positive control conditions. Driving simulator measures, cognitive and psychomotor tasks, and questionnaires querying drug effects were collected the afternoon before drug administration and for 5.5 hr the next day and analyzed using symmetry and mixed-model approaches. Morning alprazolam significantly impaired driving performance. Driving impairment was observed up to 12.5 hr after nighttime alprazolam 2 mg and for 8.5 hr after nighttime zolpidem 10 mg. Participant reports on driving ability indicated that they were not aware of their level of impairment. These results suggest that alprazolam used before bed may pose a yet unrecognized public safety risk in the form of next-day drugged driving. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Association Between Hypnotics, Accidents, and Injuries: A Study Based on the Adverse Drug Event Reporting Database in Japan

BACKGROUND/AIM

The use of hypnotic drugs can lead to accidents and injuries. However, few reports have shown their association with these events after adjusting for many concomitant medications. This study aimed to determine whether the use of hypnotic drugs was associated with accidents and injuries.

PATIENTS AND METHODS

Using the Japanese Adverse Event Reporting Database, 772,387 reports published between September 2023 and April 2004 were analyzed. Reporting odds ratios (RORs) and 95% confidence intervals (CIs) for accidents and injuries associated with each hypnotic drug were calculated after adjusting for potential confounders.

RESULTS

Of the total, 12,484 reports indicated association of hypnotic drugs with accidents and injuries. The use of each hypnotic drug was associated with accidents, injuries, and other adverse events. However, a multivariate analysis adjusted for age, sex, reporting year, and concomitant medications showed a considerable decrease in ROR for melatonin receptor agonists (adjusted ROR=1.26; 95%CI=1.03-1.55) and dual orexin receptor antagonists (DORAs) (adjusted ROR=1.04; 95%CI=0.86-1.25). Particularly in DORAs, a loss of signal for accidents and injuries was observed.

CONCLUSION

The risk of accidents and injuries may vary with hypnotic drug use; however, DORAs may be less frequently associated with these events. The results of this study provide useful information for the selection of hypnotic drugs.

A scoping review of motor vehicle operator performance assessments for benzodiazepine receptor agonists

Background

Benzodiazepines and Z-drugs (e.g., zopiclone, zolpidem) (benzodiazepine receptor agonists or BZRAs), are prescribed for anxiety and insomnia disorders. However, they are not indicated as first line therapies for long-term management due to harms and efficacy limitations. BZRAs have also been associated with traffic accident risks. Patients taking BZRAs are told to consult with health care providers regarding motor vehicle operation safety. However, advice on driving is variable. The objective of this scoping review is to identify, map, and characterize the evidence for assessments that measure driving performance in people taking BZRAs.

Methods

Embase (Elsevier), MEDLINE (Ovid), and PsycINFO (EBSCO) were searched. Covidence was used for screening. Each stage of screening included two independent reviewers. A REDCap database was used for data extraction by two independent reviewers. Results were tabulated and summarised as a narrative.

Results

Driving performance was assessed with 20 unique BZRAs across 183 studies (n = 92 experimental; n = 91 observational) in 178 publications. Zopiclone was the most studied. In experimental studies, the Standard Deviation of Lateral Position (SDLP) was used most often (n = 54, 62 %) and many studies (n = 35, 38 %) were conducted in the Netherlands. For observational studies, biological detection (e.g., urine, blood) (n = 73, 80 %) followed by prescription drug/dispensing records (n = 17, 19 %) were the most common impairment measures and Norway (n = 20) is where most studies took place. In experimental studies, most (n = 89, 97 %) were conducted using only one driving setting. Simulated driving in a car (n = 36) and road driving in traffic (n = 36) were common as compared to nontraffic driving course (n = 8) and simulated driving (n = 9). In experimental studies, seventy-eight of the 92 studies (85 %) had at least one measure that identified impairment.

Conclusions

BZRA effects on motor vehicle driving performance have been studied using heterogenous protocols with multiple measures and settings, ranging from simulation to authentic traffic situations in experimental studies to biological detection and dispensing records in observational studies. Many BZRAs have been studied but study representation does not match prescribing pattern prevalence. The interpretation and contextualization of results for clinical practice is challenging due to the complexity (i.e., protocols, measures, settings). Future work in this area should work to improve knowledge translation of results so information is more readily accessible and applicable to health care providers and patients.

Effects of new hypnotic drugs on cognition: A systematic review and network meta-analysis

Background

Insomnia is a common disease, and the application of various types of sleeping pills for cognitive impairment is controversial, especially as different doses can lead to different effects. Therefore, it is necessary to evaluate the cognitive impairment caused by different sleeping pills to provide a theoretical basis for guiding clinicians in the selection of medication regimens.

Objective

To evaluate whether various different doses (low, medium and high) of anti-insomnia drugs, such as the dual-orexin receptor antagonist (DORA), zopiclone, eszopiclone and zolpidem, induce cognitive impairment.

Methods

The PubMed, Embase, Scopus, Cochrane Library, and Google Scholar databases were searched from inception to September 20th, 2022 for keywords in randomized controlled trials (RCTs) to evaluate the therapeutic effects of DORA, eszopiclone, zopiclone and zolpidem on sleep and cognitive function. The primary outcomes were indicators related to cognitive characteristics, including scores on the Digit Symbol Substitution Test (DSST) and daytime alertness. The secondary outcomes were the indicators associated with sleep and adverse events. Continuous variables were expressed as the standard mean difference (SMD). Data were obtained through GetData 2.26 and analyzed by Stata v.15.0.

Results

A total of 8702 subjects were included in 29 studies. Eszopiclonehigh significantly increased the daytime alertness score (SMD = 3.00, 95 % CI: 1.86 to 4.13) compared with the placebo, and eszopiclonehigh significantly increased the daytime alertness score (SMD = 4.21, 95 % CI: 1.65 to 6.77; SMD = 3.95, 95 % CI: 1.38 to 6.51; SMD = 3.26, 95 % CI: 0.38 to 6.15; and SMD = 3.23, 95 % CI: 0.34 to 6.11) compared with zolpidemlow, zolpidemhigh, DORAlow, and eszopiclonemid, respectively. Compared with the placebo, zopiclone, zolpidemmid, and eszopiclonehigh, DORA significantly increased the TST (SMD = 2.39, 95 % CI: 1.11 to 3.67; SMD = 6.00, 95 % CI: 2.73 to 9.27; SMD = 1.89, 95 % CI: 0.90 to 2.88; and SMD = 1.70, 95 % CI: 0.42 to 2.99, respectively).

Conclusion

We recommend DORA as the best intervention for insomnia because it was highly effective in inducing and maintaining sleep without impairing cognition. Although zolpidem had a more pronounced effect on sleep maintenance, this drug is better for short-term use. Eszopiclone and zopiclone improved sleep, but their cognitive effects have yet to be verified.

Orexin dual receptor antagonists, zolpidem, zopiclone, eszopiclone, and cognitive research: A comprehensive dose-response meta-analysis

Background

About one-third of adults have trouble sleeping, ranging from occasional difficulty to chronic insomnia, along with difficulty maintaining sleep. Many studies reported that the long-term use of hypnotics can cause brain dysfunction and damage cognition.

Objective

The objective of the study is to evaluate whether low, medium, and high doses of orexin dual receptor antagonists (DORA), zopiclone (ZOP), eszopiclone (ESZ), and zolpidem (ZST) can impair cognition.

Methods

From the beginning through September 20, 2022, PubMed, Embase, Scopus, the Cochrane Library, and Google Scholar were searched. Randomized controlled trials (RCTs) assessing the therapeutic effects of DORA, eszopiclone, and zopiclone for sleep and cognitive function were included. The primary outcomes were indices related to the cognitive profile, including memory, alertness, execution and control function, and attention and orientation. The secondary outcomes were indices related to sleep and adverse events. The standard mean difference (SMD) was generated for continuous variables. Certain data were captured from figures by GetData 2.26 and analyzed using RStudio 4.2.

Results

Finally, a total of 8,702 subjects were included in 29 studies. Compared with the placebo, the DSST (Digit Symbol Substitution Test) scores of low, medium, and high doses of DORA were SMD = 0.77; 95% CI: 0.33-1.20; SMD = 1.58; 95% CI: 1.11-2.05; and SMD = 0.85; 95% CI: 0.33-1.36, respectively. The DSST scores of zolpidem at low, medium, and high doses were SMD = -0.39; 95% CI: 0.85-0.07; SMD = -0.88, 95% CI: -2.34-0.58; and SMD = -0.12, 95% CI: -0.85-0.60, respectively. Zopiclone's DSST scale score was SMD = -0.18; 95% CI: -0.54-0.18. In addition, the total sleep time (TST) of low, medium, and high doses of DORA was SMD = 0.28, 95% CI: -0.15-0.70; SMD = 1.36, 95% CI: 0.87-1.86; and SMD = 2.59, 95% CI: 1.89-3.30, respectively. The TST of zolpidem with low, medium, and high doses was SMD = 1.01, 95% CI: 0.18-1.83; SMD = 1.94, 95% CI: 0.46-3.43; and SMD = 1.71, 95% CI: 0.86-2.56, respectively. The TST of low, medium, and high doses of eszopiclone was relatively SMD = 2.03, 95% CI: -0.21-4.27; SMD = 2.38, 95% CI: 1.35-3.42; and SMD = 1.71, 95% CI: 0.60-2.82. Zopiclone's TST was SMD = 2.47, 95% CI: 1.36-3.58.

Conclusion

We recommend DORA as the best intervention for insomnia because it is highly effective in inducing and maintaining sleep without impairing cognition. Although zolpidem has a more pronounced effect on maintaining sleep, it is best to reduce its use because of its side effects. Eszopiclone and zopiclone improved sleep quality, but their safety in cognition remains to be verified.

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

Introduction

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

Aim

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

Method

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

Results

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

Conclusion

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

Residual effects of zopiclone on driving performance using a standardized driving simulator among healthy volunteers

RATIONALE

The effects of hypnotics on automobile driving have been attracting increasing attention. However, few driving simulators (DSs) have been confirmed to have acceptable reliability and validity for assessing the next-day residual effects of zopiclone as a positive control on driving performance.

OBJECTIVE

To investigate whether a new DS could permit detection of the next-day residual effects of zopiclone on driving performance.

METHODS

In this double-blind, randomized, placebo-controlled crossover trial, 28 healthy males received zopiclone 7.5 mg at bedtime on days 1 and 8 and placebo on the other days over a period of 16 days. The participants took part in three driving tasks-road-tracking, car-following, and harsh-braking-using a DS on days 2 and 9 at 9-h post-dosing. Scores on the Karolinska Sleepiness Scale and Profile of Mood States-Second Edition were then assessed, as was the serum concentration of zopiclone.

RESULTS

The estimated differences in the standard deviation of lateral position (cm) in the road-tracking task between the zopiclone and placebo groups on days 2 and 9 were 3.75 cm (90% confidence interval (CI): 1.71-5.79) and 4.07 cm (90% CI: 2.02-6.11), respectively. The estimated differences in the distance coefficient of variation in the car-following task and in the brake reaction time in the harsh-braking task between the zopiclone and placebo groups on day 2 were 4.31 (90% CI: 1.94-6.69) and 24.6 ms (90% CI: 12.7-36.4), respectively.

CONCLUSIONS

The DS used in this study has sufficient sensitivity to detect the next-day residual effects of zopiclone on driving performance.

Validity and reliability of a driving simulator for evaluating the influence of medicinal drugs on driving performance

RATIONALE

Although driving simulators (DS) are receiving increasing attention due to concern over traffic accidents under the influences of drugs, few DS are recognized for their reliability and validity. Therefore, the development of an evaluation system using DS for driving performance is urgently needed.

OBJECTIVES

To investigate whether the standard deviation of lateral position (SDLP) increases with blood alcohol concentration (BAC) using a DS with reliability and calculate the SDLP threshold from the difference between BAC levels of 0 and 0.05%.

METHODS

Twenty healthy Japanese men performed the DS tasks up to 60 min in Study 1 and DS tasks twice at 1-week intervals in Study 2. Twenty-six healthy men conducted the same DS tasks under BAC level (0, 0.025, 0.05, and 0.09%) in double-blind, randomized, crossover trial in Study 3. The primary outcome was SDLP in a road-tracking test. The test-retest reliability of DS data was assessed, and the estimated difference in SDLP between BAC levels of 0 and 0.05% was calculated using a linear regression model.

RESULTS

The cumulative SDLP values at 5-min intervals were stable, and the intraclass correlation coefficient for its values was 0.93. SDLP increased with BAC in a concentration-dependent manner. The predicted ΔSDLP value for the difference between BAC levels of 0 and 0.05% was 9.23 cm. No participants dropped out because of simulator sickness.

CONCLUSIONS

The new DS used in these studies has reliability, validity, and tolerability and is considered suitable for evaluating the influence of drugs on driving performance.

Assessing sleep-wake survival dynamics in relation to sleep quality in a placebo-controlled pharmacological intervention study with people with insomnia and healthy controls

RATIONALE

The mechanisms underlying impaired sleep quality in insomnia are not fully known, but an important role for sleep fragmentation has been proposed.

OBJECTIVES

The aim of this study is to explore potential mechanisms of sleep fragmentation influencing alterations of perceived sleep quality.

METHODS

We analyzed polysomnography (PSG) recordings from a double-blind crossover study with zopiclone 7.5 mg and placebo, in elderly participants with insomnia complaints and age-matched healthy controls. We compared survival dynamics of sleep and wake across group and treatment. Subsequently, we used a previously proposed model to estimate the amount of sleep onset latency (SOL) misperception from PSG-defined sleep fragmentation. Self-reported and model-estimated amount of SOL misperception were compared across group and treatment, as well as model prediction errors.

RESULTS

In the zopiclone night, the average segment length of NREM sleep was increased (group F = 1.16, p = 0.32; treatment F = 8.89, p < 0.01; group x treatment F = 0.44, p = 0.65), while the segment length of wake was decreased (group F = 1.48, p = 0.23; treatment F = 11.49, p < 0.01; group x treatment F = 0.36, p = 0.70). The self-reported and model-estimated amount of SOL misperception were lower during the zopiclone night (self-reported group F = 6.08, p < 0.01, treatment F = 10.8, p < 0.01, group x treatment F = 2.49, p = 0.09; model-estimated F = 1.70, p = 0.19, treatment F = 16.1, p < 0.001, group x treatment F = 0.60, p = 0.55). The prediction error was not altered (group F = 1.62, p = 0.20; treatment F = 0.20, p = 0.65; group x treatment F = 1.01, p = 0.37).

CONCLUSIONS

Impaired subjective sleep quality is associated with decreased NREM stability, together with increased stability of wake. Furthermore, we conclude that zopiclone-induced changes in SOL misperception can be largely attributed to predictable changes of sleep architecture.

Do hypnotics increase the risk of driving accidents or near miss accidents due to hypovigilance? The effects of sex, chronic sleepiness, sleep habits and sleep pathology

Driving accidents due to hypovigilance are common but the role of hypnotics is unclear in patients suffering from sleep disorders. Our study examined factors influencing accidents and near miss accidents attributed to sleepiness at the wheel (ANMAS). Using data from an online questionnaire aimed at patients with sleep disorders, we analysed the associations between ANMAS, sociodemographic data, symptoms of sleep disorders, severity of insomnia (Insomnia Severity Index (ISI)) symptoms of anxiety and depression (Hospital Anxiety and Depression scale with depression (HADD) and anxiety (HADA) subscales), chronic sleepiness (Epworth sleepiness scale ESS), hypnotic use and information about sleep habits. Hypnotics were hierarchically grouped into Z-drugs, sedative medication, melatonin and over the counter (OTC) alternative treatments. Of 10802 participants; 9.1% reported ANMAS (Men 11.1% women 8.3%) and 24.4% took hypnotics (Z-drugs 8.5%, sedative medication 8%, melatonin 5.6% and alternative treatments 2.5%). Logistic regression analysis identified the following risk factors for ANMAS: moderate (OR 2.4; CI: 2.10-2.79) and severe sleepiness (ESS OR 5.66; CI: 4.74-6.77), depression (HADD OR 1.2; CI: 1.03-1.47), anxiety (HADA OR 1.2;CI: 1.01-1.47), and insufficient sleep (OR1.4; CI: 1.2-1.7). Hypnotics were not associated with an increased risk of ANMAS in patients suffering from insomnia. Risk factors varied according to sex: in females, sex (OR 0.; CI: 0.55-0.74), mild insomnia (OR 0.5; CI: 0.3-0.8) and use of alternative treatments (OR 0.455, CI:0.23-0.89) were protective factors and risk was increased by sleepiness, sleep debt, social jetlag, caffeine use, anxiety and depression. In men no protective factors were identified: sleepiness, sleep debt, and severe insomnia were associated with an increased risk of ANMAS. In clinical practice, all patients with daytime sleepiness and men with severe insomnia should be counselled concerning driving risk and encouraged to avoid sleep debt.

On-the-road driving performance the morning after bedtime administration of lemborexant in healthy adult and elderly volunteers

Study Objectives

To assess potential effects of lemborexant on next-morning driving performance in adult and elderly healthy volunteers.

Methods

Randomized, double-blind, double-dummy, placebo and active-controlled, four period incomplete crossover study in 48 healthy volunteers (22 females), 23–78 years old. Participants were treated at bedtime for eight consecutive nights with two of three dose levels of lemborexant (2.5, 5, or 10 mg), zopiclone 7.5 mg (on the first and last night with placebo on intervening nights), or placebo. Driving performance was assessed in the morning on days 2 and 9 using a standardized highway driving test in normal traffic, measuring standard deviation of lateral position (SDLP). Drug–placebo differences in SDLP >2.4 cm were considered to reflect clinically meaningful driving impairment.

Results

Mean drug–placebo differences in SDLP following lemborexant 2.5, 5, and 10 mg on days 2 and 9 were 0.74 cm or less. The upper bound of the 95% confidence intervals (CIs) for lemborexant treatment groups were all below 2.4 cm and the 95% CIs included zero, indicating that the effects were neither clinically meaningful nor statistically significant. Symmetry analysis further supported the lack of clinically meaningful impairment with lemborexant.

Conclusions

When assessed starting ~9 h after lemborexant administration at bedtime the previous night, there was no statistically significant or clinically meaningful effect on driving performance in healthy adults and elderly, as assessed by either mean differences in SDLP relative to placebo or symmetry analysis. In this study, lemborexant at doses up to 10 mg was well-tolerated.

Clinical Trial Registration

clinicaltrials.gov, NCT02583451. https://clinicaltrials.gov/ct2/show/NCT02583451.

Insomnia in the Elderly: A Review

BACKGROUND

Insomnia remains one of the most common sleep disorders encountered in the geriatric clinic population, frequently characterized by the subjective complaint of difficulty falling or maintaining sleep, or nonrestorative sleep, producing significant daytime symptoms including difficulty concentrating and mood disturbances.

METHODS

A search of the literature was conducted to review the epidemiology, definition, and age-related changes in sleep, as well as factors contributing to late-life insomnia and scales utilized for the assessment of insomnia in older people. The aim is to summarize recent diagnostic guidelines and both nonpharmacological and pharmacological strategies for the management of insomnia in the older population.

RESULTS

Insomnia remains a clinical diagnosis. There are several demographic, psychosocial, biologic, and behavioral factors that can contribute to late-life insomnia. Older adults are at higher risk for the medical and psychiatric effects of insomnia.

CONCLUSIONS

The most important aspect in evaluation of insomnia is detailed history taking and thorough physical examination. Nonpharmacological treatment options have favorable and enduring benefits compared to pharmacological therapy.

Comparing the effects of oxazepam and diazepam in actual highway driving and neurocognitive test performance: a validation study

OBJECTIVE

Screening of drug-induced performance impairment is needed to provide meaningful information for users and prescribers regarding the impact of drugs on driving. The main objective was to assess the effects of oxazepam 10 mg (OXA10), oxazepam 30 mg (OXA30), and diazepam 10 mg (DIA10) on standard deviation of lateral position (SDLP) in a highway driving test in actual traffic and to determine the ability of eight neurocognitive tests to detect comparable effects.

METHODS

Twenty-three healthy volunteers participated in a four-way double-blind, placebo-controlled, crossover study. The highway driving test was conducted between 4 and 5 h after drug intake. A range of neurocognitive tests was conducted before and after driving, 2 and 6 h post-treatment, respectively.

RESULTS

Mean SDLP increased by 1.83, 3.03, and 7.57 cm after OXA10, DIA10, and OXA30, respectively. At 2 h post-treatment, all neurocognitive tests, except the useful field of view, showed performance impairment in all active treatments. Effect sizes (ES) were moderate for OXA10, large ES for DIA10, and largest ES for OXA30. Modest correlations were found between changes in SDLP and performance in the attention network test (ANT), the divided attention test (DAT), and the psychomotor vigilance test (PVT).

CONCLUSION

OXA10 caused minor, DIA10 moderate, and OXA30 severe driving impairment. No neurocognitive test was both dose dependently sensitive and able to be associated with driving impairment. No neurocognitive test can replace the on-the-road highway driving test.

New, Occasional, and Frequent Use of Zolpidem or Zopiclone (Alone and in Combination) and the Risk of Injurious Road Traffic Crashes in Older Adult Drivers: A Population-Based Case-Control and Case-Crossover Study

BACKGROUND

Previous studies on the effect of zolpidem or zopiclone use on the risk of road traffic crashes (RTCs) have shown mixed results.

OBJECTIVE

Our objective was to determine the association between zolpidem or zopiclone use (as separate drugs or combined) and the occurrence of injurious RTCs among older adult drivers.

METHODS

This was a population-based matched case-control and case-crossover study based on secondary data linked together from Swedish national registers. Cases were drivers aged 50-80 years involved in a vehicle crash resulting in injuries between January 2006 and December 2009 for the case-control study (n = 27,096) and from February 2006 to December 2009 for the case-crossover study (n = 26,586). For the first design, four controls were matched to each case by sex, age, and residential area, and exposure was categorized into new, occasional, and frequent use of zolpidem only, zopiclone only, and combined zolpidem and zopiclone. For the case-crossover study, newly dispensed zolpidem or zopiclone users were assessed during the 28 days prior to the crash and compared with an equally long control period using a 12-week washout period. Matched adjusted odds ratios (OR) were computed using conditional logistic regression.

RESULTS

Increased ORs for all users were observed. In the case-control study, the highest odds were seen among newly initiated zolpidem-only users involved in single-vehicle crashes (adjusted OR 2.27; 95% confidence interval [CI] 1.21-4.24), followed by frequent combined zolpidem and zopiclone users [adjusted OR 2.20; CI 1.21-4.00]. In the case-crossover, newly initiated treatment with zolpidem or zopiclone showed an increased risk that was highest in the 2 weeks after the start of the treatment (OR 2.66; 95% CI 1.04-6.81).

CONCLUSIONS

These results provide more compelling evidence for the role of zolpidem or zopiclone in the occurrence of RTCs among older adults, not only in frequent users, but also at the beginning of treatment.

On-the-road driving performance the morning after bedtime use of suvorexant 15 and 30 mg in healthy elderly

RATIONALE

Suvorexant is a first-in-class orexin receptor antagonist for treating insomnia. There is a general concern that hypnotics may impair next-morning driving ability.

OBJECTIVE

The objective of this study was to evaluate next-morning driving performance in older adults after single and repeated doses of suvorexant.

METHODS

Double-blind, randomized, placebo-controlled, 4-period crossover study in 24 healthy volunteers (10 females), aged 65-80 years. Subjects were treated with suvorexant (15 and 30 mg) for eight consecutive nights, zopiclone 7.5 mg nightly on days 1 and 8, and placebo. Driving performance was assessed on days 2 and 9 (9 h after dosing) using a 1-h standardized highway driving test in normal traffic, measuring standard deviation of lateral position (SDLP). Drug-placebo differences in SDLP >2.4 cm were considered to reflect clinically meaningful driving impairment.

RESULTS

Driving performance as measured by SDLP was not impaired following suvorexant. Mean drug-placebo differences in SDLP following suvorexant 15 and 30 mg on day 2 and 9 were 0.6 cm or less. Their 90 % CIs were all below the threshold of 2.4 cm for clinical relevance and included zero, indicating effects were not clinically meaningful or statistically significant. Symmetry analysis showed no significant differences between the number of participants who had SDLP differences >2.4 cm and those who had SDLP differences <-2.4 cm following suvorexant.

CONCLUSIONS

There was no clinically meaningful residual effect of suvorexant 15 and 30 mg on next-morning driving (9 h after bedtime dosing) in healthy older adults, as assessed by mean changes in SDLP and by the number of participants on drug versus placebo that exceeded a predetermined threshold for clinically meaningful impairment.

On-the-Road Driving Performance the Morning after Bedtime Use of Suvorexant 20 and 40 mg: A Study in Non-Elderly Healthy Volunteers

STUDY OBJECTIVE

To evaluate next-morning driving performance in adults younger than 65 years, after single and repeated doses of suvorexant 20 and 40 mg.

DESIGN

Double-blind, placebo-controlled, 4-period crossover study.

SETTING

Maastricht University, The Netherlands.

PARTICIPANTS

28 healthy volunteers (15 females), aged 23 to 64 years.

INTERVENTIONS

Suvorexant (20 and 40 mg) for 8 consecutive nights; zopiclone 7.5 mg nightly on day 1 and 8; placebo.

MEASUREMENTS

Performance on day 2 and 9 (9 h after dosing) using a one-hour standardized highway driving test in normal traffic, measuring standard deviation of lateral position (SDLP). Drug-placebo changes in SDLP > 2.4 cm were considered to reflect meaningful driving impairment.

RESULTS

Mean drug-placebo changes in SDLP following suvorexant 20 and 40 mg were 1.01 and 1.66 cm on day 2, and 0.48 and 1.31 cm on Day 9, respectively. The 90% CIs of these changes were all below 2.4 cm. Symmetry analysis showed that more subjects had SDLP changes > 2.4 cm than < -2.4 cm following suvorexant 20 and 40 mg on day 2, and following suvorexant 40 mg on day 9. Four female subjects requested that a total of 5 driving tests--all following suvorexant--stop prematurely due to self-reported somnolence.

CONCLUSIONS

As assessed by mean changes in standard deviation of lateral position (SDLP), there was no clinically meaningful residual effect of suvorexant in doses of 20 and 40 mg on next-morning driving (9 h after bedtime dosing) in healthy subjects < 65 years old. There may be some individuals who experience next-day effects, as suggested by individual changes in SDLP and prematurely stopped tests.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov NCT01311882.

Sensitivity and validity of psychometric tests for assessing driving impairment: effects of sleep deprivation

OBJECTIVE

To assess drug induced driving impairment, initial screening is needed. However, no consensus has been reached about which initial screening tools have to be used. The present study aims to determine the ability of a battery of psychometric tests to detect performance impairing effects of clinically relevant levels of drowsiness as induced by one night of sleep deprivation.

METHODS

Twenty four healthy volunteers participated in a 2-period crossover study in which the highway driving test was conducted twice: once after normal sleep and once after one night of sleep deprivation. The psychometric tests were conducted on 4 occasions: once after normal sleep (at 11 am) and three times during a single night of sleep deprivation (at 1 am, 5 am, and 11 am).

RESULTS

On-the-road driving performance was significantly impaired after sleep deprivation, as measured by an increase in Standard Deviation of Lateral Position (SDLP) of 3.1 cm compared to performance after a normal night of sleep. At 5 am, performance in most psychometric tests showed significant impairment. As expected, largest effect sizes were found on performance in the Psychomotor Vigilance Test (PVT). Large effects sizes were also found in the Divided Attention Test (DAT), the Attention Network Test (ANT), and the test for Useful Field of View (UFOV) at 5 and 11 am during sleep deprivation. Effects of sleep deprivation on SDLP correlated significantly with performance changes in the PVT and the DAT, but not with performance changes in the UFOV.

CONCLUSION

From the psychometric tests used in this study, the PVT and DAT seem most promising for initial evaluation of drug impairment based on sensitivity and correlations with driving impairment. Further studies are needed to assess the sensitivity and validity of these psychometric tests after benchmark sedative drug use.

Residual effects of low-dose sublingual zolpidem on highway driving performance the morning after middle-of-the-night use

STUDY OBJECTIVE

To evaluate next-morning driving performance after middle-of-the-night use of zolpidem 3.5 mg in a buffered sublingual formulation (ZST).

DESIGN

Single-center, four-period, randomized, double-blind, placebo-controlled, crossover study.

SETTING

Maastricht University, The Netherlands.

PARTICIPANTS

Forty healthy volunteers (20 females).

INTERVENTIONS

Single dose of ZST administered in the middle of the night at 3 and 4 h before driving, zopiclone 7.5 mg at bedtime 9 h before driving, and placebo.

MEASUREMENTS

Performance in a 100-km standardized highway driving test in normal traffic measuring standard deviation of lateral position (SDLP) - an index of weaving. Drug-placebo changes in SDLP > 2.5 cm were considered to reflect clinically relevant driving impairment.

RESULT

For ZST, Max McNemar symmetry analyses showed that the proportion of drivers classified as impaired was increased 3 h after dosing (P < 0.012), but not 4 h after dosing. Mean increases in SDLP from placebo, although statistically significant, were small (1.46 cm [P < 0.0001] at 3 h and 0.83 cm [P = 0.0174] at 4 h). The morning after zopiclone, 45% of the drivers were classified as impaired with a mean increase in SDLP of 2.46 cm (P < 0.0001). There were no significant sex differences in effects of ZST and zopiclone.

CONCLUSION

Zolpidem 3.5 mg in a buffered sublingual formulation has a minimal risk of impairing driving performance in the morning ≥ 4 hours after middle-of-the night use. When taken 3 hours before driving, the drug may have impairing effects so caution should be exercised if medication is taken other than as indicated.

CLINICAL TRIAL INFORMATION

ClinicalTrials.gov Identifier: NCT01106859; Trial Name: Driving Performance After Middle of the Night Administration of 3.5 mg Zolpidem Tartrate Sublingual Tablet; http://clinicaltrials.gov/ct2/show/NCT01106859.