Can patients receiving opioid maintenance therapy safely drive? A systematic review of epidemiological and experimental studies on driving ability with a focus on concomitant methadone or buprenorphine administration

Risk of motor vehicle collisions after methadone use: A systematic review and meta-analysis

INTRODUCTION

Methadone maintenance therapy is a leading treatment strategy for stabilizing and rehabilitating patients with opioid dependence; however, findings related to the risk of motor vehicle collisions after methadone use have been conflicting. In the present study, we compiled the available evidence on the risk of motor vehicle collisions after methadone use.

METHODS

We completed a systematic review and meta-analysis of studies identified on six databases. Two reviewers independently screened the identified epidemiological studies, extracted data, and used the Newcastle-Ottawa Scale to assess the quality of the studies. Risk ratios were retrieved for analysis, conducted using random-effects model. Sensitivity analyses, subgroup analyses, and tests for publication bias were conducted.

RESULTS

Among 1446 identified relevant studies, a total of 7 epidemiological studies enrolling 33226142 participants met the inclusion criteria. Overall, study participants with methadone use had a higher risk of motor vehicle collisions than did those without methadone use (pooled relative risk 1.92, 95% CI 1.25-2.95; number needed to harm 11.3, 95% CI 5.3-41.6); the I² statistic was 95.1%, indicating substantial heterogeneity. Subgroup analyses revealed that database type explained 95.36% of the between-study variance (p = 0.008). Egger's (p = 0.376) and Begg's (p = 0.293) tests revealed no evidence of publication bias. Sensitivity analyses indicated that the pooled results were robust.

CONCLUSION

The present review revealed that methadone use is significantly associated with a nearly doubled risk of motor vehicle collisions. Therefore, clinicians should exercise caution in implementing methadone maintenance therapy for drivers.

Buprenorphine in safety-sensitive positions

The permissibility of buprenorphine in safety-sensitive positions is a controversial topic. As an opioid medication, concerns have arisen regarding the potential for impairment and any effects that this would have on an employee's ability to safely perform job duties. While there are no definitive guidelines on the use of buprenorphine for those employed in safety-sensitive lines of work, most employers do not permit its use under any circumstance due to the potential risk of harm to the public. In addition to overlooking the fact that buprenorphine is a well-established and life-saving treatment for opioid use disorder (OUD), there are many flaws in making this determination. For one, buprenorphine is a partial mu opioid agonist which makes it inherently unique in comparison to other opioids. Most studies on impairment have examined acute use of full agonist opioids instead of chronic dosing of buprenorphine. Furthermore, assessments of impairment are not tailored to the tasks required of specific positions. Importantly, policies banning buprenorphine may contribute to treatment discontinuation and stigma, which can lead to relapse and overdose. Considering the morbidity and mortality associated with OUD, along with the surge in overdose deaths during the COVID19 pandemic, buprenorphine policies should be considered carefully. Given the lack of evidence showing definitive and specific impairments as a result of chronic buprenorphine use, coupled with the consequences of universal bans on its use, determinations on the permissibility of buprenorphine treatment for safety-sensitive positions should be made on a case-by-case basis.

Opioids and the Risk of Motor Vehicle Collision: A Systematic Review

Background: Opioid analgesics are among the most commonly prescribed medications, but questions remain regarding their impact on the day-to-day functioning of patients including driving. We set out to perform a systematic review on the risk of motor vehicle collision (MVC) associated with prescription opioid exposure. Method: We searched Medline, PubMed, EMBASE, Scopus, and TRID from January 1990 to August 31, 2021 for primary studies assessing prescribed opioid use and MVCs. Results: We identified 14 observational studies that met inclusion criteria. Among those, 8 studies found an increased risk of MVC among those participants who had a concomitant opioid prescription at the time of the MVC and 3 found no significant increase of culpability of fatal MVC. The 3 studies that evaluated the presence of a dose-response relationship between the dose of opioids taken and the effects on MVC risk reported the existence of a dose-response relationship. Due to the heterogeneity of the different studies, a quantitative meta-analysis to sum evidence was deemed unfeasible. Our review supports increasing evidence on the association between motor vehicle collisions and prescribed opioids. This research would guide policies regarding driving legislation worldwide. Conclusion: Our review indicates that opioid prescriptions are likely associated with an increased risk of MVCs. Further studies are warranted to strengthen this finding, and investigate additional factors such as individual opioid medications, opioid doses and dose adjustments, and opioid tolerance for their effect on MVC risk.

Effects of extended abstinence on cognitive functions in tramadol-dependent patients: A cohort study

BACKGROUND

Some pieces of the literature report impaired cognitive functioning in tramadol dependence. Whether extended abstinence improves cognitive functioning or not is not well studied.

AIM

We aimed to measure the change in cognitive functioning following complete abstinence among individuals with tramadol dependence.

METHODS

Eighty-three male tramadol-dependent (TD) and 57 matched healthy controls participated in this study. Cognitive functions were assessed using: The Trail making test (TMT), Wechsler Memory Scale-Revised (WMS-R), and Wechsler Adult Intelligence Scale (WAIS). Patients were assessed in the first week immediately after the end of the in-patient treatment program (T1), and after six months of sustained abstinence (T2).

RESULTS

At T1, the TD group showed deficits on all tested cognitive parameters (visual attention, task switching, working memory, visual memory, verbal memory, verbal knowledge, Verbal IQ, Performance IQ, and Full-Scale IQ) in comparison to the control group. At T2, significant improvements had occurred in all the tested parameters except performance IQ. The cognitive performance of the abstinent individuals at T2 was comparable to the control group for the verbal subsets of WMS-R, Verbal IQ, Performance IQ, and Full-Scale IQ. Nevertheless, it was still worse than the control group in TMT, and all other WMS subsets.

CONCLUSION

tramadol dependence has negative effects on cognitive performance, which improves with extended abstinence.

Medicinal cannabis and driving: the intersection of health and road safety policy

BACKGROUND

Recent shifting attitudes towards the medical use of cannabis has seen legal access pathways established in many jurisdictions in North America, Europe and Australasia. However, the positioning of cannabis as a legitimate medical product produces some tensions with other regulatory frameworks. A notable example of this is the so-called 'zero tolerance' drug driving legal frameworks, which criminalise the presence of THC (tetrahydrocannabinol) in a driver's bodily fluids irrespective of impairment. Here we undertake an analysis of this policy issue based on a case study of the introduction of medicinal cannabis in Australia.

METHODS

We examine the regulatory approaches used for managing road safety risks associated with potentially impairing prescription medicines and illicit drugs in Australian jurisdictions, as well as providing an overview of evidence relating to cannabis and road safety risk, unintended impacts of the 'zero-tolerance' approach on patients, and the regulation of medicinal cannabis and driving in comparable jurisdictions.

RESULTS

Road safety risks associated with medicinal cannabis appear similar or lower than numerous other potentially impairing prescription medications. The application of presence-based offences to medicinal cannabis patients appears to derive from the historical status of cannabis as a prohibited drug with no legitimate medical application. This approach is resulting in patient harms including criminal sanctions when not impaired and using the drug as directed by their doctor, or the forfeiting of car use and related mobility. Others who need to drive are excluded from accessing a needed medication and associated therapeutic benefit. 'Medical exemptions' for medicinal cannabis in comparable jurisdictions and other drugs included in presence offences in Australia (e.g. methadone) demonstrate a feasible alternative approach.

CONCLUSION

We conclude that in medical-only access models there is little evidence to justify the differential treatment of medicinal cannabis patients, compared with those taking other prescription medications with potentially impairing effects.

Drug use and pattern of injuries sustained by drivers involved in road traffic crashes

OBJECTIVE

Road traffic crashes are one of the global public health concerns and remain at high priority in many countries. Driving under the influence of drugs increases the risk of crashes through altering the driver's mental state and reactions. This study was conducted to determine the relationship between driving pattern and substance abuse among drivers in Kerman, a city in Iran, in order to enable policy makers to make the necessary decisions in planning and executing guidelines.

METHODS

The population of this descriptive study was drivers involved in road traffic crashes admitted to the emergency department of Shahid Bahonar university hospital in summer 2019. After obtaining demographic information, type of vehicle, type of collision and pattern of serious injury, 222 eligible drivers were tested for tramadol, cannabis, amphetamine, methamphetamine, morphine and methadone using one step urine test strips. Chi-square test, Fisher's exact test, Whitney-Mann and Kruskal-Wallis tests and one-way Anova test was performed using SPSS version 22.

RESULTS

The statistics showed that most drivers were male (90.5%), married (63.5%), age group (18-30) and had positive urine test (76.6%). In addition to uniqueness of dual-drug detection among male drivers (7.7%), the most common substances detected were methadone and morphine with 34.7% and 27.5% respectively. The most common injuries were lower limb and hip injuries mostly among motorcyclists. The results indicated that characteristics of being under 30's, married, school dropout, self-employed and motorcyclist had significant relationship with substance use.

CONCLUSIONS

Substance use, especially methadone, has undoubtedly a significant role in both road traffic crashes and resulted injuries. The high rate of injuries on drivers influenced by methadone in traffic crashes needs to be screened and prevented. It is recommended to not only authoritatively deal with the excessive supply of methadone in the community but also restricting the driving of people receiving methadone treatment.

Buprenorphine Prevalence in DUID Cases in Southwestern Virginia: Case Studies and Observations

Buprenorphine, a semisynthetic mixed agonist/antagonist opioid used primarily for the treatment of opioid use disorder, was reported in 194 driving under the influence of drugs (DUID) cases in Southwestern Virginia during the period of 2017 through 2019. Identifying and confirming buprenorphine in DUID cases is common in this region. Interpretation is complex due to the large range of concentrations of buprenorphine found in blood and frequent combinations with other therapeutic and abused drugs. Buprenorphine was identified by immunoassay and quantified by liquid chromatography-tandem mass spectrometry (LC-MS-MS). A sensitive method was necessary as one-third of concentrations of buprenorphine and/or norbuprenorphine were less than 1.0 µg/L. Concentrations of buprenorphine ranged from < 0.5 µg/L to 11 µg/L (mean 2.5 µg/L, median 1.8 µg/L) and concentrations of norbuprenorphine ranged from < 0.5 µg/L to > 20 µg/L (mean 3.3 µg/L, median 2.2 µg/L). Buprenorphine polysubstance use was common. Only 10% of cases examined did not contain other drugs confirmed in routine DUID screening tests. The most common drug groups confirmed were benzodiazepines, amphetamines and cannabinoids. The DUID case histories presented represent examples of buprenorphine abuse, buprenorphine with no other drug groups, buprenorphine combined with other drug groups, cases consistent with impairment and cases with minimal impairment. Central nervous system depressant and narcotic analgesic symptoms were commonly observed; however, some cases contained stimulant symptoms. Buprenorphine to norbuprenorphine ratios (B/NB) had a mean and median ratio of 1.1 and 0.8, respectively. B/NB ratios greater than 3.0 were found in 4.7% of cases. The finding of a higher B/NB ratio may indicate a more recent buprenorphine administration and a greater potential for impairment. No relationship between the concentration of buprenorphine and/or norbuprenorphine in blood and performance on Drug Recognition Expert (DRE) evaluation or Standardized Field Sobriety Tests (SFST) could be determined.

Pain management with opioids in adults

Given the ubiquitous nature of opioids in the treatment of pain, it is an interesting paradox that this class of medications also represents one of the least understood components of clinical pain medicine. For many years, there has been intense interest in the mechanisms of opioid activity, but this has not resulted in a corresponding increase in convincing clinical data. This review focuses primarily on the evidence surrounding the long-term use of opioids in chronic pain, but discussions of this research are often conflated with the very different data governing acute and cancer-related pain, where evidence of efficacy is clearer. It is therefore important to clarify the evidence-based indications for opioid therapy. There remains very little evidence that opioids improve function or quality of life beyond 3 months in people with chronic pain conditions. In all three patient populations, the development of tolerance, dependence, hyperalgesia and withdrawal are key phenomena that affect the patient experience, and in particular the decision to remain on opioids in the long term. This is a common thread that connects the opioid literature in all of these spheres, and justifies the burgeoning interest in these phenomena in the basic science literature. There is an urgent need to address these negative consequences of opioid use, in order to maximize the therapeutic benefit that opioids can offer.

Pharmacokinetics of Single Doses of Methadone and Buprenorphine in Blood and Oral Fluid in Healthy Volunteers and Correlation With Effects on Psychomotor and Cognitive Functions

PURPOSE

We aimed to study the pharmacokinetics of methadone and buprenorphine in blood and oral fluid after single-dose administration and investigate correlations between concentrations in blood and neurocognitive functions.

METHODS

A 5-way, double-blind, randomized, placebo-controlled, double-dummy, crossover study was performed to study the pharmacokinetics and neurocognitive effects of methadone (5 and 10 mg per oral) and buprenorphine (0.2 and 0.4 mg sublingual) in 22 healthy volunteers. Blood and oral fluid were collected throughout the test days, and drug concentrations in both matrices were analyzed using ultrahigh-performance liquid chromatography-tandem mass spectrometry. On-road driving testing, neurocognitive computerized tests, and subjective questionnaires were performed.

RESULTS

Large individual variations in concentrations of methadone and buprenorphine in blood and oral fluid, and accordingly oral fluid/blood drug concentration ratios, were observed. The mean ratio 6.5 hours after drug administration was 2.0 (range, 0.49-7.39) for methadone after both doses. Buprenorphine was not detected above the limit of quantification in blood after 6.5 hours. No significant correlation between methadone concentration in blood and effect was found. Significant correlations were found between buprenorphine concentration in blood and standard deviation of lateral position in the driving test and some measures of reaction time, divided attention, balance, alertness, contentedness. and sleepiness.

CONCLUSIONS

Concentrations of methadone and buprenorphine in blood and oral fluid showed large interindividual variations. No concentration-effect correlations were found for methadone, whereas low to moderate correlations were observed between buprenorphine concentration and driving, psychomotor function, and subjective rating of sleep and alertness.

Psychoactive drug consumption among truck-drivers: a systematic review of the literature with meta-analysis and meta-regression

Few studies have assessed the extent of psychoactive drug consumption in the occupational setting. The trucking sector, in particular, is an important cause for concern, since psychoactive substance use has a relevant impact on the drivers' health and safety, increasing the risk of injuries and traffic accidents, potentially affecting the general public health as well. A systematic review of the literature and meta-analysis was performed in order to provide Occupational Health Professionals and policy-makers with an updated epidemiological perspective regarding this important issue. The results showed a prevalence of overall drug consumption of 27.6% [95%CI 17.8-40.1], particularly high considering illicit CNS-stimulants (amphetamine consumption of 21.3% [95%CI 15.7-28.1], and cocaine consumption of 2.2% [95%CI 1.2-4.1]). It appears that truck-drivers choose stimulant substances as a form of performance enhancing drug, in order to increase productivity. However, chronic and high dose consumption has been shown to decrease driving skills, placing these professional drivers at risk for health and road safety. Further research is required, particularly in Europe, in order to fill the knowledge gap and improve the strength of evidence.

Sleep, chronic pain, and opioid risk for apnea

Pain is an unwelcome sleep partner. Pain tends to erode sleep quality and alter the sleep restorative process in vulnerable patients. It can contribute to next-day sleepiness and fatigue, affecting cognitive function. Chronic pain and the use of opioid medications can also complicate the management of sleep disorders such as insomnia (difficulty falling and/or staying asleep) and sleep-disordered breathing (sleep apnea). Sleep problems can be related to various types of pain, including sleep headache (hypnic headache, cluster headache, migraine) and morning headache (transient tension type secondary to sleep apnea or to sleep bruxism or tooth grinding) as well as periodic limb movements (leg and arm dysesthesia with pain). Pain and sleep management strategies should be personalized to reflect the patient's history and ongoing complaints. Understanding the pain-sleep interaction requires assessments of: i) sleep quality, ii) potential contributions to fatigue, mood, and/or wake time functioning; iii) potential concomitant sleep-disordered breathing (SDB); and more importantly; iv) opioid use, as central apnea may occur in at-risk patients. Treatments include sleep hygiene advice, cognitive behavioral therapy, physical therapy, breathing devices (continuous positive airway pressure - CPAP, or oral appliance) and medications (sleep facilitators, e.g., zolpidem; or antidepressants, e.g., trazodone, duloxetine, or neuroleptics, e.g., pregabalin). In the presence of opioid-exacerbated SDB, if the dose cannot be reduced and normal breathing restored, servo-ventilation is a promising avenue that nevertheless requires close medical supervision.

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

Aims

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

Methods

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

Results

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

Conclusions

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

Driving under the influence of prescription opioids: Self-reported prevalence and association with collision risk in a large Canadian jurisdiction

BACKGROUND

Motor vehicle collisions are an important contributor to prescription opioid use-related morbidity and mortality. The purpose of the current study was to estimate the prevalence of driving under the influence of prescription opioids (DUIPO) in Ontario, Canada, and to measure the association between this behaviour and the risk of a motor vehicle collision.

METHODS

Data were based on telephone interviews with 7857 respondents who reported having driven in the past year. Data were derived from the 2011-2016 cycles of the CAMH Monitor, an ongoing cross-sectional representative survey of adults aged 18 years and older. A binary logistic regression analysis of collision involvement in the previous 12 months was conducted and included demographic characteristics (sex, age, marital status, education, income, region), driving exposure, poor mental health, non-medical use of prescription opioids, and driving after use of alcohol.

RESULTS

The prevalence of past-year DUIPO was 3.1%. Controlling for demographic characteristics, driving exposure, and other risk factors, self-reported DUIPO significantly increased the odds of a collision (AdjOR = 1.97; 95% CI 1.08, 3.60; p = 0.026).

CONCLUSION

Based on these findings, DUIPO is a notable road safety issue. Research focused on better understanding the impact of prescription opioids on driver behaviour, reducing the prevalence of DUIPO, and improving drug-impaired driving policy and interventions should be prioritized in public health strategies.

Opioids in oral fluid of Spanish drivers

BACKGROUND

Driving under the influence of certain drugs is not allowed, and roadside drug testing is being considered an important tool for deterring driving under the influence of them. This study aimed to assess the presence and concentration of opioids, as well as their combined use with other drugs (laboratory confirmation after the on-road screening) in Spanish drivers between 2011 and 2016.

METHODS

In Spain, mandatory roadside breath alcohol and oral fluid drug testing (screening) are carried out by the Traffic Police using Dräger Alcotest^® 6810 device, and Dräger DrugTest^® 5000, DrugWipe^®, or Alere™ DDS^®2 Mobile Test System. For positive cases in the period covered, 65,244, confirmation analysis and quantification using chromatographic techniques were performed.

RESULTS

Opioids were confirmed in 8.6% of positive cases, being 7.2% positives to 6-acetylmorphine (6-AM), 6.5% to morphine, 5.4% to codeine, and 4.1% to methadone. The majority of the confirmed tests for morphine (96.5%), codeine (88.4%) and methadone (81.9) were also positive for 6-AM. The presence of other drugs, particularly cocaine and cannabis, was very common. Concentration values reached important levels. Positive results for morphine (0.1%), codeine (0.6%) or methadone (0.4%) alone were very infrequent.

CONCLUSIONS

Drivers with a confirmed positive roadside test for morphine, codeine, and methadone had also consumed heroin and/or other illicit drugs, such as cocaine and/or THC, and at relevant concentrations. Improving interventions to combat the problem of driving under the influence of driving-impairing substances is a priority.

Effects of medication assisted treatment (MAT) for opioid use disorder on functional outcomes: A systematic review

This systematic review synthesizes evidence on the effects of Medication-Assisted Treatment (MAT) for opioid use disorder (OUD) on functional outcomes, including cognitive (e.g., memory), physical (e.g., fatigue), occupational (e.g., return to work), social/behavioral (e.g., criminal activity), and neurological (e.g., balance) function. Five databases were searched from inception to July 2017 to identify English-language controlled trials, case control studies, and cohort comparisons of one or more groups; cross-sectional studies were excluded. Two independent reviewers screened identified literature, abstracted study-level information, and assessed the quality of included studies. Meta-analyses used the Hartung-Knapp method for random-effects models. The quality of evidence was assessed using the GRADE approach. A comprehensive search followed by 1411 full text publication screenings yielded 30 randomized controlled trials (RCTs) and 10 observational studies meeting inclusion criteria. The studies reported highly diverse functional outcome measures. Only one RCT was rated as high quality, but several methodologically sound observational studies were identified. The statistical power to detect differences in functional outcomes was unclear in most studies. When compared with matched "healthy" controls with no history of substance use disorder (SUD), in two studies MAT patients had significantly poorer working memory and cognitive speed. One study found MAT patients scored worse in aggressive responding than did "healthy" controls. A large observational study found that MAT users had twice the odds of involvement in an injurious traffic accident as non-users. When compared with persons with OUD not on MAT, one cohort study found lower fatigue rates among buprenorphine-treated OUD patients. No differences were reported for occupational outcomes and results for criminal activity and other social/behavioral areas were mixed. There were few differences among MAT drug types. A pooled analysis of three RCTs found a significantly lower prevalence of fatigue with buprenorphine compared to methadone, while a meta-analysis of the same RCTs found no statistical difference in insomnia prevalence. Three RCTs that focused on cognitive function compared the effects of buprenorphine to methadone; no statistically significant differences in memory, cognitive speed and flexibility, attention, or vision were reported. The quality of evidence for most functional outcomes was rated low or very low. In sum, weaknesses in the body of evidence prevent strong conclusions about the effects of MAT for opioid use disorder on functional outcomes. Rigorous studies of functional effects would strengthen the body of literature.

Cognitive effects of labeled addictolytic medications

INTRODUCTION

Alcohol, tobacco, and illegal drug usage is pervasive throughout the world, and abuse of these substances is a major contributor to the global disease burden. Many pharmacotherapies have been developed over the last 50years to target addictive disorders. While the efficacy of these pharmacotherapies is largely recognized, their cognitive impact is less known. However, all substance abuse disorders are known to promote cognitive disorders like executive dysfunction and memory impairment. These impairments are critical for the maintenance of addictive behaviors and impede cognitive behavioral therapies that are regularly administered in association with pharmacotherapies. It is also unknown if addictolytic medications have an impact on preexisting cognitive disorders, and if this impact is modulated by the indication of prescription, i.e. abstinence, reduction or substitution, or by the specific action of the medication.

METHOD

We reviewed the cognitive effects of labeled medications for tobacco addiction (varenicline, bupropion, nicotine patch and nicotine gums), alcohol addiction (naltrexone, nalmefene, baclofen, disulfiram, sodium oxybate, acamprosate), and opioid addiction (methadone, buprenorphine) in human studies. Studies were selected following MOOSE guidelines for systematic reviews of observational studies, using the keywords [Cognition] and [Cognitive disorders] and [treatment] for each medication.

RESULTS

971 articles were screened and 77 studies met the inclusion criteria and were reported in this review (for alcohol abuse, n=21, for tobacco n=22, for opioid n=34. However, very few comparative clinical trials have explored the chronic effects of addictolytic medications on cognition in addictive behaviors, and there are no clinical trials on the cognitive impact of nalmefene in patients suffering from alcohol use disorders.

DISCUSSION

Although some medications seem to enhance cognition in patients suffering from cognitive disorders, others could promote cognitive impairments, and our work highlights a lack of literature on this subject. In conclusion, more comparative clinical trials are needed to better understand the cognitive impact of addictolytic medications.

Use of prescription opioids and motor vehicle crashes: A meta analysis

OBJECTIVES

Opioid analgesics are a major driver of the ongoing opioid epidemic in the United Sates, accounting for about two thirds of drug overdose fatalities. There are conflicting reports regarding the effects of prescription opioids on driving safety. A meta-analysis was performed to assess the epidemiologic evidence for the association between use of prescription opioids and the risk of motor vehicle crashes.

METHODS

Studies examining the association between driver prescription opioid use and motor vehicle crash involvement or crash culpability and published in English were identified through a comprehensive search of 15 bibliographic databases. Eligible articles were fully reviewed and summarized. Study quality was assessed using the Newcastle-Ottawa Scale. Overall summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated through random effects models.

RESULTS

Overall, 15 studies were included in the meta-analysis; of them, 10 assessed the association of prescription opioid use with the risk of crash involvement and 5 assessed the association of prescription opioid use with the risk of crash culpability. Reported crude ORs associated with prescription opioid use ranged from 1.15 to 8.19 for the risk of crash involvement and from 0.75 to 2.78 for the risk of crash culpability. Summary ORs based on pooled data were 2.29 (95% CI: 1.51, 3.48) for crash risk and 1.47 (95% CI: 1.01, 2.13) for crash culpability.

CONCLUSIONS

The existent epidemiologic evidence indicates that use of prescription opioids by drivers is associated with significantly increased risks of crash involvement and crash culpability. Further research is needed to understand the epidemiologic patterns of prescription opioid use in the driver population and the interaction effects between opioids and alcohol on driving safety.

Assessing the practice of palliative care doctors: what driving advice do they give patients with advanced disease?

BACKGROUND

There is little research and no clear guidelines for clinicians to follow when instructing patients with advanced disease about driving.

AIMS

To investigate current practice in providing advice to patients with advanced disease and identify areas of consensus or variation with the Australian driving guidelines.

METHODS

An online survey was distributed to Australian members of the Australian and New Zealand Society of Palliative Medicine. Responses were analysed using descriptive statistics.

RESULTS

The survey was distributed to 322 Australian and New Zealand Society of Palliative Medicine members and received 92 responses (29% response rate). Most respondents were aware of the driving guidelines (76%) and about half of the respondents had read the driving guidelines (55%). The majority of respondents had been asked to provide advice about driving to their patient or patient's caregiver (91%). Most respondents had asked a patient to stop driving (94%), but only 27% had reported a patient to the Driver Licensing Authority. Only 14% of respondents were in consensus with the guidelines in providing driving advice to a patient with asymptomatic brain metastases. Most doctors (64%) advise patients to refrain temporarily from driving post-short-acting oral morphine, with 4 h (36%) being the most common time period for not driving.

CONCLUSIONS

This is the first survey investigating the practice of Australian doctors in assessing fitness to drive of patients with advanced disease. The survey found wide variability in practice and substantial discordance with current driving guidelines.

Patterns of physician prescribing for opioid maintenance treatment in Ontario, Canada in 2014

BACKGROUND

Despite concerns surrounding high patient volumes in methadone clinics, little is known about the practice patterns of opioid maintenance therapy (OMT) providers in Ontario. We examined the distribution of these services and how physician characteristics differ based on prescribing volume.

METHODS

We conducted a cross-sectional study among prescribers of methadone or buprenorphine to Ontario public drug beneficiaries in 2014 by stratifying physicians into low- (lower 50%), moderate- (51-89%) and high-volume (top 10%) prescribers. We summarized the distribution of OMT prescription days dispensed and urine drug screens (UDS) ordered using Lorenz curves and examined physician characteristics using descriptive statistics.

RESULTS

We identified 893 OMT prescribers in 2014. Physicians were mostly male (67.5%; N=603), and middle-aged (median was 50). High-volume methadone providers (N=57) prescribed approximately 56% (N=4,115,322) of the total days of methadone (Gini coefficient=0.76, 95% CI 0.74-0.79) while high-volume buprenorphine providers (N=64) prescribed 61% (N=589,463) of the total days of buprenorphine (Gini coefficient=0.78, 95% CI 0.75-0.80). On average, each high-volume methadone prescriber treated 435 OMT patients and billed 43 UDS per patient, while each high-volume buprenorphine prescriber treated 64 OMT patients and billed 22 UDS per patient. Daily OMT patient volume was on average 74 for high-volume methadone prescribers and 6 for high-volume buprenorphine prescribers.

CONCLUSIONS

OMT services are highly concentrated among a small portion of OMT providers who carry high daily patient volumes. Future research should examine the quality of primary care received by their patients to better elucidate the possible consequences of this highly unequal distribution of services.

Roadside opioid testing of drivers using oral fluid: the case of a country with a zero tolerance law, Spain

Background

Opioids can impair psychomotor performance, and driving under the influence of opioids is associated with an increased risk of accidents. The goals of this study were i) to determine the prevalence of opioids (heroin, morphine, codeine, methadone and tramadol) in Spanish drivers and ii) to explore the presence of opioids, more specifically whether they are used alone or in combination with other drugs.

Methods

The 2008/9 DRUID database regarding Spain was used, which provided information on 3302 drivers. All drivers included in the study provided a saliva sample and mass-chromatographic analyses were carried out in all cases. To determine the prevalence, the sample was weighted according to traffic intensity. In the case of opioid use combinations, the sample was not weighted. The detection limit for each substance was considered a positive result.

Results

The prevalence of opioids in Spanish drivers was 1.8% (95% CI, 1.4–2.3). Polydrug detection was common (56.2%): of these, in two out of three cases, two opioids were detected and cocaine was also detected in 86% of the cases. The concentration (median [Q1-Q3] ng/ml) of the substances was low: methadone 1.71 [0.10–15.30], codeine 40.55 [2.10–120.77], 6-acetylmorphine 5.71 [1.53–84.05], and morphine 37.40 [2.84–200.00]. Morphine was always detected with 6-acetylmorphine (heroin use).

Conclusions

Driving under the influence of opioids is relatively infrequent, but polydrug use is common. Our study shows that 6 out of 10 drivers with methadone in their OF (likely in methadone maintenance programs) are using other substances. This should be taken into account by health professionals in order to properly inform patients about the added risks of mixing substances when driving.

Medication use and the risk of motor vehicle collisions among licensed drivers: A systematic review

OBJECTIVES

Driving under the influence of prescription and over-the-counter medication is a growing public health concern. A systematic review of the literature was performed to investigate which specific medications were associated with increased risk of motor vehicle collision (MVC).

METHODS

The a priori inclusion criteria were: (1) studies published from English-language sources on or after January 1, 1960, (2) licensed drivers 15 years of age and older, (3) peer-reviewed publications, master's theses, doctoral dissertations, and conference papers, (4) studies limited to randomized control trials, cohort studies, case-control studies, or case-control type studies (5) outcome measure reported for at least one specific medication, (6) outcome measure reported as the odds or risk of a motor vehicle collision. Fourteen databases were examined along with hand-searching. Independent, dual selection of studies and data abstraction was performed.

RESULTS

Fifty-three medications were investigated by 27 studies included in the review. Fifteen (28.3%) were associated with an increased risk of MVC. These included Buprenorphine, Codeine, Dihydrocodeine, Methadone, Tramadol, Levocitirizine, Diazepam, Flunitrazepam, Flurazepam, Lorazepam, Temazepam, Triazolam, Carisoprodol, Zolpidem, and Zopiclone.

CONCLUSIONS

Several medications were associated with an increased risk of MVC and decreased driving ability. The associations between specific medication use and the increased risk of MVC and/or affected driving ability are complex. Future research opportunities are plentiful and worthy of such investigation.

New opioid analgesic use and the risk of injurious single-vehicle crashes in drivers aged 50-80 years: A population-based matched case-control study

BACKGROUND

the increasing trend in opioid analgesic use among older drivers has raised concerns about their risk of being involved in car crashes.

AIM

to investigate if older drivers who started using opioid analgesics have a higher probability of being involved in injurious crashes.

METHODS

population-based matched case-control study. Data from population registers were merged using a personal identity number. Cases were drivers aged 50-80 years responsible for a single vehicle crash between 01.07.05 and 31.12.09 that led to at least one injured passenger (n = 4,445). Four controls were randomly matched to each case by sex, birth month/year, and residence area from persons holding a valid driving license who did not crash during the study period. New use was defined as at least one dispensation within 1-30 days prior to the crash, but none within the previous 31-180 days; frequent use when ≥3 dispensations were given within 0-180 days, with at least one within 31-180 days. Individuals using 1-2 non-opioid analgesic medications were used as reference category. Conditional logistic regression was used to estimate odds ratios (OR; 95% CI) adjusting for benzodiazepine use, co-morbidity, civil status and occupation.

RESULTS

adjusted odds for new use were two-fold that of drivers using 1-2 non-opioid analgesics medications (2.0; 1.6-2.5). For frequent use, adjusted odds were also increased regardless of number of dispensations (3-4 = 1.7; 1.3-2.1, 5-6 = 1.6; 1.2-2.3, and ≥7 = 1.7; 1.3-2.1).

CONCLUSION

new, but also frequent opioid analgesic use, resulted in an increased probability of single vehicle crashes. While more epidemiologic evidence is needed, patients could be advised to refrain from driving when using opioid analgesics.

Medical marijuana and driving: a review

Medical marijuana remains a highly debated treatment regimen despite removal of state penalties against care providers prescribing the drug and patients treated with the drug in many areas of the USA. The utility of marijuana in specific medical conditions has been studied at length, but its effects on driving performance and risk of motor vehicle collision remain unclear. As with other medications that affect psychomotor function, the healthcare provider should be informed of the potential risks of driver safety prior to prescribing this psychotropic drug to give appropriate anticipatory guidance for appropriate use. The goal of this narrative review is to assess the current literature regarding marijuana as it relates to driving performance and traffic safety. With a foundation in the pharmacology of cannabinoids, we consider the limitations of testing cannabinoid and metabolite concentration. In addition, we will review studies on driving performance and epidemiological studies implicating marijuana in motor vehicle collisions. The increasing prevalence of medical marijuana laws in the USA suggests that clinicians should be aware of marijuana's influence on public safety. Patients should abstain from driving for 8 h if they achieve a subjective "high" from self-treatment with smoked marijuana and should be aware of the cumulative effects of alcohol and other psychoactive xenobiotics.

Impact of preexisting opioid use on injury mechanism, type, and outcome

BACKGROUND

The prevalence of prescription narcotic use in the United States is on the rise. Opioid use and its impact on the management of trauma patients has yet to be thoroughly studied. The aim of this study was to determine the prevalence of preinjury opioid use and its influence on specific outcomes among the trauma patient population.

METHODS

A retrospective review of all trauma patients presenting to a level 1 trauma center was performed from January 1, 2010-December 31, 2010. Patients who died within 24 h of presentation and those with incomplete medication data were excluded. Electronic medical record review of history and physical documentation and urine drug screen records were used to determine preinjury opioid status. Preexisting narcotic use, demographic data, injury mechanism and severity, injury type, and outcome variables were analyzed.

RESULTS

A total of 3953 patients met inclusion criteria. Among our sample, 644 (16.3%) were positive for preinjury opioid use. Patients in the preinjury opioid group were older (48 versus 41 y) and more likely to be female (37.9% versus 30.6%). The mechanism of injury was more often falls (32.8% versus 22.0%). Analysis of less severely injured patients (ISS <15) found a significantly increased length of stay (3.7 versus 2.9 d) in the narcotics group. Evaluation of injury type revealed that head injury, abdominal injury, and lower extremity and/or pelvic injuries had significantly increased length of stay.

CONCLUSIONS

There is a considerable prevalence of preinjury opioid use in the trauma population. These patients have unique characteristics and causes of injury. Preinjury opioid use is predictive of increased length of stay, with important ramifications for patient care and health care costs.

New developments in the management of opioid dependence: focus on sublingual buprenorphine-naloxone

Opioid maintenance therapy is a well-established first-line treatment approach in opioid dependence. Buprenorphine, a partial opioid agonist, has been found by numerous studies to be an effective and safe medication in the treatment of opioid dependence. At present, buprenorphine is available as a monodrug or in a fixed 4:1 ratio combination with naloxone. A diminished risk of diversion and abuse for the buprenorphine-naloxone combination is likely but not firmly established. Conventional formulations are given sublingually to avoid the hepatic first-pass effect. A novel film tablet is available only in the US and Australia. Other novel, sustained-release formulations (implant, depot) are currently being developed and tested. Recent studies, including a Cochrane meta-analysis, suggest that the retention with buprenorphine is lower than for methadone, but that buprenorphine may be associated with less drug use. Higher doses of buprenorphine are associated with better retention rates. Buprenorphine has a ceiling effect at the opioid receptor with regard to respiratory depression, and may cause fewer fatal intoxications than methadone. Possible antidepressant effects of buprenorphine and its use in comorbid psychiatric patients has not been studied in much detail. Clinical implications are discussed.

Opioids for low back pain

Back pain affects most adults, causes disability for some, and is a common reason for seeking healthcare. In the United States, opioid prescription for low back pain has increased, and opioids are now the most commonly prescribed drug class. More than half of regular opioid users report back pain. Rates of opioid prescribing in the US and Canada are two to three times higher than in most European countries. The analgesic efficacy of opioids for acute back pain is inferred from evidence in other acute pain conditions. Opioids do not seem to expedite return to work in injured workers or improve functional outcomes of acute back pain in primary care. For chronic back pain, systematic reviews find scant evidence of efficacy. Randomized controlled trials have high dropout rates, brief duration (four months or less), and highly selected patients. Opioids seem to have short term analgesic efficacy for chronic back pain, but benefits for function are less clear. The magnitude of pain relief across chronic non-cancer pain conditions is about 30%. Given the brevity of randomized controlled trials, the long term effectiveness and safety of opioids are unknown. Loss of long term efficacy could result from drug tolerance and emergence of hyperalgesia. Complications of opioid use include addiction and overdose related mortality, which have risen in parallel with prescription rates. Common short term side effects are constipation, nausea, sedation, and increased risk of falls and fractures. Longer term side effects may include depression and sexual dysfunction. Screening for high risk patients, treatment agreements, and urine testing have not reduced overall rates of opioid prescribing, misuse, or overdose. Newer strategies for reducing risks include more selective prescription of opioids and lower doses; use of prescription monitoring programs; avoidance of co-prescription with sedative hypnotics; and reformulations that make drugs more difficult to snort, smoke, or inject.

Chronic pain treatment with opioid analgesics: benefits versus harms of long-term therapy

Chronic non-cancer pain (CNCP) is a disabling chronic condition with a high prevalence rate around the world. Opioids are routinely prescribed for treatment of chronic pain (CP). In the past two decades there has been a massive increase in the number of opioid prescriptions, prescribed daily opioid doses and overall opioid availability. Many more patients with CNCP receive high doses of long-acting opioids on a long-term basis. Yet CP and related disability rates remain high, and majority of the patients with CNCP are dissatisfied with their treatments. Intersecting with the upward trajectory in opioid use are the increasing trends in opioid related adverse effects, especially prescription drug abuse, addiction and overdose deaths. This complex situation raises questions on the relevance of opioid therapy in the treatment of CNCP. This article reviews current evidence on opioid effectiveness, the benefits and harms of long-term therapy in CNCP.

Trends in alcohol and other drugs detected in fatally injured drivers in the United States, 1999-2010

Drugged driving is a safety issue of increasing public concern. Using data from the Fatality Analysis Reporting System for 1999-2010, we assessed trends in alcohol and other drugs detected in drivers who were killed within 1 hour of a motor vehicle crash in 6 US states (California, Hawaii, Illinois, New Hampshire, Rhode Island, and West Virginia) that routinely performed toxicological testing on drivers involved in such crashes. Of the 23,591 drivers studied, 39.7% tested positive for alcohol and 24.8% for other drugs. During the study period, the prevalence of positive results for nonalcohol drugs rose from 16.6% in 1999 to 28.3% in 2010 (Z = -10.19, P < 0.0001), whereas the prevalence of positive results for alcohol remained stable. The most commonly detected nonalcohol drug was cannabinol, the prevalence of which increased from 4.2% in 1999 to 12.2% in 2010 (Z = -13.63, P < 0.0001). The increase in the prevalence of nonalcohol drugs was observed in all age groups and both sexes. These results indicate that nonalcohol drugs, particularly marijuana, are increasingly detected in fatally injured drivers.