Association of road-traffic accidents with benzodiazepine use

The use of driving impairing medicines: a European survey

Aim

To analyse the consumption of a number of medicines with a known potential for increasing the risk of road traffic accidents in the general population of Europe.

Methods

Questionnaires were distributed through the European Drug Utilization Research Group (EuroDURG) and Post-Innovation Learning through Life-events of drugs (PILLS) networks. A total of 30 countries (the current EU Member States, Iceland, Norway and Switzerland) were asked to supply data on the use of driving impairing medicines for the period 2000–2005, aggregated at the level of the active substance and presented in Defined Daily Doses (DDDs) per 1000 inhabitants per day.

Results

National utilization data were provided by 12 of the 30 countries. Based on these data, a considerable increase in consumption was only seen for the antidepressants and the selective serotonin reuptake inhibitors. A slight increase, decrease or no increase was seen for the rest of the drugs studied (i.e. opioids, antipsychotics, anxiolytics, hypnotics and sedatives, drugs that are used in addictive disorders and antihistamines). Limitations were encountered when data on driving impairing medicines were compared between countries (e.g. variation in the data sources and providers, population coverage, inclusion of hospital data, use of divergent ATC/DDD versions) and, therefore, a cross-national comparison could not be performed.

Conclusions

During the study period, trends within countries showed slight to no increase in the consumption of selected medicinal drug groups, with the exception of the antidepressants and the selective serotonin reuptake inhibitors: they showed a remarkable increased use during the study time-frame. Our results illustrate that it is still difficult to perform a valid and comprehensive collection of drug utilization data on driving impairing medicines. Therefore, efforts to harmonize data collection techniques are required and recommended.

The use of benzodiazpines and related drugs amongst older people in Sweden: associated factors and concomitant use of other psychotropics

OBJECTIVE

To determine the factors associated with use of benzodiazepines and benzodiazepine related drugs (BZDs/BZDRDs) in a nationwide population of older people.

METHODS

We analyzed data on age, sex, type of residential area (urban/rural), and dispensed drugs for people aged > or = 75 years registered in the Swedish Prescribed Drug Register from October to December 2005 (n = 731,105; corresponds to 91% of the domain population). Multivariate logistic regression analysis was used for analyzing whether age, sex, type of residential area, number of other drugs, and concomitant psychotropic drug use was associated with use of BZDs/BZDRDs.

RESULTS

> or =1 BZDs/BZDRDs and > or =2 BZDs/BZDRDs were used by 25% and 5% of the study population, respectively. The most commonly used BZDs/BZDRDs were zopiclone, zolpidem, oxazepam, flunitrazepam, and diazepam. The probability of use BZDs/BZDRDs increased with age, female gender, living in an urban area, use of many other drugs, and concomitant use of other psychotropics, particularly antidepressants. In the comparisons of different BZDs/BZDRDs (n = 179,632), the medium-acting BZDs were associated with higher age, female gender, and use of other psychotropics, whereas BZDRDs showed the opposite pattern. Also, the two BZDRDs zopiclone and zolpidem showed different patterns regarding age, sex, and use of other drugs.

CONCLUSIONS

One in four of the elderly used one or more BZD/BZDRD, which should be prescribed cautiously and with the recognition of the potentially negative effects. There were differences in patterns of use for different BZDs/BZDRDs, even within the same drug class. Hence, large study populations are needed for future research of individual BZDs/BZDRDs.

Perceptions of nurses in nursing homes on the usage of benzodiazepines

AIM

This paper reports the findings of a qualitative study on how nurses perceive their own role in the use of benzodiazepines in nursing homes and to identify the factors that have an impact on the nurses' role in the use of benzodiazepines.

BACKGROUND

The use of benzodiazepines in nursing homes is of particular concern, as nursing-home residents receive considerably more benzodiazepines than non-institutionalised older persons. Evidence of their long-term effectiveness is lacking. Nurses are important partners in the decision-making process of starting and discontinuation of benzodiazepines.

DESIGN

Qualitative descriptive.

METHOD

Three focus group interviews and 10 additional semi-structured interviews were used with 33 registered nurses. The interviews were thematically analysed.

FINDINGS

Nurses' main concern is to work towards the comfort of the patient. Benzodiazepines are an easy option with not too many side effects and administration of benzodiazepines is experienced as a routine action. When prescribed they will almost automatically lead to chronic usage as there is no evaluation of their effect. There are three aspects that have an impact on nurse's perceptions of their role in benzodiazepine usage: their own individual attitude and perceptions, their knowledge and organisational factors.

CONCLUSION

Nurses do not see benzodiazepines as a problem drug and once a prescription is initiated it will almost automatically lead to chronic usage. Nurses should work towards a pro-active promotion of addressing sleeping problems and they can play a key role in non-pharmacological interventions.

RELEVANCE TO CLINICAL PRACTICE

Nurses can play a key role in suggesting non-pharmacological alternatives. Education to provide more insight into the problems of insomnia and anxiety may positively influence their attitudes and behaviour. All caregivers in nursing homes should be informed about the relevance of this issue.

Impairment related to blood drug concentrations of zopiclone and zolpidem compared to alcohol in apprehended drivers

BACKGROUND

About 3-7% of the adult population receives prescribed hypnotics. The benzodiazepine-like hypnotics, zopiclone and zolpidem, are the most commonly prescribed and may cause traffic-relevant impairment similar to that found for benzodiazepines. We investigated the relationship between blood zopiclone and zolpidem concentrations and driving impairment, as assessed by the clinical test for impairment. We compared these groups of drivers to a group suspected of alcohol-related impairment.

METHODS

Blood samples from suspected impaired drivers during 2000-2007, screened for approximately 25 possible impairing drugs with only one single drug detected, were studied in relation to the assessment of impairment. The 79 zopiclone positive drivers, the 43 zolpidem positive drivers, and the 3480 alcohol positive drivers were divided into groups depending on blood drug concentrations.

RESULTS/DISCUSSION

The proportion of drivers judged as impaired tended to increase the higher the blood zopiclone concentrations. Such a positive relationship was not found for zolpidem. For alcohol the proportion of impaired drivers was significantly related to blood alcohol concentrations (BACs). There were few drivers with low zopiclone or zolpidem concentrations included, which may have obscured any positive significant relationship. The percentage of impaired drivers among drivers with blood zopiclone concentrations above 130 microg/l roughly corresponded to the percentage of impaired drivers among drivers with BACs higher than 0.1%.

Alcohol, illicit and non-illicit psychoactive drug use and road traffic injury in Thailand: a case-control study

The objective of this study was to determine the relationship between alcohol use, psychoactive drug use and road traffic injury (RTI). A case-control study was conducted among drivers in Bangkok, Thailand. Two hundred cases and 849 controls were enrolled between February and November 2006. Cases who sustained a RTI were matched with four controls recruited from petrol stations within a 1-km radius of the reported crash site of the case. A positive alcohol breath test (> or =50mg/dl), and positive tests for the presence of illicit (amphetamine, cocaine, marijuana) and non-illicit psychoactive drugs (antihistamine, benzodiazepine, antidepressants), using gas chromatography/mass spectrometry (GC/MS) were documented as primary measures. There were significantly higher odds of an alcohol breath test > or =50mg/dl (adjusted odds ratio (OR) 63.6 (95% CI: 25.5-158.9)), illicit psychoactive drugs (adjusted OR 3.4 (95% CI: 1.7-6.6)) and non-illicit psychoactive drug (adjusted OR 3.1 (95% CI: 1.5-6.3)) among cases than controls. Even though driving under the influence of psychoactive drugs has been significantly linked to RTI, its contribution to road safety is much lower than driving under the influence of alcohol. With limited resources, the priority for RTI prevention should be given to control of driving under the influence of alcohol.

Prevalence of psychoactive drug use among drivers in Thailand: a roadside survey

The objective of this study was to determine the prevalence of psychoactive drug and alcohol use among general drivers and predictors of the drug use in Thailand. One thousand six hundred and thirty-five motor vehicle drivers were randomly selected from five geographical regions of Thailand between December 2005 and May 2006. The prevalence of psychoactive drugs was determined using urine tests by gas chromatography/mass spectrometry (GC/MS). Among 1635 drivers, 5.5% were tested positive for breath alcohol with 2% having a level exceeding the legal limit (> or =50mg%). Psychoactive drug was presented in 158 (9.7%) urine samples for drug analysis. The top 3 most frequently detected licit drugs were antihistamines (2.0%), sedative cough suppressant (0.7%) and benzodiazepines (0.2%). Illicit drugs detected included amphetamine (1.8%), cannabis (1.1%), mitragynine (Kratom) (0.9%) and morphine (0.1%). Only type of driver (commercial/non-commercial) was a significant predictor with psychoactive drug use. The prevalence of psychoactive drug use among drivers not involved in road crashes in Thailand was not as low as an earlier study in Europe using objective measurements, particularly among commercial drivers. However, for illicit drugs, the prevalence detected in this study was lower than those of earlier studies from high-income countries.

Alcohol consumption among Canadians taking benzodiazepines and related drugs

PURPOSE

Benzodiazepines and related drugs (BZDs) are widely used for the treatment of anxiety, insomnia and other conditions. The combination of BZDs with alcohol increases risk for oversedation, abuse, dependence and accidents. This study examines drinking behaviour among Canadians taking BZDs.

METHODS

We use data from cycle 1.2 of the Canadian Community Health Survey, a large (n = 36,984) population survey conducted in 2002 by Statistics Canada. We use bivariate methods and logistic regression to test the independent association between BZD use and 2 levels of recent drinking in the general population, and then examine associations between drinking and sociodemographic factors within the group of BZD users.

RESULTS

Any drinking and heavy drinking are less common among users of BZDs than among other respondents, but these differences are small (any drinking, OR = 0.77, p = 0.02; heavy drinking, OR = 0.81, p = 0.13) when differences in respondent characteristics are controlled statistically. Among BZD users, any drinking is associated with male sex, younger age and not meeting criteria for a past-year anxiety disorder. Heavy drinking is associated only with younger age.

CONCLUSIONS

Heavy alcohol use is uncommon among users of BZDs, and the combination of alcohol and BZD use is rare in the general population. Differences between BZD users and others are not large when other factors are taken into account, however, which may call into question the effectiveness of physician and pharmacist warnings against this combination. People treated for an anxiety disorder with BZDs may be less likely to use alcohol than those taking them for other indications.

A systematic review of research examining benzodiazepine-related mortality

PURPOSE

This paper will review literature examining the association of benzodiazepine use and mortality.

METHODS

An extensive literature review was undertaken to locate all English-language published articles that examine mortality risk associated with use of benzodiazepines from 1990 onwards.

RESULTS

Six cohort studies meeting the criteria above were identified. The results were mixed. Three of the studies assessed elderly populations and did not find an increased risk of death associated with benzodiazepine use, whereas another study of the general population did find an increased risk, particularly for older age groups. A study of a middle aged population found that regular benzodiazepine use was associated with an increased mortality risk, and a study of 'drug misusers' found a significant relationship between regular use of non-prescribed benzodiazepines and fatal overdose. Three retrospective population-based registry studies were also identified. The first unveiled a high relative risk (RR) of death due to benzodiazepine poisoning versus other outcomes in patients 60 or older when compared to those under 60. A positive but non-significant association between benzodiazepine use and driver-responsible fatalities in on-road motor vehicle accidents was reported. Drug poisoning deaths in England showed benzodiazepines caused 3.8% of all deaths caused by poisoning from a single drug.

CONCLUSION

On the basis of existing research there is limited data examining independent effects of illicit benzodiazepine use upon mortality. Future research is needed to carefully examine risks of use in accordance with doctors' prescriptions and extra-medical use.

Use of self-controlled analytical techniques to assess the association between use of prescription medications and the risk of motor vehicle crashes

Case-crossover and case-series analyses are 2 epidemiologic approaches that can be used to evaluate the association of exposures with acute events. Using a primary care database from the United Kingdom and these 2 statistical approaches, the authors investigated the impact of using benzodiazepines, nonbenzodiazepine hypnotics, beta-blockers, selective serotonin reuptake inhibitors, tricyclic antidepressants, opioids, and antihistamines on the risk of motor vehicle crashes in 1986-2004. For 49,821 individuals aged 18-74 years, involvement in a motor vehicle crash was documented. The outcome of the case-crossover analyses varied according to the choice of control period, so the case-series approach was preferred. The first 4 weeks of treatment with a combined acetaminophen and opioid preparation was associated with an increased risk of motor vehicle crash (incidence rate ratio = 2.06, 99% confidence interval: 1.84, 2.32), as was use of an opioid alone (incidence rate ratio = 1.70, 99% confidence interval: 1.39, 2.08) and benzodiazepines (incidence rate ratio = 1.94, 99% confidence interval: 1.62, 2.32). Use of selective serotonin reuptake inhibitors, nonbenzodiazepine hypnotics, and antihistamines for more than 4 weeks was associated with motor vehicle crash, but shorter term use was not. The results obtained are broadly consistent with those from well-designed case-control studies and demonstrate how case-only techniques optimize the use of routinely collected data for epidemiologic studies.

Psychoactive medication and traffic safety

Driving a car is important to maintain independence and participate in society. Many of those who use psychoactive medication are outpatients and are thus likely to drive a vehicle. Most common adverse effects that impair driving are reduced alertness, affected psychomotor functioning and impaired vision. This review discusses the effects on driving ability of most commonly prescribed psychoactive drugs, including hypnotics, antidepressants, antihistamines, analgesics and stimulant drugs. Within these categories of medicines significant differences concerning their impact on driving ability are evident. The International Council on Alcohol, Drugs and Traffic Safety (ICADTS) categorization can help physicians to make a choice between treatments when patients want to drive a car.

Trends in driving under the influence of drugs: a register-based study of DUID suspects during 1977-2007

Our aim was to describe the incidence and trends of driving under the influence of drugs (DUID) and to examine the main drug findings and their trends in suspected DUID cases in Finland. A register-based study was conducted of all suspected DUID cases during 1977-2007. The data included 31,963 DUID offenders apprehended by the police with a positive finding for illicit/licit drug impairing driving performance. Toxicological results were analyzed in blood and/or urine specimens in one central laboratory. The incidence of suspected DUID cases increased 18-fold during 1977-2007. Most of the suspects were men (89.7%). However, the male-female ratio decreased from 13.9 to 7.3. The mean age decreased from 36.2 years in 1977 to 29.9 years in 2001 but has since reincreased. Most often found substances were benzodiazepines (75.7%), amphetamines (46.0%), cannabinoids (27.7%) and opioids (13.8%). Most common illicit drugs, amphetamines and cannabinoids, started to appear at the end of the 1980s. Poly-drug findings were common (77.1%). Suspected DUID cases have increased sharply after the introduction of a zero tolerance law, especially in regard to amphetamines. DUID is an increasing problem in Finland, and needs serious attention.

Clinical Practice Guideline: Benign Paroxysmal Positional Vertigo

Objectives:

This guideline provides evidence-based recommendations on managing benign paroxysmal positional vertigo (BPPV), which is the most common vestibular disorder in adults, with a lifetime prevalence of 2.4 percent. The guideline targets patients aged 18 years or older with a potential diagnosis of BPPV, evaluated in any setting in which an adult with BPPV would be identified, monitored, or managed. This guideline is intended for all clinicians who are likely to diagnose and manage adults with BPPV.

Purpose:

The primary purposes of this guideline are to improve quality of care and outcomes for BPPV by improving the accurate and efficient diagnosis of BPPV, reducing the inappropriate use of vestibular suppressant medications, decreasing the inappropriate use of ancillary tests such as radiographic imaging and vestibular testing, and to promote the use of effective repositioning maneuvers for treatment. In creating this guideline, the American Academy of Otolaryngology—Head and Neck Surgery Foundation selected a panel representing the fields of audiology, chiropractic medicine, emergency medicine, family medicine, geriatric medicine, internal medicine, neurology, nursing, otolaryngology–head and neck surgery, physical therapy, and physical medicine and rehabilitation.

Results

The panel made strong recommendations that 1) clinicians should diagnose posterior semicircular canal BPPV when vertigo associated with nystagmus is provoked by the Dix-Hallpike maneuver. The panel made recommendations against 1) radiographic imaging, vestibular testing, or both in patients diagnosed with BPPV, unless the diagnosis is uncertain or there are additional symptoms or signs unrelated to BPPV that warrant testing; and 2) routinely treating BPPV with vestibular suppressant medications such as antihistamines or benzodiazepines. The panel made recommendations that 1) if the patient has a history compatible with BPPV and the Dix-Hallpike test is negative, clinicians should perform a supine roll test to assess for lateral semicircular canal BPPV; 2) clinicians should differentiate BPPV from other causes of imbalance, dizziness, and vertigo; 3) clinicians should question patients with BPPV for factors that modify management including impaired mobility or balance, CNS disorders, lack of home support, and increased risk for falling; 4) clinicians should treat patients with posterior canal BPPV with a particle repositioning maneuver (PRM); 5) clinicians should reassess patients within 1 month after an initial period of observation or treatment to confirm symptom resolution; 6) clinicians should evaluate patients with BPPV who are initial treatment failures for persistent BPPV or underlying peripheral vestibular or CNS disorders; and 7) clinicians should counsel patients regarding the impact of BPPV on their safety, the potential for disease recurrence, and the importance of follow-up. The panel offered as options that 1) clinicians may offer vestibular rehabilitation, either self-administered or with a clinician, for the initial treatment of BPPV and 2) clinicians may offer observation as initial management for patients with BPPV and with assurance of follow-up. The panel made no recommendation concerning audiometric testing in patients diagnosed with BPPV.

Disclaimer:

This clinical practice guideline is not intended as a sole source of guidance in managing benign paroxysmal positional vertigo. Rather, it is designed to assist clinicians by providing an evidence-based framework for decision-making strategies. The guideline is not intended to replace clinical judgement or establish a protocol for all individuals with this condition, and may not provide the only appropriate approach to diagnosing and managing this problem. ® 2008 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.

The impact of benzodiazepines on safe driving

OBJECTIVE

Benzodiazepines are prescribed to relieve anxiety and aid sleep. Studies demonstrate that benzodiazepines increase odds of crash involvement, but little evidence exists regarding their impact on crash responsibility. We examined the impact of benzodiazepines on crash responsibility by drug half-life and driver age, using a case-control design with drivers aged 20 and over involved in fatal crashes in the United States from 1993-2006.

METHODS

Drivers (all with BAC = 0) were classified as having no benzodiazepines detected versus short, intermediate, or long half-life benzodiazepines. Cases were drivers with at least one potentially unsafe driving action (UDA) in relation to the crash (e.g., speeding), a proxy measure for crash responsibility; controls had no UDAs recorded. Odds ratios (ORs) of any UDA by benzodiazepines half-life exposure were calculated, with adjustment for age, sex, other medication usage, and prior driving record.

RESULTS

Compared with drivers not using benzodiazepines, drivers taking intermediate or long half-life benzodiazepines demonstrated increased odds of an UDA from ages 25 (intermediate OR: 1.59; 95% CI = 1.08, 2.33; long OR: 1.68; 95% CI = 1.34, 2.12) to 55 (intermediate OR: 1.50; 95% CI = 1.09, 2.06; long OR: 1.33; 95% CI = 1.12, 1.57). Drivers taking short half-life benzodiazepines did not demonstrate increased odds compared to drivers not using benzodiazepines.

CONCLUSIONS

Given the potential impact of benzodiazepines on driver safety, further experimental research is needed to better understand the effect of benzodiazepines on crash responsibility.

The case-crossover study design in pharmacoepidemiology

In the study of the association of transient drug exposures with acute outcomes, the case-crossover design is an efficient alternative to the case-control approach. This design based exclusively on the case series uses within-subject comparisons of drug exposures over time to estimate the rate ratio of the outcome associated with the drug under study. This design inherently removes the biasing effects of unmeasured, time-invariant confounding factors from the estimated rate ratio, but is sensitive to several assumptions. We illustrated the case-crossover design and explored its sensitivity using data from 4028 cases of gastrointestinal bleeding from the General Practice Research Database in assessing the effects of the drug warfarin. We compared the use of different time window lengths to assess exposure and considered the use of a case-time-control design to account for exposure time trends. The case-crossover approach found no excess risk of bleeding with warfarin exposure [rate ratio 0.98; 95% confidence interval (CI): 0.74-1.28] using a 1-month time window. When we restricted the analysis to subjects with truly transient drug exposure, defined by 1 to 3 prescriptions in the previous year, the rate ratio was 2.59 (95% CI: 1.42-4.74). To consider the longer 1-year exposure time window, the case-time-control approach was used and resulted in a rate ratio of 1.72 (95% CI: 1.08-2.43). In conclusion, the case-crossover design is potentially a powerful approach to assess the risk of drugs. This design is, however, highly sensitive to assumptions about intermittency of drug use and the length of the exposure time window, as demonstrated with the example of bleeding associated with warfarin use.

[Illicit drugs, medications and traffic accidents]

The European Union (EU) has 25 member-states and 455 million inhabitants. Statistics on traffic accidents in the EU show that more than 45,000 people are killed annually, including 5200 in France. At the same time, nearly two million persons in the EU require medical treatment for traffic-accident-related injuries, including 109,000 in France. In addition, traffic accidents are the major cause of death of those individuals aged 15 to 24 years. One third of the EU inhabitants will be hospitalized during their life due to a traffic accident with a cost over 160 billion euro (2-3% of the Gross Domestic Product). An important contributing factor to crashes is the use of alcohol and/or illicit drugs or medication when driving, as they exert negative effects on cognition and psychomotor functions. For illicit drugs, abuse of cannabis with or without alcohol is a major concern for the EU. In fact, three million Europeans use cannabis daily and 80% of them drive after use. A number of French studies since 1999 have underlined the high prevalence of cannabis found in the blood of injured or killed drivers. From medical or judicial observations, it is clear that cannabis use increases the risk of traffic accidents. Many groups outside Europe have also shown the association between drug abuse and crashes. The number of casualties related to certain medicines, especially benzodiazepines remains at a high level, particularly in the elderly. In many countries the prevalence of medicinal drugs associated with car accidents is higher than with cannabis. Annex III of the European Union Council Directive of July the 29th 1991 in fact states that a driving license should not be issued to or renewed for applicants or drivers who are dependent on psychotropic substances or use them regularly. Recently, France has categorized the medicinal drugs available in the country by using three pictograms: level one yellow, "be careful"; level two orange, "be very careful"; level three red, "don't drive". It is an important campaign that increases awareness among the public and the medical professionals about the potential dangerous effects of medicinal drugs when driving. The EU objective of reducing the number of fatalities to 25,000 by 2010 will require strengthening measures against the use of alcohol, illicit and medicinal drugs by not well-informed drivers. It is not only a really great challenge, but also a significant investment towards improving public health in France as well as in Europe.

Prevalence of sleep disturbances in a cohort of older drivers

BACKGROUND

Lower levels of driving capacity in older persons are typically attributed to cognitive, visual, and/or physical impairments, with sleep disturbances rarely considered. This is in contrast to the general adult population for whom sleep disturbances are established risk factors for crashes. We thus set out to determine the prevalence of sleep disturbances in the form of insomnia symptoms, daytime drowsiness, and sleep apnea risk in a cohort of older drivers and to assess how these relate to self-reported driving capacity.

METHODS

Participants included 430 active drivers aged > or =70 years. Questionnaires measured self-reported insomnia symptoms (Insomnia Severity Index [ISI]), drowsiness (Epworth Sleepiness Scale [ESS]), apnea risk (Sleep Apnea Clinical Score [SACS]), driving mileage, driver self-ratings (overall and nighttime), and prior adverse driving events.

RESULTS

Mean age was 78.5 years, with 85% being male. Overall, 64% were dissatisfied with sleep patterns and 26% had an abnormal ISI (> or =8). A large proportion (60%) reported a moderate-to-high chance of dozing in the afternoon, and 19% had an abnormal ESS (> or =10). Habitual snoring was noted by 43%, with 20% at risk for sleep apnea (SACS > 15). Regarding driving, the most consistent finding was for lower levels of nighttime driver self-ratings in participants with insomnia symptoms or drowsiness. Lower levels of driving mileage were also noted but only with difficulty falling asleep. Otherwise, sleep disturbances were not associated with prior adverse driving events.

CONCLUSION

In our cohort of older drivers, insomnia symptoms and daytime drowsiness were prevalent and associated with lower levels of nighttime driver self-ratings. Although sleep apnea risk was also prevalent, it was not associated with self-reported driving capacity. These preliminary findings suggest that insomnia symptoms and drowsiness merit continued consideration as risk factors for lower levels of driving capacity in older persons, particularly given that effective interventions are available.

Next-day cognition, psychomotor function, and driving-related skills following nighttime administration of eszopiclone

OBJECTIVE

To evaluate next-day driving ability, as assessed by brake reaction time (BRT), and cognitive/psychomotor function following nighttime administration of 3 mg eszopiclone.

METHODS

Two randomized, double-blind, placebo-controlled, cross-over studies were performed in healthy volunteers (n = 32) and patients with primary insomnia (n = 32). Study participants received nighttime dosing of 3 mg eszopiclone or placebo. BRT and a psychometric test battery were used to assess the next-day effects of eszopiclone treatment.

RESULTS

In both studies, driving ability and measures of cognitive and psychomotor function were not impaired the morning after eszopiclone, as compared to placebo. All eszopiclone subjects reported improved ease in getting to sleep and quality of sleep with no significant changes in behavior upon awakening. A significant increase in next-day feelings of sedation was reported in healthy volunteers, but not in patients with primary insomnia, following eszopiclone treatment relative to placebo. Sleep induction, maintenance, duration, and efficiency, as assessed by PSG, were significantly improved following eszopiclone treatment in patients with insomnia.

CONCLUSIONS

Nighttime administration of 3 mg eszopiclone improved objective and subjective sleep measures in patients with insomnia (and subjective sleep measures in healthy patients) and did not impair next-day driving-related skills or measures of cognition in either study population relative to placebo.

The relation between the blood benzodiazepine concentration and performance in suspected impaired drivers

Several experimental studies have shown a negative influence of benzodiazepines on driving skills. The objective of this study is to study the relationship between the blood concentration of benzodiazepines and the influence on performance in field sobriety tests. A retrospective case file evaluation was conducted to select cases of drivers, tested positive for benzodiazepines only in the period from January 1999 to December 2004. Drivers were grouped into the categories sub therapeutic, therapeutic or elevated concentrations. The outcome of the tests (walking, walking after turn, nystagmus, Romberg's test, behavior, pupils and orientation) was binomial. A Chi square test was used to assess differences in proportions of the categorized cases. In total 171 cases were included. Observations of behavior (n=137; p<0.01), walking (n=109; p<0.01), walking after turn (n=89; p=0.02) and Romberg's test (n=88; p<0.05) were significantly related to the benzodiazepine concentration. There was no significant relation between benzodiazepine concentration and effect on pupil size, nystagmus or orientation. The results of our study indicate a relation between the concentration of benzodiazepines and the results of some performance tests. More effort is needed to standardize the tests and to determine the sensitivity and selectivity of the tests for benzodiazepines.

Post-bedtime dosing with indiplon in adults and the elderly: results from two placebo-controlled, active comparator crossover studies in healthy volunteers

OBJECTIVE

To assess the effects of post-bedtime dosing with indiplon on next-day function in adults and the elderly.

RESEARCH DESIGN AND METHODS

Two randomized, double-blind, placebo-controlled crossover studies were conducted in two groups of healthy volunteers: an adult study (18-45 years) and an elderly study (65-80 years). In adults, a single post-bedtime dose of indiplon 10 mg and 20 mg was compared to placebo, with zolpidem 10 mg and zopiclone 7.5 mg included as controls. In the elderly, a single post-bedtime dose of indiplon 5 mg and 10 mg was compared to placebo, with zopiclone 3.75 mg included as a control. Next-day residual effects were evaluated in the morning at 4 and 6 h post-dose in adults, and 4, 6, and 8 h in the elderly, by a Visual Analog Scale of sleepiness (VAS-sleepiness), Digit Symbol Substitution Test (DSST), and the Symbol Copying Test (SCT).

RESULTS

In adults, there were no statistically significant differences between indiplon and placebo on the VAS-sleepiness, DSST, or SCT at any time-point for either dose. In contrast, a significant increase versus placebo in VAS-sleepiness was observed for both zopiclone (at 4 and 6 h post-dose; p < 0.0001 and p = 0.002, respectively) and zolpidem (at 4 h post-dose; p = 0.042). In the elderly, there were no statistically significant differences between indiplon 5 mg and placebo on the VAS-sleepiness, DSST, or SCT at any time-point. DSST was significantly reduced for indiplon 10 mg versus placebo at 4 h only (p = 0.022), compared with a significant reduction in DSST for zopiclone at both 4 and 8 h post-dose (p = 0.002 and p = 0.003, respectively). In adults, the overall incidence of adverse events was higher on zopiclone compared to indiplon, zolpidem, and placebo. In the elderly, the incidence of adverse events was similar for indiplon, zopiclone, and placebo. Potential limitations of the current study include recruitment of healthy volunteers and the use of a limited pharmacodynamic battery.

CONCLUSIONS

Indiplon, at doses of 10 mg in adults and 5 mg in the elderly, was not associated with next day residual sedation or impairment in simple cognitive and psychomotor tasks when administered during the night 4 h prior to awakening.

Emerging anxiolytics

Anxiety disorders are the most common of the psychiatric disorders and are also associated with significant economic costs and impaired work productivity. The first-line pharmacotherapy of pharmatherapy for a number of anxiety disorders comprises selective serotonin re-uptake inhibitors (SSRIs) and serotonin and noradrenaline re-uptake inhibitors (SNRIs). Benzodiazepines are still widely used for the treatment of several anxiety disorders. Although these agents are effective, many patients are treatment-refractory and more effective, better tolerated medications are required. This paper discusses the understandings of mechanisms involved in the anxiety disorders and reviews emerging medications. Mechanisms underlying the use of d-cycloserine, second generation antipsychotics and beta-blockers are particularly exciting.

Drinking, drugs and driving in Ireland: more evidence for action

OBJECTIVE

To examine the prevalence of drug positivity among drivers suspected of driving under the influence of an intoxicant, and consequently apprehended by the police in Ireland.

DESIGN

2000 specimens were selected for drug analysis, 1000 with results under the limit for alcohol and 1000 over the limit. The limit for alcohol is 80 mg/100 ml in blood and 107 mg/100 ml in urine. Seven drugs/drug classes were examined; amphetamines, methamphetamines, benzodiazapines, cannabinoids, cocaine, opiates and methadone.

RESULTS

331 (33.1%) of the drivers under the legal limit for alcohol tested positive for one or more of the relevant drugs, and the corresponding figures of drivers over the limit was 142 (14.2%; p<0.001). Using weighted analysis, this corresponds to 15.7% (95% confidence interval (CI) 13.5% to 18.1%) of all tested drivers (15.8% in men and 14.5% in women). Among drivers who had minimal blood alcohol levels, 67.9% (95% CI 61.2% to 74.1%) were taking at least one type of drug. The prevalence of taking drugs reduced steadily as alcohol concentrations increased, but still remained as high as 11.1% (95% CI 8.3% to 14.6%) for drivers with blood alcohol concentrations >200 mg/100 ml. Being under the limit for alcohol, stopped in a city area, stopped between 6 am and 4 pm, or 4 pm and 9 pm, and being of a younger age were each independently associated with drug positivity.

CONCLUSIONS

There are immediate implications for the evidential breath alcohol program and for checkpoints; in the event of a nil or low alcohol reading being obtained, a separate blood or urine specimen should be sought for analysis, which is currently non-routine.

Diagnosis and treatment of agoraphobia with panic disorder

Agoraphobia with panic disorder is a phobic-anxious syndrome where patients avoid situations or places in which they fear being embarrassed, or being unable to escape or get help if a panic attack occurs. During the last half-century, agoraphobia has been thought of as being closely linked to the recurring panic attack syndrome, so much so that in most cases it appears to be the typical development or complication of panic disorder. Despite the high prevalence of agoraphobia with panic disorder in patients in primary-care settings, the condition is frequently under-recognised and under-treated by medical providers. Antidepressants have been demonstrated to be effective in preventing panic attacks, and in improving anticipatory anxiety and avoidance behaviour. These drugs are also effective in the treatment of the frequently coexisting depressive symptomatology. Among antidepressant agents, SSRIs are generally well tolerated and effective for both anxious and depressive symptomatology, and these compounds should be considered the first choice for short-, medium- and long-term pharmacological treatment of agoraphobia with panic disorder. The few comparative studies conducted to date with various SSRIs reported no significant differences in terms of efficacy; however, the SSRIs that are less liable to produce withdrawal symptoms after abrupt discontinuation should be considered the treatments of first choice for long-term prophylaxis. Venlafaxine is not sufficiently studied in the long-term treatment of panic disorder, while TCAs may be considered as a second choice of treatment when patients do not seem to respond to or tolerate SSRIs. High-potency benzodiazepines have been shown to display a rapid onset of anti-anxiety effect, having beneficial effects during the first few days of treatment, and are therefore useful options for short-term treatment; however, these drugs are not first-choice medications in the medium and long term because of the frequent development of tolerance and dependence phenomena. Cognitive-behavioural therapy is the best studied non-pharmacological approach and can be applied to many patients, depending on its availability.

The risk of traffic accidents after prescriptions of carisoprodol

OBJECTIVE

Carisoprodol, a drug used for acute lower back pain, may cause psychomotor impairment. We wanted to investigate if patients using carisoprodol had increased risk of being involved in a traffic accident.

METHODS

Data were retrieved from three population-based registries for the period April 2004-September 2005. The Norwegian Prescription Database contained individual information on all dispensed drugs at all pharmacies outside hospitals. The Norwegian Road Accident Registry contained information on all drivers involved in motor vehicle accidents with person injury. The Norwegian Central Population Registry was used to control for emigration or death. The accident incidence among carisoprodol exposed and unexposed subjects was compared by standardized incidence ratio.

RESULTS

Having a prescription for carisoprodol dispensed increased the standardized incidence ratio for being involved in an accident with person injury to 3.7 (95% CI 2.9-4.8) the first week after the date of dispensing. This was similar to diazepam (2.8; 2.2-3.6), but higher than for salbutamol (1.1; 0.6-1.8).

CONCLUSIONS

Patients receiving carisoprodol seem to have an increased risk of being involved in traffic accidents involving person injury. The study gives support to earlier work published on the impairing effects of carisoprodol.

Benzodiazepine prescribing to the Swiss adult population: results from a national survey of community pharmacies

The purpose of the study was to assess prevalence of benzodiazepine use in the Swiss adult population and to assess on benzodiazepine prescription patterns of physicians in domiciliary practice.

STUDY DESIGN

A retrospective, population-based cross-sectional study with 520 000 patients covering a 6-month period.

METHODS

We estimated the prevalence, amount and duration of benzodiazepine use using a pharmacy dispensing database.

RESULTS

Of all patients, 9.1% (n=45 309) received at least one benzodiazepine prescription in the 6-month period. Most persons receiving benzodiazepine prescriptions were women (67%), and half of all patients were aged 65 or older. Of 45 309 patients with benzodiazepine prescriptions, 44% (n=19 954) had one single prescription, mostly for a short period (<90 days) and in lower than the recommended dose range. Fifty-six percent (n=25 354) had repeated benzodiazepine prescriptions, mostly for a long time period (>90 days), and in lower than the recommended or within the recommended dose range. In patients with long-term use (n=25 354), however, 1.6% had benzodiazepine prescriptions in extremely high doses. The sample of patients with repeated prescriptions allowed an estimation of a benzodiazepine use of 43.3 daily defined doses per 1000 inhabitants in Switzerland.

CONCLUSIONS

Benzodiazepine prescriptions were appropriate for most patients and thus were prescribed in therapeutic doses, as indicated in the treatment guidelines. On the other hand, our survey showed that 1.6% of the patients had prescriptions for long time periods at very high doses, indicating an abuse or dependence on benzodiazepines in this subgroup.

Dissociation between objective psychomotor impairment and subjective sleepiness after diazepam administration in the aged people

The aim of the present study was to clarify whether subjective sleepiness accurately reflects benzodiazepine-related decline in psychomotor function after taking benzodiazepines (BZPs) in aged people. Subjects were eight healthy, young (mean age, 19.8 years) and seven healthy, older (mean age, 60.9 years) men. Placebo and diazepam (DZP) were administered orally in a single-blind crossover manner to the young subjects (placebo, 5 mg DZP and 10 mg DZP) and to the older subjects (placebo and 5 mg DZP). Plasma drug concentration, choice reaction time (CRT) as an objective measure of psychomotor function, and the Stanford Sleepiness Scale (SSS) as a measure of subjective sleepiness were monitored every 20 min from 1000 until 1600 h, being the drug administered at 1200 h. Pharmacokinetic variables did not differ significantly between the two age groups. DZP at 10 mg in young subjects induced significant increases in both the CRT and SSS score. DZP at 5 mg induced no significant increase in SSS score in either age group but did induce a significant increase in CRT only in the older subjects that matched that in young subjects given 10 mg DZP. The older subjects suffered from dissociation between subjective sleepiness and objective psychomotor impairment under DZP treatment. Such individuals may underestimate the detrimental effects on brain function.

Use of non-benzodiazepine hypnotics in the elderly: are all agents the same?

Sleep disorders, especially insomnia, are common in older adults. These disorders are frequently treated using non-benzodiazepine hypnotics. Nonetheless, there is a relative lack of data regarding the use of these agents in the elderly, and whether any of these medications is superior to any other in the class when used in the elderly is also unclear. In this article, we review, by way of the published literature, the pharmacodynamics, pharmacokinetics, drug interactions, efficacy and safety of zolpidem, zaleplon, zopiclone, eszopiclone and ramelteon in the elderly. Special emphasis is placed on identifying relevant differences between these medications when used in older adults with insomnia. Based primarily on data from placebo-controlled trials, the non-benzodiazepines reviewed were found to be most effective at improving sleep latency and sleep quality, and least effective at enhancing total sleep time. The efficacy of ramelteon was limited to improving sleep latency, while all other agents, especially at higher doses, were found to produce improvement in both sleep latency and some improvement in total sleep time. All of the medications were found to be well tolerated in the elderly. From pharmacokinetic and drug-drug interaction perspectives, zaleplon and ramelteon offer the advantage of not being primarily metabolised via the cytochrome P450 3A4 isoenzyme. In conclusion, based on relatively limited data, zopiclone, zolpidem, zaleplon, eszopiclone and ramelteon represent modestly effective and generally well tolerated treatments for insomnia in older adults. While some actual and potential differences exist among these medications, more comparative trials are needed.

Initiation of benzodiazepines in the elderly after hospitalization

OBJECTIVE

To estimate the rate of new chronic benzodiazepine use after hospitalization in older adults not previously prescribed with benzodiazepines.

DESIGN

Retrospective cohort study using linked, population-based administrative data.

SETTING

Ontario, Canada between April 1, 1992 and March 31, 2005.

PARTICIPANTS

Community-dwelling seniors who had not been prescribed benzodiazepine drugs in the year before hospitalization were selected from all 1.4 million Ontario residents aged 66 years and older.

MAIN OUTCOME MEASURES

New chronic benzodiazepine users, defined as initiation of benzodiazepines within 7 days after hospital discharge and an additional claim within 8 days to 6 months. We used multivariate logistic regression to examine for the effect of hospitalization on the primary outcome after adjusting for confounders.

RESULTS

There were 405,128 patient hospitalizations included in the cohort. Benzodiazepines were prescribed to 12,484 (3.1%) patients within 7 days of being discharged from hospital. A total of 6,136 (1.5%) patients were identified as new chronic benzodiazepine users. The rate of new chronic benzodiazepine users decreased over the study period from 1.8% in the first year to 1.2% in the final year (P < .001). Multivariate logistic regression found that women, patients admitted to the intensive care unit or nonsurgical wards, those with longer hospital stays, higher overall comorbidity, a prior diagnosis of alcoholism, and those prescribed more medications had significantly elevated adjusted odds ratios for new chronic benzodiazepine users. Older individuals had a lower risk for the primary outcome.

CONCLUSION

New benzodiazepine prescription after hospitalization occurs frequently in older adults and may result in chronic use. A systemic effort to address this risky practice should be considered.

Concentrations of scheduled prescription drugs in blood of impaired drivers: considerations for interpreting the results

We report the concentrations of scheduled prescription drugs in blood samples from people arrested in Sweden for driving under the influence of drugs (DUID). The investigation covered a 2 year period 2004 (N = 7052 cases) and 2005 (N = 7759 cases) and was prompted by recent legislation stipulating zero-concentration limits in blood for controlled substances. However, prescription drugs are exempt from the zero-limit law provided that the medication was being used in accordance with a doctor's prescription. The blood concentrations of various psychoactive substances were compared with the limits of quantitation of the analytic method used and the so-called therapeutic concentration range according to various reference books and tabulations. Diazepam [N = 1950 (26%)] and nordazepam [N = 2168 (28%)] were the therapeutic agents most frequently identified in these forensic blood samples along with other benzodiazepines such as alprazolam [N = 430 (5.6%)], flunitrazepam [N = 308 (4.0%)], and nitrazepam [N = 222 (2.9%)]. The newer hypnotics, exemplified by zolpidem [N = 148 (1.9%)] and zopiclone [N = 111 (1.5%)], were also high on the list of psychoactive substances identified. Interpreting the concentration of a prescription drug in blood in relation to whether the person had taken an overdose or was abusing the substance in question is not always easy. The age, gender, degree of obesity, and ethnicity of the person concerned; the pharmacokinetic profile of the drug; polymorphism of drug-metabolizing enzymes as well as liver and kidney function and blood hematocrit need to be considered. Among preanalytic factors, stability of the drug in blood after sampling, the type of tubes and preservatives used, the dosage form and route of administration deserve consideration. When therapeutic drug monitoring concentrations are compared with forensic toxicology results, then the plasma-to-whole blood distribution ratio of the drug also needs to be considered. In blood samples from DUID suspects, the concentrations of many commonly used sedatives and hypnotics exceeded the accepted therapeutic limits, which gives an indication of the abuse potential of these types of medications.

Cognitive, psychomotor and actual driving performance in healthy volunteers after immediate and extended release formulations of alprazolam 1 mg

RATIONALE

Alprazolam extended-release (XR) is approved for the treatment of panic disorder. This sustained formulation is absorbed in a delayed manner and is therefore expected to produce fewer and less severe side effects than its immediate release equivalent (alprazolam IR). The effect of alprazolam XR on potentially dangerous daily activities, such as driving a car, is expected to be less as compared to alprazolam IR.

OBJECTIVES

The present study was designed to compare the effects of alprazolam XR (1 mg) and alprazolam IR (1 mg) on actual driving ability and cognitive function.

METHOD

Eighteen healthy volunteers (aged 20-45 years) participated in a double-blind, placebo-controlled, three-way crossover study. At 4 h post-dose, subjects performed a standardized driving test on a primary highway in normal traffic. Cognitive and psychomotor tests were assessed 1, 2.5, and 5.5 h post-dose. Memory functioning was measured only 1 h after administration.

RESULTS

Both formulations severely impaired driving performance between 4 and 5 h after administration. The magnitude of impairment in the driving test observed with alprazolam XR was about half that observed with alprazolam IR. Laboratory test results were in line with the driving data.

CONCLUSIONS

The acute impairing effects of alprazolam XR 1 mg on driving and psychomotor functions were generally less, as compared to its immediate-release equivalent, but still of sufficient magnitude to increase the risk of becoming involved in traffic accidents.

A rapid fluorimetric screening method for the 1,4-benzodiazepines: Determination of their metabolite oxazepam in urine

Oxazepam is the major metabolite screened in urine samples for the evidence of the use of benzodiazepine drugs. The methods currently used, however, are laborious and time consuming. This paper proposes an oxazepam detection method based on its hydrolysis and cyclization--a reaction catalysed by cerium (IV) in an ortho-phosphoric acid-containing medium--to form 2-chloro-9(10H)-acridinone, a strongly fluorescent molecule. The variables involved in the hydrolysis and cyclization stages were optimised. Oxazepam was detectable in the 5-900 ng mL(-1) range, with a detection limit of 4.15 ng mL(-1) for k=3. The method was successfully used for the determination of oxazepam in urine samples collected at different times after the oral administration of Valium and Tranxilium.

Benzodiazepines and elderly drivers: a comparison of pharmacoepidemiological study designs

PURPOSE

Contradictory results were published from two studies in the late 1990s about the effects of long half-life benzodiazepine use on the risk of motor vehicle crashes (MVCs) in the elderly. The use of different study designs could explain the differences observed in these studies.

METHODS

The results of an unmatched case-control study were compared to those of a case-crossover study using the same prescription claims database to determine whether the current use of benzodiazepines increased the risk of MVCs.

RESULTS

There were 5579 cases and 12 911 controls identified between the years 1990 and 1993 in the province of Quebec, Canada. The case-control approach demonstrated an increased rate of injurious MVC associated with the current use of long-acting benzodiazepines [odds ratio (OR) 1.45; 95% confidence interval (CI): 1.12-1.88]. The case-crossover approach applied to all cases did not show any association [OR 0.99; 95%CI: 0.83-1.19]. However, among the cases restricted to subjects with four or less prescriptions filled in the previous year, corresponding more to transient exposures, the OR was elevated [OR 1.53; 95%CI: 1.08-2.16].

CONCLUSIONS

Differences in study design and analysis may explain some of the discrepancies in previous results. Both study designs provide evidence that long-acting benzodiazepines appear to be associated with an increased risk of MVC.

Severity of alcohol-related motor vehicle crashes in British Columbia: case - control study

The objective of the present study was to compare the injury severity and vehicle damage severity rates of alcohol-related crashes with rates of non-alcohol-related crashes in British Columbia (BC). Injury severity rates and vehicle damage severity rates were taken from 2002 Insurance Corporation of British Columbia traffic collision data. The data were computed in order to compare the differences in injury severity and vehicle damage severity rates of alcohol-related vs. non-alcohol-related motor vehicle crashes. Case - control methods were used in this study to analyse the risk of alcohol-related crashes compared to non-alcohol-related crashes in BC. Odds ratios (OR) and 95% CI were calculated to estimate relative risks. In the case - control analysis, the risk of fatal collision was increased for those drinking and driving compared with those driving sober (OR 4.70; 95% CI 3.15 - 7.01). Risk of injury collision was increased for those drinking and driving compared with those driving sober (OR 1.32; 95% CI 1.19 - 1.37). Importantly, the risk of vehicle damage severity was increased for those drinking and driving compared with those driving sober (write-off vehicle OR 4.24; 95% CI 3.70 - 4.86, severely damaged vehicles OR 1.98; 95% CI 1.77 - 2.21). The study reinforces existing literature to suggest that current evidence is sufficient to show an increased risk of injury and fatality to drivers and occupants in alcohol-related crashes. This paper not only emphasizes this well-known relationship, but also such consequences as increased vehicle damage severity. The connection between drinking and severity of motor vehicle crashes is popularly believed and has now received substantial scientific support. There is strong justification for injury prevention experts and policy-makers to step up motor vehicle crash injury prevention advocacy by implementing evidence-based policies to reduce rates of alcohol-impaired driving in the province of BC. Most unintentional injuries in BC are related to motor vehicle crashes. Significant improvements can be made in these statistics by: increasing the use of occupant protection (safety belt and child restraint seats); reducing alcohol-related injuries through multiple strategies including corrections in the physical environment, extensive enforcement of drinking and driving laws and health promotion/education.

Co-morbid and socio-demographic factors associated with cognitive performance in an elderly community dwelling Irish population

BACKGROUND

Epidemiological studies suggest an association between health factors and dementia. The impact of these factors on the cognitive performance of the elderly population is unclear. Possible correlates of poor cognitive performance in a community dwelling elderly Irish population were examined.

METHODS

Subjects were from a sample of individuals over 65 years agreeable to interview using the Geriatric Mental State (GMS)-Automated Geriatric Examination for Computed Assisted Taxonomy (AGECAT) package conducted at the subject's home. Associations between patient profiles and Mini Mental State Examination (MMSE) score were investigated in a multivariate model.

RESULTS

There were 793 subjects, 528 (66.6%) female with mean (s.d.) age 74.8 (6.7) yrs. Mean MMSE score was 26.5 (3.3). 169 (21.3%) were current smokers, 198 (25%) ex-smokers. Two hundred and twenty-four (28.3%) had a history of hypertension, 85 (10.7%) case level anxiety or depression, 51 (6.4%) stroke, ten0 (1.3%) epilepsy, nine (1.1%) Parkinson's disease and 29 (3.7%) dementia. Two hundred and fifty-five (32.2%) subjects were on psychotropic medications. Factors associated with MMSE score included age (p < or = 0.0001), diagnosis of dementia (p < or = 0.0001), socioeconomic group (p < or = 0.0001), education (p < or = 0.0001), previous stroke (p = 0.0013) and use of psychotropic medication (p = 0.03). Case level anxiety or depression (p = 0.99), Parkinson's disease (p = 0.52), epilepsy (p = 0.26), smoking status (p = 0.99) and hypertension (p = 0.34) were not found to be associated with cognitive performance.

CONCLUSION

Factors associated with cognitive performance included age, socioeconomic group, education, previous stroke and use of psychotropic medication. These factors should be adjusted for in studies assessing cognition in this population. Stroke prevention strategies and avoidance of psychotropic medication may benefit cognitive performance.

The impact of chronic pain patients' psychotropic drug knowledge and warning labels on the decision whether to drive a car or not

OBJECTIVE

The attitudes of patients towards driving a car while taking medication with psychotropic side effects is unclear. A growing number of patients use these psychotropic medicines on a daily basis, and this may interfere with their ability to drive a car.

METHODS

By means of a survey, we examined attitudes towards driving while using psychotropic medicinal drugs and the effect of warning labels on the decision whether to drive a car or not in patients with chronic pain.

RESULTS

Fifty-eight of 100 patients possessing a driver's license used psychotropic medication. Despite warning labels affixed on the packages that these drugs might impair driving ability, the majority (71%) of these patients continued driving a car. A point of concern is that 40% of these patients reported not to be more cautious in traffic after taking psychotropic drugs.

CONCLUSION

The results of this survey indicate that drug warning labels applied by Dutch pharmacies do not significantly change attitudes towards driving a car in patients taking medicinal drugs with psychotropic side effects. Future road-safety campaigns should pay more attention to the impairing effects of psychotropic drugs on driving.

Hypnotic use in a population-based sample of over thirty-five thousand interviewed Canadians

Background

As with most medications, benzodiazepine and similar sedative hypnotics (BDZ/SSH) can produce both beneficial and adverse effects. Pharmacoepidemiological studies have been limited in their capacity to evaluate the relationship between these medications and psychiatric diagnoses in non-clinical populations. The objective of this study was to provide a description of the pattern of use of BDZ/SSH medications in relation to both demographic and diagnostic data in a community population.

Methods

The source of data for this study was the Canadian Community Health Survey (CCHS 1.2), also known as the Canadian National Study of Mental Health and Well-being. This study was based on a nationally representative sample that included over 35 thousand subjects with a response rate of 77%. The survey interview included the latest version of the Composite International Diagnostic Interview (CIDI), which was developed for the World Health Organization's WHO Mental Health 2000 project. Current medication use was also recorded.

Results

As expected, BDZ/SSH use was more common in women than in men (4.2%, 95% CI 3.9 to 4.6 vs. 2.5%, 95% CI 2.2 to 2.8) and its frequency increased with age, 8.5% (95% CI 7.7 to 9.4) of those over the age of 65 compared to 2.4% (95% CI 2.2 to 2.7) of those aged 18 to 64 years. These medications were more frequently used in subjects with low levels of education (4.8%, 95% CI% 4.3 to 5.2) vs. high levels of education (2.4%, 95% CI 2.1 to 2.6) and low personal incomes (5.7%, 95% CI 5.2 to 6.3) vs. high personal incomes (2.3%, 95% CI 2.0 to 2.6). BDZ/SSH use was strongly associated with the presence of mood or anxiety disorders, but not with substance use disorders. Demographic differences persisted after statistical adjustment for diagnosis.

Conclusion

The observation that benzodiazepine use is more frequent in women, increases with age and is higher in low income and education groups supports previous findings. These results help to confirm that these differences are not accounted for by psychiatric diagnoses.

Acute and subchronic effects of amitriptyline 25mg on actual driving in chronic neuropathic pain patients

The acute and subchronic effects of low doses nocturnally administered amitriptyline were compared to placebo in a double-blind crossover randomized study on driving ability and driving-related skills involving seven chronic neuropathic pain patients. Performance testing occurred at the first and last day of each 15-day drug administration period, which was preceded by a 6-day washout phase. A standardized method of measuring driving ability, the on-the-road driving test, was performed on all visits. Patients were instructed to drive with a steady lateral position while maintaining a constant speed of 95 km/h. The primary outcome of the driving test is the Standard Deviation of Lateral Position (SDLP, cm), which is an index of weaving of the car. At the first treatment day, driving performance was significantly impaired in patients after nocturnal administration of 25 mg amitriptyline compared to placebo. The increase in SDLP of 3 cm was higher than the increment generally observed with a blood alcohol concentration of 0.5 mg/ml or higher, the legal limit for driving in many countries. Also, reaction times on a memory test were significantly increased, indicating worse performance after acute treatment of amitriptyline compared to placebo. In contrast, after 2 weeks of treatment, no significant differences were found between amitriptyline and placebo, suggesting that tolerance had developed to the impairing effects of amitriptyline.

Warfarin use and the risk of motor vehicle crash in older drivers

AIM

On the basis of a recent report, we assessed whether the use of warfarin by elderly drivers results in an increased risk of motor vehicle crash.

METHODS

We used computerized records of Quebec insurance programmes, covering a population of 7 million people, to conduct a case-control study based on 5,579 cases and 12,911 controls.

RESULTS

The rate of injurious motor vehicle crash associated with the use of warfarin in the past year was not elevated (rate ratio 0.74; 95% confidence interval 0.55, 1.05).

CONCLUSIONS

Warfarin therapy does not appear to increase the risk of motor vehicle accidents in elderly drivers.