Pregabalin for the treatment of social anxiety disorder

GABAergic implications in anxiety and related disorders

Evidence indicates that anxiety disorders arise from an imbalance in the functioning of brain circuits that govern the modulation of emotional responses to possibly threatening stimuli. The circuits under consideration in this context include the amygdala's bottom-up activity, which signifies the existence of stimuli that may be seen as dangerous. Moreover, these circuits encompass top-down regulatory processes that originate in the prefrontal cortex, facilitating the communication of the emotional significance associated with the inputs. Diverse databases (e.g., Pubmed, ScienceDirect, Web of Science, Google Scholar) were searched for literature using a combination of different terms e.g., "anxiety", "stress", "neuroanatomy", and "neural circuits", etc. A decrease in GABAergic activity is present in both anxiety disorders and severe depression. Research on cerebral functional imaging in depressive individuals has shown reduced levels of GABA within the cortical regions. Additionally, animal studies demonstrated that a reduction in the expression of GABAA/B receptors results in a behavioral pattern resembling anxiety. The amygdala consists of inhibitory networks composed of GABAergic interneurons, responsible for modulating anxiety responses in both normal and pathological conditions. The GABAA receptor has allosteric sites (e.g., α/γ, γ/β, and α/β) which enable regulation of neuronal inhibition in the amygdala. These sites serve as molecular targets for anxiolytic medications such as benzodiazepine and barbiturates. Alterations in the levels of naturally occurring regulators of these allosteric sites, along with alterations to the composition of the GABAA receptor subunits, could potentially act as mechanisms via which the extent of neuronal inhibition is diminished in pathological anxiety disorders.

New frontiers in the pharmacological treatment of social anxiety disorder in adults: an up-to-date comprehensive overview

INTRODUCTION

Social anxiety disorder (SAD) is associated with scarce functioning and poor quality of life. Although selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) are currently first-line treatments, side effects are common and affect treatment compliance in approximately 50% of patients. This review aimed to summarize data on the efficacy of unlabeled molecules for SAD treatment.

AREAS COVERED

Research in the main psychiatric databases was conducted (PubMed, PsychINFO, and EMBASE-Ovid) to select studies investigating the efficacy of marketed molecules not labeled for SAD treatment.

EXPERT OPINION

Pregabalin at high doses (450-600 mg/day) appears to be a reliable alternative strategy for SAD treatment. Among the SSRIs not labeled for SAD, citalopram showed the most promising results. Quetiapine, levetiracetam, and other antidepressants/serotonergic agents, such as fluoxetine, duloxetine, monoamine oxidase inhibitors, tricyclics, mirtazapine, atomoxetine, nefazodone, vilazodone, and buspirone, presented negative, limited, or contrasting results. Data on anticonvulsants, olanzapine, tiagabine, and ketamine were positive, but preliminary. The risk/benefit ratio must be considered in the prescription of unlabeled compounds; treatment with pregabalin may be associated with somnolence and dizziness. Future research may contribute to the identification of targeted molecules for the treatment of this disorder.

Die soziale Angststörung – ein Update

Es kann passieren, dass man sich vermeintlich peinlich oder insuffizient verhält; kurzfristige Gefühle wie Scham oder Selbstzweifel bleiben meist jedoch ohne Bedeutung. Kommt es aber zu überzogenen und überdauernden Befürchtungen oder signifikantem Vermeidungsverhalten, kann es sich um eine soziale Angststörung (SAS) handeln. Der vorliegende Artikel bietet eine Übersicht über den aktuellen Stand der Ätiologie, Diagnostik und Therapie der SAS.

A Review of Ocular Complications Associated with Medications Used for Anxiety, Depression, and Stress

This review of commonly prescribed psychotropic drugs aims to update the clinician on possible ophthalmic side effects that may include dry eye, diplopia, mydriasis, and cataracts. This review summarizes our current knowledge of known ocular side effects of psychotropic drugs based on reviews, case reports, case-control studies, a case series, and cross-sectional observational studies reported in the recent literature. The review covers disorders related to depression, anxiety, and stress which are commonly encountered within society and can have debilitating impacts on an individual's quality of life that may require chronic therapeutic management. The main medications used in the treatment and management of these conditions typically target receptors, metabolic enzymes, or transport pumps that alter the pre- and/or post-synaptic levels of neurotransmitters such as serotonin, norepinephrine, dopamine, gamma-aminobutyric acid, and opioids to improve mood and/or relieve pain and anxiety. Novel non-therapeutic options are undergoing clinical trials, and some patients may seek alternative therapies or have associated substance abuse issues to alleviate their symptoms. This review summarizes some of the clinical signs of depression and the main therapeutic options and their reported ocular side effects which may be pertinent today given the rise in use of psychotropic medications used to manage depression, anxiety, and stress.

Pharmacotherapy of Anxiety Disorders: Current and Emerging Treatment Options

(Appeared originally in Frontiers in Psychiatry 2020 Dec 23; 11:595584)

Synthesis, anticonvulsant, and antinociceptive activity of new 3-(3-methyl-2,5-dioxo-3-phenylpyrrolidin-1-yl)propanamides and 3-phenyl-butanamides

A focused library of new 3-(3-methyl-2,5-dioxo-3-phenylpyrrolidin-1-yl)propanamides and their nonimide analogs were synthesized and tested for anticonvulsant activity. These compounds were obtained through the coupling reaction of the starting carboxylic acids with appropriate amines. The initial anticonvulsant screening was performed in mice (intraperitoneal administration) using the maximal electroshock seizure (MES) and the subcutaneous pentylenetetrazole (scPTZ) seizure models. The most promising compound 6 showed more potent protection in the MES and scPTZ tests than valproic acid, which is still recognized as one of the most relevant first-line anticonvulsants. The structure-activity relationship analysis revealed that the presence of the pyrrolidine-2,5-dione ring is important but not indispensable to retain anticonvulsant activity. Additionally, compound 6 showed potent antinociceptive properties in the oxaliplatin-induced neuropathic pain model in mice. The most plausible mechanism of action for compound 6 may result from its influence on the neuronal sodium channel (Site 2) and the high-voltage-activated L-type calcium channel.

Pharmacotherapy of Anxiety Disorders: Current and Emerging Treatment Options

Anxiety disorders are the most prevalent psychiatric disorders and a leading cause of disability. While there continues to be expansive research in posttraumatic stress disorder (PTSD), depression and schizophrenia, there is a relative dearth of novel medications under investigation for anxiety disorders. This review's first aim is to summarize current pharmacological treatments (both approved and off-label) for panic disorder (PD), generalized anxiety disorder (GAD), social anxiety disorder (SAD), and specific phobias (SP), including selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), azapirones (e.g., buspirone), mixed antidepressants (e.g., mirtazapine), antipsychotics, antihistamines (e.g., hydroxyzine), alpha- and beta-adrenergic medications (e.g., propranolol, clonidine), and GABAergic medications (benzodiazepines, pregabalin, and gabapentin). Posttraumatic stress disorder and obsessive-compulsive disorder are excluded from this review. Second, we will review novel pharmacotherapeutic agents under investigation for the treatment of anxiety disorders in adults. The pathways and neurotransmitters reviewed include serotonergic agents, glutamate modulators, GABAergic medications, neuropeptides, neurosteroids, alpha- and beta-adrenergic agents, cannabinoids, and natural remedies. The outcome of the review reveals a lack of randomized double-blind placebo- controlled trials for anxiety disorders and few studies comparing novel treatments to existing anxiolytic agents. Although there are some recent randomized controlled trials for novel agents including neuropeptides, glutamatergic agents (such as ketamine and d-cycloserine), and cannabinoids (including cannabidiol) primarily in GAD or SAD, these trials have largely been negative, with only some promise for kava and PH94B (an inhaled neurosteroid). Overall, the progression of current and future psychopharmacology research in anxiety disorders suggests that there needs to be further expansion in research of these novel pathways and larger-scale studies of promising agents with positive results from smaller trials.

[Anxiety in the elderly]

Anxiety occurs in about one third of people over 65 years of age. However, its identification in this age has significant difficulties. The clinical manifestations, pathogenetic mechanisms, approaches to the diagnosis and treatment of various types of anxiety are described in the article. Particular attention is paid to the comorbidity of anxiety disorders in elderly patients. A comprehensive approach to the treatment of elderly patients with anxiety includes psychotherapeutic and pharmacotherapeutic approaches. Special attention should be paid to the efficacy and safety of the drugs, which is especially important in this category of patients.

Efficacy and tolerability of fluvoxamine in adults with social anxiety disorder: A meta-analysis

BACKGROUND

No meta-analysis for estimating the comprehensive efficacy and tolerability of fluvoxamine in patients with social anxiety disorder (SAD) has been published.

OBJECTIVE

To investigate the efficacy and tolerability of fluvoxamine in adults with SAD, trials meeting the following criteria were identified: population: ≥18 years of age with a diagnosis of SAD; intervention: fluvoxamine; study design: placebo-controlled randomized controlled trials (RCTs); outcomes: efficacy and tolerability outcomes.

METHODS

We conducted a comprehensive search of PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and ClinicalTrials.gov for RCTs on January 3, 2018. Review Manager 5.3 and Stata Version 12.0 software were used for all statistical analyses. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated for continuous variables, and odds ratios (ORs) with 95% CIs were calculated for dichotomous variables. Cochrane Collaboration's risk of bias tool was used to assess the likelihood of risk of bias. Efficacy was assessed by mean changes in the Liebowitz Social Anxiety scale (LSAS) total score and the Clinical Global Impression Severity of Illness (CGI-S) score as well as the response rate. Tolerability was mainly assessed by the discontinuation rate due to adverse events (AEs) and the incidence of most frequent treatment-emergent AEs (TEAEs).

RESULTS

This meta-analysis included 5 RCTs. Mean changes in LSAS total and CGI-S scores were both significantly greater in patients treated with fluvoxamine than those treated with placebo (LSAS: MD = 11.90, 95% CI = 8.09-15.71, P < .001; CGI-S: MD = 0.52, 95% CI = 0.33-0.72, P < .001). Response rate was higher in fluvoxamine group as compared with placebo (OR = 1.71, 95% CI = 1.30-2.24, P < .001). Additionally, mean change in the Sheehan disability scale score was significantly greater in fluvoxamine group than placebo group (OR = 2.11, 95% CI = 1.03-3.18, P < .001). The discontinuation rate due to AEs was higher in patients that received fluvoxamine compared to those received placebo (OR = 5.99, 95% CI = 2.24-15.99, P < .001), as was the incidence of overall TEAEs (any AE) (OR = 2.66, 95% CI = 1.77-4.02, P < .001). However, the incidence of serious AEs was not significantly different between the 2 groups (OR = 0.99, 95% CI = 0.25-3.89, P = .99).

CONCLUSION

Fluvoxamine was found to be effective in adult patients with SAD, with acceptable tolerability.

Chronic pregabalin treatment decreases excitability of dentate gyrus and accelerates maturation of adult-born granule cells

Pregabalin (PGB) is extensively prescribed to treat neurological and neuropsychiatrical conditions such as neuropathic pain, anxiety disorders, and epilepsy. Although PGB is known to bind selectively to the α2δ subunit of voltage-gated calcium channels, there is little understanding about how it exerts its therapeutic effects. In this article, we analyzed the effects of an in vivo chronic treatment with PGB over the physiology of dentate gyrus granule cells (DGGCs) using ex vivo electrophysiological and morphological analysis in adult mice. We found that PGB decreases neuronal excitability of DGGCs. In addition, PGB accelerates maturation of adult-born DGGCs, an effect that would modify dentate gyrus plasticity. Together, these findings suggest that PGB reduces activity in the dentate gyrus and modulates overall network plasticity, which might contribute to its therapeutic effects. Cover Image for this issue: doi: 10.1111/jnc.13783.

Pregabalin for Refractory Radicular Leg Pain due to Lumbar Spinal Stenosis: A Preliminary Prospective Study

We investigated the efficacy of pregabalin (PGB) for neuropathic leg pain in lumbar spinal stenosis (LSS) patients with disturbed activities of daily living (ADL)/quality of life (QOL) in a prospective observational study. Subjects were a total of 104 LSS patients with neuropathic pain (NeP) in leg and neurological intermittent claudication (IMC) refractory to nonsteroidal anti-inflammatory drugs (NSAIDs) for at least a month. NeP was identified using screening tool, Pain DETECT questionnaire. Visual analog scale (VAS) scores and responses to the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were assessed before and 6 weeks after PGB treatment initiation. Changes in IMC distance and adverse events were also recorded. PGB significantly improved their VAS scores for pain and sleep quality (P < 0.001). With respect to JOABPEQ, significant improvements were observed with regard to the following dimensions: pain-related disorders (P < 0.01), lumbar spine dysfunction (P = 0.031), gait disturbance (P = 0.028), and psychological disorders (P = 0.014). The IMC distance showed an improvement tendency after PGB treatment, albeit with no significance (P = 0.063). Minor adverse events such as dizziness were observed. PGB can be effective for neuropathic leg pain refractory to NSAIDs in LSS patients, resulting in not only pain control but also improving lower back pain-related ADL/QOL scores.