Association of road-traffic accidents with benzodiazepine use

The role of marital status in the association between benzodiazepines, psychotropics and injurious road traffic crashes: a register-based nationwide study of senior drivers in Sweden

BACKGROUND

Among senior drivers, benzodiazepines (BZDs) have a documented effect on the risk of road traffic crashes (RTCs). It remains unclear however if BZDs play the same role when considering marital status. Therefore, we aimed to investigate the role of marital status in the association between BZD use and injurious RTCs among senior drivers.

METHODS

Matched case-control study based on five national Swedish registers (n = 154 225). Cases comprised the first non-alcohol-related injurious RTC sustained by drivers aged 50-80 years from July 2005 to December 2009 and controls included registered residents with a valid license who did not crash during that period. Four controls were matched to each case by sex, age and place of residence. Conditional logistic regression analysis for injurious RTC was performed with adjustment for occupation and number of medications. The main exposure was dispensation of BZDs, alone or in combination with other psychotropic medications, 1-30 days prior to the crash date stratified by marital status.

RESULTS

BZD use, alone or in combination with other psychotropic medications, increased the risk of being involved in an RTC (BZD only: adjusted OR: 1.26, 95% CI: 1.17-1.36; BZDs and other psychotropics: adjusted OR: 1.25, 95% CI: 1.12-1.41). Compared to married drivers, those divorced (1.48, 1.43-1.53) and widowed (1.54; 1.45-1.63) had higher adjusted ORs. Marital status modified the association between BZDs and RTCs, particularly among younger male drivers.

CONCLUSIONS

Both BZDs and marital status independently affect the risk for senior drivers to be involved in an RTC. However, marital status plays a role in the association between BZD use and RTCs and this may have implications for targeting risk populations for RTCs among senior drivers.

Medications and impaired driving

OBJECTIVE

To describe the association of specific medication classes with driving outcomes and provide clinical recommendations.

DATA SOURCES

The MEDLINE and EMBASE databases were searched for articles published from January 1973 to June 2013 on classes of medications associated with driving impairment. The search included outcome terms such as automobile driving, motor vehicle crash, driving simulator, and road tests.

STUDY SELECTION AND DATA EXTRACTION

Only English-language articles that contained findings from observational or interventional designs with ≥ 10 participants were included in this review. Cross-sectional studies, case series, and case reports were excluded.

DATA SYNTHESIS

Driving is an important task and activity for the majority of adults. Some commonly prescribed medications have been associated with driving impairment measured by road performance, driving simulation, and/or motor vehicle crashes. This review of 30 studies identified findings with barbiturates, benzodiazepines, hypnotics, antidepressants, opioid and nonsteroidal analgesics, anticonvulsants, antipsychotics, antiparkinsonian agents, skeletal muscle relaxants, antihistamines, anticholinergic medications, and hypoglycemic agents. Additional studies of medication impact on sedation, sleep latency, and psychomotor function, as well as the role of alcohol, are also discussed.

CONCLUSIONS

Psychotropic agents and those with central nervous system side effects were associated with measures of impaired driving performance. It is difficult to determine if such associations are actually a result of medication use or the medical diagnosis itself. Regardless, clinicians should be aware of the increased risk of impaired driving with specific classes of medications, educate their patients, and/or consider safer alternatives.

Potentially driver-impairing (PDI) medication use in medically impaired adults referred for driving evaluation

BACKGROUND

Potentially driver-impairing (PDI) medications have been associated with poorer driving performance and increased risk of motor vehicle collision.

OBJECTIVES

To describe the frequency of medication use and to determine the association between routine use of PDI medications and performance on driving and cognitive tests.

METHODS

A total of 225 drivers with medical impairment (mean age 68 ± 12.8 years, 62.2% male) were referred to an occupational therapy-based driving evaluation clinic. Medication lists were reviewed to identify PDI drugs, as defined by a previous study examining medications and crash risk. Outcome variables included road testing on the modified Washington University Road Test and cognitive scores on Trail Making Test Parts A and B, Snellgrove Maze Task, Clock Drawing Task, Driving Health Inventory (DHI) Useful Field of View, DHI Motor Free Visual Perceptual Test, Epworth Sleepiness Scale (ESS), Geriatric Depression Scale, and Functional Assessment Questionnaire.

RESULTS

PDI medication use was documented in 68.9% of the sample, with the average subject taking 1.4 PDI drugs. Drivers taking routine PDI medications had a mean ESS score of 7.8 compared to 6.0 in the control group, suggesting increased somnolence (P = .007). Total number of routine medications, regardless of PDI designation, also correlated positively with ESS scores (P = .023).

CONCLUSIONS

Use of PDI medications was associated with informant ratings of daytime drowsiness on the ESS, which has been linked to motor vehicle crash risk. Further investigation of individual drug classes is warranted using larger sample sizes and a high-powered study design.

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

RATIONALE

Residual effects of hypnotics on driving performance have been mainly determined in studies using a standardized driving test with healthy good sleepers. Responses to effects may differ, however, between insomniacs and healthy volunteers due to the underlying sleep disorder. In addition, a majority of insomniacs uses hypnotics chronically resulting in the development of tolerance to impairing effects. Impaired driving performance in healthy volunteers may then be an overestimation of the actual effects in insomniacs.

OBJECTIVES

The present study aims to compare the residual effects of zopiclone 7.5 mg on on-the-road driving performance of 16 middle-aged insomniacs chronically using hypnotics (chronic users), 16 middle-aged insomniacs not or infrequently using hypnotics (infrequent users), and 16 healthy, age matched, good sleepers (controls).

METHODS

The study was conducted according to a 3 × 2 double-blind, placebo controlled crossover design, with three groups and two treatment conditions. Treatments were single oral doses of zopiclone 7.5 mg and placebo administered at bedtime (2330 hours). Between 10 and 11 h after administration subjects performed a standardized highway driving test.

RESULTS

Zopiclone 7.5 mg significantly impaired on-the-road driving performance in both insomnia groups and healthy controls. The magnitude of impairment was significantly less in the chronic users group as compared with the controls.

CONCLUSIONS

The smaller magnitude of effects suggests that investigating residual effects of hypnotics in healthy volunteers may yield a minor overestimation of the actual effects in insomnia patients.

Prevalence of alcohol and drugs among car and van drivers killed in road accidents in Norway: an overview from 2001 to 2010

OBJECTIVES

To examine the prevalence of alcohol and drugs in blood samples collected from car and van drivers killed in traffic accidents in Norway during the time period from 2001 to 2010.

METHODS

Blood samples (n = 676, 63% of all killed drivers) were analyzed for alcohol, psychoactive medications, and illicit drugs. The cutoff limits for positive results were set according to the new legislative limits under the Norwegian Road Traffic Act. The results were assessed in relation to sex and age, time of day and day of week, and single- versus multiple-vehicle and all investigated vehicle accidents.

RESULTS

Alcohol or one or more drugs was detected in samples from 40.2 percent of all investigated drivers, with 28.7 percent showing blood concentrations of at least 5 times the legislative limits. For the investigated female drivers, the total prevalence was 24.0 percent. Among the single-vehicle accidents, alcohol or drugs was found in 63.8 percent of the cases, with 49.1 percent showing blood concentrations of at least 5 times the legislative limits. Alcohol was detected in 25.3 and 49.1 percent of samples from all investigated drivers and among drivers killed in single-vehicle accidents, respectively. Psychoactive medications were found in 14.4 and 17.7 percent and illicit drugs in 14.1 and 19.2 percent, respectively. The most commonly detected group of medications was benzodiazepines, and amphetamines and tetrahydrocannabinol were the most commonly detected illicit drugs. The prevalence of alcohol alone was highest among drivers under the age of 25, and the combination of alcohol with other drugs was highest among drivers under the age of 35. Drivers between the ages of 25 and 54 showed the highest prevalence of medications and/or illicit drugs without the presence of alcohol. The highest prevalence of alcohol or drugs was found among drivers killed in single-vehicle accidents on weeknights (83.8%) and on weekend nights (89.3%).

CONCLUSIONS

The findings confirm that a large number of fatally injured drivers, in particular among drivers involved in single-vehicle accidents, had concentrations of alcohol or drugs above the new legislative limits introduced in 2012. In many cases, concentrations of at least 5 times the limits were found. The proportion of drivers killed who tested positive for alcohol or other drugs did not change during the study period; however, the total number of drivers killed per year decreased by about 20 percent. Some changes were also observed with regard to the types of benzodiazepines and amphetamines detected during the 10-year period.

On-the-road driving performance and driving-related skills in older untreated insomnia patients and chronic users of hypnotics

RATIONALE

Many older adults report sleep problems and use of hypnotics. Several studies have shown that hypnotics can have acute adverse effects on driving the next morning. It is unclear however whether driving of chronic hypnotic users is impaired. Therapeutic effects on insomnia and development of tolerance may reduce the residual effects on driving.

OBJECTIVES

The present study aimed to compare actual driving performance and driving-related skills of chronic hypnotic users to good sleepers. To determine whether insomnia itself affects driving performance, driving and driving-related skills were compared between insomnia patients who do not or infrequently use hypnotics and good sleepers.

METHODS

Twenty-two frequent users of hypnotics (using hypnotics ≥ 4 nights per week for more than 3 months), 20 infrequent users (using hypnotics ≤ 3 nights per week), and 21 healthy, age-matched controls participated in this study. On the night before testing, all subjects were hospitalized for an 8-h sleep recorded by polysomnography. Frequent hypnotic users used their regular medication at bedtime (2330 hours), while infrequent users and controls received no medication. Cognitive performance (word learning, digit span, tracking, divided attention, vigilance, and inhibitory control) was assessed 8.5 h and driving performance between 10 and 11 h after bedtime and dosing.

RESULTS

Polysomnographic recordings did not significantly differ between the groups, but the insomnia patients, treated or untreated, still reported subjective sleep complaints. Results show no differences in driving performance and driving-related skills between both groups of insomnia patients and controls.

CONCLUSIONS

Driving performance in chronic users of hypnotics and untreated insomnia patients is not impaired. For chronic users, this may be due to prescription of relatively safe drugs and low doses. For untreated insomniacs, this corroborates previous findings showing an absence of neuropsychological deficits in this group of patients.

Dual orexin receptor antagonists show distinct effects on locomotor performance, ethanol interaction and sleep architecture relative to gamma-aminobutyric acid-A receptor modulators

Dual orexin receptor antagonists (DORAs) are a potential treatment for insomnia that function by blocking both the orexin 1 and orexin 2 receptors. The objective of the current study was to further confirm the impact of therapeutic mechanisms targeting insomnia on locomotor coordination and ethanol interaction using DORAs and gamma-aminobutyric acid (GABA)-A receptor modulators of distinct chemical structure and pharmacological properties in the context of sleep-promoting potential. The current study compared rat motor co-ordination after administration of DORAs, DORA-12 and almorexant, and GABA-A receptor modulators, zolpidem, eszopiclone, and diazepam, alone or each in combination with ethanol. Motor performance was assessed by measuring time spent walking on a rotarod apparatus. Zolpidem, eszopiclone and diazepam [0.3–30 mg/kg administered orally (PO)] impaired rotarod performance in a dose-dependent manner. Furthermore, all three GABA-A receptor modulators potentiated ethanol- (0.25–1.5 g/kg) induced impairment on the rotarod. By contrast, neither DORA-12 (10–100 mg/kg, PO) nor almorexant (30–300 mg/kg, PO) impaired motor performance alone or in combination with ethanol. In addition, distinct differences in sleep architecture were observed between ethanol, GABA-A receptor modulators (zolpidem, eszopiclone, and diazepam) and DORA-12 in electroencephalogram studies in rats. These findings provide further evidence that orexin receptor antagonists have an improved motor side-effect profile compared with currently available sleep-promoting agents based on preclinical data and strengthen the rationale for further evaluation of these agents in clinical development.

In the Zzz zone: the effects of Z-drugs on human performance and driving

Despite their improved pharmacokinetic profile, the Z-drugs, zolpidem, zopiclone, and zaleplon, have a spectrum of adverse effects comparable to benzodiazepines. This review focuses on the impairment from Z-drugs on cognition, behavior, psychomotor performance, and driving ability. Z-drugs are short-acting GABA agonists that reduce sleep latency without disturbing sleep architecture. Bizarre behavioral effects have prompted warnings on the prescription, dispensation, and use of Z-drugs. Psychomotor impairment, falls, and hip fractures are more likely to occur with Z-drugs that have longer half-lives, that are taken at higher-than-recommended doses and when mixed with other psychoactive substances including alcohol. Zopiclone and higher doses of zolpidem are more likely to cause anterograde amnesia than zaleplon. Z-drugs, especially zolpidem, are associated with complex behaviors such as sleepwalking, sleep-driving, and hallucinations. Patients taking zopiclone and zolpidem have an increased risk of motor vehicle collisions, over double that of unexposed drivers. Driving impairment occurs with zopiclone and higher doses of zolpidem but is unlikely to occur after 4 h post-zaleplon administration. The residual effect of Z-drugs on next-day cognitive and psychomotor performance has significant impact on lifestyle, safety, and occupational considerations, including motor vehicle and machine operation. The risk-benefit analysis of Z-drugs in the treatment of insomnia, particularly in the elderly, may not favor treatment due to the increased risks of falls and motor vehicle collisions. Prescribers should warn patients taking Z-drugs of minimum time thresholds before they operate machinery or drive motor vehicles.

Risk of road accident associated with the use of drugs: a systematic review and meta-analysis of evidence from epidemiological studies

This paper is a corrigendum to a previously published paper where errors were detected. The errors have been corrected in this paper. The paper is otherwise identical to the previously published paper. A systematic review and meta-analysis of studies that have assessed the risk of accident associated with the use of drugs when driving is presented. The meta-analysis included 66 studies containing a total of 264 estimates of the effects on accident risk of using illicit or prescribed drugs when driving. Summary estimates of the odds ratio of accident involvement are presented for amphetamines, analgesics, anti-asthmatics, anti-depressives, anti-histamines, benzodiazepines, cannabis, cocaine, opiates, penicillin and zopiclone (a sleeping pill). For most of the drugs, small or moderate increases in accident risk associated with the use of the drugs were found. Information about whether the drugs were actually used while driving and about the doses used was often imprecise. Most studies that have evaluated the presence of a dose-response relationship between the dose of drugs taken and the effects on accident risk confirm the existence of a dose-response relationship. Use of drugs while driving tends to have a larger effect on the risk of fatal and serious injury accidents than on the risk of less serious accidents (usually property-damage-only accidents). The quality of the studies that have assessed risk varied greatly. There was a tendency for the estimated effects of drug use on accident risk to be smaller in well-controlled studies than in poorly controlled studies. Evidence of publication bias was found for some drugs. The associations found cannot be interpreted as causal relationships, principally because most studies do not control very well for potentially confounding factors.

Variable selection on large case-crossover data: application to a registry-based study of prescription drugs and road traffic crashes

PURPOSE

In exploratory analyses of pharmacoepidemiological data from large populations with large number of exposures, both a conceptual and computational problem is how to screen hypotheses using probabilistic reasoning, selecting drug classes or individual drugs that most warrant further hypothesis testing.

METHODS

We report the use of a shrinkage technique, the Lasso, in the exploratory analysis of the data on prescription drugs and road traffic crashes, resulting from the case-crossover matched-pair interval approach described by Orriols and colleagues (PLoS Med 2010; 7:e1000366). To prevent false-positive results, we consider a bootstrap-enhanced version of the Lasso. To highlight the most stable results, we extensively examine sensitivity to the choice of referent window.

RESULTS

Antiepileptics, benzodiazepine hypnotics, anxiolytics, antidepressants, antithrombotic agents, mineral supplements, drugs used in diabetes, antiparkinsonian treatment, and several cardiovascular drugs showed suspected associations with road traffic accident involvement or accident responsibility.

CONCLUSION

These results, in relation to other findings in the literature, provide new insight and may generate new hypotheses on the association between prescription drugs use and impaired driving ability.

A 3-year survey quantifying the risk of dose escalation of benzodiazepines and congeners to identify risk factors to aid doctors to more rationale prescribing

OBJECTIVES

This study investigated and quantified risk factors of dose escalation, as an indication of drug misuse and dependency of benzodiazepines and congeners, among presumably drug naïve patients in the Norwegian drug prescription database, observed over 3 years.

DESIGN

Observational study.

SETTING

Prescription database study.

PARTICIPANTS

We defined an excessive user as one redeeming more than two defined daily doses per day in 3 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

We examined the risk of excessive use over time and the effect of risk factors through multistate logistic regression and scenarios.

RESULTS

Most of the 81 945 patients had zopiclone or zolpidem as the initial drug (63.8%), followed by diazepam (25.3%), oxazepam (6.1%), nitrazepam/flunitrazepam (2.9%), hydroxyzine/buspirone (1.6%) and alprazolam (0.3%). At any time 23% redeemed prescriptions, about 34% did not redeem any prescriptions beyond any 3-month period and 0.9% ended up as excessive users. Patients previously using drugs, such as opioids, antialcohol or smoke cessation treatment, had a higher risk to become excessive users compared to patients who had not. Patients whose first prescription was for oxazepam or nitrazepam/flunitrazepam had a higher risk of becoming an excessive user compared to those who started with diazepam. A specialist in general practice as the first-time prescriber was associated with a lower risk compared to doctors without specialty.

CONCLUSIONS

Most benzodiazepine use occurred according to guidelines. Still, some experienced dose escalation over time, and risk factors were previous use of other psychotropic drugs, long time use, choice of first-time drug and prescriber's specialty. This could incite doctors to have a cessation plan when issuing first-time prescriptions.

Orexin receptor antagonists differ from standard sleep drugs by promoting sleep at doses that do not disrupt cognition

Current treatments for insomnia, such as zolpidem (Ambien) and eszopiclone (Lunesta), are γ-aminobutyric acid type A (GABAA)-positive allosteric modulators that carry a number of side effects including the potential to disrupt cognition. In an effort to develop better tolerated medicines, we have identified dual orexin 1 and 2 receptor antagonists (DORAs), which promote sleep in preclinical animal models and humans. We compare the effects of orally administered eszopiclone, zolpidem, and diazepam to the dual orexin receptor antagonist DORA-22 on sleep and the novel object recognition test in rat, and on sleep and two cognition tests (delayed match to sample and serial choice reaction time) in the rhesus monkey. Each compound's minimal dose that promoted sleep versus the minimal dose that exerted deficits in these cognitive tests was determined, and a therapeutic margin was established. We found that DORA-22 has a wider therapeutic margin for sleep versus cognitive impairment in rat and rhesus monkey compared to the other compounds tested. These data were further supported with the demonstration of a wider therapeutic margin for DORA-22 compared to the other compounds on sleep versus the expression of hippocampal activity-regulated cytoskeletal-associated protein (Arc), an immediate-early gene product involved in synaptic plasticity. These findings suggest that DORAs might provide an effective treatment for insomnia with a greater therapeutic margin for sleep versus cognitive disturbances compared to the GABAA-positive allosteric modulators currently in use.

Psychotropic drugs and risk of motor vehicle accidents: a population-based case-control study

AIM

To examine comprehensively the relationship between exposure to four classes of psychotropic drugs including antipsychotics, antidepressants, benzodiazepines (BZDs) and Z-drugs, and motor vehicle accidents (MVAs).

METHOD

The authors conducted a matched case-control study of 5183 subjects with MVAs and 31 093 matched controls, identified from the claims records of outpatient service visits during the period from 2000 to 2009. Inclusion criteria were defined as subjects aged equal to or more than 18 years and involved in MVAs. Conditional logistic regressions with covariates adjustment (including urbanity, psychiatric and non-psychiatric outpatient visits and Charlson comorbidity score) were applied to examine the effect of four classes of psychotropic drugs on MVAs.

RESULTS

Significant increased risk of MVAs was found in subjects taking antidepressants within 1 month (adjusted odds ratio (AOR) 1.73, 95% confidence interval (CI) 1.34, 2.22), 1 week (AOR 1.71, 95% CI 1.29, 2.26), and 1 day (AOR 1.70, 95% CI 1.26, 2.29) before MVAs occurred. Similar results were observed in subjects taking benzodiazepines (BZDs) (AOR 1.56, 95% CI 1.38, 1.75 for 1 month; AOR 1.64, 95% CI 1.43, 1.88 for 1 week, and AOR 1.62, 95% CI 1.39, 1.88 for 1 day) and Z-drugs (AOR 1.42, 95% CI 1.14, 1.76 for 1 month, AOR 1.37, 95% CI 1.06, 1.75 for 1 week, AOR 1.34, 95% CI 1.03, 1.75 for 1 day), but not antipsychotics. Moreover, significant dose effects of antidepressants (equal to or more than 0.6-1.0 DDD), BZDs (equal to or more than 0.1-0.5 DDD) and Z-drugs (more than 1 DDD) were observed, respectively, on the risk of experiencing an MVA.

CONCLUSION

Taken together, subjects taking antidepressants, BZDs and Z-drugs, separately, should be particularly cautioned for their increasing risk of MVAs.

Detection of phenazepam in impaired driving

Phenazepam is a potent 1,4-benzodiazepine that has gained notoriety among recreational drug users. First synthesized in Ukraine in the 1970s, it is one of the most commonly prescribed benzodiazepines in Russia and other commonwealth of independent state nations, where it is used therapeutically as a prescription drug. Reports of abuse are widespread and several European countries have taken steps to control its use. However, in the USA, phenazepam is not approved for use by the Food and Drug Administration, nor scheduled under the Federal Controlled Substances Act. Phenazepam is widely available on the Internet, and recreational drug users report a potency 10-fold greater than that of nordiazepam. We report a case of a 24-year-old male driver who was apprehended for impaired driving following a two-vehicle crash. The subject exhibited slurred speech and profound psychomotor impairment. Toxicology testing revealed phenazepam at a concentration of 76 ng/mL in blood, with no other drugs detected. This case report not only demonstrates the potential for adverse traffic safety consequences following the misuse of phenazepam, but also highlights the importance of analytical factors such as immunoassay cutoff concentration, cross-reactivity and comprehensive screening using chromatographic-based techniques for impaired driving investigations.

Effects of pregabalin on sleep in generalized anxiety disorder

Sleep disturbance is a cardinal symptom in both DSM-IV and ICD-10 criteria for generalized anxiety disorder (GAD). This review summarizes the results of clinical trials and pooled analyses that provide data on pregabalin's effect on sleep disturbance in patients diagnosed with GAD. The hypothesized mechanism of action of pregabalin is distinctly different from other anxiolytics. Pregabalin binds to a membrane α2δ subunit protein to inhibit release in excited central nervous system neurons of neurotransmitters implicated in pathological anxiety. Treatment with pregabalin has been found to be associated with significant improvement in GAD-related sleep disturbance across seven placebo-controlled clinical trials. Treatment with pregabalin is associated with improvement in all forms of insomnia and improvement in sleep has been found to be correlated with reduction in functional impairment and improvement in quality of life on subjective global measures. Results of a mediational analysis suggest that 53% of the effect of pregabalin on sleep disturbance was due to a direct effect and 47% was due to an indirect effect, mediated through prior reduction in anxiety symptom severity. In patients with GAD, improvement in sleep has been found to be associated with a reduction in daytime sleepiness. However, dose-related sedation is reported, typically in the first 2 wk of treatment, in approximately 10-30% of patients, depending on the dose used and the speed of titration. Insomnia is a common component of the clinical presentation of GAD and pregabalin appears to be an efficacious treatment for this often chronic and disabling symptom.

Do Benzodiazepines Still Deserve a Major Role in The Treatment of Psychiatric Disorders? A Critical Reappraisal

Discovered in the late 1950s by Leo Sternbach, the first benzodiazepine (BZD) chlordiazepoxide was followed by several congeners, which rapidly constituted one of the largest and most widely prescribed classes of psychotropic compounds. After 50 years, BZDs are still routinely utilized not only in psychiatry but, more generally, in the whole of medicine. Despite their high therapeutic index which makes BZDs safer than other compounds like barbiturates, as well as their rapidity of onset, psychiatrists and family physicians are well aware about the controversy that surrounds the wide use – often not adequately based on scientific evidence – of BZDs in many psychiatric disorders. In this overview of international treatment guidelines, systematic reviews and randomized clinical trials, the aim was to provide a critical appraisal of the current use and role of BZDs in psychiatric disorders and their disadvantages, with specific emphasis on anxiety and affective disorders, sleep disorders, alcohol withdrawal, violent and aggressive behaviours in psychoses, and neuroleptic-induced disorders. In addition, specific emphasis has been given to the extent of usage of BZDs and its appropriateness through the assessment of available international surveys. Finally, the entire spectrum of BZD-related adverse effects including psychomotor effects, use in the elderly, paradoxical reactions, tolerance and rebound, teratologic risk, dependence, withdrawal and abuse issues was examined in detail.

Challenges and Opportunities for Pharmacoepidemiology in Drug-Therapy Decision Making

Pharmacoepidemiology is a relatively new and evolving science that attempts to quantify mainly adverse drug events and patterns of drug use in a large population. The strength of pharmacoepidemiology over randomized trials is the ability to quantify rare adverse events that may occur over long periods. Recently, discordance in the results of pharmacoepidemiologic studies has made it difficult for clinicians and policy makers to make informed drug-therapy decisions. This commentary addresses the strength of pharmacoepidemiology and the advances in the methodology of pharmacoepidemiologic studies over the years. We also discuss the potential problem of discordant results and urge pharmacoepidemiologists to develop good practice guidelines for the conduct of pharmacoepidemiologic studies.

Uncovering the source of new benzodiazepine prescriptions in community-dwelling older adults'

OBJECTIVE

Initiatives to reduce benzodiazepine use have been largely unsuccessful despite strong associations with adverse outcomes. Curtailing incident use of benzodizepines is an alternate strategy that has yet to be explored. This study aims to determine the source of incident benzodiazepine prescriptions by comparing the risk of receiving a new prescription upon hospital discharge versus after an ambulatory care clinic visit.

METHODS

Data were derived from 1189 community-dwelling adults aged 65 years naive to benzodiazepine consumption, enrolled in the Étude sur la Santé des Ainés, a prospective 3-year cohort study conducted in Québec, Canada. Health survey questionnaires were linked with provincial administrative databases of prescription and health service claims. Analysis with multivariate Poisson regression models compared the risk of incident benzodiazepine use post-hospitalization versus after an ambulatory care visit. Models were adjusted for sex, age, antidepressant use, and concomitant drugs. Sub-analyses were conducted for chronic prescriptions.

RESULTS

Incident benzodiazepine use was 11% over a 2-year period, with 18.3% of prescriptions leading to chronic use (> 90 days). Hospitalization conferred a 2.7-fold greater risk of incident use than an outpatient visit (OR 2.66, 95% CI 1.78-3.98) and a 4.7-fold (OR 4.74, 95% CI 1.63-13.78) increased risk of chronic use, after adjusting for potential confounders. Despite the increased risk, only 13% of new prescriptions originated post-hospital discharge, with the remainder prescribed during outpatient visits.

CONCLUSION

Interventions are required to curb incident benzodiazepine prescriptions at their source both in hospitals and in ambulatory care settings.

Hospital outpatients' responses to taking medications with driving warnings

OBJECTIVE

The study investigates the knowledge, intentions, and driving behavior of persons prescribed medications that display a warning about driving. It also examines their confidence that they can self-assess possible impairment, as is required by the Australian labeling system.

METHOD

We surveyed 358 outpatients in an Australian public hospital pharmacy, representing a well-advised group taking a range of medications including those displaying a warning label about driving. A brief telephone follow-up survey was conducted with a subgroup of the participants.

RESULTS

The sample had a median age of 53.2 years and was 53 percent male. Nearly three quarters (73.2%) had taken a potentially impairing class of medication and more than half (56.1%) had taken more than one such medication in the past 12 months. Knowledge of the potentially impairing effects of medication was relatively high for most items; however, participants underestimated the possibility of increased impairment from exceeding the prescribed dose and at commencing treatment. Participants' responses to the safety implications of taking drugs with the highest level of warning varied. Around two thirds (62.8%) indicated that they would consult a health practitioner for advice and around half would modify their driving in some way. However, one fifth (20.9%) would drive when the traffic was thought to be less heavy and over a third (37.7%) would modify their medication regime so that they could drive. The findings from the follow-up survey of a subsample taking target drugs at the time of the first interview were also of concern. Only just over half (51%) recalled seeing the warning label on their medications and, of this group, three quarters (78%) reported following the warning label advice. These findings indicated that there remains a large proportion of people who either did not notice or did not consider the warning when deciding whether to drive. There was a very high level of confidence in this group that they could determine whether they were personally affected by the medication, which may be a problem from a safety perspective.

CONCLUSION

This study involved persons who should have had a very high level of knowledge and awareness of medication warning labeling. Even in this group there was a lack of informed response to potential impairment. A review of the Australian warning system and wider dissemination of information on medication treatment effects would be useful. Clarifying the importance of potential risk in the general community context is recommended for consideration and further research.

Consumer perceptions of medication warnings about driving: a comparison of French and Australian labels

OBJECTIVE

Little research has examined user perceptions of medication warnings about driving. Consumer perceptions of the Australian national approach to medication warnings about driving are examined. The Australian approach to warning presentation is compared with an alternative approach used in France. Visual characteristics of the warnings and overall warning readability are investigated. Risk perceptions and behavioral intentions associated with the warnings are also examined.

METHOD

Surveys were conducted with 358 public hospital outpatients in Queensland, Australia. Extending this investigation is a supplementary comparison study of French hospital outpatients (n = 75).

RESULTS

The results suggest that the Australian warning approach of using a combination of visual characteristics is important for consumers but that the use of a pictogram could enhance effects. Significantly higher levels of risk perception were found among the sample for the French highest severity label compared to the analogous mandatory Australian warning, with a similar trend evident in the French study results. The results also indicated that the French label was associated with more cautious behavioral intentions.

CONCLUSION

The results are potentially important for the Australian approach to medication warnings about driving impairment. The research contributes practical findings that can be used to enhance the effectiveness of warnings and develop countermeasures in this area. Hospital pharmacy patients should include persons with the highest level of likelihood of knowledge and awareness of medication warning labeling. Even in this context it appears that a review of the Australian warning system would be useful particularly in the context of increasing evidence relating to associated driving risks. Reviewing text size and readability of messages including the addition of pictograms, as well as clarifying the importance of potential risk in a general community context, is recommended for consideration and further research.

Acute lorazepam effects on neurocognitive performance

A double-blind, placebo-controlled, crossover design was employed to determine whether acute lorazepam (2 mg orally) cognitive side effects would emerge in a differential age-dependent fashion in 15 young (mean age=22 years) and 12 older (mean age=64 years) subjects. Acute use of lorazepam is frequently the initial treatment choice for convulsive status epilepticus or repetitive seizure clusters. Cognitive assessment was performed during drug and placebo conditions using a computerized battery of cognitive tests. With the exception of performance on the reasoning composite score, significant drug effects were present on all primary cognitive domain measures. However, the only significant drug-by-age interaction effect was seen for dual-task performance. The relationship between test performance and plasma lorazepam concentrations was generally modest and non-significant, suggesting that individual differences in pharmacokinetics are not a major factor contributing to the emergence of cognitive side effects. Despite robust lorazepam effects on multiple measures of neurocognitive function, differential age effects are largely restricted to dual-task performance. These results indicate that with the exception of dual-task performance, older individuals in the age range of this study do not appear to be at increased risk for the emergence of cognitive side effects following a single 2-mg dose of lorazepam.

Change in healthcare utilization and costs following initiation of benzodiazepine therapy for long-term treatment of generalized anxiety disorder: a retrospective cohort study

BACKGROUND

Selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, and benzodiazepine anxiolytics are used in the US to treat generalized anxiety disorder (GAD). While benzodiazepines typically provide rapid symptomatic relief, long-term use is not recommended due to risks of dependency, sedation, falls, and accidents.

METHODS

Using a US health insurance database, we identified all persons with GAD (ICD-9-CM diagnosis code 300.02) who began a long-term course of treatment (≥ 90 days) with a benzodiazepine anxiolytic between 1/1/2003 and 12/31/2007, We compared healthcare utilization and costs over the six-month periods preceding and following the date of treatment initiation ("pretreatment" and "post-treatment", respectively), and focused attention on accident-related encounters (e.g., for treatment of fractures) and care received for other reasons possibly related benzodiazepine use (e.g., sedation, dizziness).

RESULTS

A total of 866 patients met all study entry criteria; 25% of patients began treatment on an add-on basis (i.e., adjunctive to escitalopram, paroxetine, sertraline, or venlafaxine), while 75% of patients did not receive concomitant therapy. Mean total healthcare costs increased by $2334 between the pretreatment and post-treatment periods (from $4637 [SD=$9840] to $6971 [$17,002]; p<0.01); costs of accident-related encounters and other care that was possibly related to use of benzodiazepines increased by an average of $1099 ($1757 [$7656] vs $2856 [$14,836]; p=0.03).

CONCLUSIONS

Healthcare costs increase in patients with GAD beginning long-term (≥ 90 days) treatment with a benzodiazepine anxiolytic; a substantial proportion of this increase is attributable to care associated with accidents and other known sequelae of long-term benzodiazepine use.

Sleep specialists' opinion on sleep disorders and fitness to drive a car: the necessity of continued education

Whether patients with sleep disorders are fit to drive, and who should determine this, is a matter of debate. However, scientific literature is available on these topics to aid clinicians making these decisions. A survey was conducted to assess sleep specialists' views on fitness to drive for patients suffering from apnea, insomnia, and narcolepsy. Most of the 112 respondents (66%, 95%CI: 57-74%) indicated that insomnia patients would be fit to drive within days or weeks after initiating treatment, but 44% (95%CI: 35-53%) felt that, depending on the amount of excessive daytime sleepiness (EDS), they should not drive if untreated. Around half of respondents (49%, 95%CI: 40-58%) indicated that untreated patients with apnea should not drive, but the majority (66%, 95%CI: 57-74%) felt they could drive after Continuous Positive Airway Pressure treatment was established, though EDS was a significant factor. For untreated narcoleptic patients 77% (95%CI: 68-84%) indicated they should not drive, and similarly, that treated patients could drive, although EDS levels were again seen as important. It is concluded that patient education remains the most practical approach to improve compliance and reduce accidents associated with EDS. Sleep specialists should remain up-to-date of relevant scientific literature to achieve this goal.

Concentrations of diazepam and nordiazepam in 1,000 blood samples from apprehended drivers--therapeutic use or abuse of anxiolytics?

Using an in-house forensic toxicology database, we selected 1000 cases of driving under the influence of drugs (DUIDs) over a 12-month period if diazepam (D) and nordiazepam (ND) were both present in the blood samples. Quantitative analysis of D and ND in blood was done by solvent extraction (butyl acetate) and capillary column gas chromatography (GC) with a nitrogen-phosphorous (N-P) detector. The limits of quantitation of this analytical method for D and ND in blood were 0.05 mg/L. The correlation between D and ND concentrations in blood was statistically significant (r = .58, P < .001), as expected for a parent drug and its primary metabolite. However, the frequency distributions were markedly skewed to the right with mean (median) and highest concentrations of 0.37 (0.20) and 6.1 mg/L for D and 0.39 (0.20) and 5.6 mg/L for ND. The mean (median) total concentration (D + ND) was 0.76 mg/L (0.50 mg/L), and the concentration ratios D/ND and ND/D were 1.29 (median 0.95) and 1.41 (median 1.06), respectively. In 90 cases (9%), the concentration of D in blood exceeded 0.83 mg/L, which corresponds to an upper therapeutic limit in plasma (∼1.5 mg/L), assuming a plasma/blood distribution ratio of 1.8:1.

Alprazolam for depression

BACKGROUND

The 'off-label' effect of alprazolam on depression has not been systematically evaluated.

OBJECTIVES

To determine the antidepressant effect, including tolerability and acceptability, of alprazolam as monotherapy for major depression, when compared to placebo and conventional antidepressants in outpatients and patients in primary care.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials and the Cochrane Depression, Anxiety and Neurosis Group Register, which includes relevant randomised controlled trials from the following bibliographic databases: The Cochrane Library (all years to February 2012); EMBASE (1970 to February 2012); MEDLINE (1950 to February 2012) and PsycINFO (1960 to February 2012). Two review authors identified relevant trials by assessing the abstracts of all possible studies. We applied no language restrictions.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) of alprazolam versus placebo or conventional antidepressants for depression in adults, excluding studies with inpatients only.

DATA COLLECTION AND ANALYSIS

Two review authors performed the data extraction and 'Risk of bias' assessment independently with disagreements resolved through discussion with a third review author. Primary outcomes included the mean difference (MD) in reduction of depression on a continuous measure of depression symptoms, and the risk ratio (RR) of the clinical response based on a dichotomous measure, with 95% confidence intervals (CI).

MAIN RESULTS

We identified 21 alprazolam studies (22 reports) with a total of 2693 participants. Seven studies used a placebo (n = 771) and 20 used cyclic antidepressants (n = 1765). The typical duration of the studies was four to six weeks. We considered six studies to have a high risk of bias.When alprazolam was compared with placebo for reduction in symptoms all estimates indicated a positive effect for alprazolam. Pooled estimates of efficacy data showed a moderately large continuous mean difference (MD) at the end of trial (-5.34, 95% CI -7.48 to -3.20; I(2) = 68%). The risk difference (RD) for the dichotomous measure of clinical response (50% improvement) was 0.32 in favour of alprazolam (95% CI 0.22 to 0.42; I(2) = 0%), with a number needed to treat to benefit (NNTB) of 3 (95% CI 2 to 5). The RD of all-cause withdrawals did not differ between alprazolam and placebo.When depression severity was measured as a continuum the effect of alprazolam did not differ statistically or clinically from the effects of any of the conventional antidepressants combined (MD 0.25, 95% CI -0.93 to 1.43; I(2) = 55%). However, for dichotomised depression severity, alprazolam had less effect than antidepressants (RR 0.86, 95% CI 0.75 to 0.99; I(2) = 37%; RD -0.11, 95% CI -0.24 to 0.01; I(2) = 58%; NNTB 9, 95% CI 4 to 100). The RD of all-cause withdrawals was -0.04 (95% CI -0.07 to 0.00; I(2) = 35%), in favour of alprazolam.

AUTHORS' CONCLUSIONS

Alprazolam appears to reduce depressive symptoms more effectively than placebo and as effectively as tricyclic antidepressants. However, the studies included in the review were heterogeneous, of poor quality and only addressed short-term effects, thus limiting our confidence in the findings. Whilst the rate of all-cause withdrawals did not appear to differ between alprazolam and placebo, and withdrawals were less frequent in the alprazolam group than in any of the conventional antidepressants combined group, these findings should be interpreted with caution, given the dependency properties of benzodiazepines.

What non-alcohol drugs are used by drinking drivers in Sweden? Toxicological results from ten years of forensic blood samples

INTRODUCTION AND METHOD

Using a forensic toxicology database (TOXBASE), the toxicological results from 10 years of forensic blood samples from people arrested for driving under the influence of alcohol and/or other drugs were reviewed.

RESULTS

Alcohol was the only drug identified in blood in N=35,704 cases at a median blood-alcohol concentration (BAC) of 1.63 mg/g. The mean age (±SD) of these offenders was 40±15years and 89% were male. The median BAC was lower (1.30 mg/g) in drivers who had consumed alcohol and used a prescription drug before driving (N=1,251). The mean age of this group of traffic offenders was 38±13years and 85% were male. Both the median BAC (0.97 mg/g) and the mean age were lowest (36±11years, 92% male) in N=3,153 drivers who had consumed alcohol and used illicit drugs before driving. Cannabis, amphetamine, cocaine and morphine (metabolite of heroin) were the commonest illicit drugs identified in blood samples. Sedative-hypnotics (benzodiazepines) were the major prescription drugs co-ingested with alcohol. Poly-drug use was a common finding in these traffic delinquents, although individuals who only drank alcohol had a higher median BAC and were also several years older than drinking drivers combining alcohol with other drugs before driving.

IMPACT ON INDUSTRY

Zero-tolerance legislation did not deter hard-core offenders. In future there should be more focus on treatment for alcohol and substance abuse disorder rather than conventional punishments for this type of traffic crime.

Drugs for insomnia

INTRODUCTION

Sleep is a vital neurochemical process involving sleep-promoting and arousal centers in the brain. Insomnia is a pervasive disorder characterized by difficulties in initiating or maintaining or non-refreshing (poor quality) sleep and clinically significant daytime distress. Insomnia is more prevalent in women and old age and puts sufferers at significant physical and mental health risks. This review summarizes published data on the current and emerging insomnia drug classes, rationale for development and associated risks/benefits. (Summary of Product Characteristics and Medline search on "hypnotic" or specific drug names and "Insomnia").

AREAS COVERED

GABA(A) receptor modulators facilitate sleep onset and some improve maintenance but increase risk of dependence, memory, cognitive and psychomotor impairments, falls, accidents and mortality. Melatonin receptor agonists improve quality of sleep and/or sleep onset but response may develop over several days. They have more benign safety profiles and are indicated for milder insomnia, longer usage and (prolonged release melatonin) older patients. Histamine H-1 receptor antagonists improve sleep maintenance but their effects on cognition, memory and falls remain to be demonstrated. Late-stage pipeline orexin OX1/OX2 and serotonin 5HT2A receptor antagonists may hold the potential to address several unmet needs in insomnia pharmacotherapy but safety issues cast some doubts over their future.

EXPERT OPINION

Current and new insomnia drugs in the pipeline target different sleep regulating mechanisms and symptoms and have different tolerability profiles. Drug selection would ideally be based on improvement in the quality of patients' sleep, overall quality of life and functional status weighed against risk to the individual and public health.

The effects of most commonly prescribed second generation antidepressants on driving ability: a systematic review : 70th Birthday Prof. Riederer

Driving a car is vital for the functional autonomy of patients to take part in activities of daily living. Both psychopathologic symptoms and psychopharmacologic treatment may impair driving ability. This article provides a systematic review of published studies (1980-2011) on commonly prescribed newer antidepressants and driving performance. A total of 21 studies could be included in the review, indicating that there is a lack of controlled patient studies. Investigations on newer antidepressants were frequently undertaken in healthy subjects focusing on acute or subchronic effects of application, predominately in young male participants, with dosages usually given in an ambulatory setting. No data, according to selection criteria, were found with respect to agomelatine, duloxetine, bupropion and viloxazine. There is evidence that the SSRIs (citalopram, escitalopram, fluoxetine, fluvoxamine, sertraline, paroxetine) and the SNRI venlafaxine have no deleterious effects on driving ability. Acute use of mirtazapine does produce impairments that diminish to some degree when given as a nocturnal dose and cannot be seen after repeated dosing in healthy controls. Patients obviously benefit from treatment with newer antidepressants; however, at least a subgroup does not reach performance level of healthy subjects. More patient studies are needed that elaborate specific relationships between clinical subtypes of the illness and response to different antidepressants, considering course and duration of illness, co-morbidities and not least neuropsychological and neurobiological characteristics.

Road traffic crashes and prescribed methadone and buprenorphine: a French registry-based case-control study

BACKGROUND

Opioids have been shown to impair psychomotor and cognitive functioning in healthy volunteers with no history of opioid abuse. Few or no significant effects have been found in opioid-dependant patients in experimental or driving simulation studies. The risk of road traffic crash among patients under buprenorphine or methadone has not been subject to epidemiological investigation so far. The objective was to investigate the association between the risk of being responsible for a road traffic crash and the use of buprenorphine and methadone.

METHODS

Data from three French national databases were extracted and matched: the national health care insurance database, police reports, and the national police database of injurious crashes. Case-control analysis comparing responsible versus non responsible drivers was conducted.

RESULTS

72,685 drivers involved in an injurious crash in France over the July 2005-May 2008 period, were identified by their national health care number. The 196 drivers exposed to buprenorphine or methadone on the day of crash were young, essentially males, with an important co-consumption of other substances (alcohol and benzodiazepines). Injured drivers exposed to buprenorphine or methadone on the day of crash, had an increased risk of being responsible for the crash (odds ratio (OR)=2.02, 95% confidence interval (CI): 1.40 and 2.91).

CONCLUSIONS

Users of methadone and buprenorphine were at increased risk of being responsible for injurious road traffic crashes. The increased risk could be explained by the combined effect of risky behaviors and treatments.

A comparison of pharmacoepidemiological study designs in medication use and traffic safety research

In order to explore how the choice of different study designs could influence the risk estimates, a case–crossover and case–time–control study were carried out and their outcomes were compared with those of a traditional case–control study design that evaluated the association between the exposure to psychotropic medications and the risk of having a motor vehicle accident (MVA). A record-linkage database availing data for 3,786 cases and 18,089 controls during the period 2000–2007 was used. The study designs (i.e., case–crossover and case–time–control) were derived from published literature, and the following psychotropic medicines were examined: antipsychotics, anxiolytics, hypnotics and sedatives, and antidepressants, stratified in the two groups selective serotonin reuptake inhibitors (SSRIs) and other antidepressants. Moreover, in order to further investigate the effects of frequency of psychoactive medication exposure on the outcomes of the case–crossover analysis, the data were also stratified by the number of defined daily doses (DDDs) and days of medication use in the 12 months before the motor vehicle accident. Three-thousand seven-hundred fifty-two cases were included in this second part of the case–crossover analysis. The case–crossover design did not show any statistically significant association between psychotropic medication exposure and MVA risk [e.g., SSRIs—Adj. OR = 1.00 (95 % CI: 0.69–1.46); Anxiolytics—Adj. OR = 0.95 (95 % CI: 0.68–1.31)]. The case–time–control design only showed a borderline statistically significant increased traffic accident risk in SSRI users [Adj. OR = 1.16 (95 % CI: 1.01–1.34)]. With respect to the stratifications by the number of DDDs and days of medication use, the analyses showed no increased traffic accident risk associated with the exposure to the selected medication groups [e.g., SSRIs, <20 DDDs—Adj. OR = 0.65 (95 % CI: 0.11–3.87); SSRIs, 16–150 days—Adj. OR = 0.55 (95 % CI: 0.24–1.24)]. In contrast to the above-mentioned results, our recent case–control study found a statistically significant association between traffic accident risk and exposure to anxiolytics [Adj. OR = 1.54 (95 % CI: 1.11–2.15)], and SSRIs [Adj. OR = 2.03 (95 % CI: 1.31–3.14)]. Case–crossover and case–time–control analyses produced different results than those of our recent case–control study (i.e., case–crossover and case–time–control analyses did not show any statistically significant association whereas the case–control analysis showed an increased traffic accident risk in anxiolytic and SSRI users). These divergent results can probably be explained by the differences in the study designs. Given that the case–crossover design is only appropriate for short-term exposures and the case–time–control design is an elaboration of this latter, it can be concluded that, probably, these two approaches are not the most suitable ones to investigate the relation between MVA risk and psychotropic medications, which, on the contrary, are often use chronically.

When should case-only designs be used for safety monitoring of medical products?

PURPOSE

To assess case-only designs for surveillance with administrative databases.

METHODS

We reviewed literature on two designs that are observational analogs to crossover experiments: the self-controlled case series (SCCS) and the case-crossover (CCO) design.

RESULTS

SCCS views the 'experiment' prospectively, comparing outcome risks in windows with different exposures. CCO retrospectively compares exposure frequencies in case and control windows. The main strength of case-only designs is they entail self-controlled analyses that eliminate confounding and selection bias by time-invariant characteristics not recorded in healthcare databases. They also protect privacy and are computationally efficient, as they require fewer subjects and variables. They are better than cohort designs for investigating transient effects of accurately recorded preventive agents, for example, vaccines. They are problematic if timing of self-administration is sporadic and dissociated from dispensing times, for example, analgesics. They tend to have less exposure misclassification bias and time-varying confounding if exposures are brief. Standard SCCS designs are bidirectional (using time both before and after the first exposure event), so they are more susceptible than CCOs to reverse-causality bias, including immortal-time bias. This is true also for sequence symmetry analysis, a simplified SCCS. Unidirectional CCOs use only time before the outcome, so they are less affected by reverse causality but susceptible to exposure-trend bias. Modifications of SCCS and CCO partially deal with these biases. The head-to-head comparison of multiple products helps to control residual biases.

CONCLUSION

The case-only analyses of intermittent users complement the cohort analyses of prolonged users because their different biases compensate for one another.

Are selective serotonin reuptake inhibitors safe for drivers? What is the evidence?

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) are widely used medications to treat several psychiatric diseases and, above all, depression. They seem to be as effective as older antidepressants but have a different adverse effect profile. Despite their favorable safety profile, little is known about their influence on traffic safety.

OBJECTIVE

To conduct a literature review to summarize the current evidence on the role of SSRIs in traffic safety, particularly concerning undesirable effects that could potentially impair fitness to drive, experimental and pharmacoepidemiologic studies on driving impairment, 2 existing categorization systems for driving-impairing medications, and the European legislative procedures for assessing fitness to drive before issuing a driver's license and driving under the influence of medicines.

METHODS

The article search was performed in the following electronic databases: MEDLINE, PsycINFO, ScienceDirect, and SafetyLit. The English-language scientific literature was searched using key words such as SSRIs and psychomotor performance, car crash or traffic accident, and adverse effects. For inclusion in this review, papers had to be full-text articles, refer to possible driving-related adverse effects, and be experimental or pharmacoepidemiologic studies on SSRIs and traffic accident risks. No restrictions concerning publication year were applied.

RESULTS

Ten articles were selected as background information on driving-related adverse effects, and 15 articles were selected regarding experimental and pharmacoepidemiologic work. Regarding SSRI adverse effects, the most reported undesirable effects referring to driving impairment were anxiety, agitation, sleep disturbances, headache, increased risk of suicidal behavior, and deliberate self-harm. Regarding the remaining issues addressed in this article, inconsistencies were found between the outcomes of the selected experimental and epidemiologic studies and between the 2 existing categorization systems under evaluation. Some pitfalls of the current legislative scenario were identified as well.

CONCLUSIONS

Based on the current evidence, it was concluded that more experimental and epidemiologic research is needed to elucidate the relationship between SSRI use and traffic safety. Furthermore, a revision of the existing categorization systems and harmonized European legislation in the field of medication use and driving were highly recommended.

Risk of road traffic accidents in patients discharged following treatment for psychotropic drug overdose: a self-controlled case series study in Australia

BACKGROUND

Use of psychotropic drugs is known to impair driving and increase the risk of road traffic accidents. They are also the most common drugs taken in overdose in hospital-treated episodes of self-poisoning. Most patients who take psychotropic drug overdoses are discharged within 48 hours, while they still have possible subclinical drug effects.

OBJECTIVE

Using a self-controlled case series design, we aimed to determine whether patients with psychotropic drug overdose are at a higher risk of a traffic accident in the period following discharge compared with a control period not associated with hospital-treated drug overdose.

METHODOLOGY

Using the New South Wales (NSW) Admitted Patient Data Collection (APDC) as the primary source, we retrieved 40 845 hospital separation records dated between 1 July 2000 and 30 June 2008 (8 years) in patients aged 18-80 years admitted to a hospital in NSW following an intentional self-poisoning with a psychotropic drug (coded X61 or X62 as the International Classification of Diseases, 10th Edition, [ICD-10] external cause of injury). Of these, 33459 hospital separations (i.e. discharges, transfers and deaths) involving 24 284 patients were considered eligible as the patients were discharged directly into the community where they could have driven a motor vehicle. We selected three separate post-admission periods (3 days, 1 week and 4 weeks), subtracted the number of inpatient days from each and calculated three separate post-discharge periods (immediate, intermediate and extended, respectively) for each episode of overdose. The control period was the duration of the study period where the individual was aged 18 years or older, excluding the total person-days in the post-discharge period/s and the index inpatient period/s. The APDC dataset was linked to the NSW Roads and Traffic Authority CrashLink dataset to identify any accidents in which each patient was involved as a motor-vehicle driver during the follow-up period. Incidence rate ratio (IRR) for matched post-discharge and control periods was found using random effects Poisson regression.

RESULTS

Seventy-two percent of the subjects were discharged within 2 days following their admission with overdose. Compared with the corresponding control periods the risk of a traffic accident was 3.5 times higher (IRR = 3.49; 95% CI 1.66, 7.33; p = 0.001) during the immediate, 1.9 times higher (IRR = 1.88; 95% CI 1.09, 3.25; p = 0.023) during the intermediate and 1.6 times higher (IRR = 1.65; 95% CI 1.27, 2.15; p = 0.0002) during the extended post-discharge period.

CONCLUSIONS

Self-poisoning with psychotropic drugs is associated with a markedly increased risk of a traffic accident during the first few days following discharge. These findings raise clinical and medico-legal implications concerning fitness-to-drive during this period. The risk reduces with time but remains significantly elevated after 4 weeks post-overdose. Further research is necessary to find out the factors contributing to this ongoing risk.

The role of alprazolam for the treatment of panic disorder in Australia

OBJECTIVE

To investigate the potential impact of increasing prescription rates of alprazolam for the treatment of panic disorder (PD) in Australia through a review of efficacy, tolerability and adverse outcome literature.

METHODS

Data were sourced by a literature search using MEDLINE, Embase, PsycINFO and a manual search of scientific journals to identify relevant articles. Clinical practice guidelines from the American Psychiatric Association, National Institute of Clinical Excellence, Royal Australian and New Zealand College of Psychiatrists and World Federation of Societies of Biological Psychiatry were sourced. Prescription data were sourced from Australian governmental sources.

RESULTS

Alprazolam has shown efficacy for control of PD symptoms, particularly in short-term controlled clinical trials, but is no longer recommended as a first-line pharmacological treatment due to concerns about the risks of developing tolerance, dependence and abuse potential. Almost no evidence is available comparing alprazolam to current first-line pharmacological treatment. Despite this, prescription rates are increasing. A number of potential issues including use in overdose and impact on car accidents are noted. conclusion: Although effective for PD symptoms in clinical trials, a number of potential issues may exist with use. Consideration of its future place in PD treatment in Australia may be warranted.

Utilização de benzodiazepínicos no Serviço Municipal de Saúde de Coronel Fabriciano, Minas Gerais

Neste estudo foram avaliadas as indicações de benzodiazepínicos no Serviço Municipal de Saúde de Coronel FabricianoMG, verificando sua conformidade com o preconizado pela literatura. O estudo avaliou todas as receitas desses medicamentos provenientes das Unidades Municipais de Saúde no período de Setembro a Outubro de 2006, os formulários de indicação clínica preenchidos pelo prescritor e cadastros informatizados do serviço. Analisaram-se 1.866 receitas, sendo 59,7% do Diazepam e o restante do Clonazepam. A Dose Diária Definida por mil habitantes por dia foi de 24,69 para o Diazepam e de 3,58 para o Clonazepam. Cerca de 50% das indicações relatadas pelos médicos foram como hipnótico ou ansiolítico, 21,9% para "uso crônico/dependência" e o restante para outras indicações. Das receitas que atenderam aos critérios de inclusão para análise da adequação da indicação (1618), cerca de 70% foram consideradas não adequadas, tendo em vista a indicação e o tempo de tratamento. Houve um alto percentual de inadequação na utilização de benzodiazepínicos, principalmente pelo uso prolongado e para atender a casos considerados pelos prescritores como uso crônico/dependência. Assim, há responsabilidade do serviço de saúde na manutenção da dependência.

Within-person study designs had lower precision and greater susceptibility to bias because of trends in exposure than cohort and nested case-control designs

OBJECTIVE

To compare precision and apparent bias between cohort, nested case-control, self-controlled case series, case-crossover, and case-time-control study designs.

STUDY DESIGN AND SETTING

Study designs were implemented to evaluate the association between thiazolidinediones (TZDs) and heart failure, TZDs and fracture, and liver enzyme-inducing anticonvulsants and fracture.

RESULTS

Effect estimates were similar for the cohort and case-control study; for the association between TZDs and fracture in women, the hazard ratio was 1.36 (1.18, 1.56) and odds ratio (OR) was 1.44 (1.21, 1.70). For this clinical example, the self-controlled case series gave upward bias when follow-up was censored at the outcome (incidence rate ratio [IRR], 7.08; 4.96, 10.09) but was otherwise unbiased (IRR, 1.41; 1.14, 1.75). The retrospective case-crossover OR was 3.24 (2.18, 4.80), which was reduced by either bidirectional sampling (OR, 1.20; 0.98, 1.46) or with the case-time-control design (OR, 1.40; 1.09, 1.81). Findings on apparent bias were similar for the other two clinical examples. In each clinical example, within-person designs had considerably lower precision than the cohort or case-control study designs.

CONCLUSION

When long-term exposures are analyzed, within-person study designs may have lower precision and greater susceptibility to bias. Bias may be reduced by sampling follow-up both before and after the outcome or with the case-time-control study design.

At-fault motor vehicle crash risk in elderly patients treated with antidepressants

OBJECTIVE

To assess whether antidepressant treatment is associated with a temporary increase in the risk of a motor vehicle crash among older adults.

DESIGN

Population-based case-only time-to-event analysis.

SETTING AND SUBJECTS

Data from transportation and healthcare databases for adults age 65 and older in Ontario, Canada, between January 1, 2000, and October 31, 2007. Consecutive adults who had a motor vehicle crash anytime following their 66th birthday.

MEASUREMENTS

The primary exposure variable was treatment with antidepressant medication, and the primary outcome measure was a motor vehicle crash.

RESULTS

A total of 159,678 individuals had a crash during the study, of whom 7,393 (5%) received an antidepressant in the month prior to the crash. The hazard ratio (HR) of crash associated with second-generation antidepressants was 1.10 (95% confidence interval [CI]: 1.07-1.13, χ² = 41.77, df = 1, p <0.0001), adjusted for gender, license suspensions, and other medications, but the risk for first-generation antidepressants was not significant. The increased risk was restricted to those who were also concurrently prescribed a benzodiazepine (adjusted HR: 1.23, 95% CI: 1.17-1.28, χ² = 85.28, df = 1, p <0.0001) or a strong anticholinergic medication (adjusted HR: 1.63, 95% CI: 1.57-1.69, χ² = 627.31, df = 1, p <0.0001), and was confined to crashes where the patient was at fault. The increased risk was apparent for the first 3-4 months following initiation of an antidepressant and returned to baseline thereafter.

CONCLUSIONS

Prescriptions for second-generation antidepressants in older adults are associated with a modest increased risk of motor vehicle crashes, when combined with other medications that can impair cognition.