The discovery of chlordiazepoxide and the clinical introduction of benzodiazepines: half a century of anxiolytic drugs

Medicinal Chemistry of Drugs with N-Oxide Functionalities

Molecules with N-oxide functionalities are omnipresent in nature and play an important role in Medicinal Chemistry. They are synthetic or biosynthetic intermediates, prodrugs, drugs, or polymers for applications in drug development and surface engineering. Typically, the N-oxide group is critical for biomedical applications of these molecules. It may provide water solubility or decrease membrane permeability or immunogenicity. In other cases, the N-oxide has a special redox reactivity which is important for drug targeting and/or cytotoxicity. Many of the underlying mechanisms have only recently been discovered, and the number of applications of N-oxides in the healthcare field is rapidly growing. This Perspective article gives a short summary of the properties of N-oxides and their synthesis. It also provides a discussion of current applications of N-oxides in the biomedical field and explains the basic molecular mechanisms responsible for their biological activity.

Prescribing and deprescribing guidance for benzodiazepine and benzodiazepine receptor agonist use in adults with depression, anxiety, and insomnia: an international scoping review

Background

Clinical practice guidelines and guidance documents routinely offer prescribing clinicians' recommendations and instruction on the use of psychotropic drugs for mental illness. We sought to characterise parameters relevant to prescribing and deprescribing of benzodiazepine (BZD) and benzodiazepine receptor agonist (BZRA), in clinical practice guidelines and guidance documents internationally, for adult patients with unipolar depression, anxiety disorders and insomnia to understand similarities and discrepancies between evidence-based expert opinion.

Methods

A Scoping Review was conducted to characterize documents that offered evidence-based and/or consensus pharmacologic guidance on the management of unipolar depression, anxiety disorders, obsessive-compulsive disorders, post-traumatic stress disorders and insomnia. A systematic search was conducted of PubMed, SCOPUS, PsycINFO and CINAHL from inception to October 13, 2023 and supplemented by a gray literature search. Documents were screened in Covidence for eligibility. Subsequent data-charting on eligible documents collected information on aspects of both prescribing and deprescribing.

Findings

113 documents offering guidance on BZD/BZRA use were data-charted. Overall, documents gathered were from Asia (n = 11), Europe (n = 34), North America (n = 37), Oceania (n = 7), and South America (n = 4) with the remainder being "International" (n = 20) and not representative to any particular region or country. By condition the documents reviewed covered unipolar depressive disorders (n = 28), anxiety disorders, obsessive-compulsive disorder and post-traumatic stress disorder (n = 42) and Insomnia (n = 25). Few documents (n = 18) were sufficiently specific and complete to consider as de-prescribing focused documents.

Interpretation

Documents were in concordance in terms of BZD and BZRA not being used routinely as first-line pharmacologic agents. When used, it is advisable to restrict their duration to "short-term" use with the most commonly recommended duration being less than four weeks. Documents were less consistent in terms of prescriptive recommendations for specific drug, dosing and administration pattern (i.e regular or 'as needed') selection for each condition. Deprescribing documents were unanimously in favor of gradual dose reduction and patient shared decision-making. However, approaches towards dose-tapering differed substantially. Finally, there were inconsistencies and/or insufficiency of detail, among deprescribing documents, in terms of switching to a long-acting BZD, use of adjunctive pharmacotherapies and micro-tapering.

Funding

The authors received no funding for this work.

Anxiolytic-like Effects by trans-Ferulic Acid Possibly Occur through GABAergic Interaction Pathways

Numerous previous studies reported that ferulic acid exerts anxiolytic activity. However, the mechanisms have yet to be elucidated. The current study aimed to investigate the anxiolytic effect of trans-ferulic acid (TFA), a stereoisomer of ferulic acid, and evaluated its underlying mechanism using in vivo and computational studies. For this, different experimental doses of TFA (25, 50, and 75 mg/kg) were administered orally to Swiss albino mice, and various behavioral methods of open field, hole board, swing box, and light-dark tests were carried out. Diazepam (DZP), a positive allosteric modulator of the GABAA receptor, was employed as a positive control at a dose of 2 mg/kg, and distilled water served as a vehicle. Additionally, molecular docking was performed to estimate the binding affinities of the TFA and DZP toward the GABAA receptor subunits of α2 and α3, which are associated with the anxiolytic effect; visualizations of the ligand-receptor interaction were carried out using various computational tools. Our findings indicate that TFA dose-dependently reduces the locomotor activity of the animals in comparison with the controls, calming their behaviors. In addition, TFA exerted the highest binding affinity (-5.8 kcal/mol) to the α2 subunit of the GABAA receptor by forming several hydrogen and hydrophobic bonds. Taken together, our findings suggest that TFA exerts a similar effect to DZP, and the compound exerts moderate anxiolytic activity through the GABAergic interaction pathway. We suggest further clinical studies to develop TFA as a reliable anxiolytic agent.

In situ construction of Fe3O4@PDA@Au multi hotspot SERS probe for trace detection of benzodiazepines in serum

The abuse of benzodiazepines is a serious health hazard that can cause damage to the central nervous system.Trace monitoring of benzodiazepines in serum can effectively prevent the damage caused by these drugs. Therefore, in this study, a Fe₃O₄@PDA@Au core-shell satellite nanomaterial SERS(Surface-Enhanced Raman Scattering) probe that integrates magnetic separation techniques and a multi-hotspot structure was synthetized by in situ growth of gold nanoparticles on the surface of PDA(Polymerized dopamine)-coated Fe₃O₄. The size and gap of Au nanoparticles on the surface of the SERS probe can be modulated by regulating the amount of HAuCl₄ to create 3D multi-hotspot structures. The good dispersion and superparamagnetic properties of this SERS probe enable it to fully contact and load the target molecules in the serum, and the applied magnetic field facilitates separation and enrichment.This process increases the molecular density and number of SERS hotspots, thereby enhancing detection sensitivity. Based on the above considerations, this SERS probe can detect traces of eszopiclone and diazepam in serum at concentrations as low as 1 μg/ml with good linearity, offering promising applications in clinical monitoring of drug concentrations in blood.

Pharmacological Treatment of Generalised Anxiety Disorder: Current Practice and Future Directions

INTRODUCTION

Generalized Anxiety Disorder (GAD) is a common psychiatric condition, characterized by the presence of general apprehensiveness and excessive worry. Current management consists of a range of pharmacological and psychological treatments. However, many patients do not respond to first-line pharmacological treatments and novel anxiolytic drugs are being developed.

AREAS COVERED

In this review, the authors first discuss the diagnostic criteria and epidemiology of GAD. The effective pharmacological treatments for GAD and their tolerability are addressed. Current consensus guidelines for treatment of GAD are discussed, and maintenance treatment, the management of treatment resistance, and specific management of older adults and children/adolescents are considered. Finally, novel anxiolytics under development are discussed, with a focus on those which have entered clinical trials.

EXPERT OPINION

A range of effective treatments for GAD are available, particularly duloxetine, escitalopram, pregabalin, quetiapine, and venlafaxine. There is a limited evidence base to support the further pharmacological management of patients with GAD who have not responded to initial treatment. Although many novel anxiolytics have progressed to clinical trials, translation from animal models has been mostly unsuccessful. However, the potential of several compounds including certain psychedelics, ketamine, oxytocin, and agents modulating the orexin, endocannabinoid, and immune systems merits further study.

The use of benzodiazepines and the mental health of women in prison: a cross-sectional study

In this article we assessed the prevalence of benzodiazepine (BZD) use in women before and during imprisonment, as well as its related factors and association with symptoms of anxiety, depression, and posttraumatic stress disorder in a quantitative, cross-sectional, analytical study of regional scope. Two female prisons in the Brazilian Prison System were included. Seventy-four women participated by completing questionnaires about their sociodemographic data, BZD use and use of other substances. These questionnaires included the Generalized Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-9 (PHQ-9), and Posttraumatic Stress Disorder Checklist-Civilian Version (PCL-C). Of the 46 women who reported no BZDs use before arrest, 29 (63%) began using BZDs during imprisonment (p < 0.001). Positive scores for PTSD, anxiety, and depression, as well as associations between BZD use during imprisonment and anxiety (p = 0.028), depression (p = 0.001) and comorbid anxiety and depression (p = 0.003) were found when a bivariate Poisson regression was performed. When a multivariate Poisson regression was performed for tobacco use, the PHQ-9 and GAD-7 scales, BZD use was associated with depression (p = p = 0.008), with tobacco use (p = 0.012), but not with anxiety (p = 0.325). Imprisonment increases the psychological suffering of women, consequently increasing BZD use. Nonpharmacological measures need to be considered in the health care of incarcerated women.

Examining behavioural test sensitivity and locomotor proxies of anxiety-like behaviour in zebrafish

This study assessed the sensitivity of four anxiety-like behaviour paradigms in zebrafish: the novel tank dive test, shoaling test, light/dark test, and the less common shoal with novel object test. A second goal was to measure the extent to which the main effect measures are related to locomotor behaviours to determine whether swimming velocity and freezing (immobility) are indicative of anxiety-like behaviour. Using the well-established anxiolytic, chlordiazepoxide, we found the novel tank dive to be most sensitive followed by the shoaling test. The light/dark test and shoaling plus novel object test were the least sensitive. A principal component analysis and a correlational analysis also showed the locomotor variables, velocity and immobility, did not predict the anxiety-like behaviours across all behaviour tests.

Multicomponent DNA-Compatible Synthesis of an Annelated Benzodiazepine Scaffold for Focused Chemical Libraries

Annelated benzodiazepines are attractive drug-like scaffolds with a broad spectrum of biological activities. Incorporation of this heterocyclic core into DNA-encoded chemical libraries (DELs) via multicomponent assembly is highly demanded. Herein, we developed a DNA-compatible method to generate the tricyclic benzodiazepine scaffold via catalyst-free three-component condensation using a broad range of aldehyde, o-phenylenediamine, and diketone sources. With either aldehyde or o-phenylenediamine conjugated with DNA tags, functionalized 1,5-benzodiazepine scaffolds were efficiently forged, expanding the chemical space of the diazepine-centered drug-like DEL.

New Saccharin Salt of Chlordiazepoxide: Structural and Physicochemical Examination

Since the formation of organic salts can improve the solubility, bioavailability, and stability of active pharmaceutical ingredients, the aim of this work was to prepare an organic salt of chlordiazepoxide with saccharin. To achieve this goal, the saccharin salt of chlordiazepoxide was obtained from a physical mixture of both components by grinding them with a small volume of solvent and by crystallizing them with complete evaporation of the solvent. The resulting salt was examined by methods such as Powder X-ray Diffraction (PXRD), Single Crystal X-ray Diffraction (SCXRD), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Fourier Transform Infrared (FT-IR), and Raman spectroscopy. The results of the studies proved that saccharin salt of chlordiazepoxide crystallizes in the orthorhombic Pbca space group with one chlordiazepoxide cation and one saccharin anion in the asymmetric unit. In the crystal of the title compound, the chlordiazepoxide cation and the saccharin anion interact through strong N–H···O hydrogen bonds and weak C–H···O hydrogen bonds. The disappearance of the N–H band in the FT-IR spectrum of saccharin may indicate a shift of this proton towards chlordiazepoxide, while the disappearance of the aromatic bond band in the chlordiazepoxide ring in the Raman spectrum may suggest the formation of intermolecular hydrogen bonds between chlordiazepoxide molecules. The melting point of the salts differs from that of the starting compounds. Thermal decomposition of the salt begins above 200 °C and shows at least two overlapping stages of mass loss. In summary, the results of the research showed that the crystalline salt of the saccharin and chlordiazepoxide can be obtained by various methods: grinding with the addition of acetonitrile and crystallization from acetonitrile or a mixture of methanol with methylene chloride.

Role of serendipity in the discovery of classical antidepressant drugs: Applying operational criteria and patterns of discovery

The role played by serendipity in the origin of modern psychopharmacology has proven to be controversial in scientific literature. In its original meaning (Walpole), serendipity refers to discoveries made through a combination of accidents and sagacity. We have implemented an operational definition of serendipity based on finding something unexpected or unintended, regardless of the systematic process that led to the accidental observation, and we have established four different patterns of serendipitous attributability. In this paper, we have analyzed the role of serendipity in the discovery and development of classical antidepressant drugs, tricyclic antidepressants and monoamine oxidase inhibitors as well as heterocyclic, “atypical” or “second generation” antidepressants. The discovery of the antidepressant properties of imipramine and iproniazid, the prototypes of tricyclic antidepressants and monoamine oxidase inhibitors, respectively, fits the mixed type II pattern; initial serendipitous discoveries (imipramine was an antipsychotic and iproniazid was an anti-tuberculosis agent) led secondarily to non-serendipitous discoveries. But the other components of these two families of drugs were developed specifically as antidepressants, modifying the chemical structure of the series leaders, thereby allowing all of them to be included in the type IV pattern, characterized by the complete absence of serendipity. Among the heterocyclic drugs, mianserin (originally developed as an antihistamine) also falls into the type II pattern.

Study protocol-Evoked craving in high-dose benzodiazepine users

Benzodiazepine (BDZ) abuse, especially concerning high doses of BDZs, is an impairing substance use disorder (SUD) that is often difficult to treat. Craving and cue reactivity (CR) are two important phenomena that have a prominent role in maintaining addiction and triggering relapses in BDZ abuse; nevertheless, they have rarely been addressed in scientific literature. The present study aims to fill these gaps by implementing a highly innovative virtual reality (VR) design to assess the impact of substance-related environmental cues on BDZ craving, as well as their influence on patients' affective states. Therefore, on one hand, this research will contribute to the assessment of VR feasibility in the study of these phenomena, and, on the other, it will help disentangle the role that CR and craving have on mood and attention, which are equally important factors to consider when treating SUDs. We will recruit a healthy control group and a patient group comprising people seeking treatment for BDZ detoxification. The experimental design will consist of the presentation of three VR scenarios, one neutral, one BDZ-related but without BDZ cues, and another with BDZ cues. The craving will be measured through a virtual analog scale (VAS); the Profile of Mood States (POMS) and Alcohol Attention Scale (AAS) questionnaires in a modified version will also be administered. We will additionally control for VR-induced feelings of sickness by administering the Simulator Sickness Questionnaire (SSQ), and the Presence Questionnaire (PQ) will be used to investigate participants' sense of presence in virtual environments. We expect patients to exhibit higher levels of craving, and that the craving will be higher after exposure to a cue-related virtual environment as compared to a neutral scenario.

The blood-to-plasma ratio and predicted GABAA-binding affinity of designer benzodiazepines

PURPOSE

The number of benzodiazepines appearing as new psychoactive substances (NPS) is continually increasing. Information about the pharmacological parameters of these compounds is required to fully understand their potential effects and harms. One parameter that has yet to be described is the blood-to-plasma ratio. Knowledge of the pharmacodynamics of designer benzodiazepines is also important, and the use of quantitative structure-activity relationship (QSAR) modelling provides a fast and inexpensive method of predicting binding affinity to the GABA_A receptor.

METHODS

In this work, the blood-to-plasma ratios for six designer benzodiazepines (deschloroetizolam, diclazepam, etizolam, meclonazepam, phenazepam, and pyrazolam) were determined. A previously developed QSAR model was used to predict the binding affinity of nine designer benzodiazepines that have recently appeared.

RESULTS

Blood-to-plasma values ranged from 0.57 for phenazepam to 1.18 to pyrazolam. Four designer benzodiazepines appearing since 2017 (fluclotizolam, difludiazepam, flualprazolam, and clobromazolam) had predicted binding affinities to the GABA_A receptor that were greater than previously predicted binding affinities for other designer benzodiazepines.

CONCLUSIONS

This work highlights the diverse nature of the designer benzodiazepines and adds to our understanding of their pharmacology. The greater predicted binding affinities are a potential indication of the increasing potency of designer benzodiazepines appearing on the illicit drugs market.

Polysubstance Use Patterns Among High Dose Benzodiazepine Users: A Latent Class Analysis and Differences Between Male and Female Use

Benzodiazepines (BZDs) represent one of the most widely used groups of pharmaceuticals, but if used for long periods of time they are associated with dependence and an increased risk of harmful effects. High-dose (HD) BZD dependence is a specific substance use disorder associated with a poor quality of life. It is especially important to pinpoint differences in HD BZD addict subgroups in order to tailor treatment to the individual's specific needs, also considering possible comorbidities with other substance use disorders. We conducted a study to evaluate HD BZD dependence (converted doses to diazepam equivalents, mg) in an Italian sample of 1,354 participants. We also investigated if and to which extent participants co-used other substances (alcohol, tobacco, cannabis/cannabinoids, cocaine, and heroin). We then performed latent class analysis (LCA) to identify the use patterns of these substances, finding three classes: participants in Class 1 (4.3% of the sample) had the highest probability of also using cocaine and alcohol (Polysubstance BZD users); Class 2 comprised subjects with the highest probability of being former heroin, cocaine, THC, and alcohol users (Former polysubstance BZD users); Class 3 represented mono-dependence BZD users (78.5% of the sample) and was the most prevalent among women, while young men were most prevalent in Class 1. The present study underlines different characteristics in HD BZD users both concerning other addictions and sex, and also highlights the need for a stricter control of BZD use, ranging from prescriptions to sales.

Benzodiazepine and Z-Drug Use and the Risk of Developing Dementia

BACKGROUND

Benzodiazepines (BZDs) and Z-drugs (BZDRs) are among the most prescribed medications for anxiety and insomnia, especially among older adults. Our objective was to investigate the association between the use of BZDRs and the risk of dementia.

METHODS

A community-based retrospective cohort study was conducted based on the data available from 2002 to 2015 in Catalan Health Service. This cohort included all BZDR users (N = 83 138) and nonusers (N = 84 652) older than 45 years. A minimum 5-year lag window and an adjustment for psychiatric problems were applied for the data analysis.

RESULTS

The hazard ratio (HR) for the risk of incident dementia among BZDR users was 1.22 (95% CI = 1.15 to 1.31). This risk was not significant after adjusting the data confounding factors (HR = 1.01; 95% CI = 0.94 to 1.08). We observed a higher risk with short-to-intermediate half-life BZDs (HR = 1.11; 95% CI = 1.04 to 1.20) and Z-drugs (HR = 1.20; 95% CI = 1.07 to 1.33) than for intermediate-to-long half-life BZDs (HR = 1.01; 95% CI = 0.94 to 1.08). We demonstrated a higher risk of incident dementia (HR = 1.23; 95% CI = 1.07 to 1.41 and odds ratio = 1.38; 95% CI = 1.27 to 1.50, respectively) in patients who received 91 to 180 defined daily doses (DDDs) and >180 DDDs compared with patients who received <90 DDD. Regarding patient sex, the risk of dementia was higher in women than in men.

CONCLUSION

We found that the incidence of dementia was not higher among all BZDR users. Short half-life BZDs and Z-drugs increased the risk of dementia at the highest doses, especially in female patients, showing a dose-response relationship.

Risk of long-term benzodiazepine and Z-drug use following the first prescription among community-dwelling adults with anxiety/mood and sleep disorders: a retrospective cohort study

OBJECTIVE

To measure the incidence of long-term benzodiazepine receptor agonist (BZRA) use among individuals with anxiety, mood and/or sleep disorders. To identify factors associated with long-term use following the first prescription.

METHODS

This was a population-based retrospective cohort study using administrative databases in Manitoba, Canada. Individuals with anxiety/mood or sleep disorder who received their first BZRA between 1 April 2001 and 31 March 2015 were included. Long-term use was defined as ≥180 days. Logistic regression modelling was used to examine predictors of long-term use.

RESULTS

Among 206 933 individuals included, long-term BZRA use in the first episode of use was 4.5% (≥180 days) following their first prescription. Factors associated with ≥180 days of use included male sex (adjusted OR (aOR) 1.33, 95% CI 1.27 to 1.39), age ≥65 (aOR 5.15, 95% CI 4.81 to 5.52), income assistance (aOR 1.68, 95% CI 1.55 to 1.81), previous non-BZRA psychotropic (aOR 1.93, 95% CI 1.83 to 2.02) or opioid use (aOR 1.16, 95% CI 1.11 to 1.22), high comorbidity (aOR 1.43, 95% CI 1.32 to 1.55), high healthcare use (aOR 1.46, 95% CI 1.33 to 1.60) and psychiatrist prescriber (aOR 2.11, 95% CI 1.93 to 2.32).

CONCLUSIONS

Less than 1 in 20 patients use BZRAs ≥180 days in their first treatment episode. Several factors were associated with long-term use following the first prescription and further investigation into whether these factors need to be considered at the point of prescribing is warranted. In light of these findings, future research should examine the predictors of cumulative repeat episodes of BZRA exposure.

Multicomponent reactions as a potent tool for the synthesis of benzodiazepines

Benzodiazepines (BZDs), a diverse class of benzofused seven-membered N-heterocycles, display essential pharmacological properties and play vital roles in some biochemical processes. They have mainly been prescribed as potential therapeutic agents, which interestingly represent various biological activities such as anticancer, anxiolytic, antipsychotic, anticonvulsant, antituberculosis, muscle relaxant, and antimicrobial activities. The extensive biological activities of BZDs in various fields have encouraged medicinal chemists to discover and design novel BZD-based scaffolds as potential therapeutic candidates with the favorite biological activity through an efficient protocol. Although certainly valuable and important, conventional synthetic routes to these bicyclic benzene compounds contain methodologies often requiring multistep procedures, which suffer from waste materials generation and lack of sustainability. By contrast, multicomponent reactions (MCRs) have recently advanced as a green synthetic strategy for synthesizing BZDs with the desired scope. In this regard, MCRs, especially Ugi and Ugi-type reactions, efficiently and conveniently supply various complex synthons, which can easily be converted to the BZDs via suitable post-transformations. Also, MCRs, especially Mannich-type reactions, provide speedy and economic approaches for the one-pot and one-step synthesis of BZDs. As a result, various functionalized-BZDs have been achieved by developing mild, efficient, and high-yielding MCR protocols. This review covers all aspects of the synthesis of BZDs with a particular focus on the MCRs as well as the mechanism chemistry of synthetic protocols. The present manuscript opens a new avenue for organic, medicinal, and industrial chemists to design safe, environmentally benign, and economical methods for the synthesis of new and known BZDs.

Benzodiazepines: Their Use either as Essential Medicines or as Toxics Substances

This review highlights the nature, characteristics, properties, pharmacological differences between different types of benzodiazepines, the mechanism of action in the central nervous system, and the degradation of benzodiazepines. In the end, the efforts to reduce the benzodiazepines' adverse effects are shown and a reflection is made on the responsible uses of these medications.

Early life exposures and risk of adult respiratory disease during 50 years of follow-up

Adult health is influenced by factors during fetal life affecting organ development and birth weight. We aimed to study such factors in relation to adult respiratory disease (ARD) risk. The Helsingborg Birth Cohort, Sweden, contributed baseline data collected by medical staff through clinical examination and questionnaires on maternal and birth characteristics 1964-1967. Register linkages were performed with completions of data on ARD by ICD 8-10 classifications (1969-2016), and/or ARD-related drug usage (2005-2016) enabling a 50-year follow-up time. Cox proportional hazard regression analyses were made to adjust for potential confounders, adjusted hazard ratio (aHR). A total of 3675 mothers and their offspring were included. Female offspring showed higher frequency of ARD than males, aHR 1.5 (95% CI 1.3-1.8). Maternal use of sedatives during second trimester, aHR 2.2 (95% CI 1.4-3.4), and maternal smoking during most of pregnancy, aHR 1.2 (95% CI 1.0-1.4), were associated with offspring ARD. Stratified by sex, large-for-gestational-age, aHR 1.4 (95% CI 1.0-1.9), was significantly associated with ARD in female offspring along with maternal sedative use during second trimester and maternal smoking during most of pregnancy. Maternal sedative use during second trimester or all trimesters were the only significant risk factors for male offspring. In conclusion, maternal sedative use in second trimester was independently associated with subsequent respiratory disease in adult offspring irrespective of sex.

Trends in the consumption rates of benzodiazepines and benzodiazepine-related drugs in the health region of Lleida from 2002 to 2015

Background

The high prevalence and long-term use of benzodiazepines (BZDs) treatment are debated topics because of the risk they can cause to the patients. Despite the current information on the risk-benefit balance of these drugs, their consumption remains particularly high. We determined the trend in the consumption prevalence of benzodiazepines (BZDs) and drugs related to BZDs (Z-drugs) in the population of the Health Region of Lleida to explore patterns of use and the associated characteristics associated between 2002 and 2015.

Methods

An analysis of secular trends was carried out between 2002 and 2015; the databased included all individuals from the Health Region of Lleida, which had 358,157 inhabitants in 2015, that consumed BZDs. The consumption of BZDs was evaluated using prescription billing data from the Public Health System. All types of BZDs and BZD analogues that had been approved by the drug agency were included. Trends by age and sex were investigated.

Results

Over the whole study period, a total of 161,125 individuals accounted for 338,148 dispensations. Overall, 59% were women, and the mean age was 56 years. The dispensing prevalence of BZDs use in 2015 was 14.2% overall —18.8% in women and 9.6% in men—and was 36% in those over 65 years. According to the half-life of BZDs, the prevalence of short-intermediate BZD use, intermediate-long BZD use, and Z-drugs use was 9.7, 5.5 and 0.8%, respectively. The evolution of the annual prevalence of BZD dispensing showed a progressive decline, from 15.3% in 2002 to 14.2% in 2015, which was attributed to a decrease in the consumption of intermediate-long half-life BZDs (8.0% vs. 5.5%) and Z-drugs (1.4% vs. 0.8%).

Conclusion

The dispensing prevalence of BZDs and Z-drugs was high, although a small reduction was observed during this time period. The dispensing prevalence was especially high in the population over 65, despite the risk of cognitive decline and falls. Integral actions are required to lower the BZD prescription rate.

Increased use of benzodiazepines among older adults: Bambuí Project

BACKGROUND

Benzodiazepines are the most widely used psychoactive drugs, despite the risks associated with their prolonged use, especially among older adults.

OBJECTIVE

To investigate the use of benzodiazepines among community-dwelling people aged ≥ 75 years.

METHODS

The study was conducted among members of the baseline (in 1997) and survivors (in 2012) of the Bambuí Project cohort. The prevalence of benzodiazepine use was estimated separately for each year, and the comparison between them was performed using the Poisson regression model with robust variance.

RESULTS

The prevalence of benzodiazepine use was higher in 2012 (33.9%) compared to 1997 (24.9%). After multiple adjustments, the difference in prevalence did not remain significant in study population (PR = 1.25; 95%CI 0.99 - 1.60), unlike that observed in the female stratum (PR = 1.38; 95%CI 1.04 - 1.84). Clonazepam was the strongest-growing drug between the two years (PR = 4.94; 95%CI 2.54 - 9.62).

CONCLUSION

This study showed an important increase in benzodiazepine use in an older adult population. These results are concerning as these drugs are contraindicated for use in older adults, mainly if used chronically, and are available in the national list of essential medicines. Health professionals should be aware of the risks involved in its use regarding this population.

Psychotropic Drug-Associated Pneumonia in Older Adults

The use of psychotropic drugs (antipsychotics, benzodiazepines and benzodiazepine-related drugs, and antidepressants) is common, with a prevalence estimates range of 19-29% among community dwelling older adults. These drugs are often prescribed for off-label use, including neuropsychiatric symptoms. The older adult population also has high rates of pneumonia and some of these cases may be associated with adverse drug events. In this narrative review, we summarize the findings from current observational studies on the association between psychotropic drug use and pneumonia in older adults. In addition to studies assessing the use of psychotropics, we included antiepileptic drugs, as they are also central nervous system-acting drugs, whose use is becoming more common in the aging population. The use of antipsychotics, benzodiazepine, and benzodiazepine-related drugs are associated with increased risk of pneumonia in older adults (≥ 65 years of age), and these findings are not limited to this age group. Minimal and conflicting evidence has been reported on the association between antidepressant drug use and pneumonia, but differences between study populations make it difficult to compare findings. Studies regarding antiepileptic drug use and risk of pneumonia in older persons are lacking, although an increased risk of pneumonia in antiepileptic drug users compared with non-users in persons with Alzheimer's disease has been reported. Tools such as the American Geriatric Society Beers Criteria and the STOPP/START criteria for potentially inappropriate medications aids prescribers to avoid these drugs in order to reduce the risk of adverse drug events. However, risk of pneumonia is not mentioned in the current criteria and more research on this topic is needed, especially in vulnerable populations, such as persons with dementia.

Recent advances in synthesis and medicinal chemistry of benzodiazepines

Benzodiazepines (BZDs) represent a diverse class of bicyclic heterocyclic molecules. In the last few years, benzodiazepines have emerged as potential therapeutic agents. As a result, several mild, efficient and high yielding protocols have been developed that offer access to various functionalized benzodiazepines (BZDs). They are known to possess a wide array of biological activities such as anxiolytic, anticancer, anticonvulsant, antipsychotics, muscle relaxant, anti-tuberculosis, and antimicrobial activities. The fascinating spectrum of biological activities exhibited by BZDs in various fields has prompted the medicinal chemist to design and discover novel benzodiazepine-based analogs as potential therapeutic candidates with the desired biological profile. In this review, an attempt has been made by to summarize (1) Recent advances in the synthetic chemistry of benzodiazepines which enable their synthesis with desired substitution pattern; (2) Medicinal chemistry of BZDs as therapeutic candidates with promising biological profile including insight of mechanistic studies; (3) The correlation of biological data with the structure i.e. structure-activity relationship studies were also included to provide an insight into the rational design of more active agents.

Effect of reimbursement restriction policy on the use of benzodiazepines in the Netherlands: an interrupted time series analysis

OBJECTIVES

Use of benzodiazepines has health risks. Reimbursement was restricted in the Netherlands from January 2009 onwards with the goal to reduce chronic use and healthcare expenditures. The aim of this study is to assess the initial and long-term effects of this policy on benzodiazepine use.

DESIGN

Interrupted time series analysis, segmented regression models, Kaplan-Meier survival analysis and Cox proportional hazards analysis.

SETTING

A 10% random sample of benzodiazepine dispensings by outpatient pharmacies between January 2002 and August 2015 were obtained from the PHARMO database. This database covered a catchment area representing about 3.6 million residents in 2015.

PARTICIPANTS

2 500 800 benzodiazepine prescriptions from 128 603 patients were included.

INTERVENTION

Reimbursement restriction policy from January 2009 onwards.

OUTCOME MEASURES

Changes in: the volume of dispensed prescriptions and doses, the incidence, prevalence of incidental, regular and chronic use and discontinuation rates of benzodiazepines.

RESULTS

The volume of dispensed prescriptions and doses decreased by 12.5% (95% CI 9.0% to 15.9%) and 15.1% (95% CI 11.4% to 17.3%) respectively in January 2009 compared with December 2008. A clear initial effect on the overall incidence (-14.7%; 95% CI -19.8% to 9.6%) and the prevalence of incidental (-17.8%; 95% CI -23.9% to 11.7%), regular (-20.0%; 95% CI -26.1% to 13.9%) and chronic (-16.0%; 95% CI -23.1% to 8.9%) use was observed. A statistically significant reduction in the monthly trend per 1000 medication users was observed for the overall incidence (-0.017; 95% CI -0.031 to 0.003) and the prevalence of incidental (-3.624; 95% CI -4.996 to 2.252) but not for regular (-0.304; 95% CI -1.204 to 0.596) and chronic (0.136; 95% CI -0.858 to 1.130) use. Patients who started treatment before policy had a slightly higher probability of discontinuation (HR=1.013; 95% CI 1.004 to 1.022).

CONCLUSIONS

The reimbursement policy had a significant initial effect on the volume, incidence and prevalence of benzodiazepine use. In addition, there is a statistically significant reduction in the monthly trend of overall incidence and of the prevalence of incidental use. No statistically significant reduction in the monthly trend of chronic use, the main purpose of the reimbursement restriction, could be demonstrated.

Anticraving therapy for alcohol use disorder: A clinical review

Aim

In this review, the author focused on anticraving therapy for alcohol use disorder (AUD) defined by DMS‐5. A comprehensive review was carried out on the available published papers on anticraving drugs for treating AUD patients.

Methods

The author described all drugs with anticraving benefits for treating AUD patients approved by the Food and Drug Administration of the United States (US FDA) and European Medicines Agency of the European Union. Then, the commonly prescribed anticraving drugs and those under development were also described.

Results

The US FDA‐approved anticraving drugs included acamprosate and naltrexone, and those approved by European Medicines Agency were gamma‐hydroxybutyrate and nalmefene. The author also highlighted topiramate, gabapentin, ondansetron, LY196044, ifenprodil, varenicline, ABT‐436, mifepristone, citicoline, and baclofen. The putative mechanisms of action of and the use in clinical practice of those anticraving drugs were also described.

Conclusion

Although slowly developing, the field of anticraving drugs is getting into shape as a promising entity of a pharmaceutical class of drugs. Then, the author addressed on the underused issues of those recommended, and suggested anticraving drugs by the practice guideline of the American Psychiatric Association. The author urges that clinicians should be more “adventurous” in prescribing those promising drugs because benefits of those anticraving drugs are far‐outweighing the possible side effects of anticraving drugs, or the harms of untreated AUD itself.

Novel pharmacological targets in drug development for the treatment of anxiety and anxiety-related disorders

Current medication for anxiety disorders is suboptimal in terms of efficiency and tolerability, highlighting the need for improved drug treatments. In this review an overview of drugs being studied in different phases of clinical trials for their potential in the treatment of fear-, anxiety- and trauma-related disorders is presented. One strategy followed in drug development is refining and improving compounds interacting with existing anxiolytic drug targets, such as serotonergic and prototypical GABAergic benzodiazepines. A more innovative approach involves the search for compounds with novel mechanisms of anxiolytic action using the growing knowledge base concerning the relevant neurocircuitries and neurobiological mechanisms underlying pathological fear and anxiety. The target systems evaluated in clinical trials include glutamate, endocannabinoid and neuropeptide systems, as well as ion channels and targets derived from phytochemicals. Examples of promising novel candidates currently in clinical development for generalised anxiety disorder, social anxiety disorder, panic disorder, obsessive compulsive disorder or post-traumatic stress disorder include ketamine, riluzole, xenon with one common pharmacological action of modulation of glutamatergic neurotransmission, as well as the neurosteroid aloradine. Finally, compounds such as D-cycloserine, MDMA, L-DOPA and cannabinoids have shown efficacy in enhancing fear-extinction learning in humans. They are thus investigated in clinical trials as an augmentative strategy for speeding up and enhancing the long-term effectiveness of exposure-based psychotherapy, which could render chronic anxiolytic drug treatment dispensable for many patients. These efforts are indicative of a rekindled interest and renewed optimism in the anxiety drug discovery field, after decades of relative stagnation.

The compromise of virtual screening and its impact on drug discovery

Introduction: Docking and structure-based virtual screening (VS) have been standard approaches in structure-based design for over two decades. However, our understanding of the limitations, potential, and strength of these techniques has enhanced, raising expectations. Areas covered: Based on a survey of reports in the past five years, we assess whether VS: (1) predicts binding poses in agreement with crystallographic data (when available); (2) is a superior screening tool, as often claimed; (3) is successful in identifying chemical scaffolds that can be starting points for subsequent lead optimization cycles. Data shows that knowledge of the target and its chemotypes in postprocessing lead to viable hits in early drug discovery endeavors. Expert opinion: VS is capable of accurate placements in the pocket for the most part, but does not consistently score screening collections accurately. What matters is capitalization on available resources to get closer to a viable lead or optimizable series. Integration of approaches, subjective hit selection guided by knowledge of the receptor or endogenous ligand, libraries driven by experimental guides, validation studies to identify the best docking/scoring that reproduces experimental findings, constraints regarding receptor-ligand interactions, thoroughly designed methodologies, and predefined cutoff scoring criteria strengthen VS's position in pharmaceutical research.

Initiation and long-term use of benzodiazepines and Z-drugs in bipolar disorder

OBJECTIVES

Increasing evidence points to the harmful effects of long-term benzodiazepine treatment. Our objective was to study the incidence of, and predictors for, long-term use of benzodiazepines and Z-drugs in bipolar disorder.

METHODS

We conducted a population-based cohort study, using data from Swedish national registers. Swedish residents aged 18-75 years with a recorded diagnosis of bipolar disorder or mania between July 2006 and December 2012, and no history of benzodiazepine/Z-drug use in the past year, were included. Patients were followed for 1 year with regard to prescription fills of benzodiazepines/Z-drugs. Initiators were followed for another year during which continuous use for >6 months was defined as "long-term". Patient and prescription characteristics were investigated as potential predictors for long-term use in multivariate logistic regression models.

RESULTS

Out of the 21 883 patients included, 29% started benzodiazepine/Z-drug treatment, of whom one in five became long-term users. Patients who were prescribed clonazepam or alprazolam had high odds for subsequent long-term use (adjusted odds ratios [aORs] 3.78 [95% confidence interval (CI) 2.24-6.38] and 2.03 [95% CI 1.30-3.18], respectively), compared to those prescribed diazepam. Polytherapy with benzodiazepines/Z-drugs also predicted long-term use (aOR 2.46, 95% CI 1.79-3.38), as did age ≥60 years (aOR 1.93, 95% CI 1.46-2.53, compared to age <30 years), and concomitant treatment with psychostimulants (aOR 1.78, 95% CI 1.33-2.39).

CONCLUSIONS

The incidence of subsequent long-term use among bipolar benzodiazepine initiators is high. Patients on clonazepam, alprazolam or benzodiazepine/Z-drug polytherapy have the highest risk of becoming long-term users, suggesting that these treatments should be used restrictively.

A History of the Pharmacological Treatment of Bipolar Disorder

In this paper, the authors review the history of the pharmacological treatment of bipolar disorder, from the first nonspecific sedative agents introduced in the 19th and early 20th century, such as solanaceae alkaloids, bromides and barbiturates, to John Cade's experiments with lithium and the beginning of the so-called "Psychopharmacological Revolution" in the 1950s. We also describe the clinical studies and development processes, enabling the therapeutic introduction of pharmacological agents currently available for the treatment of bipolar disorder in its different phases and manifestations. Those drugs include lithium salts, valproic acid, carbamazepine, new antiepileptic drugs, basically lamotrigine and atypical antipsychotic agents (olanzapine, risperidone, quetiapine, ziprasidone, aripiprazole, asenapine, cariprazine and lurasidone). Finally, the socio-sanitary implications derived from the clinical introduction of these drugs are also discussed.

Studying emotion in invertebrates: what has been done, what can be measured and what they can provide

Until recently, whether invertebrates might exhibit emotions was unknown. This possibility has traditionally been dismissed by many as emotions are frequently defined with reference to human subjective experience, and invertebrates are often not considered to have the neural requirements for such sophisticated abilities. However, emotions are understood in humans and other vertebrates to be multifaceted brain states, comprising dissociable subjective, cognitive, behavioural and physiological components. In addition, accumulating literature is providing evidence of the impressive cognitive capacities and behavioural flexibility of invertebrates. Alongside these, within the past few years, a number of studies have adapted methods for assessing emotions in humans and other animals, to invertebrates, with intriguing results. Sea slugs, bees, crayfish, snails, crabs, flies and ants have all been shown to display various cognitive, behavioural and/or physiological phenomena that indicate internal states reminiscent of what we consider to be emotions. Given the limited neural architecture of many invertebrates, and the powerful tools available within invertebrate research, these results provide new opportunities for unveiling the neural mechanisms behind emotions and open new avenues towards the pharmacological manipulation of emotion and its genetic dissection, with advantages for disease research and therapeutic drug discovery. Here, we review the increasing evidence that invertebrates display some form of emotion, discuss the various methods used for assessing emotions in invertebrates and consider what can be garnered from further emotion research on invertebrates in terms of the evolution and underlying neural basis of emotion in a comparative context.

Trends in the long-term use of benzodiazepine anxiolytics and hypnotics: A national register study for 2006 to 2014

PURPOSE

Long-term benzodiazepine (BZD) treatment continues to be a debated topic. Because individual BZDs have different clinical profiles, we assessed the nationwide trends of long-term BZD use at active substance level during years 2006 to 2014.

METHODS

This study covered all reimbursed BZD purchases (n = 408 572-521 823 annually) for adults recorded in the Finnish Prescription Register. We assessed long-term use (annual cumulative purchase of ≥180 defined daily doses) in general, and at active substance level with the most commonly used BZD anxiolytics (oxazepam, diazepam, alprazolam, and clonazepam for nonepilepsy indications) and hypnotics (zopiclone, zolpidem, and temazepam) included. The persistence rates for each substance were assessed separately.

RESULTS

The prevalence of long-term BZD use among Finnish adults declined significantly from 5.3% to 3.6%, during years 2006 to 2014. Despite this decline, there was a significant increase in the long-term use of clonazepam for nonepilepsy indications and zolpidem (28.0% and 17.5%, respectively). Long-term use was common in the aged population, as well as among the users of hypnotics or clonazepam. Persistent use of 9 consecutive calendar years varied between 7.5% for incident alprazolam users and 21.0% for incident clonazepam users.

CONCLUSIONS

We found a declining trend in long-term BZD use, but the decline was not uniform between the substances-the long-term use of clonazepam and zolpidem even increased. Follow-up research is needed to assess whether the decline in BZD use is accompanied by an increased use of other types of anxiolytic or hypnotic drugs or other forms of treatment.

Psychedelics: Where we are now, why we got here, what we must do

The purpose of this commentary is to provide an introduction to this special issue of Neuropharmacology with a historical perspective of psychedelic drug research, their use in psychiatric disorders, research-restricting regulatory controls, and their recent emergence as potential breakthrough therapies for several brain-related disorders. It begins with the discovery of lysergic acid diethylamide (LSD) and its promising development as a treatment for several types of mental illnesses during the 1940s. This was followed by its abuse and stigmatization in the 1960s that ultimately led to the placement of LSD and other psychedelic drugs into the most restrictively regulated drug schedule of the United States Controlled Substances Act (Schedule I) in 1970 and its international counterparts. These regulatory controls severely constrained development of psychedelic substances and their potential for clinical research in psychiatric disorders. Despite the limitations, there was continued research into brain mechanisms of action for psychedelic drugs with potential clinical applications which began during the 1990s and early 2000s. Finding pathways to accelerate clinical research in psychedelic drug development is supported by the growing body of research findings that are documented throughout this special issue of Neuropharmacology. Accumulated research to date suggests psychedelic drug assisted psychotherapy may emerge as a potential breakthrough treatment for several types of mental illnesses including depression, anxiety, post-traumatic stress disorder, and addiction that are refractory to current evidenced based therapies. This research equally shows promise in advancing the understanding of the brain, brain related functioning, and the consequential effects of untreated brain related diseases that have been implicated in causing and/or exacerbating numerous physical disease state conditions. The authors conclude that more must be done to effectively address mental illnesses and brain related diseases which have become so pervasive, destructive, and whose treatments are becoming increasingly resistant to current evidenced based therapies. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'.

The Discovery of Suvorexant, the First Orexin Receptor Drug for Insomnia

Historically, pharmacological therapies have used mechanisms such as γ-aminobutyric acid A (GABA_A) receptor potentiation to drive sleep through broad suppression of central nervous system activity. With the discovery of orexin signaling loss as the etiology underlying narcolepsy, a disorder associated with hypersomnolence, orexin antagonism emerged as an alternative approach to attenuate orexin-induced wakefulness more selectively. Dual orexin receptor antagonists (DORAs) block the activity of orexin 1 and 2 receptors to both reduce the threshold to transition into sleep and attenuate orexin-mediated arousal. Among DORAs evaluated clinically, suvorexant has pharmacokinetic properties engineered for a plasma half-life appropriate for rapid sleep onset and maintenance at low to moderate doses. Unlike GABA_A receptor modulators, DORAs promote both non-rapid eye movement (NREM) and REM sleep, do not disrupt sleep stage-specific quantitative electroencephalogram spectral profiles, and allow somnolence indistinct from normal sleep. The preservation of cognitive performance and the ability to arouse to salient stimuli after DORA administration suggest further advantages over historical therapies.

Long-term use of benzodiazepines in older patients in Germany: a retrospective analysis

BACKGROUND

The purpose of this study was to analyze the prevalence of long-term benzodiazepine use in older adults treated in general and neuropsychiatric practices in Germany.

METHODS

This study included 32,182 patients over the age of 65 years who received benzodiazepine prescriptions for the first time between January 2010 and December 2014 in general and neuropsychiatric practices in Germany. Follow up lasted until July 2016. The main outcome measure was the proportion of patients treated with benzodiazepines for >6 months.

RESULTS

The proportion of patients with benzodiazepine therapy for >6 months increased with age (65-70 years: 12.3%; 71-80 years: 15.5%; 81-90 years: 23.7%; >90 years: 31.6%) but did not differ significantly between men (15.5%) and women (17.1%). The proportion of patients who received benzodiazepines for >6 months was higher among those with sleep disorders (21.1%), depression (20.8%) and dementia (32.1%) than among those with anxiety (15.5%). By contrast, this proportion was lower among people diagnosed with adjustment disorders (7.7%) and back pain (3.8%).

CONCLUSION

Overall, long-term use of benzodiazepines is common in older people, particularly in patients over the age of 80 and in those diagnosed with dementia, sleep disorders, or depression.

Screening of benzodiazepines in thirty European rivers

Pharmaceuticals as environmental contaminants have received a lot of interest over the past decade but, for several pharmaceuticals, relatively little is known about their occurrence in European surface waters. Benzodiazepines, a class of pharmaceuticals with anxiolytic properties, have received interest due to their behavioral modifying effect on exposed biota. In this study, our results show the presence of one or more benzodiazepine(s) in 86% of the analyzed surface water samples (n = 138) from 30 rivers, representing seven larger European catchments. Of the 13 benzodiazepines included in the study, we detected 9, which together showed median and mean concentrations (of the results above limit of quantification) of 5.4 and 9.6 ng L^-1, respectively. Four benzodiazepines (oxazepam, temazepam, clobazam, and bromazepam) were the most commonly detected. In particular, oxazepam had the highest frequency of detection (85%) and a maximum concentration of 61 ng L^-1. Temazepam and clobazam were found in 26% (maximum concentration of 39 ng L^-1) and 14% (maximum concentration of 11 ng L^-1) of the samples analyzed, respectively. Finally, bromazepam was found only in Germany and in 16 out of total 138 samples (12%), with a maximum concentration of 320 ng L^-1. This study clearly shows that benzodiazepines are common micro-contaminants of the largest European river systems at ng L^-1 levels. Although these concentrations are more than a magnitude lower than those reported to have effective effects on exposed biota, environmental effects cannot be excluded considering the possibility of additive and sub-lethal effects.

Quetiapine Misuse and Abuse: Is it an Atypical Paradigm of Drug Seeking Behavior?

Recent case reports in medical literatures suggest that more and more second-generation atypical antipsychotics (AAs) have been prescribed for off-label use; quetiapine (Brand name: Seroquel^®) showed increase in its trend for off-label use. Little is known about the reasons behind this trend, although historical sedative and hypnotic prescription patterns suggest that despite relatively superior safety profiles of quetiapine (especially for movement disorders), it may be used for treating substance abuse disorder. In addition, recent studies have shown a strong potential for misuse and abuse (MUA) of quetiapine beyond Food and Drug Administration-approved indications. This includes drug-seeking behaviors, such as feigning symptoms, motivated by quetiapine and use of quetiapine in conjunction with alcohol. Quetiapine appears to be the most documented AA with street values bartered illicitly on the street. A recent report from the Drug Abuse Warning Network has shown a high prevalence of quetiapine-related emergency department visits involving MUA. Several other case studies have found that quetiapine causes seeking behaviors observed in substance use disorder. In fact, the majority of quetiapine MUA involved patients diagnosed with substance use disorder. In the absence of a definitive mechanism of action of quetiapine's reinforcing properties, it is imperative to gather robust evidence to support or refute increasing off-label use of AAs.

Slow subcutaneous infusion of flumazenil for the treatment of long-term, high-dose benzodiazepine users: a review of 214 cases

Despite the first reports concerning benzodiazepine dependence being published in the early 1960s literature, the risk of benzodiazepine addiction is still greatly debated. The severe discomfort and life threatening complications usually experienced by long-term benzodiazepine users who suddenly interrupt benzodiazepine intake have led to the development of several detoxification protocols. A successful strategy used by our Addiction Unit is abrupt benzodiazepine cessation by administering flumazenil slow subcutaneous infusion (FLU-SSI) with an elastomeric pump. Although some studies proved the efficacy of flumazenil infusion more than 20 years ago, only a few centres in the world offer this method to their patients. This paper reports the data related to 214 subjects addicted to high doses of benzodiazepine and treated with the FLU-SSI method between 2012 and 2014. This technique is less invasive and requires less nursing intervention than intravenous infusion. Our data support FLU-SSI as a possible efficient strategy for the treatment of patients with long-term, high-dose benzodiazepine addiction, and could become a routine therapy as long as the necessary further studies on dose, duration of infusion and safety issues are carried out.

Benzodiazepines: Sedation and Agitation

Dental anxiety is common and frequently poses a barrier to necessary dental treatment. The increasing availability of conscious sedation in dental practice has made treatment much more accessible for anxious patients. At present, benzodiazepines are the most commonly used drugs in sedation practice and provide a pleasant experience for most, but not all, patients. An understanding of the mechanism of action of benzodiazepines should inform our practice and deepen our understanding of why and how sedation may fail. CPD/CLINICAL RELEVANCE: As an increasing number of dentists provide sedation for their patients an update on benzodiazepines is timely.

Neuropharmacology beyond reductionism - A likely prospect

Neuropharmacology had several major past successes, but the last few decades did not witness any leap forward in the drug treatment of brain disorders. Moreover, current drugs used in neurology and psychiatry alleviate the symptoms, while hardly curing any cause of disease, basically because the etiology of most neuro-psychic syndromes is but poorly known. This review argues that this largely derives from the unbalanced prevalence in neuroscience of the analytic reductionist approach, focused on the cellular and molecular level, while the understanding of integrated brain activities remains flimsier. The decline of drug discovery output in the last decades, quite obvious in neuropharmacology, coincided with the advent of the single target-focused search of potent ligands selective for a well-defined protein, deemed critical in a given pathology. However, all the widespread neuro-psychic troubles are multi-mechanistic and polygenic, their complex etiology making unsuited the single-target drug discovery. An evolving approach, based on systems biology considers that a disease expresses a disturbance of the network of interactions underlying organismic functions, rather than alteration of single molecular components. Accordingly, systems pharmacology seeks to restore a disturbed network via multi-targeted drugs. This review notices that neuropharmacology in fact relies on drugs which are multi-target, this feature having occurred just because those drugs were selected by phenotypic screening in vivo, or emerged from serendipitous clinical observations. The novel systems pharmacology aims, however, to devise ab initio multi-target drugs that will appropriately act on multiple molecular entities. Though this is a task much more complex than the single-target strategy, major informatics resources and computational tools for the systemic approach of drug discovery are already set forth and their rapid progress forecasts promising outcomes for neuropharmacology.

Long-term use of benzodiazepines: Definitions, prevalence and usage patterns – a systematic review of register-based studies

Background

Numerous treatment guidelines recommend that long-term use of benzodiazepines (BZD) should be avoided primarily due to development of tolerance and a risk for BZD dependence. Despite this, long-term BZD use remains a controversial subject in clinical patient care with “for and against” debates. However, there is no explicit understanding of what is meant by long-term BZD use in real world. The aim of this study was to assess different definitions, usage patterns, prevalence and other characteristics of long-term BZD use based on published register-based studies. Synthesis of these characteristics is essential to derive a meaningful definition of long-term BZD.

Methods

Systematic review of register-based studies on long-term BZD use published in 1994–2014.

Results

Fourty-one studies met our predetermined inclusion criteria. The length of BZD use defined as “long-term” varied in these studies ranging from one month to several years. The most common definition was six months or longer during a year. The prevalence of long-term BZD use in the general population was estimated to be about 3%. The relative proportion of long-term BZD users (all definitions) in adult BZD users ranged from 6% to 76% (mean 24%; 95% CL 13–36%). The estimates were higher in studies only on the elderly (47%; 95% CL 31–64%). Long-term use involved typically steady treatment with low BZD doses. However, in elderly patients long-term BZD use and exceeding recommended doses was relatively common. Several characteristics associated with long-term use were found.

Conclusions

Long-term BZD use is common and a clinical reality. Uniform definitions for “long-term”, which is in line with population-based evidence, is needed to have more comparable results between studies. Our systematic review suggests that duration of BZD treatment over six months, the most common definition for long-term BZD use in the included studies. As also recommended previously, it is a useful starting point for further analyses on disadvantages but also potential advantages associated with long-term BZD use.

Serotonin, but not dopamine, controls the stress response and anxiety-like behavior in the crayfish Procambarus clarkii

In the animal kingdom, biogenic amines are widespread modulators of the nervous system that frequently interact to control mood. Our previous investigations in crayfish (Procambarus clarkii) have established that stress induces changes in brain serotonin (5-HT) concentrations that are responsible for the appearance of anxiety-like behavior (ALB). Here, we further analyze the roles of 5-HT and another biogenic amine, dopamine (DA), on the crayfish response to stress. We show that the intensity of crayfish ALB depends on the intensity of stressful stimulation and is associated with increased concentrations of 5-HT in the brain. These 5-HT levels were significantly correlated, before, as well as after stress, with those of DA, which were approximately 3- to 5-times less abundant. However, whereas the degree of ALB was clearly correlated with brain 5-HT concentrations, it was not significantly correlated with DA. Moreover, in contrast to injections of 5-HT, DA injections were not able to elicit a stress response or ALB. In addition, 5-HT and DA levels were not modified by treatment with the anxiolytic chlordiazepoxide, confirming that suppression of ALB by this GABA-A receptor ligand acts downstream and is independent of changes in crayfish bioamine levels. Our study also provides evidence that the anxiogenic effect of 5-HT injections can be prevented by a preliminary injection of 5-HT antagonists. Altogether, our results emphasize that the rises in brain concentrations of 5-HT, but not DA, play a role in controlling the induction and the intensity of crayfish ALB.

Anxiolytic effects of orcinol glucoside and orcinol monohydrate in mice

CONTEXT

Anxiety is a common psychological disorder, often occurring in combination with depression, but therapeutic drugs with high efficacy and safety are lacking. Orcinol glucoside (OG) was recently found to have an antidepressive action.

OBJECTIVE

To study the therapeutic potential of OG and orcinol monohydrate (OM) as anxiolytic agents.

MATERIALS AND METHODS

Anxiolytic effects in mice were measured using the elevated plus-maze, hole-board, and open-field tests. Eight groups of mice were included in each test. Thirty minutes before each test, mice in each group received one oral administration of OG (5, 10, or 20 mg/kg), OM (2.5, 5, or 10 mg/kg), the positive control diazepam (1 or 5 mg/kg), or control vehicle. Each mouse underwent only one test. Uptake of orcinol (5 mg/kg) in the brain was qualitatively detected using the HPLC-MS method.

RESULTS

OG (5, 10, and 20 mg/kg) and OM (2.5 and 5 mg/kg) increased the time spent in open arms and the number of entries into open arms in the elevated plus-maze test. OG (5 and 10 mg/kg) and OM (2.5 and 5 mg/kg) increased the number of head-dips in the hole-board test. At all tested doses, OG and OM did not significantly affect the locomotion of mice in the open-field test. Orcinol could be detected in the mouse brain homogenates 30 min after oral OM administration, having confirmed that OM is centrally active.

DISCUSSION AND CONCLUSION

The results demonstrated that OG and OM are anxiolytic agents without sedative effects, indicating their therapeutic potential for anxiety.

Concerns about quetiapine

Quetiapine is subsidised by the Pharmaceutical Benefits Scheme to treat schizophrenia and bipolar disorder. An extended-release formulation is also approved for use, but not subsidised, for treatment-resistant depression and generalised anxiety disorder. There is increasing off-label prescribing of quetiapine for indications such as insomnia that have little evidence to support them. This prescribing is often for at-risk patients, such as people with personality or social vulnerabilities and those at risk of metabolic complications or cardiovascular events. More evidence is required to support prescribing decisions regarding these off-label indications. In the meantime prescribers should be supported with alternatives to prescribing for these conditions, such as psychological therapies that have a better evidence base and safety record.