Anxiety, sedation, and simulated driving in binge drinkers

Silexan does not affect driving performance after single and multiple dose applications: Results from a double-blind, placebo and reference-controlled study in healthy volunteers

Anxiolytic drugs often have sedative effects that impair the ability to drive. Our double-blind, randomized crossover trial investigated the effect of Silexan, a non-sedating, anxiolytic herbal medicinal product, on driving performance in healthy volunteers. Part 1 aimed at demonstrating equivalence between 80 mg/d Silexan and placebo. Part 2 was performed to demonstrate superiority of 160 and 320 mg Silexan over 1 mg lorazepam and included a placebo arm for assay sensitivity. Driving performance was assessed in a validated, alcohol-calibrated simulator test. The primary outcome was the standard deviation of the lane position (SDLP). Secondary outcomes included driving errors and sleepiness. Fifty and 25 subjects were randomized in Parts 1 and 2, respectively. In Part 1, Silexan 80 mg was confirmed to be equivalent to placebo after single administration (equivalence range: δ = ±2 cm). The 95% confidence interval (CI) for the SDLP marginal mean value difference Silexan-placebo for single administration was -1.43; +1.38 and thus similar to the 95% CI of -1.45; +0.79 cm for 7 days' multiple dosing. In Part 2, 95% CIs for SDLP marginal mean value differences to lorazepam were -8.58; -5.42 cm for Silexan 160 mg and -8.65; -5.45 cm for 320 mg (p < 0.001). Confirmatory results were supported by secondary outcomes, where results for Silexan were comparable to placebo and more favorable than for lorazepam. The study demonstrates that single doses of up to 320 mg Silexan and multiple doses of 80 mg/d have no adverse effect on driving performance.

Context, acute tolerance, and subjective response affect alcohol-impaired driving decisions

RATIONALE

Alcohol intoxication produces effects that can impair judgment and increase engagement in risky behaviors, including alcohol-impaired driving (AID). Real-world AID decisions are informed by contextual circumstances and judgments of associated risk. How individuals vary in their AID decision-making across contexts and whether subjective alcohol responses (stimulation, sedation, acute tolerance) differentially affect AID decisions are critical, but under-studied research questions.

OBJECTIVES

We systematically investigated predictors of AID decisions at different hypothetical driving distances across the blood alcohol concentration (BAC) curve.

METHODS

Young adults (n = 40; 55% female) completed two laboratory sessions in a within-subjects alcohol/placebo design. At multiple points along the BAC curve (M peak BAC = 0.101 g%), participants rated their subjective intoxication, stimulation, sedation, and perceived dangerousness of driving prior to indicating their willingness to drive distances of 1, 3, and 10 miles. Multilevel mixed models assessed within- and between-person predictors of the maximum distance participants were willing to drive at matched BACs on the ascending and descending limb.

RESULTS

Under intoxication (but not placebo), participants were willing to drive greater distances on the descending versus ascending limb. At the momentary level, participants were willing to drive further when they felt less intoxicated, stimulated, and sedated, and perceived driving as less dangerous.

CONCLUSIONS

Individuals differed in the distance they were willing to drive as a function of indicators of intoxication, implicating driving distance as an important contextual factor relevant to AID decisions. Individuals may simultaneously perceive themselves as "unsafe" to drive, but "safe enough" to drive short distances, particularly when BAC is falling.

Prevalence of at-risk drinking among Brazilian truck drivers and its interference on the performance of executive cognitive tasks

BACKGROUND

Binge drinking (BD) has been associated with an increase in the risk of alcohol-related injuries. Alcohol continues to be the main substance consumed by truck drivers, a population of special concern, since they are often involved in traffic accidents. The aim of this study was to estimate the prevalence of BD and its interference in the executive functioning among truck drivers in Sao Paulo, Brazil.

METHODS

A non-probabilistic sample of 684 truck drivers was requested to answer a structured research instrument on their demographic data and alcohol use. They performed cognitive tests to assess their executive functioning and inventories about confounding variables. The participants were then divided according to their involvement in BD.

RESULTS

17.5% of the interviewees have reported being engaged in BD. Binge drinkers showed a better performance on one test, despite having done so at the expense of more mistakes and lower accuracy. More interestingly, binge drinkers took three seconds longer than non-binge drinkers to inhibit an inadequate response, which is worrisome in the context of traffic. Overall, the deleterious effect of BD on performance remained after controlling for the effects of confounding variables in regression logistic models.

CONCLUSIONS

As the use of alcohol among truck drivers may be as a way to get by with their work conditions, we believe that a negotiation between their work organization and public authorities would reduce such use, preventing negative interferences on truck drivers' cognitive functioning, which by its turn may also prevent traffic accidents.

Assessing the Validity of Participant-Derived Compared to Staff-Derived Values to Compute a Binge Score

AIMS

This study examined the validity of two methods of classifying binge drinkers.

METHODS

Adult drinkers (n = 166) completed the Alcohol Use Questionnaire (AUQ) and a Timeline Followback (TLFB) interview to characterize drinking during the past 28 days. Using Townshend and Duka's (2005) recommendations, answers on three AUQ items (average drinks per hour, number of times drunk within the prior 6 months and percentage of times drunk when drinking) were used to derive a binge score that was then used to classify drinkers as Binge, Non-Binge and Unclassifiable. Two methods for calculating binge scores were compared: (a) Participant-derived, using participants' answers on the 3 AUQ items; and (b) Staff-derived, staff used TLFB interview information to answer the 3 AUQ items. Additionally, Participant- and Staff-derived classifications were used to predict future drinking behaviors assessed by a second TLFB interview.

RESULTS

Participant- and Staff-derived binge scores had a low concordance rate. Staff-derived classifications were better than Participant-derived classifications at predicting future binge drinking behavior and identifying group differences in drinking behavior reported during the second TLFB interview (average drinks per hour, number of times drunk within the prior 6 months, and percentage of times drunk when drinking).

CONCLUSIONS

Classifying drinkers using staff-guided TLFB interview methods instead of self-reported participant generalizations of typical drinking habits better relates to real-world drinking. Classification schemes that rely on dichotomous categorization of drinkers (Binge vs. Non-Binge) may be missing individuals who engage in harmful patterns of drinking. A continuous scale or index characterizing problematic drinking may be more useful.

Adapting to alcohol: Dwarf hamster (Phodopus campbelli) ethanol consumption, sensitivity, and hoard fermentation

Ethanol consumption and sensitivity in many species are influenced by the frequency with which ethanol is encountered in their niches. In Experiment 1, dwarf hamsters (Phodopus campbelli) with ad libitum access to food and water consumed high amounts of unsweetened alcohol solutions. Their consumption of 15%, but not 30%, ethanol was reduced when they were fed a high-fat diet; a high carbohydrate diet did not affect ethanol consumption. In Experiment 2, intraperitoneal injections of ethanol caused significant dose-related motor impairment. Much larger doses administered orally, however, had no effect. In Experiment 3, ryegrass seeds, a common food source for wild dwarf hamsters, supported ethanol fermentation. Results of these experiments suggest that dwarf hamsters may have adapted to consume foods in which ethanol production naturally occurs.