Effects of single doses of alprazolam and diazepam, alone and in combination with ethanol, on psychomotor and cognitive performance and on autonomic nervous system reactivity in healthy volunteers

Acute administration of alprazolam, alcohol and their combination on cognitive performance and mood: A randomised, double-blind, placebo-controlled study

BACKGROUND

Recreational co-consumption of benzodiazepines and alcohol is a common practise; yet, the cognitive effects of this combination remain poorly understood. This study aimed to investigate the acute cognitive effects of combining a 1 mg dose of alprazolam with a moderate dose of alcohol (target 0.04% blood alcohol concentration (BAC)) in a non-clinical population.

METHODS

In this randomised, double-blind, placebo-controlled, crossover trial, participants completed computerised cognitive assessments and the brief biphasic alcohol effects scale (B-BAES) after consuming 1 mg of alprazolam, both with and without a moderate dose of alcohol (target 0.04% BAC).

RESULTS

Among 20 healthy participants (mean age = 28.6, SD ± 4.0 years, 60% female), we found that a peak BAC of 0.03% had no significant impact on cognitive performance. Both the individual use of alprazolam and its combination with alcohol resulted in impaired reaction time, digit vigilance, and verbal, spatial and numeric working memory tasks, although an additive effect when alcohol and alprazolam were consumed together was not evident. The most pronounced cognitive effects occurred at 100 min after dosing, coinciding with increased alprazolam concentrations. Sedative effects were heightened with alcohol, alprazolam and their combination while no stimulative effects were reported.

CONCLUSIONS

Our findings highlight the significant implications of a therapeutic dose of alprazolam on impairing cognitive performance. This is particularly relevant considering the frequency of non-medical alprazolam use. Future studies should explore different dosages, administration timings and long-term effects to inform the development of public health policies and guidelines regarding the combined use of alcohol and benzodiazepines.

Alcohol-medication interactions: A systematic review and meta-analysis of placebo-controlled trials

Alcohol and other xenobiotics may limit the therapeutic effects of medications. We aimed at investigating alcohol-medication interactions (AMI) after the exclusion of confounding effects related to other xenobiotics. We performed a systematic review and meta-analysis of controlled studies comparing the effects induced by alcohol versus placebo on pharmacodynamic and/or pharmacokinetic parameters of approved medications. Certainty in the evidence of AMI was assessed when at least 3 independent studies and at least 200 participants were available. We included 107 articles (3097 participants): for diazepam, cannabis, opioids, and methylphenidate, we found significant AMI and enough data to assign the certainty of evidence. Alcohol consumption significantly increases the peak plasma concentration of diazepam (low certainty; almost 290 participants), cannabis (high certainty; almost 650 participants), opioids (low certainty; 560 participants), and methylphenidate (moderate certainty; 290 participants). For most medications, we found some AMI but not enough data to assign them the certainty grades; for some medications, we found no differences between alcohol and placebo in any outcomes evaluated. Our results add further evidence for interactions between alcohol and certain medications after the exclusion of confounding effects related to other xenobiotics. Physicians should advise patients who use these specific medications to avoid alcohol consumption. Further studies with appropriate control groups, enough female participants to investigate sex differences, and elderly population are needed to expand our knowledge in this field. Short phrases suitable for indexing terms.

Conversion factors for assessment of driving impairment after exposure to multiple benzodiazepines/z-hypnotics or opioids

AIMS

Norway has introduced legal concentration limits in blood for 28 non-alcohol drugs in driving under the influence cases. As of 2016 this legislation also regulates the assessment of combined effects of multiple benzodiazepines and opioids. We herein describe the employed methodology for the equivalence tables for concentrations of benzodiazepines/z-hypnotics and opioids implemented in the Norwegian Road Traffic Act.

METHODS

Legislative limits corresponding to impairment at blood alcohol concentrations (BAC) of 0.02%, 0.05% and 0.12% were established for 15 different benzodiazepines and opioids. This was based on a concept of a linear relationship between blood drug concentration and impairment in drug naïve users. Concentration ratios between these drugs were used to establish conversion factors and calculate net impairment using diazepam and morphine equivalents.

RESULTS

Conversion factors were established for 14 benzodiazepines/z-hypnotics (alprazolam, bromazepam, clobazam, clonazepam, etizolam, flunitrazepam, lorazepam, nitrazepam, nordiazepam, oxazepam, phenazepam, temazepam, zolpidem and zopiclone) and two opioids (methadone and oxycodone).

CONCLUSIONS

Conversion factors to calculate diazepam and morphine equivalents for benzodiazepines/z-hypnotics and selected opioids, respectively, have been operative in the Norwegian Road Traffic Act as of February 2016. Calculated equivalents can be applied by the courts to meter out sanctions.

Impairment due to alcohol, tetrahydrocannabinol, and benzodiazepines in impaired drivers compared to experimental studies

OBJECTIVE

In some countries, per se laws for other drugs than alcohol are used to judge drunk and drugged drivers. These blood concentration limits are often derived from experimental studies on traffic relevant behavior of healthy volunteers. Knowledge about how results from experimental studies could be transferred to a real-life setting is missing. The aim of this study was to compare impairment seen in experimental studies to the impairment seen at equivalent concentrations in apprehended drunk and drugged drivers.

METHODS

Results from previously performed meta-analyses of experimental studies regarding impairment from alcohol, tetrahydrocannabinol (THC), and benzodiazepines were compared to impairment in apprehended drunk and drugged drivers as judged by a clinical test of impairment. Both experimental studies and real-life cases were divided into 4 groups according to increasing blood drug concentration intervals. The percentage of impaired test results in experimental studies was compared to the percentage of impaired subjects among drivers within the same blood drug concentration window.

RESULTS

For ethanol, the percentage of impaired drivers (n = 1,223) increased from 59% in the lowest drug concentration group to 95% in the highest drug concentration group, compared to 7 and 72% in the respective groups in experimental studies. For THC, the percentage of impaired drivers (n = 950) increased from 42 to 58%, the corresponding numbers being 11 and 42% for experimental studies. For benzodiazepines, the percentage of impaired drivers (n = 245) increased from 46 to 76%, the corresponding numbers being 16 and 60% for experimental studies. The increased odds ratio for impairment between 2 concentration groups was comparable for experimental studies and impaired drivers.

CONCLUSIONS

Fewer test results indicated impairment in experimental studies compared to impaired drivers in real life when influenced by similar blood concentrations of either ethanol, THC, or benzodiazepines. In addition, a comparable relationship between drug concentration and impairment was seen for both experimental studies and real-life cases. We believe that the present study strengthens the background for using experimental studies to establish fixed concentration limits for drunk and drugged drivers, but experimental studies in an impaired driver population could further expand our knowledge.

Behavioral and Neurophysiological Signatures of Benzodiazepine-Related Driving Impairments

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

Dipeptidyl-peptidase IV (DPP-IV) inhibitor delays tolerance to anxiolytic effect of ethanol and withdrawal-induced anxiety in rats

Dipeptidyl-peptidase IV (DPP-IV) is an enzyme responsible for the metabolism of endogenous gut-derived hormone, glucagon-like peptide-1 (GLP-1). DPP-IV is known for its role in energy homeostasis and pharmacological blockade of this enzyme is a recently approved clinical strategy for the management of type II diabetes. Accumulating evidences suggest that enzyme DPP-IV can affect spectrum of central nervous system (CNS) functions. However, little is known about the role of this enzyme in ethanol-mediated neurobehavioral complications. The objective of the present study was to examine the impact of DPP-IV inhibitor, sitagliptin on the development of tolerance to anxiolytic effect of ethanol and anxiety associated with ethanol withdrawal in rats. A dose-response study revealed that sitaglitpin (20 mg/kg, p.o.) per se exhibit anxiolytic effect in the elevated plus maze (EPM) test in rats. Tolerance to anxiolytic effect of ethanol (2 g/kg, i.p.; 8 % w/v) was observed from 7(th) day of ethanol-diet (6 % v/v) consumption. In contrast, tolerance to anxiolytic effect of ethanol was delayed in rats that were treated daily with sitagliptin (20 mg/kg, p.o.) as tolerance was observed from 13(th)day since commencement of ethanol-diet consumption. Discontinuation of rats from ethanol-diet after 15-days of ethanol consumption resulted in withdrawal anxiety between 8 h and 12 h post-abstinence. However, rats on 15-day ethanol-diet with concomitant sitagliptin (20 mg/kg, p.o.) treatment exhibited delay in appearance (24 h post-withdrawal) of withdrawal anxiety. In summary, DPP-IV inhibitors may prove as an attractive research strategy against ethanol tolerance and dependence.

The medico-legal significance of pharmacokinetic interactions with ethanol

In the UK, the maximal permitted ethanol concentration for driving is 80 mg ethanol/100 mL blood, 35 μg ethanol/100 mL breath or 107 mg ethanol/100 mL urine. Drivers exceeding the prescribed limit face severe penalties, which they are often anxious to avoid, either by acquittal or by putting forward 'special reasons' why they should not be disqualified from driving. One frequently explored defence is that the accused was taking prescribed medication. Defence solicitors often ask the question whether the prescribed medication could have caused significantly altered blood ethanol concentrations. This paper reviews the impact of various medications and how they can influence the blood ethanol concentration. Although many drugs can interact with ethanol at a pharmacodynamic level, causing increased impairment, relatively few drugs interact with ethanol pharmacokinetically leading to significantly altered blood ethanol concentrations.

The additive effects of alcohol and benzodiazepines on driving

OBJECTIVES

To examine the relationship between the combination of alcohol and benzodiazepines and the risk of committing an unsafe driver action.

METHODS

We used data from the Fatality Analysis Reporting System (1993-2006) on drivers aged 20 or older who were tested for both alcohol and drugs. Using a case-control design, we compared drivers who had at least one unsafe driver action (UDA; e.g., weaving) recorded in relation to the crash (cases) to drivers who did not (controls).

RESULTS

Drivers who tested positive for intermediate- and long-acting benzodiazepines in combination with alcohol had significantly greater odds of a UDA compared to those under the influence of alcohol alone, up to blood alcohol concentrations (BACs) of 0.08 and 0.05 g/100 ml, respectively. The odds of a UDA with short-acting benzodiazepines combined with alcohol were no different than for alcohol alone.

CONCLUSIONS

This study demonstrates that the combination of alcohol and benzodiazepines can have detrimental effects on driving beyond those of alcohol alone. By describing these combined effects in terms of BAC equivalencies, this study also allows for the extrapolation of simple, concrete concepts that communicate risk to the average benzodiazepine user.

[Illicit drugs, medications and traffic accidents]

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

Metabolic interaction between ethanol, high-dose alprazolam and its two main metabolites using human liver microsomes in vitro

Alprazolam is widely used as a short-acting antidepressant and anxiolytic agent and its effect appears at very low doses while ethanol is used as a social drug worldwide. Sometimes, toxic interactions occur following combined administration of these two drugs. In this study we have investigated the interaction between ethanol and high-dose alprazolam using human liver microsomes in vitro. The interaction effects between ethanol and alprazolam were examined by a mixed-function oxidation reaction using a human liver microsomal preparation. Alprazolam and its two main metabolites (alpha-hydroxyalprazolam: alpha-OH alprazolam, 4-hydroxyalprazolam: 4-OH alprazolam) were measured by HPLC/UV. The production of 4-OH alprazolam, one main metabolite of alprazolam, was weakly inhibited by higher dose of ethanol, but not alpha-OH alprazolam. These results using a human liver microsomal preparation show that the production of 4-OH alprazolam is weakly inhibited by ethanol but not alpha-OH alprazolam. Toxic levels may be reached by simultaneous administration of ethanol and high-dose alprazolam.

Risks of combined alcohol/medication use in older adults

BACKGROUND

Many older adults (ie, those aged >65 years) drink alcohol and use medications that may be harmful when consumed together.

OBJECTIVE

This article reviews the literature on alcohol and medication interactions, with a focus on older adults.

METHODS

Relevant articles were identified through a search of MEDLINE and International Pharmaceutical Abstracts (1966-August 2006) for English-language articles. The following medical subject headings and key words were used: alcohol medication interactions, diseases worsened by alcohol use, and alcohol metabolism, absorption, and distribution. Additional articles were identified by a manual search of the reference lists of the identified articles, review articles, textbooks, and personal reference sources.

RESULTS

Many older adults drink alcohol and take medications that may interact negatively with alcohol. Some of these interactions are due to age-related changes in the absorption, distribution, and metabolism of alcohol an medications. Others are due to disulfiram-like reactions observed with some medications, exacerbation of therapeutic effects and adverse effects of medications when combined with alcohol, and alcohol's interference with the effectiveness of some medications.

CONCLUSIONS

Older adults who drink alcohol and who take medications are at risk for a variety of adverse consequences depending on the amount of alcohol and the type of medications consumed. It is important for clinicians to know how much alcohol their older patients are drinking to be able to effectively assess their risks and to counsel them about the safe use of alcohol and medications. Similarly, it is important for older adults to understand the potential risks of their combined alcohol and medication use to avoid the myriad of problems possible with unsafe use of these substances..

Application of a computational decision model to examine acute drug effects on human risk taking

In 3 previous experiments, high doses of alcohol, marijuana, and alprazolam acutely increased risky decision making by adult humans in a 2-choice (risky vs. nonrisky) laboratory task. In this study, a computational modeling analysis known as the expectancy valence model (J. R. Busemeyer & J. C. Stout, 2002) was applied to individual-participant data from these studies, for the highest administered dose of all 3 drugs and corresponding placebo doses, to determine changes in decision-making processes that may be uniquely engendered by each drug. The model includes 3 parameters: responsiveness to rewards and losses (valence or motivation); the rate of updating expectancies about the value of risky alternatives (learning/memory); and the consistency with which trial-by-trial choices match expected outcomes (sensitivity). Parameter estimates revealed 3 key outcomes: Alcohol increased responsiveness to risky rewards and decreased responsiveness to risky losses (motivation) but did not alter expectancy updating (learning/memory); both marijuana and alprazolam produced increases in risk taking that were related to learning/memory but not motivation; and alcohol and marijuana (but not alprazolam) produced more random response patterns that were less consistently related to expected outcomes on the 2 choices. No significant main effects of gender or dose by gender interactions were obtained, but 2 dose by gender interactions approached significance. These outcomes underscore the utility of using a computational modeling approach to deconstruct decision-making processes and thus better understand drug effects on risky decision making in humans.

Drugs and chronic alcohol abuse in drivers

Blood specimens from 210 drivers (179 male and 31 female) apprehended in Luxembourg from autumn 2001 to spring 2002 and requested for the determination of their blood alcohol concentration (BAC) were tested for medicinal drugs, illicit drugs, and chronic alcohol abuse (by quantification of the carbohydrate-deficient transferrin: CDT). These additional analyses were performed anonymously and with permission of state prosecutor. The 22.8% had consumed medicinal drugs, with benzodiazepines and antidepressants (10.9 and 7.6%, respectively) as main psychoactive classes. Cannabis was the most detected illicit drug (9.5%) but only one in three had THC detectable in their blood. Association of two or more psychoactive substances (poly-drug use) was observed in 27.6% of drivers (90.6% of drug consumers). On the basis of CDT values, 29.5% of drivers investigated were assumed to be chronic alcohol abusers. Statistical analysis revealed that chronic alcohol abuse and medicinal psychoactive drugs were associated with significantly higher BAC. Medicinal psychoactive drugs were clearly associated with poly-drug use, and were furthermore detected at supra-therapeutic levels in 34.9%.

A method for determining the magnitude of change across different cognitive functions in clinical trials: the effects of acute administration of two different doses alprazolam

While there is no doubt that benzodiazepine administration leads to transient cognitive impairment in healthy adults, the nature and magnitude of such impairment has not been well described. The cognitive effects of a single dose of alprazolam 0.5 and 1 mg were therefore assessed in 36 healthy adults on measures of psychomotor function, visual attention, working memory, planning and learning in a double-blind parallel-groups study. Measures of these different cognitive functions were selected on the basis of their brevity and because they yielded distributions of performance data that were without skew, floor or ceiling effects of range restriction (i.e. normal distributions). With data satisfying the assumptions for parametric analysis, measures of effect size could be computed in addition to significance testing, thus allowing for direct and meaningful comparison between the different performance measures used. Alprazolam 0.5 mg reduced only the speed of attentional performance although the magnitude of this reduction was large (d = 0.8). At 1.0 mg, impairments in psychomotor function, equivalent to that seen for attentional function at the lower dose, were observed. In addition, moderate (d approx = 0.5) impairments in working memory, and learning also became obvious. When considered together, these results suggest that low-dose alprazolam primarily alters visual attentional function. At the higher dose psychomotor functions also become impaired, and it is likely that the combination of these led to the observed moderate impairments in higher level executive and memory processes. The current study also illustrates a method for directly comparing the magnitude of change in cognitive function between measures with different performance metrics.

Drugs and driving

The authors present a global overview on the issue of drugs and driving covering four major areas: (1) Epidemiology and Prevalence--which reviews epidemiological research, summarizes available information, discusses the methodological shortcomings of extant studies, and makes recommendations for future research to better define prevalence and epidemiology; (2) Effects of Medicinal and Illegal Drugs on Driving Performance--focuses on the six classes of drugs most often found in impaired and injured drivers, draws conclusions regarding the risk of these drugs to traffic safety and discusses the need for additional research; (3) Toxicological Issues--discusses ways to identify drug users via behavioral testing and analytical techniques, reviews the approaches used by different countries, screening and confirmation techniques, alternative specimens (e.g., urine, oral fluid, sweat), and how rapid roadside testing could be coupled with behavioral and laboratory testing in an effective approach to identifying and prosecuting drugged drivers; (4) Driving Under the Influence of Drugs [DUID] Laws--provides an overview of DUID laws in the United States and Europe, discusses the basic tenets of these laws, the various types of DUID statutes, the reasons why many existing laws hinder the prosecution of drugged drivers and the rationale for developing per se legislation as a strategy to more effectively manage the drugged driver problem.

Clinical pharmacology, clinical efficacy, and behavioral toxicity of alprazolam: a review of the literature

Alprazolam is a benzodiazepine derivative that is currently used in the treatment of generalized anxiety, panic attacks with or without agoraphobia, and depression. Alprazolam has a fast onset of symptom relief (within the first week); it is unlikely to produce dependency or abuse. No tolerance to its therapeutic effect has been reported. At discontinuation of alprazolam treatment, withdrawal and rebound symptoms are common. Hence, alprazolam discontinuation must be tapered. An exhaustive review of the literature showed that alprazolam is significantly superior to placebo, and is at least equally effective in the relief of symptoms as tricyclic antidepressants (TCAs), such as imipramine. However, although alprazolam and imipramine are significantly more effective than placebo in the treatment of panic attacks, Selective Serotonin Reuptake Inhibitors (SSRIs) appear to be superior to either of the two drugs. Therefore, alprazolam is recommended as a second line treatment option, when SSRIs are not effective or well tolerated. In addition to its therapeutic effects, alprazolam produces adverse effects, such as drowsiness and sedation. Since alprazolam is widely used, many clinical studies investigated its cognitive and psychomotor effects. It is evident from these studies that alprazolam may impair performance in a variety of skills in healthy volunteers as well as in patients. Since the majority of alprazolam users are outpatients, this behavioral impairment limits the safe use of alprazolam in patients routinely engaged in potentially dangerous daily activities, such as driving a car.

Testing for benzodiazepine inebriation--relationship between benzodiazepine concentration and simple clinical tests for impairment in a sample of drugged drivers

OBJECTIVE

To study how the various 25 subtests and observations of the Norwegian clinical test for impairment related to the blood benzodiazepine concentrations of apprehended drivers suspected of driving under the influence of benzodiazepines. The impact of single-dose intake in non-daily users of benzodiazepines on the clinical picture of inebriation was also studied.

METHODS

Included in the study were 818 drivers suspected of driving under the influence of non-alcoholic drugs with blood samples containing only one benzodiazepine. We determined which of the 25 subtests and observations of the clinical test for impairment related significantly to the blood benzodiazepine concentrations.

RESULTS

Significantly related to blood benzodiazepine concentrations were 13 subtests and observations. Of these, 9 withstood adjustment for a variety of background variables. Single dose intake in non-daily users only influenced 3 subtests and observations after adjustment for blood benzodiazepine concentration and background variables. Romberg's test, 1 observation concerning alertness (oriented for time and place), 4 tests on motor and coordination (walk and turn on line, finger-to-nose and finger-to-finger tests), 2 observations on speech (articulation and content) and 1 observation regarding appearance (general conduct) were related to blood benzodiazepine concentrations.

CONCLUSION

Many of these simple clinical tests are included in the standardized field sobriety test and are of value in revealing benzodiazepine impairment. The present study offered some possible additions. Combinations of these robust tests can also be used to reveal benzodiazepine inebriation in other contexts.

Biomarkers for the effects of benzodiazepines in healthy volunteers

Studies of novel centrally acting drugs in healthy volunteers are traditionally concerned with kinetics and tolerability, but useful information may also be obtained from biomarkers of clinical endpoints. A useful biomarker should meet the following requirements: a consistent response across studies and drugs; a clear response of the biomarker to a therapeutic dose; a dose-response relationship; a plausible relationship between biomarker, pharmacology and pathogenesis. In the current review, all individual tests found in studies of benzodiazepine agonists registered for anxiety in healthy volunteers since 1966 were progressively evaluated for compliance with these requirements. A MedLine search yielded 56 different studies, investigating the effects of 16 different benzodiazepines on 73 different (variants of ) neuropsychological tests, which could be clustered into seven neuropsychological domains. Subjective and objective measures of alertness were most sensitive to benzodiazepines. The most consistent effects were observed on saccadic peak velocity (SPV) and visual analogue scores ( VAS) of alertness, where 100% and 79% of all studies respectively showed statistically significant effects. A dose-response relationship could be constructed for temazepam and SPV, which was used to determine dose equivalencies relative to temazepam, for seven different benzodiazepines. These dose equivalencies correlated with the lowest recommended daily maintenance dose (r2 = 0.737, P < 0.05). This relationship between SPV reduction and clinical efficacy could reflect the clinical practice of aiming for maximum tolerated levels, or it could represent a common basis behind SPV reduction and anxiolytic activity for benzodiazepines (probably sedation). The number of tests used in human psychopharmacology appears to be excessive and their sensitivity and reproducibility low.

The effects of alprazolam and buspirone in light and moderate female social drinkers

Individuals who are moderate/heavy drinkers are at increased risk to abuse benzodiazepines and this risk is increased in women compared to men. However, no studies have determined whether female moderate drinkers (MD) show a differential response to the subjective and performance effects of benzodiazepines compared to female light drinkers (LD). Fourteen female MD who consumed an average of 36 drinks/month were compared to 14 female LD who consumed an average of 4.2 drinks/month. None of the participants had either a first- or second-degree family history of alcoholism. The acute effects of placebo, alprazolam (0.25, 0.50, 0.75 mg) and buspirone (5, 10, 15 mg) were evaluated using a double-blind, placebo-controlled outpatient design. Drug effects were assessed using a full range of performance measures and subjective-effects questionnaires. Alprazolam impaired performance in a dose-related manner on all performance tasks for both groups of females, whereas buspirone had minimal effects on performance. There were few differences between LD and MD with respect to subjective response or performance impairment following either alprazolam or buspirone. Although MD reported greater ratings of Good Drug Effect and Drug Liking than LD, this was neither dose-related, nor specific to alprazolam. The results of the present study suggest that female MD without a family history of alcoholism experience the same level of performance impairment as female LD, although they tend to report greater positive subjective effects from alprazolam.

Toxicological interactions between alcohol and benzodiazepines

BACKGROUND

We review recentfindings on the toxicological interactions between alcohol (ethanol) and benzodiazepines, and the combined use of benzodiazepines and alcohol in fatal poisoning. Acute ingestion of alcohol combined with benzodiazepines is responsible for several toxicological interactions that can have significant clinical implications. In general, metabolism of these drugs is delayed when combined with acute alcohol ingestion although some reports suggest otherwise. Alternately, the drugs metabolized during chronic alcohol ingestion have an increased clearance. The net effect may also be influenced by internal (e.g., disease, age) and external (e.g., environment, diet) factors. Fatal poisoning involving coadministration of alcohol and benzodiazepine, especially triazolam, continues to be a serious problem.

Acute performance-impairing and subject-rated effects of triazolam and temazepam, alone and in combination with ethanol, in humans

The acute behavioural effects of triazolam (0.125 and 0.25 mg), temazepam (15 and 30 mg), and placebo, alone and in combination with ethanol (0 and 0.5 g/kg), were assessed in 10 volunteers. Ethanol alone did not impair performance and produced only a few subject-rated drug effects. Triazolam and temazepam alone produced some performance impairment and a few subject-rated drug effects. These effects tended to be dose-dependent and were comparable for the two drugs across the range of doses tested. The triazolam-ethanol and temazepam-ethanol combinations produced robust performance impairment and sedative-like subject-rated drug effects that were similar in magnitude. The findings of the present study suggest that even a moderate amount of ethanol in combination with a clinical dose of triazolam or temazepam can cause performance impairment that might diminish an individual's ability to respond adequately to unexpected demands (e.g. smoke alarms or middle-of-the-night child care).

The prevalence of alcohol, cannabinoids, benzodiazepines and stimulants amongst injured drivers and their role in driver culpability: part i: the prevalence of drug use in drive the drug-positive group

Blood samples from 2,500 injured drivers were analysed for alcohol, cannabinnoids, benzodiazepines and stimulants. Overall, three-quarters of drivers tested negative for drugs. Alcohol was the most frequently detected drug. Cannabinoids were also detected at high rates, but the majority of drivers tested positive for THC-acid, the inactive metabolite of THC. Benzodiazepines and stimulants were detected at low rates, and detection rates for combinations of drugs were also low. Males were more likely to test positive for drugs, especially alcohol and THC, whereas females were more likely to test positive for benzodiazepines. A similar proportion of car drivers and motorcycle riders tested positive for drugs, although riders were more likely to test positive for THC. Single-vehicle crashes were particularly associated with alcohol for both car driver and riders, and for riders, multiple-vehicle crashes were particularly associated with THC.

The prevalence of alcohol, cannabinoids, benzodiazepines and stimulants amongst injured drivers and their role in driver culpability: part ii: the relationship between drug prevalence and drug concentration, and driver culpability

Blood samples from 2,500 injured drivers were analysed for alcohol, cannabinoids (measured by the presence of THC), benzodiazepines and stimulants. The relationship between the prevalence and concentration of drugs and the culpability of the driver was examined using an objective method for assessing culpability. There were no significant differences between males and females with respect to culpability. However, there was a relationship between age and culpability: drivers under 26 years and over 60 years were more likely to be culpable. Drivers who tested positive for alcohol only, benzodiazepines only and the combinations of alcohol and THC and alcohol and benzodiazepines were significantly more likely to be culpable for the crash compared with the drug-free group. Conversely, a lower percentage of drivers who only tested positive for THC were culpable for the crash compared with drug-free drivers. This difference was not statistically significant. For car drivers in single-vehicle crashes, the majority of drivers were judged culpable irrespective of drug use. In multiple-vehicle crashes, car drivers testing positive for alcohol only or benzodiazepines only were more likely to be culpable for the crash compared with drug-free drivers. For motorcycle riders in both single- and multiple-vehicle crashes, there were no significant differences between the drug-positive and drug-free groups. A higher percentage of drug-free riders in multiple-vehicle crashes were culpable compared with riders who only tested positive for THC, but this difference was not statistically significant. There was a significant concentration-dependent relationship between alcohol and culpability: as blood alcohol concentration increased, so did the percentage of culpable drivers. When THC was used alone, there was no significant increase in culpability. For those drivers with benzodiazepines at therapeutic concentrations and above, there was a significant increase in culpability. The relationship between stimulants and culpability was not significant, although a higher proportion of stimulant-positive drivers were culpable compared with drug-free drivers. The combinations of alcohol and THC, and alcohol and benzodiazepines also produced a significant increase in culpability, but this increase was not significantly greater than that produced by alcohol alone.

Incidence of xenobiotics among drivers killed in single-vehicle crashes

The authors have performed a study of single-vehicle crashes (SVCs) in order to verify a correlation between the loss of vehicle control and the presence of drugs in the body. Overall, 129 cases were recorded and occurred in the catchment area of the Institute of Legal Medicine in Milan between 1986 to 1996. Among the 129 cases under study, respectively 121 men and eight women, 101 were car-drivers and 28 motor-cyclists. The median age was equal to 29 years, while the average age to 32.0 years (range 15-65 years). Fifty eight cases (45.0%) were "positive" for the presence of ethanol > or = 0.8 g/l or other drugs. The sample of "positive cases" was studied according to sex, age, day, hour and type of vehicle. Considering the cases with presence of ethanol, although under the legal limit (20 cases), the total amount of cases (78) becomes even more consistent. The amount of ethanol was found to be respectively 0.34 g/l in daily drivers and 0.87 g/l in nightly drivers (p < 0.01). Our considerations confirm the importance of toxicological analyses in the forensic investigation of traffic deaths being the sample under study recorded following criteria which minimised other possible factors effecting road accidents.

Influence of endogenous progesterone on alprazolam pharmacodynamics

The results of a recently completed study demonstrated that postmenopausal women were more sensitive to triazolam-induced psychomotor performance impairment when progesterone was administered concomitantly. That clinical evidence agrees with the emerging in vitro information regarding the rapid membrane effects of a progesterone metabolite that positively modulates the gamma-aminobutyric acid-A-benzodiazepine receptor complex. The objective of this study in premenopausal women was to determine whether the response to a benzodiazepine is altered when endogenous progesterone concentrations are high (luteal phases of a menstrual cycle) compared with when progesterone concentrations are low (follicular phases of a menstrual cycle). The pharmacokinetics and pharmacodynamics of oral alprazolam were evaluated in twelve healthy, normally menstruating women who were not receiving oral contraceptive agents. On two separate occasions, once during each phase of the menstrual cycle, the women randomly received an oral alprazolam 2-mg dose. Blood samples were collected, and psychomotor performance tests were conducted at selected times before and after dosing. These data show that fluctuations of endogenous progesterone across the menstrual cycle do not influence alprazolam pharmacodynamics. Despite endogenous progesterone concentrations being significantly higher during the midluteal than during the midfollicular drug administrations, no differences were observed in either the digit-symbol substitution test, card sorting by suit, or sedation scores on these two occasions. No pharmacokinetic differences were observed between the two menstrual cycle-phase drug administrations. In conclusion, the lack of changes during the menstrual cycle in demonstrable cognitive impairment and pharmacokinetics after alprazolam administration is reassuring. This implies that a dose adjustment made on the basis of menstrual timing is not required.

Brief hypnosis substitutes for alprazolam use in college students: transient experiences and quantitative EEG responses

We sought to determine: 1) whether a simple hypnotic induction with an alprazolam experience derived suggestion could recreate the subjective effects of alprazolam (Xanax), 2) whether the effects of alprazolam are greater than the effects of hypnosis plus this suggestion, and 3) whether the effects of hypnosis plus this suggestion were greater than the relaxation effects produced by hypnosis alone. High and low hypnotizable student volunteer subjects (Ss) ingested 1 mg of alprazolam. A hypnotic suggestion was developed on the basis of their reported reactions to alprazolam. Four days later the same Ss were exposed to hypnosis only and hypnosis plus the alprazolam experience based suggestion conditions in counterbalanced order. Ss exposed to the hypnosis plus suggestion condition demonstrated greater levels of relaxation as measured by the tension-anxiety scale of the Profile of Mood States (POMS) (Eichman & Umstead, 1971) than in the alprazolam condition or the hypnosis only condition. High hypnotizables showed significantly greater levels of relaxation than the low hypnotizables in each of the three conditions (hypnosis plus suggestion, hypnosis only, alprazolam only). EEG data showed frontal and occipital sites were specifically involved in both the alprazolam and the hypnotic suggestion conditions. The findings indicate a basis for the use of hypnosis as a substitute for sedative drug use. Limitations and implications for clinicians are discussed.

Pharmacokinetic interactions between acute alcohol ingestion and single doses of benzodiazepines, and tricyclic and tetracyclic antidepressants -- an update

Recent reports of interactions between alcohol and benzodiazepines, tricyclic and tetracyclic antidepressants during their acute concomitant use are reviewed. Acute ingestion of alcohol (ethanol) with tranquilizers or hypnotics is responsible for several pharmacokinetic interactions that can have significant clinical implications. In general, metabolism of these drugs is delayed when combined with alcohol but some reports have suggested otherwise. The amount of alcohol consumed, the presence or absence of liver disease, and differences in the dosage and administration of these drugs may account for the observed discrepancies. In recent years, the cytochrome P450 (P450 or CYP) isoenzyme that catalyses the metabolism of these drugs has also been identified. However, since changes in the pharmacogenetic metabolism of benzodiazepines and tricyclic and tetracyclic antidepressants are mainly governed by CYP2C19 and CYP2D6, caution is needed when used together with alcohol.

Noninvasive indices of autonomic regulation after alprazolam and lorazepam: effects on sympathovagal balance

Skin conductance level (SCL) and spectral analysis of variations in heart rate (HR) and blood pressure (BP), in relation to plasma catecholamine concentrations, were used to evaluate autonomic nervous system activity during situations of supine rest within a period of 4 h after oral administration of 1 mg alprazolam and 2 mg lorazepam. Twelve healthy men received in a double-blind, randomized crossover design, either 1 mg alprazolam, or 2 mg lorazepam, or a placebo on different days. ECG, BP, respiration, and SCL were monitored continuously during each session. For HR, systolic and diastolic BP (SBP, DBP) time series, power spectra were calculated per 5 min for three 15-min periods at 30 min, 1 h and 45 min, and 3 h after dosing. Spectral power was assessed for three frequency bands: low (0.02-0.06 Hz), mid (0.07-0.14 Hz), and high (0.15-0.50 Hz). Per time segment, the gain in the mid-frequency band between the systolic BP values and the RR interval times was computed as index of baroreflex sensitivity (BRS). Blood samples for assay of plasma catecholamines were obtained after each 15-min period. Alprazolam reduced DBP during the whole recording period; the effect was accompanied by an initial increase of mid-frequency band fluctuations of BP at 30 min, which subsequently decreased at 1 h 45 min and 3 h after dose administration, in comparison with placebo (suggesting an initial reflectory increase, followed by an attenuation of sympathetic tone). The BP effects were accompanied by a reduction of plasma noradrenaline concentrations. HR showed a time-dependent decrease after alprazolam and an increase in high-frequency band fluctuations of HR and BRS (suggesting a time-dependent increase in cardiac vagal tone). SCL was decreased after alprazolam administration. Lorazepam did not show a time-dependent reduction of HR and had no effect on BP, but increased low-frequency band power of HR and DBP and mildly reduced SCL. Alprazolam and lorazepam had no effect on respiratory frequency. Noninvasive indices of autonomic regulation revealed several small, but significant, time-dependent effects of 1 mg alprazolam on sympathetic and parasympathetic processes, whereas for 2 mg lorazepam, these effects were less clear. The reduction in noninvasive indices of sympathetic tone after alprazolam administration corresponded with the attenuation of plasma noradrenaline concentrations by alprazolam.

Pharmacokinetic interactions between alcohol and other drugs

The frequent use of alcohol (ethanol) together with prescription drugs gives any described pharmacokinetic interaction significant clinical implications. The issue is both the effect of alcohol on the pharmacokinetics of various drugs and also the effect of those drugs on the pharmacokinetics of alcohol. This review discusses these pharmacokinetic interactions but also briefly describes some other effects of alcohol that are clinically relevant to drug prescribing. The use of several different study designs may be required before we can confidently state the presence or absence of any alcohol-drug interaction. Short term administration of alcohol in volunteers is the most common study design but studies of social drinking and prolonged moderate alcohol intake can be important in some situations. Community-based studies may illustrate the clinical relevance of any interaction. Alcohol can affect the pharmacokinetics of drugs by altering gastric emptying or liver metabolism (by inducing cytochrome P450 2E1). Drugs may affect the pharmacokinetics of alcohol by altering gastric emptying and inhibiting gastric alcohol dehydrogenase. The role of gastric alcohol dehydrogenase in the first-pass metabolism of alcohol is reviewed in this article and the arguments for and against any potential interaction between alcohol and H2 receptor antagonists are also discussed. The inhibition of the metabolism of acetaldehyde may cause disulfiram-like reactions. Pharmacodynamic interactions between alcohol and prescription drugs are common, particularly the additive sedative effects with benzodiazepines and also with some of the antihistamine drugs; other interactions may occur with tricyclic antidepressants. Alcohol intake may be a contributing factor to the disease state which is being treated and may complicate treatment because of various pathophysiological effects (e.g. impairment of gluconeogenesis and the risk of hypoglycaemia with oral hypoglycaemic agents). The combination of nonsteroidal anti-inflammatory drugs and alcohol intake increases the risk of gastrointestinal haemorrhage.

Preference for diazepam, but not buspirone, in moderate drinkers

The purpose of the present study was to determine the preference for buspirone, an anxiolytic predicted to have minimal abuse potential, in comparison with diazepam in moderate drinkers. Preference for diazepam and buspirone was assessed in 55 moderate drinkers using a seven-session procedure consisting of four sampling sessions followed by three choice sessions. On each sampling session subjects ingested five capsules, one every 30 min. Color-coded capsules contained placebo on two sessions and drug on two sessions. Each drug capsule contained diazepam (4 mg) for 30 subjects and buspirone (5 mg) for 25 subjects. On choice sessions subjects chose whichever of the two color-coded capsules, i.e., drug or placebo, they wished to take. After ingesting one capsule, every 30 min they had the option of ingesting another capsule of the same color and content, for a maximum of seven capsules over the session (maximum of 28 mg diazepam or 35 mg buspirone). In the diazepam group 70% of subjects chose diazepam over placebo on at least two of the three choice sessions, whereas in the buspirone group only 24% of subjects chose buspirone over placebo on at least two sessions. Both diazepam and buspirone increased measures of sedation. Only diazepam increased ratings of liking and impaired performance, whereas only buspirone decreased ratings of feeling Friendly. These results replicate previous findings indicating that diazepam has reinforcing effects in moderate drinkers. Further, these results demonstrate the pharmacological specificity of this effect by showing that buspirone did not function as a reinforcer under these same conditions.

Interactions between alcohol and other drugs

More than 75% of people age 65 and older use medications. Of the drugs most commonly used by older people, many have potential to interact adversely with alcohol. The absorption, distribution, metabolism, and effects of drugs or alcohol may be affected. The major adverse clinical outcomes of drug-alcohol interactions are altered blood levels of the medication or of alcohol, liver toxicity, gastrointestinal inflammation and bleeding, sedation and delirium, disulfiram-like reactions, and interference with the desired effect of medications. Since alcohol is commonly used by elderly people, educating patients about the potential for these interactions should be a routine part of health care visits.

Potential for adverse drug-alcohol interactions among retirement community residents

OBJECTIVES

Medications and alcohol are both used commonly by older people. Thus, the potential for adverse drug-alcohol interactions is very high in this population, but data on actual concurrent use of alcohol and medicines likely to interact with alcohol are lacking. The objectives of this study were to determine the frequency of alcohol and medication use and the potential for specific adverse drug-alcohol interactions in residents of retirement communities.

DESIGN

Cross-sectional study using a mailed survey.

SETTING

Three retirement communities in suburban Milwaukee, Wisconsin.

PARTICIPANTS

All 454 independently living residents of the communities were surveyed. Of these, 311 residents (68%) returned completed questionnaires. Mean age of respondents was 83 +/- 6 years, 100% were white, 77% were female.

MEASUREMENTS

The questionnaire included alcohol use questions adapted from the Khavari questionnaire and the CAGE questionnaire to screen for alcohol abuse. Respondents were asked to list all prescription and nonprescription medications.

RESULTS

Thirty-eight percent of the population reported using both alcohol and a high risk medication. Six percent had seven or more drinks per week and took a high risk medication. High risk drugs commonly used by drinkers were antihypertensives in 50%, aspirin in 27%, nonsteroidal anti-inflammatory drugs in 20%, medication for congestive heart failure in 18%, antacids or H2 blockers in 16%, sedatives in 11%, narcotics in 5%, and warfarin in 5%.

CONCLUSIONS

Concurrent use of alcohol and medications is common in residents of these retirement communities. Many of the drugs taken by regular drinkers have potential for adverse drug-alcohol interactions even at moderate levels of alcohol use. This represents a strong possibility of adverse outcomes and a need for increased awareness on the part of both the public and physicians of the potential for interactions between drugs and alcohol.

Low blood alcohol concentrations and driving impairment. A review of experimental studies and international legislation

While noting that there is no international scientific or legislative uniformity in blood alcohol concentration (BAC) levels admissible for driving motor vehicles, the authors analyse problems concerning the effects of low levels of ethyl alcohol on driving ability. A summary of the international literature on this subject reveals: the existence of contrasting assumptions, with scientific evidence clearly demonstrating altered psychomotor functions; the need to adopt sufficiently complex psychometric tests to reveal the effects of low BACs; the need to improve standardization of experimental studies on man-machine interaction; the need to investigate the following areas: tolerance to alcohol; low BACs with inexperienced, infrequent drinkers and chronic, heavy drinkers; hangover effects; alcohol-gender-age interactions, and specific effects on young drivers; alcohol-drug combinations. The analysis of legislation and enforcement policies also reveals the need for: re-evaluation of the international legal BAC threshold and standardization of procedures for ascertaining the degree of driving disability; further scientific research to compare and evaluate selected legislative initiatives currently in place in most states; to identify the best strategies and procedures to detect and arrest impaired drivers; to determine the optimum random testing rate to maximize deterrent effects in the workplace at minimal cost; to design innovative and comprehensive approaches to rehabilitation programs needed for subgroups of offenders and of workers; to study the effectiveness of new legislations and policies.

Abuse liability of alprazolam relative to other commonly used benzodiazepines: a review

Nonhuman and human studies comparing the abuse liability of alprazolam to other commonly used benzodiazepines are reviewed. These studies are reviewed to determine to what extent prospective, controlled, experimental studies support opinions that alprazolam's abuse liability is greater than that of other commonly used benzodiazepines. Studies comparing the self-administration of alprazolam, the discriminative stimulus effects of alprazolam, self-reported effects of alprazolam, physiological dependence on alprazolam, and adverse effects of alprazolam relative to other benzodiazepines are reviewed. Overall, the experimental literature does not support the widely held belief that alprazolam's abuse liability is greater than that of other benzodiazepines, but much more research is needed. Such research should focus explicitly on alprazolam's reinforcing effects, and the nature and severity of the discontinuation syndrome associated with its long-term use. Important issues such as selection of an appropriate comparison drug, selection of an appropriate population, dosing regimen and test doses need to be considered in future studies.

The use of microcomputer-based psychomotor tests for the evaluation of benzodiazepine effects on human performance: a review with emphasis on temazepam

1. The literature relating to the effects of benzodiazepines in general, and temazepam in particular, on human psychomotor performance as assessed using microcomputer-based testing batteries is surveyed. 2. The adverse effects of central nervous system depressants on performance is an important mediocolegal issue and frequently comes into question in on-the-road and on-the-job accidents. The use of microcomputer-based testing batteries allows for performance evaluation both in the laboratory and at-the-scene, as well as providing the opportunity to model a large number of different behaviours required in routine yet complex psychomotor tasks. 3. The conclusions in general are: (1) The benzodiazepines as a class of drugs impair both cognitive and motor performance. These effects are often subtle when low doses are involved or when testing occurs the morning following evening administration of the medication. (2) No single psychomotor task adequately simulates complex daily tasks such as automobile driving. A battery of tests that evaluates a number of the components of such tasks is necessary to determine adequately the full range of effects of these medications.

The effects of alprazolam alone and combined with alcohol on central integrative activity

The effects of alprazolam 1 mg both alone and in combination with 0.5 g/kg of alcohol were examined on self-ratings of intoxication and measures of central and peripheral activity such as EEG, auditory evoked response, tremor at 90, 150 and 210 min post drug. Forty-eight healthy volunteers were assigned randomly to 4 independent groups who received: alprazolam and placebo drink, alprazolam and alcohol, placebo capsule and alcohol, placebo capsule and placebo drink respectively. Alprazolam decreased the amplitudes of the 3 potentials of the evoked response, decreased activity in the 8-13 Hz and increased activity in the 13.5-26 Hz wavebands of the EEG and decreased the frequency at which fusion was perceived. Alcohol prolonged reaction time and increased tremor. The effects were not always additive and alprazolam was dominant in the combination.