Effects of alprazolam, caffeine, and zolpidem in humans trained to discriminate triazolam from placebo

Prevalence and correlates of the misuse of z-drugs and benzodiazepines in the National Survey on Drug Use and Health

Background

Benzodiazepines and non-benzodiazepine hypnotics (z-drugs) are commonly prescribed for their anxiolytic and hypnotic properties, though they can also be misused. In studies examining the epidemiology of prescription drug misuse, these medication classes are commonly combined, rendering inadequate knowledge of their patterns of misuse. The objective of this study was to characterize the population prevalence, conditional dependence, and sociodemographic and clinical correlates of the misuse of benzodiazepines and z-drugs.

Methods

Data from the National Survey on Drug Use and Health from 2015 to 2019 were used to estimate population-level prevalence and characteristics of benzodiazepine and z-drug misuse. Groups were derived based on past-year misuse of benzodiazepines alone, z-drugs alone, or both drug types. Unadjusted regression analyses were used to compare groups on characteristics of interest.

Results

Exposure to benzodiazepines and/or z-drugs via prescription or misuse was common; however, only 2% of the population was estimated to have misused a benzodiazepine in the past year, and less than 0.5% misused z-drugs. People who misused only z-drugs were generally older, more likely to have health insurance, more educated, and had less severe psychiatric symptoms. This group was also more likely to report misuse to cope with sleep difficulty. Although concurrent substance use was highly prevalent in all groups, people who misused z-drugs alone generally reported less concurrent substance use than the other groups.

Conclusion

The misuse of z-drugs is less common than benzodiazepines, and people who misuse only z-drugs appear to generally have lower clinical severity. Nonetheless, a substantial subgroup of people exposed to z-drugs report concurrent, past-year use of other substances. Further research on z-drug misuse, including consideration of whether it should be grouped with other anxiolytic/hypnotic drugs, is needed.

Effects of eszopiclone and zolpidem on sleep-wake behavior, anxiety-like behavior and contextual memory in rats

At present, eszopiclone and zolpidem are the most commonly prescribed drugs for treating insomnia. Despite the established relationship between sleep disturbance and anxiety, it remains unknown whether targeted treatment for insomnia may affect acute anxiety. Therefore, the objective of this study was to examine the effects of three different doses (1, 3, and 10mg/kg) of eszopiclone and zolpidem on the states of sleep and wakefulness, levels of anxiety-like behavior, and long-term contextual memory in footshock-induced anxious rats. The results of this study demonstrated that the administration of eszopiclone and zolpidem both were equally effective in attenuating footshock stressor-induced suppression of slow-wave sleep (SWS). The administration of eszopiclone at 1mg/kg or zolpidem at 1 and 3mg/kg doses showed a tendency for attenuating stressor-induced suppression of REM sleep. However, the REM sleep attenuating effects of these drugs disappeared when they were administered at higher doses. The administration of eszopiclone at 3 and 10mg/kg doses and zolpidem at all three doses reduced the power of electroencephalographic theta band frequencies during wakefulness. In addition, the administration of eszopiclone at 1 and 3mg/kg doses suppressed stressor-induced anxiety-like behavior. The administration of zolpidem at 1, 3, or 10mg/kg doses was not effective in attenuating stressor-induced anxiety-like behavior. Contextual memory after administration of eszopiclone at 1mg/kg dose had no effects, but was reduced significantly with increased dosage. Contextual memory after administration of zolpidem, at all three doses, was severely disrupted. The results of this study suggest that eszopiclone at a low dose could be used effectively to control anxiety and anxiety-induced insomnia.

Relative abuse liability of indiplon and triazolam in humans: a comparison of psychomotor, subjective, and cognitive effects

Indiplon [N-methyl-N-[3-[3-(2-thienylcarbonyl)-pyrazolo[1,5-alpha]pyrimidin-7-yl]phenyl]acetamide; NBI 34060] is a positive allosteric GABA(A) receptor modulator that is under development for the treatment of insomnia. This study compared the abuse potential of indiplon, a compound with preferential affinity for GABA(A) receptors containing an alpha(1) subunit, with triazolam in 21 volunteers with histories of drug abuse. Placebo, triazolam (0.25, 0.5, and 0.75 mg), and indiplon (30, 50, and 80 mg) were studied in counterbalanced order under double-blind conditions at two different residential research facilities. Both drugs impaired psychomotor and cognitive performance and produced similar dose-related increases in participant and observer ratings of drug strength. The onset of action of both drugs was rapid (30 min); however, the duration of action of indiplon (3-4 h) was shorter than that of triazolam (4-6 h). The profiles of subjective effects of triazolam and indiplon were similar; however, a maximum of 52% of participants identified indiplon as a benzodiazepine or barbiturate, compared with 81% of participants after 0.75 mg of triazolam. On participantrated subjective effects relevant to sedation, the slope of the triazolam dose-effect curve was significantly steeper than that of indiplon. Neither the largest doses of indiplon and triazolam nor the slope of the indiplon and triazolam dose-effect curves were significantly different from each other on any of the same-day or next-day measures of positive drug effects or next-day measures of reinforcing effects. Together, these data suggest that although the abuse potential of indiplon is not different from that of triazolam at these doses, psychomotor and cognitive impairment after large doses of indiplon might be less.

Smoked cocaine discrimination in humans: effects of gabapentin

Gamma-aminobutyric acid (GABA) agonists, such as the GABA analogue, gabapentin, may provide new avenues for pharmacological treatment of cocaine dependence. The purpose of this study was to develop a smoked cocaine drug discrimination procedure in humans to test the effects of gabapentin maintenance on the discriminative stimulus, subjective, cognitive and cardiovascular effects of smoked cocaine. Eight male, nontreatment-seeking, cocaine-dependent volunteers, residing on an inpatient research unit for 47 days completed a within-subjects, counter-balanced design. Participants learned to discriminate between cocaine (25 mg) and placebo, and once the criterion for discrimination was met, smoked cocaine dose-effect functions (0, 6, 12, 25 and 50 mg) were determined under three gabapentin maintenance conditions (0, 600 and 1200 mg/day po). The highest dose of gabapentin tested (1200 mg/day) decreased the discriminative stimulus effects of cocaine (6 mg), decreased cocaine craving by 41-53% following cocaine administration (6 and 12 mg), and increased heart rate following either placebo or cocaine (12 mg) administration. Gabapentin did not significantly affect psychomotor task performance or the subjective effects of cocaine. Although the direction of gabapentin's effects was appropriate for a potential treatment medication, i.e., a decrease in cocaine-elicited craving and a decrease in cocaine's discriminative stimulus effects, these effects were limited to low doses of cocaine. The results suggest gabapentin may not produce effects sufficiently robust to be clinically useful, at least at this dose regimen.

Clinical neuropharmacology of drugs of abuse: a comparison of drug-discrimination and subject-report measures

Advances in molecular pharmacology and behavioral science have helped elucidate the structure and function of the central nervous system and its relationship to behavior and has sparked the development of pharmacological agents that have increasingly selective and potent effects with fewer adverse side effects. The sensitivity and predictive validity of the two most commonly used methodologies for assessing the neuropharmacological effects of centrally active drugs, subject report of drug effects and drug discrimination, were examined. The sensitivity of the measures was comparable across stimulant, sedative, and opioid drugs. Results with drug-discrimination methodologies were generally consistent with hypothesized neuropharmacological mechanisms across all drug classes, whereas subject reports conformed under more limited testing conditions. Firm conclusions regarding the relative utility of drug-discrimination and subject-report measures for clinical studies of neuropharmacological mechanisms are limited by the small number of studies in which the two methodologies have been tested using identical pharmacological pretreatment manipulations.