Abuse and dependence liability of benzodiazepine-type drugs: GABA(A) receptor modulation and beyond

GABAergic compounds for the treatment of alcohol use disorder

Decades of research have implicated the gamma-aminobutyric acid (GABA)ergic system as one of the main mediators of the behavioral effects of alcohol. Of importance, the addiction-related effects of alcohol also have been shown to be mediated in part by GABAergic systems, raising the possibility that pharmacotherapies targeting GABAergic receptors may be promising candidates for the treatment of alcohol use disorder (AUD). Alcohol modulates the activity of GABAA and GABAB receptors, and studies show that compounds targeting some of those receptors may decrease the addiction-related behavioral effects of alcohol. Specifically, drugs that share similar pharmacological properties with alcohol, such as positive allosteric modulators (PAMs) of GABAA and GABAB receptors, have been proposed as substitution therapies for AUD. Available evidence also suggests that negative allosteric modulators (NAMs) of GABAergic receptors may be potential therapeutics for AUD, although this effect is selective for specific receptor subtypes. Therefore, this Chapter reviews the available evidence on the use of GABAergic compounds for the treatment of AUD. Several GABAA and GABAB ligands show promising results, with a particularly positive therapeutic profile demonstrated for α5GABAA receptor NAMs, α4/6δGABAA receptor modulators (both positive and negative, including neurosteroids), and GABAB receptor PAMs. As newer and better GABAergic compounds become available, future research should focus on understanding how these ligands can modulate different clinical symptoms of AUD, with potential new areas of research encompassing alcohol withdrawal syndrome and AUD-related insomnia.

Hypnotic Use and the Risk of Cardiovascular Diseases in Insomnia Patients

AIMS

We aimed to examine the association between hypnotic agents and cardiovascular outcomes in general individuals with insomnia.

METHODS

In a propensity score matched cohort of UK Biobank (UKB) participants with insomnia, Cox proportional hazard model was used to estimate the association between regular use of hypnotic agents and predetermined cardiovascular outcomes including incident coronary heart diseases (CHD), heart failure (HF), stroke, and cardiovascular death. Inverse probability of treatment weighting, competing risk models, and shared frailty models were further performed during sensitivity analysis. Drug-target Mendelian randomization (MR) analyses were employed for further evaluation of the association between therapeutic targets of hypnotics and cardiovascular diseases.

RESULTS

During a median follow-up of 14.3 years, the matched cohort documented a total of 929 CHD cases, 360 HF cases, 262 stroke cases, and 180 cardiovascular deaths. No significant association was detected between Z-meds and CHD, stroke, and cardiovascular mortality. Benzodiazepine use was significantly associated with the increased risk of CHD, HF, and cardiovascular mortality. The inverse probability of treatment weighting, competing risk models, and shared frailty models didn't alter the above associations. Moreover, drug-target MR analyses corroborated the safety of Z-meds in the general population regarding cardiovascular health.

CONCLUSIONS

Our findings suggested the heterogeneous associations between different categories of hypnotics and incident cardiovascular events in individuals with insomnia. Both observational and genetic evidence raised safety concerns regarding the cardiovascular impact of benzodiazepines. No cardiovascular hazard of Z-meds was discovered in the UKB population with insomnia.

Onset of Prolonged High-Potency Benzodiazepine Use Among ICU Survivors: A Nationwide Cohort Study

OBJECTIVES

Exposure to critical illness and intensive care may lead to long-term psychologic and physical impairments. To what extent ICU survivors become prolonged users of benzodiazepines after exposure to critical care is not fully explored. This study aimed to describe the extent of onset of prolonged high-potency benzodiazepine use among ICU survivors not using these drugs before admission, identify factors associated with this use, and analyze whether such usage is associated with increased mortality.

DESIGN

Retrospective cohort study.

SETTING

Sweden, including all registered ICU admissions between 2010 and 2017.

PATIENTS

ICU patients surviving for at least 3 months, not using high-potency benzodiazepine before admission, were eligible for inclusion.

INTERVENTIONS

Admission to intensive care.

MEASUREMENTS AND MAIN RESULTS

A total of 237,904 patients were screened and 137,647 were included. Of these 5338 (3.9%) became prolonged users of high-potency benzodiazepines after ICU discharge. A peak in high-potency benzodiazepine prescriptions was observed during the first 3 months, followed by sustained usage throughout the follow-up period of 18 months. Prolonged usage was associated with older age, female sex, and a history of both somatic and psychiatric comorbidities, including substance abuse. Additionally, a longer ICU stay, a high estimated mortality rate, and prior consumption of low-potency benzodiazepines were associated with prolonged use. The risk of death between 6 and 18 months post-ICU admission was significantly higher among high-potency benzodiazepine users, with an adjusted hazard ratio of 1.8 (95% CI, 1.7-2.0; p < 0.001). No differences were noted in causes of death between users and nonusers.

Conclusions

Despite the lack of evidence supporting long-term treatment, prolonged usage of high-potency benzodiazepines 18 months following ICU care was notable and associated with an increased risk of death. Considering the substantial number of ICU admissions, prevention of benzodiazepine misuse may improve long-term outcomes following critical care.

Abuse potential assessment of the dual orexin receptor antagonist daridorexant in rats

BACKGROUND

Drugs that act on the central nervous system (CNS) and have sedative effects can lead to abuse in humans. New CNS-active drugs often require evaluation of their abuse potential in dedicated animal models before marketing approval. Daridorexant is a new dual orexin receptor antagonist (DORA) with sleep-promoting properties in animals and humans. It was approved in 2022 in the United States and Europe for the treatment of insomnia disorder.

AIMS

Nonclinical evaluation of abuse potential of daridorexant using three specific rat models assessing reinforcement, interoception, and withdrawal.

METHODS

Reinforcing effects of daridorexant were assessed in an operant rat model of intravenous drug self-administration. Similarity of interoceptive effects to those of the commonly used sleep medication zolpidem was tested in an operant drug discrimination task. Withdrawal signs indicative of physical dependence were evaluated upon sudden termination of chronic daridorexant treatment. Rat experiments were conducted at a dose range resulting in daridorexant plasma concentrations equaling or exceeding those achieved at the clinically recommended dose of 50 mg in humans.

RESULTS

Daridorexant had no reinforcing effects, was dissimilar to zolpidem in the drug discrimination task, and did not induce any withdrawal-related signs upon treatment discontinuation that would be indicative of physical dependence.

OUTCOMES

Daridorexant showed no signs of abuse or dependence potential in rats. Our data indicate that daridorexant, like other DORAs, has a low potential for abuse in humans.

Racial disparities in emergency department utilization among patients with newly diagnosed depression

OBJECTIVE

To test the hypothesis that racial and ethnic minorities have increased emergency department visit rates, despite being established with a primary care provider.

METHODS

In this retrospective cohort study, ED visits without hospital admission in a 12-month period among patients with a new primary care provider-issued diagnosis of depression were assessed. Electronic medical record (EMR) data was obtained from 47 family medicine clinics in a large Michigan-based healthcare system. General linear regression models with Poisson distribution were used to predict frequency of ED visits.

RESULTS

A total of 4159 patients were included in the analyses. In multivariable analyses, Black / African American race was associated with an additional 0.90 (95% CI 0.64, 1.16) ED visits and American Indian or Alaska Native race was associated with an additional 1.39 (95% CI 0.92, 1.87) ED visits compared to White or Caucasians (null value 0). These risks were only exceeded by patients who received a prescription for a typical antipsychotic drug agent.

CONCLUSION

Despite being established patients at primary care providers and having follow-up encounters, Black / African American and American Indian or Alaska Native patients with depression were considerably more likely to seek ED treatment compared to White/Caucasian patients with depression.

Adinazolam, a Benzodiazepine-Type New Psychoactive Substance, Has Abuse Potential and Induces Withdrawal Symptoms in Rodents

Adinazolam (ADZ) is a benzodiazepine-type new psychoactive substance (NPS) with anxiolytic, anticonvulsant, and antidepressant effects. High ADZ doses have been reported to impair psychomotor performance and memory; however, the abuse potential and drug dependence of ADZ have not yet been fully investigated. In this study, we evaluated whether ADZ has abuse potential and leads to drug dependence and withdrawal symptoms. The intravenous self-administration (IVSA) test revealed that ADZ (0.01, 0.03, and 0.1 mg/kg/infusion) was self-administered significantly above vehicle levels, suggesting the reinforcing effect of ADZ. Furthermore, we revealed that treatment discontinuation following chronic ADZ administration (3 and 6 mg/kg) caused several somatic withdrawal symptoms in mice, including body tremor. Moreover, it induced motivational withdrawal signs, such as anxiety-related behavior in the elevated plus maze (EPM) test and memory deficits in the Y-maze test. After the IVSA test, an enzyme-linked immunosorbent assay (ELISA) showed that ADZ administration significantly increased the dopamine contents in the thalamus, nucleus accumbens (NAc), and ventral tegmental area (VTA). This finding was also supported by the results of the Western blot. Taken together, our results suggest that ADZ has abuse potential and can lead to drug dependence and withdrawal syndrome.

Behavioral effects of triazolam and pregnanolone combinations: reinforcing and sedative-motor effects in female rhesus monkeys

Introduction

Benzodiazepines (BZs) are prescribed as anxiolytics, but their use is limited by side effects including abuse liability and daytime drowsiness. Neuroactive steroids are compounds that, like BZs, modulate the effects of GABA at the GABAA receptor. In a previous study, combinations of the BZ triazolam and neuroactive steroid pregnanolone produced supra-additive (i.e., greater than expected effects based on the drugs alone) anxiolytic effects but infra-additive (i.e., lower than expected effects based on the drugs alone) reinforcing effects in male rhesus monkeys, suggestive of an improved therapeutic window.

Methods

Female rhesus monkeys (n=4) self-administered triazolam, pregnanolone, and triazolam-pregnanolone combinations intravenously under a progressive-ratio schedule. In order to assess characteristic sedative-motor effects of BZ-neuroactive steroid combinations, female rhesus monkeys (n=4) were administered triazolam, pregnanolone, and triazolam-pregnanolone combinations. Trained observers, blinded to condition, scored the occurrence of species-typical and drug-induced behaviors.

Results

In contrast to our previous study with males, triazolam-pregnanolone combinations had primarily supra-additive reinforcing effects in three monkeys but infra-additive reinforcing effects in one monkey. Scores for deep sedation (i.e., defined as atypical loose-limbed posture, eyes closed, does not respond to external stimuli) and observable ataxia (any slip, trip, fall, or loss of balance) were significantly increased by both triazolam and pregnanolone. When combined, triazolam-pregnanolone combinations had supra-additive effects for inducing deep sedation, whereas observable ataxia was attenuated, likely due to the occurrence of robust sedative effects.

Discussion

These results suggest that significant sex differences exist in self-administration of BZ-neuroactive steroid combinations, with females likely to show enhanced sensitivity to reinforcing effects compared with males. Moreover, supra-additive sedative effects occurred for females, demonstrating a higher likelihood of this adverse effect when these drug classes are combined.

Defining Prescription Drug Misuse: A Naturalistic Evaluation of National Survey on Drug Use and Health Data From 2012-2014 to 2015-2017

OBJECTIVES

Prescription drug misuse (PDM) is a significant public health problem. As research has evolved, the definitions of misuse have varied over time, yet the implications of this variability have not been systematically studied. The objective of this study was to leverage a change in the measurement of PDM in a large population survey to identify its impact on the prevalence and correlates of this behavior.

METHODS

Data from the National Survey on Drug Use and Health were compared before and after a change in the definition of PDM from one that restricted the source and motive for use to one that captured any misuse other than directed by a prescriber. Three-year cohorts were constructed, representing a restricted definition of PDM (2012-2014) and a broad definition of PDM (2015-2017).

RESULTS

Segmented logistic regression models indicated a significant increase in PDM prevalence for all 3 drug types examined (opioids, tranquilizers, and sedatives). Although the magnitude of differences varied somewhat based on drug type, the broader definition was generally associated with older age, higher prevalence of health insurance, and higher odds of misusing one's own prescription. Some worsening of mental health indicators was observed, but results indicated few other clinical or substance use differences.

CONCLUSIONS

Definitions of prescription drug misuse have a substantial impact on the prevalence of misuse and some impact on the characteristics of the population. Further research is needed to understand the optimal strategy for measuring this behavior, based on the scientific or public health question or interest.

Individual differences in the effects of midazolam on anxiety-like behavior, learning, reward, and choice behavior in male mice

Introduction

The aim of the present study was to investigate the behavioral effects of the benzodiazepine midazolam in male mice, in models of anxiolysis, learning, and abuse-related effects.

Methods

In a first set of experiments, male Swiss mice were submitted to the training session of a discriminative avoidance (DA) task on the elevated plus maze to evaluate anxiety-like behavior and learning after vehicle or midazolam (1, 2 or 5 mg/kg, i.g.) administration. The same animals were submitted to a conditioned place preference (CPP) protocol with midazolam (1, 2 or 5 mg/kg, i.g.). In a second experiment, outbred (Swiss) and inbred (C57BL/6) male mice were submitted to a two-bottle choice (TBC) oral midazolam drinking procedure. Animals were exposed to one sucrose bottle and one midazolam (0.008, 0.016 or 0.032 mg/ml) plus sucrose bottle.

Results

Midazolam (1 and 2 mg/kg) induced anxiolytic-like effects, and all doses of midazolam prevented animals from learning to avoid the aversive closed arm during the DA training session. Assessment of midazolam reward via the CPP procedure and choice via the TBC procedure showed notable variability. A 2-step cluster analysis for the CPP data showed that midazolam data were well-fitted to 2 separate clusters (preference vs. aversion), albeit with the majority of mice showing preference (75%). Correlational and regression analyses showed no relationship between midazolam reward and anxiolytic-like effects (time spent in the open arms in the DA test) or learning/memory. Two-step cluster analysis of the TBC data also demonstrated that, regardless of strain, mice overall fell into two clusters identified as midazolam-preferring or midazolam-avoiding groups. Both midazolam preference and avoidance were concentration-dependent in a subset of mice.

Discussion

Our findings show that midazolam preference is a multifactorial behavior, and is not dependent solely on the emergence of therapeutic (anxiolytic-like) effects, learning impairments, or on genetic factors (inbred vs. outbred animals).

Exploring the Anticonvulsant Activity of Aqueous Extracts of Ficus benjamina L. Figs in Experimentally Induced Convulsions

Background. Ficus benjamina L. is an evergreen tree, native to Southeast Asia, and often known as a weeping fig. Its latex and fruit extracts are used by indigenous cultures to cure skin conditions, inflammation, vomiting, leprosy, malaria, and nasal ailments. The aqueous extract of the figs of Ficus benjamina L. has various therapeutic values, including biological activities on the central nervous system. Materials and Methods. The extract of the dried figs of Ficus benjamina L. (FBE) was prepared by defatting with petroleum ether for 16 h followed by soxhelation with 70% methanol (1 : 10 w/v) for 24 h, and standardization of the extract was carried out using HPLC with 5-HT as a standard. Electroconvulsions were induced by the maximal electroshock model, and chemoconvulsions were induced by picrotoxin. Results. The HPLC chromatogram of the Ficus benjamina L. extract showed an absorption peak with a retention time of 1.797 min, similar to that observed with standard serotonin (5-HT) solution. In the maximal electroshock model, FBE significantly reduced the duration of the tonic hind limb extensor and extensor-to-flexor ratio (E/F ratio) in a dose-dependent manner. Moreover, in the picrotoxin-induced seizure model, FBE increased the seizure latency and decreased the duration of tonic-clonic convulsions dose-dependently. We confirmed the anticonvulsant activity of the FBE extract as it attenuated both maximal electroshock and picrotoxin-induced convulsions. Conclusion. The in vivo studies revealed that the Ficus extract was found to protect the animals in electroshock-induced and picrotoxin-induced convulsions.

Anhedonia modulates benzodiazepine and opioid demand among persons in treatment for opioid use disorder

Background

Benzodiazepine (BZD) misuse is a significant public health problem, particularly in conjunction with opioid use, due to increased risks of overdose and death. One putative mechanism underlying BZD misuse is affective dysregulation, via exaggerated negative affect (e.g., anxiety, depression, stress-reactivity) and/or impaired positive affect (anhedonia). Similar to other misused substances, BZD consumption is sensitive to price and individual differences. Although purchase tasks and demand curve analysis can shed light on determinants of substance use, few studies have examined BZD demand, nor factors related to demand.

Methods

This ongoing study is examining simulated economic demand for alprazolam (among BZD lifetime misusers based on self-report and DSM-5 diagnosis; n = 23 total; 14 male, 9 female) and each participant's preferred-opioid/route using hypothetical purchase tasks among patients with opioid use disorder (n = 59 total; 38 male, 21 female) who are not clinically stable, i.e., defined as being early in treatment or in treatment longer but with recent substance use. Aims are to determine whether: (1) BZD misusers differ from never-misusers on preferred-opioid economic demand, affective dysregulation (using questionnaire and performance measures), insomnia/behavioral alertness, psychiatric diagnoses or medications, or urinalysis results; and (2) alprazolam demand among BZD misusers is related to affective dysregulation or other measures.

Results

Lifetime BZD misuse is significantly (p < 0.05) related to current major depressive disorder diagnosis, opioid-negative and methadone-negative urinalysis, higher trait anxiety, greater self-reported affective dysregulation, and younger age, but not preferred-opioid demand or insomnia/behavioral alertness. Alprazolam and opioid demand are each significantly positively related to higher anhedonia and, to a lesser extent, depression symptoms but no other measures of negative-affective dysregulation, psychiatric conditions or medications (including opioid agonist therapy or inpatient/outpatient treatment modality), or sleep-related problems.

Conclusion

Anhedonia (positive-affective deficit) robustly predicted increased BZD and opioid demand; these factors could modulate treatment response. Routine assessment and effective treatment of anhedonia in populations with concurrent opioid and sedative use disorder may improve treatment outcomes.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT03696017, identifier NCT03696017.

GABAA receptor subtypes and benzodiazepine use, misuse, and abuse

Benzodiazepines have been in use for over half a century. While they remain highly prescribed, their unfavorable side-effect profile and abuse liability motivated a search for alternatives. Most of these efforts focused on the development of benzodiazepine-like drugs that are selective for specific GABAA receptor subtypes. While there is ample evidence that subtype-selective GABAA receptor ligands have great potential for providing symptom relief without typical benzodiazepine side-effects, it is less clear whether subtype-selective targeting strategies can also reduce misuse and abuse potential. This review focuses on the three benzodiazepine properties that are relevant to the DSM-5-TR criteria for Sedative, Hypnotic, or Anxiolytic Use Disorder, namely, reinforcing properties of benzodiazepines, maladaptive behaviors related to benzodiazepine use, and benzodiazepine tolerance and dependence. We review existing evidence regarding the involvement of different GABAA receptor subtypes in each of these areas. The reviewed studies suggest that α1-containing GABAA receptors play an integral role in benzodiazepine-induced plasticity in reward-related brain areas and might be involved in the development of tolerance and dependence to benzodiazepines. However, a systematic comparison of the contributions of all benzodiazepine-sensitive GABAA receptors to these processes, a mechanistic understanding of how the positive modulation of each receptor subtype might contribute to the brain mechanisms underlying each of these processes, and a definitive answer to the question of whether specific chronic modulation of any given subtype would result in some or all of the benzodiazepine effects are currently lacking from the literature. Moreover, how non-selective benzodiazepines might lead to the maladaptive behaviors listed in DSM and how different GABAA receptor subtypes might be involved in the development of these behaviors remains unexplored. Considering the increasing burden of benzodiazepine abuse, the common practice of benzodiazepine misuse that leads to severe dependence, and the current efforts to generate side-effect free benzodiazepine alternatives, there is an urgent need for systematic, mechanistic research that provides a better understanding of the brain mechanisms of benzodiazepine misuse and abuse, including the involvement of specific GABAA receptor subtypes in these processes, to establish an informed foundation for preclinical and clinical efforts.

A pilot study of benzodiazepine cue-induced craving

OBJECTIVES

The misuse of benzodiazepines is a growing concern due to increases in both access to these medications and their associated public health harms, most concerningly risk for overdose when combined with other substances. Although cue reactivity-the subjective and physiological response to cues or reminders of substance use-has been identified for most major classes of substances, it has yet to be studied with benzodiazepines. In this preliminary study, our objective was to assess whether images of benzodiazepines were associated with greater craving and anxiety than neutral images in adults who reported misuse of benzodiazepines.

METHODS

We recruited a sample of 38 adults from a substance use disorder treatment setting and administered a standard cue reactivity task using pictorial images along with a battery of self-report measures.

RESULTS

Results indicated significantly higher craving and anxiety in response to benzodiazepine relative to neutral cues, with cues eliciting a moderate to high level of craving, on average. Craving was associated with several risk factors for benzodiazepine misuse, including insomnia and distress intolerance.

CONCLUSIONS

This preliminary study suggests that benzodiazepine cues can become conditioned to elicit craving responses and that the degree of cue reactivity is correlated with known risk factors for benzodiazepine misuse.

Emerging trends in point-of-care sensors for illicit drugs analysis

Consumption of illicit narcotic drugs and fatal or criminal activities under their influence has become an utmost concern worldwide. These drugs influence an individual's feelings, perceptions, and emotions by altering the state of consciousness and thus can result in serious safety breaches at critical workplaces. Point-of-care drug-testing devices have become the need-of-the-hour for many sections such as the law enforcement agencies, the workplaces, etc. for safety and security. This review focuses on the recent progress on various electrochemical and optical nanosensors developed for the analysis of the most common illicit drugs (or their metabolites) such as tetrahydrocannabinol (THC), cocaine (COC), opioids (OPs), amphetamines & methamphetamine, and benzodiazepine (BZDs). The paper also highlights the sensitivity and selectivity of various sensing modalities along with evolving parameters such as real-time monitoring and measurement via a smart user interface. An overall outlook of recent technological advances in point of care (POC) devices and guided insights and directions for future research is presented.

Benzodiazepine misuse and cigarette smoking status in US adults: Results from the National Survey on Drug Use and Health, 2015-2018

BACKGROUND

Benzodiazepines are the third most commonly misused drugs in the U.S.

POPULATION

There is a growing public health concern related to recent increases in benzodiazepine-related overdose deaths, emergency department visits, and treatment admissions. Although benzodiazepine misuse often occurs along with other drug use, little is known about the association between benzodiazepine and cigarette smoking.

METHODS

We used a pooled dataset from the National Survey on Drug Use and Health (NSDUH) for 2015-2018 (N = 171,766). We estimated a multivariable logistic regression model of past-year benzodiazepine misuse as a function of past-year tobacco use (cigarette smoking, other tobacco use), controlling for survey years, sociodemographics, past-year substance use, and psychiatric comorbidities.

RESULTS

Among the analytic sample (N = 171,766), 2.1% (weighted; unweighted n = 4,942) reported they misused benzodiazepines in the past 12 months. In the multivariable logistic regression model, correlates of past-year benzodiazepine misuse were past-year cigarette smoking (aOR = 1.85, 95% CI = 1.67, 2.06) and other tobacco use (e.g., cigars and smokeless tobacco) (aOR = 1.17, 95% CI = 1.03, 1.34), female (aOR = 1.14, 95% CI = 1.04, 1.26), uninsured (aOR = 1.26, 95% CI = 1.12, 1.42), past-year use of alcohol (aOR = 1.48, 95% CI = 1.21, 1.80), cannabis (aOR = 2.76, 95% CI = 2.46, 3.10), and other drugs (aOR = 7.92, 95% CI = 7.08, 8.86), as well as, past-year distress (aOR = 1.84, 95% CI = 1.61, 2.10), and depressive symptoms (aOR = 1.32, 95% CI = 1.16, 1.51).

CONCLUSION

Nicotine is independently associated with benzodiazepine misuse, even after controlling for other drug use and psychiatric variables. Future studies examining potential mechanisms linking nicotine and benzodiazepine use are necessary.

Zao Ren An Shen capsule for insomnia: A double-blind, randomized, placebo-controlled trial

STUDY OBJECTIVES

The aim of this study was to test the efficacy and safety of Zao Ren An Shen (ZRAS) capsule, a Chinese herbal medicine product, for the treatment of insomnia.

METHODS

We conducted a double-blind randomized placebo-controlled trial. After a one-week placebo run-in, a total of 85 people with insomnia were randomly allocated to receive ZRAS or placebo for four weeks. The primary outcomes were insomnia severity assessed with the Insomnia Severity Index (ISI) and the number of participants with adverse events. Secondary outcomes included objective and subjective sleep parameters, psychological status, fatigue level, quality of life, acceptability, and tolerability.

RESULTS

A non-significant (p > 0.05) difference of 0.7 points in ISI in favor of ZRAS capsule was found at the end of the treatment. The number of participants with adverse events was not significantly different (p > 0.05) between the two groups. Except for subjective sleep onset latency, which had a non-significant (p > 0.05) medium effect (Cohen's d = 0.5), the effects in secondary efficacy outcomes were all small (Cohen's d < 0.4) and non-significant (p > 0.05). The acceptability and tolerability were high in the active group.

CONCLUSIONS

ZRAS capsule is safe, acceptable, and tolerable, yet not more effective than placebo in the treatment of insomnia. As previous evidence showed that Chinese herbal medicine was effective for insomnia, these results may be explained by the dose of the product, which was lower than the dose generally used in the clinic.

Tolerance and dependence following chronic alprazolam treatment in rhesus monkeys: Role of GABAA receptor subtypes

BACKGROUND

To assess GABA_A receptor subtypes involved in benzodiazepine tolerance and dependence, we evaluated the ability of subtype-selective and non-selective ligands to substitute for (i.e., produce "cross-tolerance") or precipitate withdrawal during chronic alprazolam treatment.

METHODS

Four female rhesus monkeys (Macaca mulatta) were implanted with chronic intravenous catheters and administered alprazolam (1.0 mg/kg every 4 h). Following 14+ days of chronic alprazolam, acute administration of selected doses of non-selective and subtype-selective ligands were substituted for, or administered with, alprazolam, followed by quantitative behavioral observations. The ligands included alprazolam and midazolam (positive modulators, non-selective), zolpidem (positive modulator, preferential affinity for α1-containing GABA_A receptors), HZ-166 (positive modulator, preferential efficacy at α2- and α3-containing GABA_A receptors), and βCCT (antagonist, preferential affinity for α1-containing GABA_A receptors).

RESULTS

Acutely, alprazolam and midazolam both induced observable ataxia along with a mild form of sedation referred to as "rest/sleep posture" at a lower dose (0.1 mg/kg, i.v.), whereas at a higher dose (1.0 mg/kg, i.v.), induced deep sedation and observable ataxia. With chronic alprazolam treatment, observable ataxia and deep sedation were reduced significantly, whereas rest/sleep posture was unchanged or emerged. Zolpidem showed a similar pattern of effects, whereas no behaviors engendered by HZ-166 were changed by chronic alprazolam. Administration of βCCT, but not HZ-166, resulted in significant withdrawal signs.

CONCLUSIONS

These results are consistent with a role for α1-containing GABA_A receptor subtypes in tolerance and dependence observed with chronic alprazolam, although other receptors may be involved in the withdrawal syndrome.

Mind-Body Therapies for Cancer Patients Living with Depression, Anxiety or Insomnia (MIRACLE): A Systematic Review with Individual Participant Data Network Meta-Analysis

Depression, anxiety, and insomnia are common in cancer patients. Mind-body therapies (MBTs) are promising forms of treatment for cancer patients living with depression, anxiety, and insomnia. The objective of this study is to assess the effectiveness and acceptability of MBTs in cancer patients living with depression, anxiety, or insomnia. EMBase, PubMed, Cinahl, PsychINFO, IndMED, CSI-NISCAIR, CNKI, Clinicaltrial.gov, ChiCTR, and CTRI will be searched until October 2020 for relevant studies. Randomized controlled studies in which MBTs were tested in a cancer population will be selected. The authors of the selected studies will be contacted to obtain individual participant data. The participants who reached a defined clinical threshold for depression, anxiety, or insomnia will be selected for the three sub-studies on depression, anxiety, and insomnia, respectively. Pairwise and network meta-analyses will be used to assess the changes in depression, anxiety, sleep quality, and completion rate. We will assess the effect of the treatment dose (number and frequency of interventions) on effectiveness. The results of this study will inform clinical decision-making for the treatment of psychological disturbances in cancer patients. If MBTs are found effective, they will potentially be recommended as treatments for cancer patients with psychological symptoms.

BDZs, designer BDZs, and Z-drugs: pharmacology and misuse insights

Benzodiazepines (BZDs) are a widely prescribed class of sedative-hypnotics compounds for the treatment of a broad range of conditions as anxiety and obsessive-compulsive disorders, phobias, sleep related problems associated with insomnia and for the management of alcohol and GHB withdrawal. Zolpidem, zopiclone and zaleplon, commonly known as Z-drugs are non-benzodiazepine hypnotic drug with pharmacology similar to BDZs. Despite their usefulness, BDZs and Z-drugs present a potential for abuse and dependence. Moreover, the non-medical use of BDZs is a well-known phenomenon and represents an increasingly widespread public health problem since is associated with an elevated risk of serious health consequences or fatal overdose, especially among specific group of users. The spectrum of BDZs and Z-drugs misuse is extended by new synthetic BDZs, which may pose high risks to users, since the majority have never undergone clinical trials or tests and consequently their pharmacology and toxicology is largely unknown.

Designer Benzodiazepines: A Review of Toxicology and Public Health Risks

The rising use of designer benzodiazepines (DBZD) is a cat-and-mouse game between organized crime and law enforcement. Non-prohibited benzodiazepines are introduced onto the global drug market and scheduled as rapidly as possible by international authorities. In response, DBZD are continuously modified to avoid legal sanctions and drug seizures and generally to increase the abuse potential of the DBZD. This results in an unpredictable fluctuation between the appearance and disappearance of DBZD in the illicit market. Thirty-one DBZD were considered for review after consulting the international early warning database, but only 3-hydroxyphenazepam, adinazolam, clonazolam, etizolam, deschloroetizolam, diclazepam, flualprazolam, flubromazepam, flubromazolam, meclonazepam, phenazepam and pyrazolam had sufficient data to contribute to this scoping review. A total of 49 reports describing 1 drug offense, 2 self-administration studies, 3 outpatient department admissions, 44 emergency department (ED) admissions, 63 driving under the influence of drugs (DUID) and 141 deaths reported between 2008 and 2021 are included in this study. Etizolam, flualprazolam flubromazolam and phenazepam were implicated in the majority of adverse-events, drug offenses and deaths. However, due to a general lack of knowledge of DBZD pharmacokinetics and toxicity, and due to a lack of validated analytical methods, total cases are much likely higher. Between 2019 and April 2020, DBZD were identified in 48% and 83% of postmortem and DUID cases reported to the UNODC, respectively, with flualprazolam, flubromazolam and etizolam as the most frequently detected substances. DBZD toxicology, public health risks and adverse events are reported.

Mental health service use and its associated factors among nurses in China: a cross-sectional survey

Background

To facilitate mental health service planning for nurses, data on the patterns of mental health service use (MHSU) among nurses are needed. However, MHSU among Chinese nurses has seldom been studied. Our study aimed to explore the rate of MHSU among Chinese nurses and to identify the factors associated with MHSU.

Methods

A self-designed anonymous questionnaire was used in this study. MHSU was assessed by the question, “Have you ever used any kind of mental health services, such as mental health outpatient services or psychotherapies, when you felt that your health was suffering due to stress, insomnia, or other reasons?” The answer to the question was binary (yes or no). Sleep quality, burnout, and depressive symptoms were assessed using the Chinese version of the Pittsburgh Sleep Quality Index , the Chinese version of the Maslach Burnout Inventory-General Survey and the two-item Patient Health Questionnaire, respectively. Chi-square tests and binary logistic regression were used for univariate and multivariate analyses.

Results

A total of 10.94% (301/2750) of the nurses reported MHSU. 10.25% (282/2750) of the nurses had poor sleep quality, burnout and depressive symptoms, and only 26.95% of these nurses reported MHSU. Very poor sleep quality (OR 9.36, 95% CI [5.38-16.29]), mid-level professional title (OR 1.48, 95% CI [1.13-1.93]) and depressive symptoms (OR 1.66, 95% CI [1.28-2.13]) were independent factors associated with MHSU.

Conclusions

Most of the nurses have experienced burnout, poor sleep quality or depressive symptoms and the MHSU rate among them was low. Interventions to improve the mental health of nurses and to promote the use of mental health services are needed.

Induction and maintenance of procedural sedation in adults: focus on remimazolam injection

Introduction: Procedural sedation (PS) is a humane way to help patients get through painful medical procedures by the administration of sedative drugs combined with analgesics. However, each of the currently used medications has certain shortcomings, urging the search for a new drug. Remimazolam, a novel benzodiazepine, is an ultra-short-acting hypnotic agent invented out of the 'soft drug' development.Areas covered: This presented review provides an overview of the drugs used in clinical practice for the induction and maintenance of procedural sedation in adults, focusing on the newly investigated benzodiazepine remimazolam. Literature search was conducted using the MEDLINE and ClinicalTrial.gov databases from January 2007 to December 2020.Expert opinion: Based on the reported clinical trials so far, remimazolam has demonstrated its effectiveness and safety with promising properties including rapid onset, short duration of action, predictable and consistent recovery profile, metabolism almost unaffected by liver or renal function, with non or minimal cardiorespiratory depression, and availability with a reversal drug. With marketing approval received recently, remimazolam is expected to have a place in the practice for procedural sedation in the near future if its efficacy and safety are further confirmed by more clinical trials and post-market analyses.

Allopregnanolone Decreases Evoked Dopamine Release Differently in Rats by Sex and Estrous Stage

Mesolimbic dopamine transmission is dysregulated in multiple psychiatric disorders, including addiction. Previous studies found that the endogenous GABAergic steroid (3α,5α)-3-hydroxy-5-pregnan-20-one (allopregnanolone) modulates dopamine levels in the nucleus accumbens and prefrontal cortex. As allopregnanolone is a potent positive allosteric modulator of GABA_A receptors, and GABA_A receptors can regulate dopamine release, we hypothesized that allopregnanolone would reduce phasic fluctuations in mesolimbic dopamine release that are important in learning and reward processing. We used fast-scan cyclic voltammetry in anesthetized female and male rats to measure dopamine release in the nucleus accumbens evoked by electrical stimulation of the ventral tegmental area, before and after administration of allopregnanolone. Allopregnanolone (7.5–25 mg/kg, IP) reduced evoked dopamine release in both male and female rats, compared to β-cyclodextrin vehicle. In males, all doses of allopregnanolone decreased dopamine transmission, with stronger effects at 15 and 25 mg/kg allopregnanolone. In females, 15 and 25 mg/kg allopregnanolone reduced dopamine release, while 7.5 mg/kg allopregnanolone was no different from vehicle. Since allopregnanolone is derived from progesterone, we hypothesized that high endogenous progesterone levels would result in lower sensitivity to allopregnanolone. Consistent with this, females in proestrus (high progesterone levels) were less responsive to allopregnanolone than females in other estrous cycle stages. Furthermore, 30 mg/kg progesterone reduced evoked dopamine release in males, similar to allopregnanolone. Our findings confirm that allopregnanolone reduces evoked dopamine release in both male and female rats. Moreover, sex and the estrous cycle modulated this effect of allopregnanolone. These results extend our knowledge about the pharmacological effects of neurosteroids on dopamine transmission, which may contribute to their therapeutic effects.

The effects of daily mitotane or diazepam treatment on the formation of chronic stress symptoms in newly captured wild house sparrows

Wild animals brought into captivity frequently experience chronic stress and typically need a period of time to adjust to the conditions of captivity (restraint, artificial lighting, altered diet, human presence, etc.), to which they may never fully acclimate. Changes in mass, the hypothalamic-pituitary-adrenal axis and heart rate parameters have been observed over the first week in newly captive house sparrows (Passer domesticus). In this study, we tested the effects of two drugs, diazepam and mitotane, in preventing the chronic stress symptoms caused by captivity, compared with oil-injected control animals. Diazepam is an anxiolytic that is widely prescribed in humans and other animals and has been shown in some cases to reduce physiological stress. Mitotane is an agent that causes chemical adrenalectomy, reducing the body's capacity to produce glucocorticoid hormones. Our mitotane treatment did not cause the expected change in corticosterone concentrations. Baseline corticosterone was higher after a week in captivity regardless of the treatment group, while stress-induced corticosterone did not significantly increase above baseline after a week in captivity in any treatment group. However, mitotane treatment did have some physiological effects, as it reduced the resting heart rate and the duration of the heart rate response to a sudden noise. It also prevented the increase in nighttime activity that we observed in control animals. There was no effect of diazepam on corticosterone, resting heart rate, activity or heart rate response to a sudden noise, and no effect of either treatment on the sympathetic vs parasympathetic control of the resting heart rate. Together, these data suggest that mitotane, but not diazepam, can have a modest impact on helping house sparrows adapt to captive conditions. Easing the transition to captivity will likely make conservation efforts, such as initiating captive breeding programs, more successful.

Self-Designed Ningxin Anshen Formula for Treatment of Post-ischemic Stroke Insomnia: A Randomized Controlled Trial

This study aimed to assess the efficacy and safety of self-designed Ningxin Anshen (NXAS) Formula for post-ischemic stroke insomnia of blood-deficient and liver-heat syndrome. Ninety patients were randomized into NXAS group, Placebo group and Zopiclone group. Patients in the NXAS group, Placebo group and Zopiclone group were treated with Ningxin Anshen Formula, placebo and zopiclone for 4 weeks, respectively. The scores of the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI) and traditional Chinese Medicine (TCM) Syndromes of self-designed scale and the number of adverse events (AEs) were determined. Results showed that the overall effective rate in the NXAS group and Placebo group was 76.67 and 30.00%, respectively, showing significant difference (P < 0.01). There was no marked difference between Zopiclone group (80.00%) and NXAS group. In both NXAS group and Zopiclone group, the scores of PSQI, ISI, and TCM Syndromes of self-designed scale after 4-week treatment were significantly different from those before treatment (P < 0.01). After 4-week treatment, the scores of PSQI, ISI, and TCM Syndromes of self-designed score were comparable between NXAS group and Zopiclone group (P > 0.05). Only one patient in the NXAS group developed gastrointestinal discomfort, which resolved without treatment discontinuation. In conclusion, self-designed NXAS Formula is effective and safe and has little adverse effect in treating post-stroke insomnia of blood-deficient and liver-heat syndrome.

Benzodiazepine misuse among adults receiving psychiatric treatment

Benzodiazepines are among the most commonly prescribed psychiatric medications and have the potential for misuse. People with psychiatric disorders may have a heightened liability to the reinforcing effects of benzodiazepines. Yet, the prevalence of benzodiazepine misuse in psychiatric care settings is not well characterized. The aim of the current study was to characterize the prevalence and correlates of benzodiazepine misuse in a sample of adults receiving psychiatric treatment (N = 589). The majority of participants reported a lifetime history of benzodiazepine prescription (68%) and 26% reported a lifetime history of misuse (defined as use without a prescription or at a dose or frequency higher than prescribed). Multivariable analyses indicated that history of a benzodiazepine prescription and drug use problems were significantly associated with lifetime benzodiazepine misuse. People with a history of benzodiazepine prescription had four times higher odds of misusing benzodiazepines and the primary source of misused benzodiazepines was from family or friends. Results suggest that benzodiazepine misuse is not exclusive to substance use disorder populations. The misuse of benzodiazepines should be assessed in psychiatric settings. Further research is needed to understand the impact of benzodiazepine misuse in this population and to develop tools to identify those at risk for misuse.

Suan-Zao-Ren decoction for insomnia: A protocol for a systematic review and meta-analysis

BACKGROUND

Chinese herbal medicine has been widely used to relieve insomnia. Among them, Suan-Zao-Ren decoction (SZRD) has a significant effect in alleviating insomnia. The purpose of this systematic review is to evaluate the effectiveness and safety of SZRD in treating insomnia.

METHODS

Relevant randomized controlled trials (RCTs) will be searched from the databases of Embase, PubMed, the Cochrane Library, the China National Knowledge Infrastructure, Wanfang Database and Chinese Science and Technology Periodical Database from their inception to July 2020. Two independent reviewers will select studies, collect data, and assess the methodology quality by the Cochrane risk of bias tool. Statistical analysis is processed by RevMan V.5.3 software.

RESULTS

The results of this systematic review will provide an assessment of SZRD treatment of insomnia, and aims to prove the effectiveness and safety of SZRD.

CONCLUSION

This study will provide a credible Evidence-based for the treatment of Insomnia with SZRD.

Randomized Crossover Trial to Compare Abuse Liability of Intravenous Remimazolam Versus Intravenous Midazolam and Placebo in Recreational Central Nervous System Depressant Users

Remimazolam (RMZ) is a new and ultra-fast-acting, short-duration intravenous benzodiazepine, a drug class associated with abuse potential. This trial was designed to compare the abuse potential of remimazolam with placebo and midazolam (MDZ), a well-characterized member of the same pharmacological class in healthy, recreational drug users 18-55 years-of-age, who demonstrated good drug tolerance and were able to discriminate between midazolam and placebo. At equipotent intravenous doses selected to produce effects ranging from mild/moderate to relatively strong sedation without loss of consciousness (RMZ: 5, 10 mg versus MDZ: 2.5, 5 mg), peak scores (E_max or E_min , respectively) for drug liking, good/bad/any effects, and sedation (drowsiness and relaxation) were significantly greater than placebo for both active drugs and were broadly comparable between RMZ and MDZ. In contrast, areas under the effect-time curves (TA_AUE) were notably lower for RMZ versus MDZ, particularly for measures of good and any effects, reflecting the shorter duration of action and consistent with the more rapid observed plasma clearance for RMZ versus MDZ and the lack of an active RMZ metabolite. Scores for willingness to take drug again were also lower for RMZ versus MDZ, but not significantly so. We concluded that the abuse potential of RMZ is comparable to or lower than that of MDZ, a drug known to have a low potential for intravenous abuse.

Clonazepam: Indications, Side Effects, and Potential for Nonmedical Use

After participating in this activity, learners should be better able to:• Assess the misuse potential of clonazepam• Characterize the nonmedical use of clonazepam• Identify the health problems associated with long-term use of clonazepam ABSTRACT: Clonazepam, a benzodiazepine, is commonly used in treating various conditions, including anxiety disorders and epileptic seizures. Due to its low price and easy availability, however, it has become a commonly misused medication, both in medical and recreational contexts. In this review, we aim to highlight the behavioral and pharmacological aspects of clonazepam and its history following its approval for human use. We examine the circumstances commonly associated with the nonmedical use of clonazepam and raise points of particular concern. Clonazepam, alone or in combination with other psychoactive substances, can lead to unwanted effects on health, such as motor and cognitive impairment, sleep disorders, and aggravation of mood and anxiety disorders. Prolonged use of clonazepam may lead to physical dependence and tolerance. There is therefore a need to find safer therapeutic alternatives for treating seizures and anxiety disorders. Greater awareness of its frequent nonmedical use is also needed to achieve safer overall use of this medication.

Long-term users of benzodiazepines in Colombia: Patterns of use and cessation of treatment

BACKGROUND

Benzodiazepines have low abuse potential, but patients often develop physical dependence and neurological impairments. The objective of this study was to investigate treatment cessation and use of high doses in long-term benzodiazepine users in Colombia.

METHODS

Retrospective study. Patients who used benzodiazepines for at least six months (long-term) were selected from a prescription database and followed from initiation of benzodiazepine treatment for up to 30 months. We investigated treatment duration and compared patients who received normal and high (≥2 mean prescribed daily dose) doses.

RESULTS

Only 1255 (6.1 %) out of 20,567 patientsprescribed benzodiazepines became long-term users; their mean age was 60.6 years (SD=20.0) and 61.7 % were women. Mean high doses were used by 42.5 % (n=534) of the sample. Age under 20 years was a protector, whereas the long half-life benzodiazepines and use of other neurological medications were predictors of high dosage. Overall, 44.8 % (n=563) of the sample was still using benzodiazepines at the end of the study period. The use of antidepressants, antipsychotics, and anticonvulsants were negatively associated with cessation of benzodiazepine treatment.

CONCLUSIONS

A low proportion of patients starting benzodiazepines became long-term users. Nearly half of them used high doses and continued the medication for up to 30 months. Use of concomitant neurological drugs was associated with higher doses and less cessation.

Tolerance and dependence following chronic alprazolam treatment: quantitative observation studies in female rhesus monkeys

RATIONALE

In order to understand mechanisms underlying tolerance and dependence following chronic benzodiazepine treatments, quantitative and reproducible behavioral models of these phenomena are required.

OBJECTIVES

This research evaluated the ability of chronic treatment with a commonly prescribed benzodiazepine, alprazolam, to induce tolerance to sedative effects and physical dependence using a novel set of behavioral measurements in rhesus monkeys.

METHODS

Four female rhesus monkeys (Macaca mulatta) were implanted with chronic intravenous catheters and administered i.v. alprazolam (1.0 mg/kg every 4 h, 38 days total). Quantitative observation measures were obtained during the 38 days of treatment. Acute administration of the benzodiazepine receptor antagonist flumazenil (0.1, 0.3 mg/kg, i.v.) was given to assess precipitated withdrawal. On day 39, saline was substituted for alprazolam and withdrawal signs were assessed for 7 days.

RESULTS

Maximal sedation ("deep sedation") was evident on day 1 but was not significantly different from baseline levels by day 4 and was absent for the remainder of the 38 days of treatment. A milder form of sedation, "rest/sleep posture," emerged by day 3 and did not decline over 38 days. Cessation of alprazolam treatment resulted in significant withdrawal signs (nose rub, vomit, procumbent posture, tremor/jerk, rigid posture) that dissipated by day 3. These signs also were observed with flumazenil (0.3 mg/kg).

CONCLUSIONS

Chronic alprazolam treatment resulted in rapid tolerance to some behaviors (e.g., deep sedation) but no tolerance to others (e.g., rest/sleep posture). Physical dependence was observed via both spontaneous and precipitated withdrawal. Based on previous research, these phenomena may reflect differential plasticity at GABAA receptor subtypes.

Associations of Benzodiazepine With Adverse Prognosis in Heart Failure Patients With Insomnia

Background

The prognostic impact of benzodiazepines has been unclear in patients with heart failure (HF).

Methods and Results

This was a historical observational cohort study. A total of 826 patients who had been hospitalized for HF and were being treated for insomnia with either benzodiazepines or Z‐drugs (zolpidem, zopiclone, or eszopiclone), were enrolled and divided on the basis of their hypnotics: benzodiazepine group (n=488 [59.1%]) and Z group (n=338 [40.9%]). We compared the patient characteristics and postdischarge prognosis between the groups. The primary end points were rehospitalization for HF and cardiac death. The benzodiazepine group was older (age, 72.0 versus 69.0 years; P=0.010), had a higher prevalence of depression (17.4% versus 8.9%; P<0.001), and showed a higher use of loop diuretics (77.9% versus 67.8%; P=0.001). In the laboratory data, the benzodiazepine group demonstrated lower levels of hemoglobin (12.3 versus 13.0 g/dL; P=0.001), sodium (139.0 versus 140.0 mEq/L; P=0.018), and albumin (3.7 versus 3.9 g/dL; P=0.003). Kaplan‐Meier analysis showed that both end points were higher in the benzodiazepine group (rehospitalization for HF, log‐rank P=0.001; cardiac death, log‐rank P=0.043). Multiple Cox proportional hazard analysis revealed that the use of benzodiazepines was an independent predictor of rehospitalization for HF (hazard ratio, 1.530; 95% CI, 1.025–2.284; P=0.038). Furthermore, rehospitalization for HF was higher in the benzodiazepine group after propensity score matching (log‐rank P=0.036).

Conclusions

Benzodiazepine is associated with higher risk of rehospitalization for HF compared with Z‐drugs in patients with HF.

Acute Nicotine Exposure Alters Ventral Tegmental Area Inhibitory Transmission and Promotes Diazepam Consumption

Nicotine use increases the risk for subsequent abuse of other addictive drugs, but the biological basis underlying this risk remains largely unknown. Interactions between nicotine and other drugs of abuse may arise from nicotine-induced neural adaptations in the mesolimbic dopamine (DA) system, a common pathway for the reinforcing effects of many addictive substances. Previous work identified nicotine-induced neuroadaptations that alter inhibitory transmission in the ventral tegmental area (VTA). Here, we test whether nicotine-induced dysregulation of GABAergic signaling within the VTA increases the vulnerability for benzodiazepine abuse that has been reported in smokers. We demonstrate in rats that nicotine exposure dysregulates diazepam-induced inhibition of VTA GABA neurons and increases diazepam consumption. In VTA GABA neurons, nicotine impaired KCC2-mediated chloride extrusion, depolarized the GABAA reversal potential, and shifted the pharmacological effect of diazepam on GABA neurons from inhibition toward excitation. In parallel, nicotine-related alterations in GABA signaling observed ex vivo were associated with enhanced diazepam-induced inhibition of lateral VTA DA neurons in vivo Targeting KCC2 with the agonist CLP290 normalized diazepam-induced effects on VTA GABA transmission and reduced diazepam consumption following nicotine administration to the control level. Together, our results provide insights into midbrain circuit alterations resulting from nicotine exposure that contribute to the abuse of other drugs, such as benzodiazepines.

The epidemiology of benzodiazepine misuse: A systematic review

BACKGROUND

Benzodiazepine misuse is a growing public health problem, with increases in benzodiazepine-related overdose deaths and emergency room visits in recent years. However, relatively little attention has been paid to this emergent problem. We systematically reviewed epidemiological studies on benzodiazepine misuse to identify key findings, limitations, and future directions for research.

METHODS

PubMed and PsychINFO databases were searched through February 2019 for peer-reviewed publications on benzodiazepine misuse (e.g., use without a prescription; at a higher frequency or dose than prescribed). Eligibility criteria included human studies that focused on the prevalence, trends, correlates, motives, patterns, sources, and consequences of benzodiazepine misuse.

RESULTS

The search identified 1970 publications, and 351 articles were eligible for data extraction and inclusion. In 2017, benzodiazepines and other tranquilizers were the third most commonly misused illicit or prescription drug in the U.S. (approximately 2.2% of the population). Worldwide rates of misuse appear to be similar to those reported in the U.S. Factors associated with misuse include other substance use, receipt of a benzodiazepine prescription, and psychiatric symptoms and disorders. Benzodiazepine misuse encompasses heterogeneous presentations of motives, patterns, and sources. Moreover, misuse is associated with myriad poor outcomes, including mortality, HIV/HCV risk behaviors, poor self-reported quality of life, criminality, and continued substance use during treatment.

CONCLUSIONS

Benzodiazepine misuse is a worldwide public health concern that is associated with a number of concerning consequences. Findings from the present review have implications for identifying subgroups who could benefit from prevention and treatment efforts, critical points for intervention, and treatment targets.

Functional Coupling of K+-Cl- Cotransporter (KCC) to GABA-Gated Cl- Channels in the Central Nervous System of Drosophila melanogaster Leads to Altered Drug Sensitivities

GABAergic signaling is the cornerstone for fast synaptic inhibition of neural signaling in arthropods and mammals and is the molecular target for insecticides and pharmaceuticals, respectively. The K+-Cl- cotransporter (KCC) is the primary mechanism by which mature neurons maintain low intracellular Cl- concentration, yet the fundamental physiology, comparative physiology, and toxicological relevance of insect KCC is understudied. Considering this, we employed electrophysiological, genetic, and pharmacological methods to characterize the physiological underpinnings of KCC function to the Drosophila CNS. Our data show that genetic ablation or pharmacological inhibition of KCC results in an increased spike discharge frequency and significantly ( P < 0.05) reduces the CNS sensitivity to γ-aminobutyric acid (GABA). Further, simultaneous inhibition of KCC and ligand-gated chloride channel (LGCC) complex results in a significant ( P < 0.001) increase in CNS spontaneous activity over baseline firing rates that supports functional coupling of KCC to LGCC function. Interestingly, 75% reduction in KCC mRNA did not alter basal neurotransmission levels indicating that only a fraction of the KCC population is required to maintain the Cl- ionic gradient when at rest, but prolonged synaptic activity increases the threshold for GABA-mediated inhibition and reduces nerve sensitivity to GABA. These data expand current knowledge regarding the physiological role of KCC in a model insect and provides the necessary foundation to develop KCC as a novel biochemical target of insecticides, as well as complements existing research to provide a holistic understanding of the plasticity in mammalian health and disease.

Local GABAA Receptor-Mediated Suppression of Dopamine Release within the Nucleus Accumbens

Benzodiazepines make up a class of psychoactive drugs that act as allosteric co-activators of the inhibitory GABA_A receptor. These drugs are useful for the treatment of several psychiatric disorders but also hold considerable abuse liability. Despite the common use and misuse of benzodiazepines, the mechanisms through which these drugs exert their reinforcing effects remain incompletely understood. Transient phasic increases in dopamine levels are believed to play an important role in defining the reinforcing properties of drugs of abuse, and we recently demonstrated that systemic administration of benzodiazepines increased the frequency of these events but concomitantly reduced their amplitude. This observation provides insight into the pharmacological effects of benzodiazepines on dopamine signaling, but the processes through which benzodiazepines drive changes in phasic dopamine signals remain unclear. In these studies, we investigated the mechanisms through which benzodiazepines may reduce the phasic dopamine transient amplitude. We tested the effect of the benzodiazepine diazepam and the GABA_A agonist muscimol on evoked dopamine release from nucleus accumbens brain slices using fast scan cyclic voltammetry. We found that both diazepam and muscimol reduce dopamine release and that reductions in dopamine release following GABA_A receptor activation can be blocked by co-application of a GABA_B receptor antagonist. These results suggest that activation of GABA_A receptors in the nucleus accumbens decreases dopamine release by disinhibition of local GABA signaling and subsequent activation of GABA_B receptors. Overall, this work provides a putative mechanism through which benzodiazepines reduce the amplitude of phasic dopamine release in vivo.

Zao Ren An Shen capsule for chronic insomnia: Study protocol for a randomized, placebo-controlled trial

BACKGROUND

Zao Ren An Shen (ZRAS), a Chinese Herbal Medicine product, has been proposed as an alternative to recommended treatments for chronic insomnia. There is a lack of strong evidence supporting this proposition.

AIMS

To assess the efficacy and safety of ZRAS capsule for chronic insomnia compared to placebo.

METHODS

A parallel-group, double-blind, randomized-controlled trial will be performed in Western Sydney University, Australia. After a 1-week placebo run-in, adults with chronic insomnia (n = 90) will be randomized in a 1:1 ratio to receive either ZRAS capsule or placebo for 4 weeks. Insomnia severity (Insomnia Severity Scale score), sleep parameters (measured with the Consensus Sleep Diary and actigraphy), fatigue levels (Fatigue Severity Scale score), psychological status (Depression Anxiety Stress Scale score), quality of life (Assessment of Quality of Life score), and adverse events will be assessed at baseline, mid-treatment, post-treatment and at a 1-month follow-up.

EXPECTED OUTCOMES

We hypothesize that ZRAS capsule will improve insomnia severity, sleep parameters, fatigue levels, psychological status, and quality of life better than placebo at mid-treatment, post-treatment, and follow-up. We also hypothesize that the number of adverse events provoked by ZRAS capsule will be similar to placebo at these time-points.

TRIAL REGISTRATION

Australia New-Zealand Clinical Trial Registry (Registration number ACTRN12619000140156).

A pilot study showing that repeated exposure to stress produces alterations in subsequent responses to anesthetics in rats

The repeated use of a drug frequently leads to alterations in the response to that drug. We undertook this study to determine whether multiple exposures to the general anesthetic produced alterations in subsequent exposures to this anesthetic. For this study, adult male rats were anesthetized with 2.5% isoflurane for one hour. The rats were divided into 4 groups of 8 rats each. Groups 1-3 were transported between their homeroom and the anesthesia testing room and were handled in an identical manner weekly for a period of 12 weeks, but were anesthetized on different schedules. Group 1 was anesthetized weekly for 12 weeks, Group 2 on either a 3 or 4 week schedule and Group 3 was anesthetized a single time, at the end of the 12 week period. To receive anesthesia multiple times, animals were transported from their homeroom to the anesthesia location and handled repeatedly. We took into consideration of the frequency of anesthesia exposure and the stress involved. Rats in groups 2 and 3 were placed in the anesthesia chamber, with O2 but with no anesthetic, every week when they were not scheduled to receive anesthesia. In Group 4, rats were not transported or handled in any way and stayed in the home room for a period of 12 weeks. Rats in this group were anesthetized once, at the very end of the study. Recovery of the rat's righting reflex was used to assess the acceleration of recovery time from general anesthesia. Group 1 rats showed dramatically faster emergence from anesthesia after several rounds of anesthesia. Surprisingly, Groups 2 and 3 rats, treated in an identical manner as Group 1, but which were anesthetized on different schedules, also exhibited more rapid emergence from anesthesia, when compared to Group 4 rats, which were never handled or transported prior to a single anesthesia. These results suggest that the stress of transportation and handling altered responsiveness to anesthesia. Our results show that responsiveness to anesthetic agents can change over time outside of the normal developmental changes taking place in rats as they age.

Mesoporous particle-based microcontainers for intranasal delivery of imidazopyridine drugs

The aim of this study was to develop mesoporous containers for entrapment of imidazopyridines, such as sedative-hypnotic medicine zolpidem, anxiolytic agent alpidem and their derivatives. For this purpose, calcium carbonate (size 1.2 µm (PDI: 0.6), zeta potential: -10 mV), manganese carbonate (2.5 µm (PDI: 0.5), zeta potential: -12 mV) and titanium dioxide particles (3.7 µm (PDI: 0.4), zeta potential: -15 mV) were used. The compounds were encapsulated applying two techniques: adsorption on the preformed particles and co-precipitation during the synthesis of the particles. The polymer shell of the containers was formed by electrostatic adsorption of polyelectrolytes on the surface of the particles. The best encapsulation efficacy was shown for zolpidem incorporated into calcium carbonate (5.4%) and manganese carbonate (4.6%) by adsorption. Release of the compounds from the containers based on the proposed particles were characterised by the short time burst effect (<10 min) followed by desorption prolongation by formation of polymer shell. X-ray microtomography results demonstrate the prolonged retention of the containers with the mucoadhesive shell in the nasal cavity.

Low stress resilience in late adolescence and risk of smoking, high alcohol consumption and drug use later in life

BACKGROUND

While compromised stress resilience constitutes a recognised risk factor for somatic and psychiatric disease development in general, the knowledge about how individual variation in vulnerability to stress may specifically influence the long-term risks of disadvantageous health behaviours is limited.

METHODS

In this Swedish cohort study, we aimed to investigate the association between stress resilience in late adolescence and adult use of addictive substances. We included 9381 men with information on psychological stress resilience measured during military conscription examinations, who later responded to an extensive health survey (mean age 34.0±7.2 years) including detailed information on substance use. We modelled continuous outcomes using linear regression, binary outcomes with logistic regression and other categorical outcomes with multinomial logistic regression.

RESULTS

We found that low stress resilience in adolescence conferred increased risks of all studied measures of addictive behaviour. After adjusting for childhood socioeconomic information, low stress resilience was associated with adult current regular smoking (relative risk ratio: 5.85, 95% CI 4.32 to 7.93), higher nicotine dependence scores (beta: 0.76, 95% CI 0.29 to 1.23), hazardous use of alcohol (>14 alcoholic drink-equivalents per week, OR: 1.72, 95% CI 1.37 to 2.16), DSM-IV criteria for alcohol dependence (OR: 1.74, 95% CI 1.35 to 2.25), and drug use (OR: 1.77, 95% CI 1.51 to 2.08). The results remained largely unchanged after further adjustments for adult educational attainment and occupation as well as for additional conscription covariates.

CONCLUSION

Low stress resilience in late adolescence appears to be associated with an increased risk of disadvantageous and addictive health behaviours in adulthood.

Intermittent hypoxia training: Powerful, non-invasive cerebroprotection against ethanol withdrawal excitotoxicity

Ethanol intoxication and withdrawal exact a devastating toll on the central nervous system. Abrupt ethanol withdrawal provokes massive release of the excitatory neurotransmitter glutamate, which over-activates its postsynaptic receptors, causing intense Ca2+ loading, p38 mitogen activated protein kinase activation and oxidative stress, culminating in ATP depletion, mitochondrial injury, amyloid β deposition and neuronal death. Collectively, these mechanisms produce neurocognitive and sensorimotor dysfunction that discourages continued abstinence. Although the brain is heavily dependent on blood-borne O2 to sustain its aerobic ATP production, brief, cyclic episodes of moderate hypoxia and reoxygenation, when judiciously applied over the course of days or weeks, evoke adaptations that protect the brain from ethanol withdrawal-induced glutamate excitotoxicity, mitochondrial damage, oxidative stress and amyloid β accumulation. This review summarizes evidence from ongoing preclinical research that demonstrates intermittent hypoxia training to be a potentially powerful yet non-invasive intervention capable of affording robust, sustained neuroprotection during ethanol withdrawal.

Psychopharmacological effects and safety of styryl-2-pyrones and dihydrostyryl-2-pyrones-rich fraction from Polygala sabulosa: absence of withdrawal syndrome and tolerance to anxiolytic-like and anticonvulsant effects

Objectives

To investigate whether mice develop tolerance to the anxiolytic‐like and anticonvulsant effects of subchronic treatment with EA (the styryl‐2‐pyrones and dihydrostyryl‐2‐pyrones‐rich fraction of Polygala sabulosa), as well as any withdrawal symptoms after abrupt discontinuation; to compare the effects of EA with those of diazepam (DZP) on withdrawal‐induced anxiety; and to evaluate the toxicity of EA according to OECD guidelines.

Methods

Male or female mice were acutely or subchronically treated with EA or DZP, and their tolerance to anxiolytic (evaluated in the elevated plus maze, EPM) and anticonvulsant effects (measured against pentylenetetrazole (PTZ)‐induced convulsions) were investigated. Other groups received EA or DZP for 28 days followed by withdrawal, being the anxiety‐like behaviour evaluated in the EPM.

Key findings

Both acute and subchronic treatments with EA induced an anxiolytic effect in the EPM. The anticonvulsant activity of DZP, but not EA, was reduced by protracted treatment. EA withdrawal retained the anxiolytic profile, while DZP withdrawal induced anxiogenesis. EA counteracted the anxiogenic‐like actions of DZP withdrawal. EA has low toxicity as it did not cause any changes in the biochemical, haematological and histopathological markers.

Conclusions

EA avoids the development of tolerance to its anxiolytic‐like and anticonvulsant actions, and does not promote withdrawal syndrome. EA does not cause relevant toxic effects in rodents.

Patterns of zolpidem use among Iraq and Afghanistan veterans: A retrospective cohort analysis

BACKGROUND

Although concern exists regarding the adverse effects and rate of zolpidem use, especially long-term use, limited information is available concerning patterns of zolpidem use.

OBJECTIVE

To examine the prevalence and correlates of zolpidem exposure in Iraq and Afghanistan Veterans (IAVs).

METHODS

A retrospective cohort study of zolpidem prescriptions was performed with National Veterans Health Administration (VHA) data. We gathered national VA inpatient, outpatient, and pharmacy data files for IAV's who received VA care between fiscal years (FY) 2013 and 2014. The VA pharmacy database was used to identify the prevalence of long term (>30 days), high-dose zolpidem exposure (>10mg immediate-release; >12.5mg extended-release) and other medications received in FY14. Baseline characteristics (demographics, diagnoses) were identified in FY13. Bivariate and multivariable analyses were used to examine the demographic, clinical, and medication correlates of zolpidem use.

RESULTS

Of 493,683 IAVs who received VHA care in FY 2013 and 2014, 7.6% (n = 37,422) were prescribed zolpidem in FY 2014. Women had lower odds of high-dose zolpidem exposure than men. The majority (77.3%) of IAVs who received zolpidem prescriptions had long-term use with an average days' supply of 189.3 days and a minority (0.9%) had high-dose exposure. In multivariable analyses, factors associated with long-term zolpidem exposure included age greater than 29 years old, PTSD, insomnia, Selim Index, physical 2-3 conditions, opioids, antidepressants, benzodiazepines, atypical antipsychotics, and stimulants. High dose exposure was associated with PTSD, depression, substance use disorder, insomnia, benzodiazepines, atypical antipsychotics, and stimulant prescriptions.

CONCLUSION

The current practices of insomnia pharmacotherapy in IAVs fall short of the clinical guidelines and may reflect high-risk zolpidem prescribing practices that put Iraq and Afghanistan Veterans at risk for adverse effects of zolpidem and poor health outcomes.