The role of anticonvulsant drugs in anxiety disorders: a critical review of the evidence

Anxiolytic-like effect of the leaves of Pseudospondias microcarpa (A. Rich.) Engl. in mice

BACKGROUND

Pseudospondias microcarpa is a plant used for managing various diseases including CNS disorders. Previous studies showed sedative and anticonvulsant effects, suggesting possible anxiolytic activity. This study therefore assessed the anxiolytic effects of P. microcarpa hydroethanolic leaf extract (PME) in mice.

METHODS

In the present study, anxiolytic-like effect of the extract in behavioural paradigms of anxiety - the elevated plus maze (EPM), light/dark box (LDB), social interaction test and stress-induced hyperthermia (SIH) - was evaluated.

RESULTS

Mice treated with PME (30-300 mg kg-1, p.o.) exhibited anxiolytic-like activity similar to diazepam in all the anxiety models used. The extract increased open arm activity (p<0.05) in the EPM as well as increasing the time spent in the lit area in relation to the time spent in the dark area of the LDB. Sociability and preference for social novelty significantly (p<0.05-0.001) increased in mice treated with PME. In the SIH paradigm in mice, both PME and the benzodiazepine receptor agonist, diazepam, significantly (p<0.05) reduced the stress-induced increase in rectal temperature. The extract did not impair motor coordination and balance in the beam walk test.

CONCLUSIONS

Results of the present study indicate that PME possesses anxiolytic-like effects in mice.

Anxiolytic activity and active principles of Piper amalago (Piperaceae), a medicinal plant used by the Q'eqchi' Maya to treat susto, a culture-bound illness

ETHNOPHARMACOLOGICAL RELEVANCE

The medicinal plant, Piper amalago L. (Piperaceae), is used traditionally by Q'eqchi' Maya healers for the treatment of "susto" a culture-bound syndrome. Previous research suggests that susto symptoms may be a manifestation of anxiety. The objectives were to characterize the effect of ethanolic extract of P. amalago in behavioral assays of anxiety at doses representative of traditional use and to isolate active principles.

MATERIALS AND METHODS

Rats treated orally with low dose ethanolic extracts of P. amalago leaves (8-75mg/kg) were tested in several behavioral paradigms including the elevated plus maze (EPM), social interaction (SI), and conditioned emotional response (CER) tests, and compared to diazepam, a positive control. The active anxiolytic principle was isolated by bioassay guided isolation using an in vitro GABAA competitive binding assay.

RESULTS

Extracts had significant anxiolytic activity in all behavioral tests, with the strongest activity in the SI and the CER paradigms. In an in vitro GABAA competitive binding assay, a 66.5µg/mL concentration of P. amalago ethanol extract displaced 50% of the GABAA-BZD receptor ligand [(3)H]-Flunitrazepam. Bioassay-guided fractionation identified a furofuran lignan, a molecule with structural similarity to yangambin, with high affinity for the GABAA-BZD receptor as the principle bioactive.

CONCLUSION

The results suggest that the ethnobotanical use of this plant may have a pharmacological basis in its anxiolytic activity, as demonstrated in animal behaviour tests.

Assessing and Managing Sleep Disturbance in Patients with Chronic Pain

Chronic pain is associated with symptoms that may impair a patient's quality of life, including emotional distress, fatigue, and sleep disturbance. There is a high prevalence of concomitant pain and sleep disturbance. Studies support the hypothesis that sleep and pain have a bidirectional and reciprocal relationship. Clinicians who manage patients with chronic pain often focus on interventions that relieve pain, and assessing and treating sleep disturbance are secondary or not addressed. This article reviews the literature on pain and co-occurring sleep disturbance, describes the assessment of sleep disturbance, and outlines nonpharmacologic and pharmacologic treatment strategies to improve sleep in patients with chronic pain.

Anxiety disorders in people with epilepsy

Anxiety disorders are frequent, though probably underdiagnosed, comorbidities in epilepsy. Epilepsy and anxiety may share common neurobiological correlates as shown in animal models and suggested by studies demonstrating anxiety disorders before the manifestation of epilepsy. Comorbid anxiety disorders have a major impact on the affected patients' quality of life and may increase the risk for suicidality. Successful treatment of the epilepsy may alleviate anxiety symptoms. Treatment of anxiety is based on selective serotonin reuptake inhibitors, benzodiazepines (although only as second-line choices), and psychotherapy. Specific AEDs (especially pregabalin) have been shown to have anxiolytic properties. This paper is aimed at reviewing anxiety disorders in patients with epilepsy discussing current scientific evidence about pathophysiology, clinical aspects, and treatment strategies.

Stress and epilepsy: fact or fiction, and what can we do about it?

People with epilepsy report that stress is their most common trigger for seizures and some believe it caused their epilepsy in the first place. The extensive preclinical, epidemiological and clinical studies examining the link between stress and epilepsy have given confusing results; the clinical studies in particular are fraught with confounders. However stress is clearly bad for health, and we now have substantial preclinical evidence suggesting that chronic stress worsens epilepsy; in selected cases it may even be a causal factor for epilepsy. Healthcare professionals working with people with epilepsy should pay more attention to stress in clinical practice. This review includes some practical advice and guidance for stress screening and management.

The crossroads of anxiety: distinct neurophysiological maps for different symptomatic groups

BACKGROUND

Despite the devastating impact of anxiety disorders (ADs) worldwide, long-lasting debates on causes and remedies have not solved the clinician's puzzle: who should be treated and how? Psychiatric classifications conceptualize ADs as distinct entities, with strong support from neuroscience fields. Yet, comorbidity and pharmacological response suggest a single "serotonin dysfunction" dimension. Whether AD is one or several disorders goes beyond academic quarrels, and the distinction has therapeutic relevance. Addressing the underlying dysfunctions should improve treatment response. By its own nature, neurophysiology can be the best tool to address dysfunctional processes.

PURPOSE

To search for neurophysiological dysfunctions and differences among panic disorder (PD), agoraphobia-social-specific phobia, obsessive-compulsive disorder (OCD) and generalized anxiety disorder.

METHODS

A sample population of 192 unmedicated patients and 30 aged-matched controls partook in this study. Hypothesis-related neurophysiological variables were combined into ten independent factors: 1) dysrhythmic patterns, 2) delta, 3) theta, 4) alpha, 5) beta (whole-head absolute power z-scores), 6) event-related potential (ERP) combined latency, 7) ERP combined amplitude (z-scores), 8) magnitude, 9) site, and 10) site of hyperactive networks. Combining single variables into representative factors was necessary because, as in all real-life phenomena, the complexity of interactive processes cannot be addressed through single variables and the multiplicity of potentially implicated variables would demand an extremely large sample size for statistical analysis.

RESULTS

The nonparametric analysis correctly classified 81% of the sample. Dysrhythmic patterns, decreased delta, and increased beta differentiated AD from controls. Shorter ERP latencies were found in several individual patients, mostly from the OCD group. Hyperactivities were found at the right frontorbital-striatal network in OCD and at the panic circuit in PD.

CONCLUSIONS

Our findings support diffuse cortical instability in AD in general, with individual differences in information processing deficits and regional hyperactivities in OCD and PD. Study limitations and the rationale behind the variable selection and combination strategy will be discussed before addressing the therapeutic implications of our findings.

Pharmacological treatment for generalized anxiety disorder in adults: an update

INTRODUCTION

Modest response and remission rates for the selective serotonin reuptake inhibitors and the serotonin-norepinephrine reuptake inhibitors, coupled with mounting evidence that the tolerability of the antidepressants (ADs) may have been overstated in the literature, has contributed to changes in prescribing patterns for generalized anxiety disorder (GAD). New interest in the absence of evidence that supports these standard therapies as superior to benzodiazepines stimulated a review of the literature.

AREAS COVERED

A literature search was conducted in the MedLine database with search terms 'generalized anxiety disorder' and 'treatment' for purposes of including relevant literature related to pharmacologic treatment of GAD. Aside from a review of pivotal literature, the authors also included newer studies that evaluated novel drug treatments. Last, the database was searched for benzodiazepine comparisons to standard therapy secondary to concerns that such literature is sparse. The review of newer modalities and the decision to include related literature was also based on the strength of the evidence and the status of their approval for the treatment of GAD.

EXPERT OPINION

Although ADs remain the most frequently prescribed medications for GAD, alternative and off-label therapies such as pregabalin, the atypical antipsychotics and vortioxetine are garnering interest. Based on the evidence available to us, it is our recommendation that along with the ADs, benzodiazepines be considered a possible first-line therapy in eligible patients based on the discretion and clinical judgment of the treating physician.

The relevance of neuropsychiatric symptoms and cognitive problems in new-onset epilepsy - Current knowledge and understanding

Neurobehavioral and cognition problems are highly prevalent in epilepsy, but most research studies to date have not adequately addressed the precise nature of the relationship between these comorbidities and seizures. To address this complex issue and to facilitate collaborative, innovative research in the rising field of neurobehavioral comorbidities and cognition disturbances in new-onset epilepsy, international epilepsy experts met at the 3rd Halifax International Epilepsy Conference & Retreat at White Point, South Shore, Nova Scotia, Canada from September 18 to 20, 2014. This Conference Proceedings provides a summary of the conference proceedings. Specifically, the following topics are discussed: (i) role of comorbidities in epilepsy diagnosis and management, (ii) role of antiepileptic medications in understanding the relationship between epilepsy and neurobehavioral and cognition problems, and (iii) animal data and diagnostic approaches. Evidence to date, though limited, strongly suggests a bidirectional relationship between epilepsy and cognitive and psychiatric comorbidities. In fact, it is likely that seizures and neurobehavioral problems represent different symptoms of a common etiology or network-wide disturbance. As a reflection of this shared network, psychiatric comorbidities and/or cognition problems may actually precede the seizure occurrence and likely get often missed if not screened.

Abolition of lifelong specific phobia: a novel therapeutic consequence of left mesial temporal lobectomy

Numerous imaging studies have confirmed the amygdala as prominent within a neural network mediating specific phobia, including arachnophobia. We report the case of a patient in whom arachnophobia was abolished after left temporal mesial lobectomy, with unchanged fear responses to other stimuli. The phenomenon of abolition of specific phobia after amygdala removal has not, to our knowledge, been previously reported.

Treating anxiety disorders in children and adolescents with epilepsy: what do we know?

Children with epilepsy are at significant risk of psychiatric disorders, which can in turn negatively impact social skills development, academic achievement, and quality of life. The most commonly reported psychiatric comorbidities in pediatric epilepsy are ADHD, depression, and anxiety. The prevalence rates of anxiety disorders in pediatric epilepsy range from 5 to 49%, and in the general population, anxiety disorders are the most common psychiatric disorder in childhood. For the purposes of this review, anxiety disorders will be examined in order to 1) examine rates of anxiety disorders in children and adolescents with epilepsy, 2) review treatment options for anxiety disorders in children with epilepsy, and 3) identify future avenues for the development of evidence-based practices for the treatment of anxiety disorders in youth with epilepsy.

Anticonvulsants to treat post-traumatic stress disorder

OBJECTIVE

We reviewed the existing literature on the efficacy of anticonvulsants in treating post-traumatic stress disorder.

METHODS

We performed a literature search using PubMed, EMBASE and the Cochrane database on 30 September 2013. Randomized,controlled studies that investigated the efficacy of anticonvulsants for post-traumatic stress disorder were included in this review. Studies with retrospective designs, case reports and case series were excluded.

RESULTS

A total of seven studies met the inclusion criteria for this review. Three studies used topiramate with negative findings regarding its efficacy. Two studies used divalproex, both of which failed to show superiority over placebo. One study used lamotrigine, with favourable results, and one study used tiagabine, with negative results.

CONCLUSIONS

Future long-term studies with larger sample sizes are needed to investigate the clinical utility of anticonvulsants for posttraumatic stress disorder treatment.

Topiramate and cognitive impairment: evidence and clinical implications

Topiramate is an antiepileptic drug (AED) with multiple mechanisms of action that has been shown to be effective in a number of neuropsychiatric disorders. However, cognitive dysfunction is frequently observed in such patients, often representing a relevant challenge in their management. Moreover, there is a long-held recognition that AEDs may profoundly affect cognitive functions. This paper reviews available data on cognitive adverse events in patients with neurological disorders treated with topiramate, discussing the role of different contributing factors such as the pharmacological properties of the drug, the specific features of the brain disorder, and other variables pertinent to the discussion. All studies agree that up to 10% of patients may complain of treatment-emergent adverse events on cognition. Such problems occur early during treatment (i.e. within 6 weeks) and emerge in a dose-dependent fashion, suggesting that such prevalence may be significantly reduced using the drug in monotherapy and adopting individualized doses and titration schedules. The magnitude of the problem is generally mild to moderate and the subjective perception of the patient needs to be taken into account. In fact, apart from language problems, data are not conclusive. Comparisons with new AEDs are limited to levetiracetam and lamotrigine, in both cases generally disfavoring topiramate, while data regarding first-generation AEDs show clear differences only for verbal fluency.

Depression and anxiety in people with epilepsy

Many recent epidemiological studies have found the prevalence of depression and anxiety to be higher in people with epilepsy (PWE) than in people without epilepsy. Furthermore, people with depression or anxiety have been more likely to suffer from epilepsy than those without depression or anxiety. Almost one-third of PWE suffer from depression and anxiety, which is similar to the prevalence of drug-refractory epilepsy. Various brain areas, including the frontal, temporal, and limbic regions, are associated with the biological pathogenesis of depression in PWE. It has been suggested that structural abnormalities, monoamine pathways, cerebral glucose metabolism, the hypothalamic-pituitary-adrenal axis, and interleukin-1b are associated with the pathogenesis of depression in PWE. The amygdala and the hippocampus are important anatomical structures related to anxiety, and γ-aminobutyric acid and serotonin are associated with its pathogenesis. Depression and anxiety may lead to suicidal ideation or attempts and feelings of stigmatization. These experiences are also likely to increase the adverse effects associated with antiepileptic drugs and have been related to poor responses to pharmacological and surgical treatments. Ultimately, the quality of life is likely to be worse in PWE with depression and anxiety than in PWE without these disorders, which makes the early detection and appropriate management of depression and anxiety in PWE indispensable. Simple screening instruments may be helpful for in this regard, particularly in busy epilepsy clinics. Although both medical and psychobehavioral therapies may ameliorate these conditions, randomized controlled trials are needed to confirm that.

Discovery of anxiolytic 2-ferrocenyl-1,3-thiazolidin-4-ones exerting GABAA receptor interaction via the benzodiazepine-binding site

Herein, we report on the synthesis, spectral, crystallographic and electrochemical properties of a small library of N-substituted 2-ferrocenyl-1,3-thiazolidin-4-ones, designed as novel GABAA benzodiazepine-binding site ligands. The anxiolytic properties of the title compounds were evaluated in several different in vivo models, whereas the involvement of the GABAA receptor complex in the activity of the most potent compound, 2-ferrocenyl-3-(4-methoxyphenylethyl)-1,3-thiazolidin-4-one, was inferred from experiments with known GABAA-targeting agents. Ligand docking experiments revealed that the high, dose-dependent, anxiolytic activity of the new compounds might be due to their favorable interactions with the benzodiazepine-binding site of the GABAA receptor complex. The incorporation of the ferrocene core and fine tuning of the distance between the thiazolidinone core and an additional aromatic ring were judged to be crucial structural requirements for the observed anxiolytic effect.

Co-occurrence of anxiety and bipolar disorders: clinical and therapeutic overview

BACKGROUND

Anxiety commonly co-occurs with bipolar disorders (BDs), but the significance of such "co-morbidity" remains to be clarified and its optimal treatment adequately defined.

METHODS

We reviewed epidemiological, clinical, and treatment studies of the co-occurrence of BD and anxiety disorder through electronic searching of Pubmed/MEDLINE and EMBASE databases.

RESULTS

Nearly half of BD patients meet diagnostic criteria for an anxiety disorder at some time, and anxiety is associated with poor treatment responses, substance abuse, and disability. Reported rates of specific anxiety disorders with BD rank: panic ≥ phobias ≥ generalized anxiety ≥ posttraumatic stress ≥ obsessive-compulsive disorders. Their prevalence appears to be greater among women than men, but similar in types I and II BD. Anxiety may be more likely in depressive phases of BD, but relationships of anxiety phenomena to particular phases of BD, and their temporal distributions require clarification. Adequate treatment trials for anxiety syndromes in BD patients remain rare, and the impact on anxiety of treatments aimed at mood stabilization is not clear. Benzodiazepines are sometimes given empirically; antidepressants are employed cautiously to limit risks of mood switching and emotional destabilization; lamotrigine, valproate, and second-generation antipsychotics may be useful and relatively safe.

CONCLUSIONS

Anxiety symptoms and syndromes co-occur commonly in patients with BD, but "co-morbid" phenomena may be part of the BD phenotype rather than separate illnesses.

Human hippocampus arbitrates approach-avoidance conflict

Animal models of human anxiety often invoke a conflict between approach and avoidance [1, 2]. In these, a key behavioral assay comprises passive avoidance of potential threat and inhibition, both thought to be controlled by ventral hippocampus [2–6]. Efforts to translate these approaches to clinical contexts [7, 8] are hampered by the fact that it is not known whether humans manifest analogous approach-avoidance dispositions and, if so, whether they share a homologous neurobiological substrate [9]. Here, we developed a paradigm to investigate the role of human hippocampus in arbitrating an approach-avoidance conflict under varying levels of potential threat. Across four experiments, subjects showed analogous behavior by adapting both passive avoidance behavior and behavioral inhibition to threat level. Using functional magnetic resonance imaging (fMRI), we observe that threat level engages the anterior hippocampus, the human homolog of rodent ventral hippocampus [10]. Testing patients with selective hippocampal lesions, we demonstrate a causal role for the hippocampus with patients showing reduced passive avoidance behavior and inhibition across all threat levels. Our data provide the first human assay for approach-avoidance conflict akin to that of animal anxiety models. The findings bridge rodent and human research on passive avoidance and behavioral inhibition and furnish a framework for addressing the neuronal underpinnings of human anxiety disorders, where our data indicate a major role for the hippocampus.

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Human behavior in a spatial approach-avoidance conflict resembles animal behavior

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Threat level in this context specifically engages anterior hippocampus

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Hippocampal lesions reduce passive avoidance and inhibition

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The study provides human evidence for an anterior hippocampus role in anxiety

Treatment of pediatric anxiety disorders

This article provides a brief review of the current available data concerning present treatment and potential new treatment advances for pediatric anxiety disorders, such as generalized anxiety disorder, separation anxiety disorder, social phobia, obsessive-compulsive disorder, and posttraumatic stress disorder. Disorder-specific treatment methods and innovations, particularly computer-assisted methods of delivery for cognitive behavioral therapy (CBT) will be reviewed. Additionally, the paper will discuss novel psychopharmacological compounds (e.g., D-cycloserine, riluzole, memantine, and anticonvulsant medications). Available evidence for the efficacy of novel medication strategies in adult studies and implications for their use in pediatrics will be discussed.

The chemistry and biological potential of azetidin-2-ones

Azetidin-2-ones, commonly referred as β-lactams, represent a unique ring system, with interesting chemistry and great biological potential. Besides its well known antibiotic activity, this ring system exhibits a wide range of activities, attracting the attention of researchers. The biological and pharmacological profile of azetidin-2-ones is reviewed here comprehensively with several examples under fourteen different activity heads. The chemistry and methods of synthesis have also been discussed.

Abnormal coherence imaging in panic disorder: a magnetoencephalography investigation

Increased coherence imaging values, as determined by magnetoencephalography, are indicative of increased neural excitability. The purpose of this investigation was to examine coherence imaging values in patients suffering from panic disorder (PD). We also ascertained whether regions with increased coherence had higher representation in the limbic frontotemporal regions (LFTRs). The highest coherence imaging values and their locations, among 54 Brodmann areas, were determined in six PD patients and six age-matched healthy controls. Magnetoencephalography scans were acquired using 148 magnetometer channels and 32 simultaneous EEG channels. Despite the small sample size, coherence imaging values were significantly higher in PD patients. Brain regions with increased coherence were significantly more in areas typically associated with LFTRs in PD patients when compared with controls. The above data suggest that coherence values may be increased in LFTRs of patients with PD. Recent advances in epilepsy research suggest that increased coherence may reflect increased excitability in these brain regions. On the basis of the data provided here as well as in the available literature, we propose that additional research examining coherence values in LFTRs of PD patients could inform the choice of medication in this patient population, with increased coherence (i.e. increased excitability) being a biomarker for favorable responses to medications that limit excitatory transmission, such as benzodiazepines or antiseizure drugs.

Low single dose gabapentin does not affect prefrontal and occipital gamma-aminobutyric acid concentrations

The γ-aminobutyric acid (GABA) system has been proposed as a target for novel antidepressant and anxiolytic treatments. Emerging evidence suggests that gabapentin (GBP), an anticonvulsant drug that significantly increases brain GABA levels, is effective in the treatment of anxiety disorders. The current study was designed to measure prefrontal and occipital GABA levels in medication-free healthy subjects after taking 0mg, 150mg and 300mg GBP. Subjects were scanned on a 3T scanner using a transmit-receive head coil that provided a relatively homogenous radiofrequency field to obtain spectroscopy measurement in the medial prefrontal (MPFC) and occipital cortex (OCC). There was no dose-dependent effect of GBP on GABA levels in the OCC or MPFC. There was also no effect on Glx, choline or N-acetyl-aspartate concentrations. The previously reported finding of increased GABA levels after GBP treatment is not evident for healthy subjects at the dose of 150 and 300mg. As a result, if subjects are scanned on a 3T scanner, low dose GPB is not useful as an experimental challenge agent on the GABA system.

Efficacy and safety of pregabalin in refractory focal epilepsy with and without comorbid anxiety disorders - results of an open-label, parallel group, investigator-initiated, proof-of-concept study

Anxiety disorders are prevalent in people with epilepsy and severely influence daily living and quality of life. Pregabalin (PGB) is licensed in Germany for the add on-treatment of focal epilepsy and for generalized anxiety disorder in adults. To our knowledge, PGB has not been studied before in patients with epilepsy and comorbid anxiety disorder. We included 41 adult patients with focal epilepsy in a monocentric, noncontrolled open-label study adding up to 600 mg of PGB to an antiepileptic baseline medication. Patients were allocated to two groups: patients with epilepsy plus anxiety disorder (EAG) and patients with epilepsy only (EOG). Endpoints were responder rate, seizure frequency, adverse events, and anxiety symptoms. The responder rate in the EAG was higher compared to that in the EOG (per protocol population: 9 [75.0%] vs. 2 [12.5%], p=0.001). Improvements in several psychological scales were found.

Depletion of serotonin in the basolateral amygdala elevates glutamate receptors and facilitates fear-potentiated startle

Our previous experiments demonstrated that systemic depletion of serotonin (5-hydroxytryptamine, 5-HT), similar to levels reported in patients with emotional disorders, enhanced glutamateric activity in the lateral nucleus of the amygdala (LA) and potentiated fear behaviors. However, the effects of isolated depletion of 5-HT in the LA, and the molecular mechanisms underlying enhanced glutamatergic activity are unknown. In the present study, we tested the hypothesis that depletion of 5-HT in the LA induces increased fear behavior, and concomitantly enhances glutamate receptor (GluR) expression. Bilateral infusions of 5,7-dihydroxytryptamine (4 μg per side) into the LA produced a regional reduction of serotonergic fibers, resulting in decreased 5-HT concentrations. The induction of low 5-HT in the LA elevated fear-potentiated startle, with a parallel increase in GluR1 mRNA and GluR1 protein expression. These findings suggest that low 5-HT concentrations in the LA may facilitate fear behavior through enhanced GluR-mediated mechanisms. Moreover, our data support a relationship between 5-HT and glutamate in psychopathologies.

Epilepsy, cognition, and neuropsychiatry (Epilepsy, Brain, and Mind, part 2)

Epilepsy is, of course, not one disease but rather a huge number of disorders that can present with seizures. In common, they all reflect brain dysfunction. Moreover, they can affect the mind and, of course, behavior. While animals too may suffer from epilepsy, as far as we know, the electrical discharges are less likely to affect the mind and behavior, which is not surprising. While the epileptic seizures themselves are episodic, the mental and behavioral changes continue, in many cases, interictally. The episodic mental and behavioral manifestations are more dramatic, while the interictal ones are easier to study with anatomical and functional studies. The following extended summaries complement those presented in Part 1.

Glutamate-based anxiolytic ligands in clinical trials

INTRODUCTION

With regard to anxiety, the role of the balance between glutamatergic and GABAergic systems was pursued for many years. The majority of drugs used presently as effective anxiolytics enhance the GABAergic system activity, thus increasing inhibition within the central nervous system (CNS). On the other hand, decreasing the activity of glutamatergic neurotransmission may attenuate excitation in the CNS, thus resulting in anxiolysis.

AREAS COVERED

The present review focuses on clinical data of well-known and recently discovered glutamatergic and, to a lesser extent, GABAergic agents, which reached at least the Phase II criteria.

EXPERT OPINION

A variety of glutamatergic agents active at both N-acetylo-D-asparaginian and metabotropic glutamate (mGlu) receptors have been tested in humans to examine their potential anxiolytic activity. Many compounds acting on the glutamatergic system and approved for the treatment of other disorders than anxiety were shown to exert anxiolytic effects in clinical trials. Those are mainly voltage-dependent ion channel ligands as well as d-cycloserin and memantine. Also, ligands active at mGlu receptors, such as fenobam and LY354740, exhibited activity in controlled clinical trials. However, relatively few trials are found on the agents that are focused on GABAergic neurotransmission. Therefore, it seems that glutamatergic system may become a novel target for modern and effective anxiolytics.

Antiepileptic drug effects on mood and behavior: molecular targets

With almost 100 years of clinical experience, antiepileptic drugs (AEDs) remain the mainstay of epilepsy treatment. They suppress epileptic seizures by acting on a variety of mechanisms and molecular targets involved in the regulation of neuronal excitability. These include inhibitory-GABAergic and excitatory-glutamatergic neurotransmission, as well as ion (sodium and calcium) conductance through voltage-gated channels. On the other hand, accruing evidence indicates that these mechanisms and targets are also implicated in the regulation of mood and behavior, which may explain why each AED is associated with specific psychotropic effects. These effects, however, cannot be explained solely on the basis of the known mode of action of each AED, and other mechanisms or targets are likely to be implicated. In this article, we review positive and negative effects of AEDs on mood and behavior, discuss putative underlying mechanisms, and highlight knowledge gaps which should be addressed in future studies.

Does Pregabalin (Lyrica(®) ) help patients reduce their use of benzodiazepines? A comparison with gabapentin using the Norwegian Prescription Database

Pregabalin (Lyrica(®) ) may have an anxiolytic effect. It has also been reported that the use of this drug helps prevent excessive use of benzodiazepines. The aim of the present study was to examine if pregabalin reduced the intake of benzodiazepines. In a pharmacoepidemiological study, we compared pregabalin to the older drug gabapentin (Neurontin(®) ) in the Norwegian Prescription Database. The database has total capture of all prescribed drugs outside institutions. We identified all prescriptions for the two drugs for patients aged 18-69 years between 2004 and 2007. Patients were grouped as psychiatric patients, patients with epilepsy, patients with neuropathic pain or non-specified users. We measured the use of benzodiazepines 182 days before and after the initiation of treatment with pregabalin and gabapentin. Between 15% and 29% of the patients were able to stop using benzodiazepines after starting pregabalin or gabapentin treatment. Psychiatric patients who started pregabalin were able to reduce the amount of benzodiazepines used by 48%, compared to only 14% among starters of gabapentin. This study shows that some patients reduced their use of benzodiazepines substantially after starting pregabalin.

Lamotrigine in the treatment of unipolar depression with and without comorbidities: a literature review

To review the available data behind the use of lamotrigine in unipolar depression and common comorbid conditions. A PubMed based literature review was conducted using keywords related to lamotrigine, depression, anxiety, post traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), and personality disorders. A large number of trials using lamotrigine for unipolar depression and various comorbid conditions were reviewed. A major limitation behind the majority of studies was a limited course of the treatment phase. The most robust data was found among studies that followed patients for over 8 weeks, and used higher dosages. Patients with comorbid anxiety states appeared to benefit. Patients with borderline personality disorder also appeared to benefit. The benefits of lamotrigine in unipolar depression have been inconsistently noted in a number of studies. This is due in part to short treatment phases, atypical domains of benefit and different patient populations across studies. Patients with more treatment-resistance, comorbid anxiety and borderline personality disorder may be more able to benefit from lamotrigine.

Optimal treatment of social phobia: systematic review and meta-analysis

This article proposes a number of recommendations for the treatment of generalized social phobia, based on a systematic literature review and meta-analysis. An optimal treatment regimen would include a combination of medication and psychotherapy, along with an assertive clinical management program. For medications, selective serotonin reuptake inhibitors and dual serotonin-norepinephrine reuptake inhibitors are first-line choices based on their efficacy and tolerability profiles. The nonselective monoamine oxidase inhibitor, phenelzine, may be more potent than these two drug classes, but because of its food and drug interaction liabilities, its use should be restricted to patients not responding to selective serotonin reuptake inhibitors or serotonin-norepinephrine reuptake inhibitors. There are other medication classes with demonstrated efficacy in social phobia (benzodiazepines, antipsychotics, alpha-2-delta ligands), but due to limited published clinical trial data and the potential for dependence and withdrawal issues with benzodiazepines, it is unclear how best to incorporate these drugs into treatment regimens. There are very few clinical trials on the use of combined medications. Cognitive behavior therapy appears to be more effective than other evidence-based psychological techniques, and its effects appear to be more enduring than those of pharmacotherapy. There is some evidence, albeit limited to certain drug classes, that the combination of medication and cognitive behavior therapy may be more effective than either strategy used alone. Generalized social phobia is a chronic disorder, and many patients will require long-term support and treatment.

Evidence-based pharmacotherapy of panic disorder: an update

The evidence-based pharmacotherapy of panic disorder continues to evolve. This paper reviews data on first-line pharmacotherapy, evidence for maintenance treatment, and management options for treatment-refractory patients. A Medline search of research on pharmacotherapy was undertaken, and a previous systematic review on the evidence-based pharmacotherapy of panic disorder was updated. Selective serotonin reuptake inhibitors remain a first-line pharmacotherapy of panic disorder, with the serotonin noradrenaline reuptake inhibitor venlafaxine also an acceptable early option. Temporary co-administration of benzodiazepines can be considered. Maintenance treatment reduces relapse rates, but further research to determine optimal duration is needed. For patients not responding to first-line agents several pharmacotherapy options are available, but there is a notable paucity of data on the optimal choice.

Pregabalin for the Treatment of Generalized Anxiety Disorder

Objective:

To evaluate the efficacy and tolerability of pregabalin in the treatment of generalized anxiety disorder (GAD).

Data Sources:

A search of PubMed (1966-December 2011) and International Pharmaceutical Abstracts (1970-December 2011) was conducted using the MeSH and free-text terms pregabalin, anxiety disorders, and anxiety.

Study Selection and Data Extraction:

All English-language articles identified through the search were evaluated for inclusion. Only randomized controlled trials involving the use of pregabalin for the treatment of GAD were included in the review.

Data Synthesis:

Eight published trials were identified through the search strategy. Successful treatment of GAD with pregabalin versus placebo and active comparators has been reported in clinical trials. Pregabalin lowered total Hamilton Rating Scale for Anxiety scores within 1 week and was effective against both somatic and psychic subcomponents. In 1 controlled clinical trial, pregabalin was found to be effective in patients aged 65 years and older. Another trial demonstrated improved relapse rates when pregabalin, compared with placebo, was used for up to 6 months. The most commonly experienced adverse events were somnolence, dizziness, headache, and dry mouth.

Conclusions:

Available evidence suggests that pregabalin is effective and well tolerated in the treatment of GAD. As somnolence and dizziness are common adverse effects, caution should be used in elderly patients. Pregabalin rapidly relieves anxiety, a benefit that it may have over many other currently available therapeutic options besides benzodiazepines. While not a first-line therapy in GAD, pregabalin offers another treatment option in patients who do not respond to or who suffer intolerable adverse effects from other agents.

Pharmacotherapy of anxiety disorders: a critical review

Given the enormous contribution of anxiety disorders to the burden of disease, it is key to optimize their prevention and treatment. In this critical review we assess advances in the pharmacotherapy of anxiety disorders, as well as remaining challenges, in recent decades, the field has seen rigorous clinical trial methods to quantify the efficacy and safety of serendipitously discovered agents, more focused development of medications with selective mechanisms of action, and the gradual translation of insights from laboratory research into proof-of-principle clinical trials. On the positive side, a considerable database of studies shows efficacy and relative tolerability of the selective serotonin reuptake inhibitors in the major anxiety disorders, and secondary analyses of such datasets have informed questions such as optimal definition of response and remission, optimal dose and duration, and comparative efficacy of different agents. Significant challenges in the field include barriers to appropriate diagnosis and treatment of anxiety disorders, failure of a significant proportion of patients to respond to first-line pharmacotherapy agents, and a limited database of efficacy or effectiveness studies to guide treatment in such cases.

Interactions between antiepileptics and second-generation antipsychotics

INTRODUCTION

Pharmacokinetic and pharmacodynamic drug interactions (DIs) can occur between antiepileptics (AEDs) and second-generation antipsychotics (SGAPs). Some AED and SGAP pharmacodynamic mechanisms are poorly understood. AED-SGAP combinations are used for treating comorbid illnesses or increasing efficacy, particularly in bipolar disorder.

AREAS COVERED

This article provides a comprehensive review of the interactions between antiepileptics and second-generation antipsychotics. The authors cover pharmacokinetic AED-SGAP DI studies, the newest drug pharmacokinetics in addition to the limited pharmacodynamic DI studies.

EXPERT OPINION

Dosing correction factors and measuring SGAP levels can help to compensate for the inductive properties of carbamazepine, phenytoin, phenobarbital and primidone. Further studies are needed to establish the clinical relevance of combining: i) AED strong inducers with amisulpride, asenapine, iloperidone, lurasidone and paliperidone; ii) valproate with aripiprazole, asenapine, clozapine and olanzapine; iii) high doses of oxcarbazepine (≥ 1500 mg/day) or topiramate (≥ 400 mg/day) with aripiprazole, lurasidone, quetiapine, risperidone, asenapine and olanzapine. Two pharmacodynamic DIs are beneficial: i) valproate-SGAP combinations may have additive effects in bipolar disorder, ii) combining topiramate or zonisamide with SGAPs may decrease weight gain. Three pharmacodynamic DIs contributing to decreased safety are common: sedation, weight gain and swallowing disturbances. A few AED-SGAP combinations may increase risk for osteoporosis or nausea. Three potentially lethal but rare pharmacodynamic DIs include pancreatitis, agranulocytosis/leukopenia and heat stroke. The authors believe that collaboration is needed from drug agencies and pharmaceutical companies, the clinicians using these combinations, researchers with expertise in meta-analyses, grant agencies, pharmacoepidemiologists and DI pharmacologists for future progression in this field.

Depression in temporal lobe epilepsy: a review of prevalence, clinical features, and management considerations

Depression in temporal lobe epilepsy has been established as a frequent occurrence, and various possible mechanisms for this significant comorbidity have been posited. However, there is still little to guide a clinician in the recognition and management of depression in patients with temporal lobe epilepsy. This is in part due to the lack of consistent findings in earlier studies, which was likely partly due to variabilities in methodology, sampling, and diagnosis of both temporal lobe epilepsy and depression. However, in recent years, significant effort has been made to address these issues and provide a framework for diagnosis and management of depression in this population. The following is a review of the literature, with special emphasis on clinical phenomenology of depressive symptoms, described bidirectional risk between depression and temporal lobe epilepsy, and treatment strategies in the context of potential drug interactions with antiepileptic drugs.