Predicting psychopharmacological drug effects on actual driving performance (SDLP) from psychometric tests measuring driving-related skills

The Effect of Partial Sleep Deprivation and Time-on-Task on Young Drivers' Subjective and Objective Sleepiness

Despite sleepiness being considered one of the main factors contributing to road crashes, and even though extensive efforts have been made in the identification of techniques able to detect it, the assessment of fitness-to-drive regarding driving fatigue and sleepiness is still an open issue. In the literature on driver sleepiness, both vehicle-based measures and behavioral measures are used. Concerning the former, the one considered more reliable is the Standard Deviation of Lateral Position (SDLP) while the PERcent of eye CLOSure over a defined period of time (PERCLOS) seems to be the most informative behavioral measure. In the present study, using a within-subject design, we assessed the effect of a single night of partial sleep deprivation (PSD, less than 5 h sleeping time) compared to a control condition (full night of sleep, 8 h sleeping time) on SDLP and PERCLOS, in young adults driving in a dynamic car simulator. Results show that time-on-task and PSD affect both subjective and objective sleepiness measures. Moreover, our data confirm that both objective and subjective sleepiness increase through a monotonous driving scenario. Considering that SDLP and PERCLOS were often used separately in studies on driver sleepiness and fatigue detection, the present results have potential implications for fitness-to-drive assessment in that they provide useful information allowing to combine the advantages of the two measures for drowsiness detection while driving.

Pharmacokinetic and pharmacodynamic interactions between daridorexant, a dual orexin receptor antagonist, and citalopram in healthy subjects

Daridorexant (ACT-541468) is a new dual orexin receptor antagonist being evaluated for the treatment of insomnia, which is a common comorbidity of depression and anxiety. Therefore, daridorexant is likely to be administered concomitantly with agents (e.g., citalopram) used to treat these disorders. In this single-centre, single-blind, randomized, placebo-controlled, sequential design Phase 1 study with the inclusion of two double-blind crossover parts, the pharmacokinetic (PK; blood sampling at regular intervals) and pharmacodynamic (PD; battery of objective and subjective PD tests performed at regular intervals) interactions between daridorexant (50 mg) and citalopram (20 mg, single dose and at steady state) as well as the safety/tolerability in healthy subjects were investigated. There were no relevant effects of citalopram (single dose/steady state) on daridorexant exposure and vice versa. PD variables measured after morning administration of daridorexant alone showed effects consistent with a sleep-promoting compound. Only co-administration of daridorexant with citalopram at steady state led to relevant changes in objective (unstable tracking) and subjective (visual analogue scale alertness and Karolinska Sleepiness Scale) PD endpoints compared to daridorexant alone. No serious or severe adverse events were reported, while no clinically relevant treatment-emergent effects on ECG parameters, clinical laboratory, or vital signs were observed. In conclusion, the co-administration of daridorexant and citalopram lead to only minor changes in PK parameters, while performance of PD assessments following co-administration were mainly driven by the expected central nervous system effects of daridorexant. Doses up to 50 mg daridorexant can be safely co-administered with citalopram.

Effects of Mixing Energy Drinks With Alcohol on Driving-Related Skills

BACKGROUND

Energy drinks (EDs) reduce sleepiness and fatigue and improve driving performance whereas alcohol does just the opposite. Although it is a trendy combination among young people, the effects of alcohol mixed with EDs on driving performance have been poorly studied. The aim was to assess if there is an interaction between the effects of both drinks on driving-related skills as well as perceptions about driving ability.

METHODS

We conducted a randomized, double-blind, and placebo-controlled 4-way crossover clinical trial. Participants were 16 healthy volunteers. Interventions of 60 g of ethanol and 750 mL of Red Bull (RB) were administered in 2 separated doses. Conditions were alcohol + RB placebo, alcohol + RB, alcohol placebo + RB, and both placebos. Objective performance was assessed using a tracking test and simple reaction time, N-Back, and movement estimation tasks. Additionally, willingness to drive, other subjective effects, and ethanol and caffeine blood concentrations were also measured.

RESULTS

Alcohol increased the time outside the road in the tracking test and increased simple reaction time, but the addition of RB had no main or interaction effects on performance. Nonetheless, driving-related skills after alcohol + RB were better than after alcohol alone. Willingness to drive increased with the combination of drinks. RB also reduced alcohol-induced sedation whereas drunkenness did not change. These effects were seen even though alcohol + RB increased alcohol (14.8%) and caffeine plasma concentrations (17.6%).

CONCLUSIONS

Mixing EDs with alcohol predisposes consumers to drive under alcohol influence, perhaps in part because EDs counteract its detrimental effects on driving-related skills. Clinicaltrials.gov: NCT02771587.

On-the-road driving performance of patients with central disorders of hypersomnolence

INTRODUCTION

Excessive Daytime Sleepiness is a core symptom of narcolepsy and idiopathic hypersomnia, which impairs driving performance. Adequate treatment improves daytime alertness, but it is unclear whether driving performance completely normalizes. This study compares driving performance of patients with narcolepsy and idiopathic hypersomnia receiving treatment to that of healthy controls.

METHODS

Patients diagnosed with narcolepsy type 1 (NT1, n = 33), narcolepsy type 2 (NT2, n = 7), or idiopathic hypersomnia (IH, n = 6) performed a standardized one-hour on-the-road driving test, measuring standard deviation of lateral position (SDLP).

RESULTS

Results showed that mean SDLP in patients did not differ significantly from controls, but the 95%CI of the mean difference (+1.02 cm) was wide (-0.72 to +2.76 cm). Analysis of subgroups, however, showed that mean SDLP in NT1 patients was significantly increased by 1.90 cm as compared to controls, indicating impairment. Moreover, four NT1 patients requested to stop the test prematurely due to self-reported somnolence, and two NT1 patients were stopped by the driving instructor for similar complaints.

CONCLUSION

Driving performance of NT1 patients may still be impaired, despite receiving treatment. No conclusions can be drawn for NT2 and IH patients due to the low sample sizes of these subgroups. In clinical practice, determination of fitness to drive for these patients should be based on an individual assessment in which also coping strategies are taken into account.

The Drives for Driving Simulation: A Scientometric Analysis and a Selective Review of Reviews on Simulated Driving Research

Driving behaviors and fitness to drive have been assessed over time using different tools: standardized neuropsychological, on-road and driving simulation testing. Nowadays, the great variability of topics related to driving simulation has elicited a high number of reviews. The present work aims to perform a scientometric analysis on driving simulation reviews and to propose a selective review of reviews focusing on relevant aspects related to validity and fidelity. A scientometric analysis of driving simulation reviews published from 1988 to 2019 was conducted. Bibliographic data from 298 reviews were extracted from Scopus and WoS. Performance analysis was conducted to investigate most prolific Countries, Journals, Institutes and Authors. A cluster analysis on authors' keywords was performed to identify relevant associations between different research topics. Based on the reviews extracted from cluster analysis, a selective review of reviews was conducted to answer questions regarding validity, fidelity and critical issues. United States and Germany are the first two Countries for number of driving simulation reviews. United States is the leading Country with 5 Institutes in the top-ten. Top Authors wrote from 3 to 7 reviews each and belong to Institutes located in North America and Europe. Cluster analysis identified three clusters and eight keywords. The selective review of reviews showed a substantial agreement for supporting validity of driving simulation with respect to neuropsychological and on-road testing, while for fidelity with respect to real-world driving experience a blurred representation emerged. The most relevant critical issues were the a) lack of a common set of standards, b) phenomenon of simulation sickness, c) need for psychometric properties, lack of studies investigating d) predictive validity with respect to collision rates and e) ecological validity. Driving simulation represents a cross-cutting topic in scientific literature on driving, and there are several evidences for considering it as a valid alternative to neuropsychological and on-road testing. Further research efforts could be aimed at establishing a consensus statement for protocols assessing fitness to drive, in order to (a) use standardized systems, (b) compare systematically driving simulators with regard to their validity and fidelity, and (c) employ shared criteria for conducting studies in a given sub-topic.

First-in-human study with ACT-539313, a novel selective orexin-1 receptor antagonist

AIMS

The orexin system is involved in anxiety behaviour and corresponding physiological reactions and constitutes a target for treatment of anxiety disorders. ACT-539313 is a potent, selective orexin-1 receptor antagonist being developed for the treatment of anxiety disorders. This first-in-human study investigated its single-dose pharmacokinetics (PK) including food effect, pharmacodynamics (PD), safety and tolerability.

METHODS

This double-blind, placebo-controlled, randomized study included 40 healthy male subjects. Ascending oral doses of 10-400 mg ACT-539313 were investigated in 5 dose groups of 8 subjects (of whom 2 received placebo per dose group). At 100 mg, subjects received ACT-539313 in fasted and fed conditions in a fixed sequential design. PK, PD (objective and subjective measures of sedation and effects on central nervous system), safety and tolerability were assessed.

RESULTS

In fasted conditions, ACT-539313 was rapidly absorbed (median time to maximum plasma concentration [C_max ] 0.7-3.5 h) and cleared from plasma with a mean terminal half-life of 3.3-5.7 h across dose levels. A 1.63-fold (90% confidence interval: 1.26-2.11) increase in C_max and no change in area under the concentration-time curve extrapolated to infinity was observed under fed compared to fasted conditions. No relevant PD signals were detected except for a trend of reduced saccadic peak velocity around time to C_max . The most commonly reported adverse events were somnolence and headache. All adverse events were transient and of mild or moderate intensity. No treatment-related effects on vital signs, clinical laboratory or 12-lead electrocardiogram were observed.

CONCLUSIONS

ACT-539313 exhibits good safety and tolerability at single doses of up to and including 400 mg that warrant further investigations.

Zolpidem and Gender: Are Women Really At Risk?

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation of simulated driving in comparison to laboratory-based tests to assess the pharmacodynamics of alprazolam and alcohol

RATIONALE

Assessment of the effects of medicines on the risks of car driving must be derived from laboratory tests, simulated driving or real on-road driving tests. Relevance of tests is determined by their sensitivity and predictive ability for the probability of accidents or damage. This cannot be determined directly, but methods should be able to at least detect the effects of a positive control in dosage known to be clearly associated with increased risk.

OBJECTIVES

A driving simulator was evaluated in comparison with a battery of validated tests of CNS performance, the NeuroCart®. Alcohol in a concentration exactly at the legal limit (0.5 g L^-1) and well above (1.0 g L^-1) as well as alprazolam (1 mg) was used as positive control.

METHODS

This was a randomised, cross-over study using a double dummy blinded design in 24 healthy study subjects (12 M, 12 F) aged 20-43 years. Alcohol was infused intravenously using a validated clamping protocol to obtain concentrations of 0.5 g L^-1 and on another occasion 1.0 g L^-1. Alprazolam was given orally. Driving tests and lab tests were done at regular time intervals during a study day.

RESULTS

Alprazolam and alcohol significantly affected the main parameters of driving in the simulator and affected scores of safe driving and alprazolam increased the odds ratio of a virtual crash. Several laboratory measurements of psychomotor performance were affected by the reference substances as expected and correlated significantly with the driving performance.

CONCLUSIONS

The driving simulator can detect effects of reference substances at levels that are known to negatively affect driving.

Memory and attention during an alcohol hangover

OBJECTIVE

This study aims to investigate attention, memory functioning, and mood in a natural setting with real-life alcohol consumption levels.

METHODS

Seventy-four participants with a mean (SD) age of 24.5 (7.0) years old participated in a naturalistic study. A between subjects design was applied comparing a hangover group with an (alcohol-free) control group. Participants in the hangover group consumed a mean (SD) of 13.8 (10.2) alcoholic drinks the night before testing. Cognitive tests included the Stroop test, Eriksen's flanker test, a divided attention test, intradimensional-extradimensional set shifting test, spatial working memory test, and free word recall test.

RESULTS

The hangover group had increased reaction times compared with the control group. Selective attention (Stroop and Eriksen's Flanker test performance) was significantly impaired during alcohol hangover. However, the number of errors did not differ significantly between the groups in any task. Mood assessments revealed that the hangover group reported significantly higher levels of drowsiness and clumsiness compared with the control group.

CONCLUSION

Selective attention was significantly impaired during alcohol hangover. The differences between the hangover and control group did not reach significance for other forms of attention or memory.

A clinical trial on the acute effects of methadone and buprenorphine on actual driving and cognitive function of healthy volunteers

Aims

The present study assessed the acute effects of methadone and buprenorphine on actual on‐road driving performance and neurocognitive function.

Methods

Methadone (5 and 10 mg per os) and buprenorphine (0.2 and 0.4 mg sublingual) were administered to 22 healthy volunteers in a five‐way, double‐blind, randomized, placebo‐controlled, double‐dummy, cross‐over study. Driving performance was assessed with an on‐road driving test. The primary outcome measure was standard deviation of lateral position (SDLP), a measure of road tracking control. Laboratory tests were used to measure cognitive function (e.g. reaction time and attention) and questionnaires were used to assess subjective measures of mood and sedation.

Results

There was no significant main effect of treatment on SDLP. Yet, analysis of individual drug‐placebo contrast data revealed that buprenorphine 0.4 mg significantly increased SDLP. Driving impairment was mild and below the impairment threshold of a blood alcohol concentration of 0.5 mg ml⁻¹. Four participants stopped their driving test while under the influence of either opioid due to sleepiness. Both opioids produced impairments of cognitive task performance and increased sleepiness particularly at the highest dose.

Conclusions

Analgesic doses of buprenorphine produced mild impairing effects on driving and related cognitive skills, while methadone impaired cognitive task performance but not driving performance. Large individual variations were observed for both drugs. Patients should be informed about the possibility of driving impairment when initiating opioid treatment.

The impact of therapeutic opioid agonists on driving-related psychomotor skills assessed by a driving simulator or an on-road driving task: A systematic review

BACKGROUND

Driving cessation is associated with poor health-related outcomes. People with chronic diseases are often prescribed long-term opioid agonists that have the potential to impair driving. Studies evaluating the impact of opioids on driving-related psychomotor skills report contradictory results likely due to heterogeneous designs, assessment tools and study populations. A better understanding of the effects of regular therapeutic opioid agonists on driving can help to inform the balance between individual's independence and community safety.

AIM

To identify the literature assessing the impact of regular therapeutic opioid agonists on driving-related psychomotor skills for people with chronic pain or chronic breathlessness.

DESIGN

Systematic review reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis statement; PROSPERO Registration CRD42017055909.

DATA SOURCES

Six electronic databases and grey literature were systematically searched up to January, 2017. Inclusion criteria were as follows: (1) empirical studies reporting data on driving simulation, on-the-road driving tasks or driving outcomes; (2) people with chronic pain or chronic breathlessness; and (3) taking regular therapeutic opioid agonists. Critical appraisal used the National Institutes of Health's quality assessment tools.

RESULTS

From 3809 records screened, three studies matched the inclusion criteria. All reported data on people with chronic non-malignant pain. No significant impact of regular therapeutic opioid agonists on people's driving-related psychomotor skills was reported. One study reported more intense pain significantly worsened driving performance.

CONCLUSION

This systematic review does not identify impaired simulated driving performance when people take regular therapeutic opioid agonists for symptom control, although more prospective studies are needed.

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.

Effects of valerian on subjective sedation, field sobriety testing and driving simulator performance

INTRODUCTION

The availability of herbal medicines over-the-counter (OTC) has increased the use of natural products for self-treatment. Valerian has been used to effectively treat generalized anxiety disorder and insomnia. Studies suggest that valerenic acid may increase gamma-aminobutyric acid (GABA) modulation in the brain. Benzodiazepines have a similar mechanism of action and have been linked to an increased risk of hospitalizations due to traffic accidents. Despite the risk of somnolence, the safety of driving while under the influence of valerian remains unknown.

PURPOSE

The purpose of the study was to determine the effects of a one-time valerian 1600mg dose on subjective sedation effects, standardized field sobriety testing (SFST) and driving simulator performance parameters.

METHODS

The study design was a randomized, placebo-controlled, double-blind, cross-over trial. For each session, participants received either a dose of valerian or placebo. The outcome measures included a simple visual reaction test (SVRT), subjective sleepiness scales, SFST performance scores, and driving simulator performance parameters.

RESULTS

There were no significant differences in the SVRT or sleepiness scales between placebo and valerian exposures, but the study may have been underpowered. SFST total and individual test failure rates were not significantly different between the two exposures. The driving simulator performance parameters were equivalent between the two exposure conditions.

CONCLUSIONS

A one-time valerian 1600mg dose, often used to treat insomnia, does not appear to impair driving simulator performance after acute ingestion.

The sensitivity of laboratory tests assessing driving related skills to dose-related impairment of alcohol: A literature review

Laboratory tests assessing driving related skills can be useful as initial screening tools to assess potential drug induced impairment as part of a standardized behavioural assessment. Unfortunately, consensus about which laboratory tests should be included to reliably assess drug induced impairment has not yet been reached. The aim of the present review was to evaluate the sensitivity of laboratory tests to the dose dependent effects of alcohol, as a benchmark, on performance parameters. In total, 179 experimental studies were included. Results show that a cued go/no-go task and a divided attention test with primary tracking and secondary visual search were consistently sensitive to the impairing effects at medium and high blood alcohol concentrations. Driving performance assessed in a simulator was less sensitive to the effects of alcohol as compared to naturalistic, on-the-road driving. In conclusion, replicating results of several potentially useful tests and their predictive validity of actual driving impairment should deserve further research. In addition, driving simulators should be validated and compared head to head to naturalistic driving in order to increase construct validity.

Behavioral and Neurophysiological Signatures of Benzodiazepine-Related Driving Impairments

Impaired driving due to drug use is a growing problem worldwide; estimates show that 18-23.5% of fatal accidents, and up to 34% of injury accidents may be caused by drivers under the influence of drugs (Drummer et al., 2003; Walsh et al., 2004; NHTSA, 2010). Furthermore, at any given time, up to 16% of drivers may be using drugs that can impair one's driving abilities (NHTSA, 2009). Currently, drug recognition experts (DREs; law enforcement officers with specialized training to identify drugged driving), have the most difficult time with identifying drivers potentially impaired on central nervous system (CNS) depressants (Smith et al., 2002). The fact that the use of benzodiazepines, a type of CNS depressant, is also associated with the greatest likelihood of causing accidents (Dassanayake et al., 2011), further emphasizes the need to improve research tools in this area which can facilitate the refinement of, or additions to, current assessments of impaired driving. Our laboratories collaborated to evaluate both the behavioral and neurophysiological effects of a benzodiazepine, alprazolam, in a driving simulation (miniSim(TM)). This drive was combined with a neurocognitive assessment utilizing time synched neurophysiology (electroencephalography, ECG). While the behavioral effects of benzodiazepines are well characterized (Rapoport et al., 2009), we hypothesized that, with the addition of real-time neurophysiology and the utilization of simulation and neurocognitive assessment, we could find objective assessments of drug impairment that could improve the detection capabilities of DREs. Our analyses revealed that (1) specific driving conditions were significantly more difficult for benzodiazepine impaired drivers and (2) the neurocognitive tasks' metrics were able to classify "impaired" vs. "unimpaired" with up to 80% accuracy based on lane position deviation and lane departures. While this work requires replication in larger studies, our results not only identified criteria that could potentially improve the identification of benzodiazepine intoxication by DREs, but also demonstrated the promise for future studies using this approach to improve upon current, real-world assessments of impaired driving.

Bilastine vs. hydroxyzine: occupation of brain histamine H1 -receptors evaluated by positron emission tomography in healthy volunteers

AIM

A close correlation exists between positron emission tomography (PET)-determined histamine H1 -receptor occupancy (H1 RO) and the incidence of sedation. Antihistamines with H1 RO <20% are classified as non-sedating. The objective was to compare the H1 RO of bilastine, a second generation antihistamine, with that of hydroxyzine.

METHODS

This randomized, double-blind, crossover study used PET imaging with [(11) C]-doxepin to evaluate H1 RO in 12 healthy males (mean age 26.2 years), after single oral administration of bilastine (20 mg), hydroxyzine (25 mg) or placebo. Binding potentials and H1 ROs were calculated in five cerebral cortex regions of interest: frontal, occipital, parietal, temporal, insula. Plasma bilastine concentrations, subjective sedation (visual analogue scale), objective psychomotor performance (digital symbol substitution test), physiological variables and safety (adverse events, AEs), were also evaluated.

RESULTS

The mean binding potential of all five regions of interest (total binding potential) was significantly greater with bilastine than hydroxyzine (mean value 0.26 vs. 0.13, P < 0.01; mean difference and 95% CI -0.130 [-0.155, 0.105]). There was no significant difference between bilastine and placebo. Overall H1 RO by bilastine was significantly lower than that by hydroxyzine (mean value -3.92% vs. 53.95%, P < 0.01; mean difference and 95% CI 57.870% [42.664%, 73.075%]). There was no significant linear relationship between individual bilastine plasma concentrations and total binding potential values. No significant between-treatment differences were observed for sedation and psychomotor performance. Twenty-six non-serious AEs were reported. Sleepiness or sedation was not reported with bilastine but appeared in some subjects with hydroxyzine.

CONCLUSIONS

A single oral dose of bilastine 20 mg had minimal H1 RO, was not associated with subjective sedation or objective impairment of psychomotor performance and was devoid of treatment-related sedative AEs, thus satisfying relevant subjective, objective and PET criteria as a non-sedating antihistamine.

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.

Mirtazapine as positive control drug in studies examining the effects of antidepressants on driving ability

The development of effective and safe antidepressant medications is ongoing, and driving studies are critical to assess a drug's safety. The current review summarizes the effects of a sedating effective antidepressant, mirtazapine, on driving ability, and its potential to serve as positive control drug in future driving studies. Three on-road driving studies and four driving simulator studies of mirtazapine were identified. The studies, conducted in healthy volunteers, showed a significant dose-dependent driving impairment, the first day following bedtime administration of mirtazapine. The magnitude of impairment after a single dose of 15 mg or 30 mg mirtazapine was comparable to that observed with a blood alcohol concentration of 0.05%, the legal limit for driving in many countries. After 1 or 2 weeks of daily treatment with mirtazapine, partial tolerance developed to mirtazapine's effects on driving. Driving studies conducted in patients were less informative, as the effect on driving caused by mirtazapine was obscured by a drug-disease interaction and increased variability in patient groups. In conclusion, mirtazapine is useful as positive control drug to assess the potential effects of new antidepressant drugs on driving. Studies in normal healthy volunteers are more sensitive to drug effects than studies in patient populations.

Effects of alcohol hangover on simulated highway driving performance

BACKGROUND

The purpose of this study was to examine the effects of alcohol hangover on simulated highway driving performance.

METHODS

Driving performance of forty-two social drinkers was tested the morning following an evening of consuming on average 10.2 (SD = 4.2) alcoholic drinks (alcohol hangover) and on a control day (no alcohol consumed). Subjects performed a standardized 100-km highway driving test in the STISIM driving simulator. In addition to the standard deviation of lateral position (SDLP; i.e., the weaving of the car), lapses of attention were examined. Self-reported driving quality and driving style were scored, as well as mental effort to perform the test, sleepiness before and after driving, and hangover severity.

RESULTS

Driving performance was significantly impaired during alcohol hangover as expressed by an SDLP increase of +1.9 cm (t (1,41) = 2.851, p = 0.007), increased number of lapses relative to the control day (7.7 versus 5.3 lapses, t (1,41) = 2.125, p = 0.019), and an increased total lapse time (182.7 versus 127.3 s, p = 0.040). During alcohol hangover, subjects reported their driving quality to be significantly poorer (t (1,41) = 4.840, p = 0.001) and less safe (t (1,41) = 5.078, p = 0.001), wise (t (1,41) = 4.061, p = 0.001), predictable (t (1,41) = 3.475, p = 0.001), and responsible (t (1,41) = 4.122, p = 0.001). Subjects further reported being significantly more tense while driving (t (1,41) = 3.280, p = 0.002), and more effort was needed to perform the driving test (t (1,41) = 2.941, p = 0.001). There was a significant interaction with total sleep time and hangover effects on SDLP and the number of lapses.

CONCLUSIONS

In conclusion, driving is significantly impaired during alcohol hangover, as expressed in an elevated SDLP and increased number of lapses. Total sleep time has a significant impact on the magnitude of driving impairment.

Allergic rhinitis is a risk factor for traffic safety

BACKGROUND

Allergic rhinitis (AR) affects up to 30% of the adult population and symptomatic patients continue to engage in daily life activities, including car driving. Previous studies have shown that AR can impair cognitive functions, especially during longer-lasting tasks. Other reports suggest negative effects on psychomotor functions such as driving, but no clear evidence has been presented yet.

OBJECTIVES

Primary objective was to determine the effect of AR per se on actual driving performance and compare it with the effects of treated AR.

METHODS

Nineteen patients with documented AR history underwent a unique and validated 1-h on-the-road driving test outside the pollen season. In a 4-leg repeated measures design, patients underwent a nasal provocation test with either pollen or inactive control prior to the driving test. In the three conditions with pollen provocation, patients were pretreated with either cetirizine 10 mg, fluticasone furoate 27.5 μg, or placebo to alleviate the provoked AR symptoms.

RESULTS

The driving performance of patients when symptomatic and not treated was significantly impaired compared to the placebo condition. When engaging in a secondary memory task during driving, their performance deteriorated further. The magnitude of impairment was relevant and comparable to that seen at a blood alcohol level of 0.05%, the legal limit in many countries. Treatment of AR symptoms partially counteracted the effect of AR on driving.

CONCLUSIONS

Untreated AR can impair driving ability and put patients at risk. Drug therapy reduces this impairment, and AR patients should therefore be advised to always treat their condition.

Effects of alcohol on automated and controlled driving performances

RATIONALE

Alcohol is the most frequently detected substance in fatal automobile crashes, but its precise mode of action is not always clear.

OBJECTIVE

The present study was designed to establish the influence of blood alcohol concentration as a function of the complexity of the scenarios. Road scenarios implying automatic or controlled driving performances were manipulated in order to identify which behavioral parameters were deteriorated.

METHOD

A single blind counterbalanced experiment was conducted on a driving simulator. Sixteen experienced drivers (25.3 ± 2.9 years old, 8 men and 8 women) were tested with 0, 0.3, 0.5, and 0.8 g/l of alcohol. Driving scenarios varied: road tracking, car following, and an urban scenario including events inspired by real accidents. Statistical analyses were performed on driving parameters as a function of alcohol level.

RESULTS

Automated driving parameters such as standard deviation of lateral position measured with the road tracking and car following scenarios were impaired by alcohol, notably with the highest dose. More controlled parameters such as response time to braking and number of crashes when confronted with specific events (urban scenario) were less affected by the alcohol level.

CONCLUSION

Performance decrement was greater with driving scenarios involving automated processes than with scenarios involving controlled processes.

Psychomotor and subjective effects of bilastine, hydroxyzine, and cetirizine, in combination with alcohol: a randomized, double-blind, crossover, and positive-controlled and placebo-controlled Phase I clinical trials

OBJECTIVE

The aim of this study was to compare the effects of concomitant administration of alcohol and bilastine versus alcohol alone on the central nervous system.

METHODS

Twenty-four healthy young volunteers of both sexes participated in a randomized, double-blind, double-dummy, crossover, and positive-controlled and placebo-controlled clinical trials. At 1-week intervals, subjects received six different treatments: (i) placebo; (ii) alcohol 0.8 g/kg alone (ALC); (iii) ALC in combination with: bilastine 20 mg (B20 + A); (iv) bilastine 80 mg (B80 + A); (v) cetirizine 10 mg (CET + A); and (vi) hydroxyzine 25 mg (HYD + A). Psychomotor performance tests (fine motor, finger tapping, nystagmus, critical flicker-fusion frequency, temporal estimation, 'd2' cancellation, and simple reaction time) and subjective self-reports (drunkenness, drowsiness, mental slowness, clumsiness, anger, attentiveness, competence, happiness, hostility, interest, and extroversion) were carried out at baseline and multiple points thereafter.

RESULTS

All active treatments induced a significant psychomotor impairment. The greatest and most lasting impairment was observed with HYD + A followed by B80 + A and CET + A. In contrast, objective measures showed less impairment with B20 + A and ALC, both with a similar magnitude. Self-reports showed a subjective perception of performance impairment in all active treatments.

CONCLUSION

Concomitant administration of bilastine (at therapeutic dose) and alcohol does not produce greater central nervous system depressant effects than ACL alone.

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.

Effects of central nervous system drugs on driving: speed variability versus standard deviation of lateral position as outcome measure of the on-the-road driving test

BACKGROUND

The on-the-road driving test in normal traffic is used to examine the impact of drugs on driving performance. This paper compares the sensitivity of standard deviation of lateral position (SDLP) and SD speed in detecting driving impairment.

METHODS

A literature search was conducted to identify studies applying the on-the-road driving test, examining the effects of anxiolytics, antidepressants, antihistamines, and hypnotics. The proportion of comparisons (treatment versus placebo) where a significant impairment was detected with SDLP and SD speed was compared.

RESULTS

About 40% of 53 relevant papers did not report data on SD speed and/or SDLP. After placebo administration, the correlation between SDLP and SD speed was significant but did not explain much variance (r = 0.253, p = 0.0001). A significant correlation was found between ΔSDLP and ΔSD speed (treatment-placebo), explaining 48% of variance. When using SDLP as outcome measure, 67 significant treatment-placebo comparisons were found. Only 17 (25.4%) were significant when SD speed was used as outcome measure. Alternatively, for five treatment-placebo comparisons, a significant difference was found for SD speed but not for SDLP.

CONCLUSIONS

Standard deviation of lateral position is a more sensitive outcome measure to detect driving impairment than speed variability.

Meta-analysis of on-the-road experimental studies of hypnotics: effects of time after intake, dose, and half-life

BACKGROUND

The use of hypnotics is prevalent in the general population. Though these drugs have been shown to be effective, their residual effects may cause significant impairment to the user's driving ability. The objective of this meta-analysis is to determine whether there is a residual effect on driving and better evaluate the safety of hypnotics.

METHOD

Randomized double-blind placebo-controlled studies were selected that employed a commonly used and valid driving measure to determine the user's driving ability the day after drug administration. The primary outcome measure for the driving task in all included studies was the Standard Deviation of Lateral Position (SDLP). Fixed effects model meta-analyses were performed.

RESULTS

Fourteen studies, published from 1984 to 2013 (295 subjects), were included in this meta-analysis. Overall, significant impairment was found when morning testing (i.e., 10-11 h after initiating sleep) was compared to afternoon testing (i.e., 16-17 h after initiating sleep; P = .0001). Twice the standard dose also showed significant impairment (P = .0001) relative to the standard dose. The time of the test, morning versus afternoon, also had an impact on individual drugs. Middle of the night administration (MOTN) of zolpidem and zopiclone caused significant impairment the following morning, though no such impairment was seen with zaleplon. Finally, half-life was also assessed (short: <6 h, intermediate: 6-12 h, long: >12 h) and both intermediate- and long-acting drugs caused significant impairment the morning after bedtime administration, whereas short acting hypnotics did not.

CONCLUSIONS

These analyses indicate that the half-life, dose of the hypnotic, as well as time between treatment and driving, as measured by SDLP, all significantly impact the ability to drive a car after taking hypnotic drugs.

Driving during alcohol hangover among dutch professional truck drivers

OBJECTIVES

Alcohol hangover may impair potentially dangerous daily activities such as driving a car or operating heavy machinery. The purpose of the present study was to determine (1) whether driving during alcohol hangover is a problem of concern among professional Dutch truck drivers and (2) to what extent they think their hangover state affects driving performance.

METHODS

Three hundred forty-three professional truck drivers were interviewed at a Dutch trucker festival. In addition to demographics, data were gathered on normal driving, alcohol consumption and hangover, and driving style during alcohol hangover.

RESULTS

More than half of the professional drivers who consume alcohol and report occasionally having a hangover (56.4%) acknowledge that they have driven while having a hangover during the past year: 26.5 percent only when driving private, 2.6 percent only when driving professionally, and 27.4 percent both private and professionally. Additionally, 45.3 percent reported driving while having a hangover sometimes, whereas 7.7 percent and 1.7 percent reported doing so often or always, respectively. During alcohol hangover, professional drivers rated their driving style as significantly less relaxed, less safe, and less responsible (P < .001).

CONCLUSIONS

Driving with a hangover is a common phenomenon, and professional drivers acknowledge that their driving is impaired. Therefore, future experimental research should examine the magnitude of impairment while driving with an alcohol hangover.

Alcohol calibration of tests measuring skills related to car driving

RATIONALE

Medication and illicit drugs can have detrimental side effects which impair driving performance. A drug's impairing potential should be determined by well-validated, reliable, and sensitive tests and ideally be calibrated by benchmark drugs and doses. To date, no consensus has been reached on the issue of which psychometric tests are best suited for initial screening of a drug's driving impairment potential.

OBJECTIVE

The aim of this alcohol calibration study is to determine which performance tests are useful to measure drug-induced impairment. The effects of alcohol are used to compare the psychometric quality between tests and as benchmark to quantify performance changes in each test associated with potentially impairing drug effects.

METHODS

Twenty-four healthy volunteers participated in a double-blind, four-way crossover study. Treatments were placebo and three different doses of alcohol leading to blood alcohol concentrations (BACs) of 0.2, 0.5, and 0.8 g/L.

RESULTS

Main effects of alcohol were found in most tests. Compared with placebo, performance in the Divided Attention Test (DAT) was significantly impaired after all alcohol doses and performance in the Psychomotor Vigilance Test (PVT) and the Balance Test was impaired with a BAC of 0.5 and 0.8 g/L. The largest effect sizes were found on postural balance with eyes open and mean reaction time in the divided attention and the psychomotor vigilance test.

CONCLUSIONS

The preferable tests for initial screening are the DAT and the PVT, as these tests were most sensitive to the impairing effects of alcohol and being considerably valid in assessing potential driving impairment.

Effects of repeated dosing with mirtazapine, trazodone, or placebo on driving performance and cognitive function in healthy volunteers

OBJECTIVE

This study aimed to evaluate the effects of repeated treatments with the sedative antidepressants mirtazapine and trazodone on driving performance and cognitive function.

METHODS

Nineteen healthy men received continuous nocturnal doses of 15-mg mirtazapine , 25-mg trazodone, or placebo for 8 days in a double-blinded, three-way crossover trial. Subjects were asked to perform three driving tasks (road tracking, car following, and harsh braking) using a driving simulator and cognitive tasks (the Wisconsin Card Sorting Test, Continuous Performance Test, and N-back Test) at baseline and on Days 2 and 9. Stanford Sleepiness Scale scores were also assessed.

RESULTS

Mirtazapine significantly increased the standard deviation of lateral position in the road-tracking task as compared with trazodone on Day 2. Mirtazapine significantly increased Stanford Sleepiness Scale scores as compared with trazodone and placebo. For the remaining tasks, no significant effects of treatment were observed.

CONCLUSIONS

Acute treatment of mirtazapine impaired road-tracking performance and increased sleepiness, but sedative effects disappeared under repeated administrations. Trazodone did not affect driving performance or cognitive function under acute or repeated administrations. Both initial sedative effects and pharmacological profiles should be taken into consideration when using sedative antidepressants.