Efficacy of pregabalin in the treatment of generalized anxiety disorder: double-blind, placebo-controlled comparison of BID versus TID dosing

A single injection of pregabalin induces short- and long-term beneficial effects on fear memory and anxiety-like behavior in rats with experimental type-1 diabetes mellitus

Anxiety Disorders and Posttraumatic Stress Disorders (PTSD) associated with type-1 diabetes mellitus (T1DM) are increasingly common comorbidities and the treatment is quite challenging. In that sense, evidence indicates that the anticonvulsant pregabalin is highly effective in treating severe cases of anxiety, as well as PTSD and diabetic neuropathic pain which is also very prevalent in T1DM. Herein, the short- and long-term effects of a single injection of pregabalin on the acquisition of a fear extinction memory and parameters of anxiety in induced-T1DM animals were investigated. For that, we used the contextual fear conditioning (CFC) and elevated plus maze paradigms, respectively. A putative antioxidant activity was also evaluated. Our findings demonstrated that induced-T1DM animals presented greater expression of fear memory, difficulty in extinguishing this fear memory, associated with a more pronounced anxiety-like response. Pregabalin was able to induce a short and long-lasting effect by facilitating the acquisition of the fear extinction memory and inducing a later anxiolytic-like effect. Also, the increased lipid peroxidation levels in the hippocampus and prefrontal cortex of induced-T1DM rats were reduced after pregabalin injection, while the decreased levels of reduced glutathione were increased in the hippocampus. Despite the need for more studies to understand the mechanism of action of pregabalin under these conditions, our data demonstrate for the first time that a single injection of pregabalin in a specific time window was able to improve behavioral parameters in addition to inducing neuroprotective effect. Thus, pregabalin has potential worth exploring for the treatment of PTSD and/or Anxiety associated with T1DM.

Pregabalin induced visual hallucinations - a rare adverse reaction

Background

Pregabalin is an anticonvulsive, analgesic and anxiolytic medication. The typical side effects include dizziness, somnolence and weight gain. Few studies or case reports have demonstrated psychiatric side effects resulting from its use.

Case presentation

We present a patient who suffered visual hallucinations and agitation associated with an increase in pregabalin dose, resolving completely after pregabalin discontinuation.

Conclusions

Acute visual hallucinations should be considered in the clinical spectrum of very rare side effects of pregabalin use, especially at higher doses. Tapered discontinuation of the medication can improve and resolve symptoms.

Acceptance of Anxiety through Art Therapy: A Case Report Exploring How Anthroposophic Art Therapy Addresses Emotion Regulation and Executive Functioning

Anxiety is a major problem for many individuals, causing impairment in daily life. Art therapy is often deployed and although positive results are communicated in clinical practice, its effectiveness and working mechanisms have hardly been studied. Therefore, it is important to systematically describe the intervention process and to detect the working mechanisms to be able to evaluate them. Narrative case studies help to understand the intervention in more depth. A typical case file was selected for case reporting according to scientific (CARE & CARE-AAT) guidelines, with the aim to explore the therapeutic elements that contributed to the reduction of anxiety. The report describes the intervention process of a 54-year-old female, suffering from anxiety since childhood and diagnosed with panic disorder, agoraphobia, claustrophobia and hypochondria. After 14 sessions of anthroposophic art therapy, reduction of anxiety was shown, as well as improvements of emotion regulation and executive functioning. The client indicated that she became more tolerant and accepting towards her anxiety. She noted a softened attitude towards herself and her complaints, even one year after art therapy. The course of treatment suggests that aspects of emotion regulation and executive functioning were addressed through implicit learning processes in different art therapy assignments.

Pharmacological and psychological interventions for generalized anxiety disorder in adults: A network meta-analysis

Generalized anxiety disorder (GAD) is a significant and common mental illness with a lifetime prevalence of 3.7%. Regardless of the complexity of treatment decisions for GAD, few studies have conducted systematic comparisons of the efficacies of varying interventions. Thus, this study performed a valid network meta-analysis (NMA) of randomized controlled trials (RCTs) to synthesize direct and indirect evidence for alternative interventions for GAD. We searched four major bibliographic databases, the Cochrane Central Register of Controlled Trials, Embase, PsycINFO, and PubMed, for published RCTs of adult patients with a diagnosis of GAD and allowed for all comorbidities. A total of 91 articles (14,812 participants) were identified in the final NMA. The results showed that all pharmacological treatments except for serotonin modulators and second-generation antipsychotics had greater effects than placebo: norepinephrine-dopamine reuptake inhibitors (standardized mean difference (SMD) -1.84, 95% credible interval -3.05 to -0.62), noradrenergic and specific serotonergic antidepressants (-0.91, -1.62 to -0.20), melatonergic receptor agonists (-0.68, -1.15 to -0.21), selective serotonin reuptake inhibitors (SSRIs; -0.67, -0.90 to -0.43), azapirones (-0.58, -1.00 to -0.17), anticonvulsants (-0.56, -0.85 to -0.28), serotonin-norepinephrine reuptake inhibitors (SNRIs; -0.54, -0.79 to -0.30), and benzodiazepines (BZDs; -0.40, -0.65 to -0.15). Most psychological and self-help interventions exerted greater effects than the waitlist group. However, no psychological interventions had greater effects compared with the psychological placebo. Overall, most pharmacological interventions had larger effect sizes than psychological interventions, and most psychological interventions showed larger effect sizes than self-help interventions.

Telmisartan and captopril ameliorate pregabalin-induced heart failure in rats

Pregabalin (PRG) is highly effective in the treatment of epilepsy, neuropathic pain and anxiety disorders. Despite its potential benefits, PRG administration has been reported to induce or exacerbate heart failure (HF). It has been previously documented that overactivation of the renin angiotensin system (RAS) is involved in HF pathophysiological mechanism. The target of the current study was to examine the possible cardioprotective effect of telmisartan (Tel), an angiotensin II type 1 receptor (AT1R) blocker, compared with that of captopril (Cap), an angiotensin converting enzyme (ACE) inhibitor, in ameliorating PRG-induced HF in rats by assessing morphometric, echocardiographic and histopathological parameters. Furthermore, to investigate the role of RAS blockade by the two drugs in guarding against PRG-induced changes in cardiac angiotensin 1-7 (Ang 1-7) and angiotensin II (Ang II) levels, in addition to myocardial expression of ACE2, ACE, Mas receptor (MasR) and AT1R. Results showed that PRG administration induced morphometric, echocardiographic and histopathological deleterious alterations and significantly elevated cardiac Ang II, ACE and AT1R levels, while reduced Ang 1-7, ACE2 and MasR cardiac levels. Concurrent treatment with either Tel or Cap reversed PRG-induced morphometric, echocardiographic and histopathological abnormalities and revealed prominent protection against PRG-induced HF via downregulation of ACE/Ang II/AT1R and upregulation of ACE2/Ang 1-7/MasR axes. These are the first findings to demonstrate that the potential benefits of Tel and Cap are mediated by counteracting the altered balance between the RAS axes induced by PRG. Hence; Tel and Cap may attenuate PRG-induced HF partially through stimulation of ACE2/Ang 1-7/MasR pathway.

The Effectiveness of Art Therapy for Anxiety in Adult Women: A Randomized Controlled Trial

OBJECTIVES

Art therapy (AT) as a treatment option for anxiety is regularly employed in clinical practice, but scientific evidence for its effectiveness is lacking, since this intervention has hardly been studied. The aim was to study the effectiveness of AT on anxiety in adult women. The specific type of AT studied was anthroposophic AT.

METHODS

A RCT comparing AT versus a waiting list (WL) condition on anxiety symptom severity, quality of life, and emotion regulation. Factors influencing treatment outcome were additionally explored. Participants were women, aged 18-65 years, diagnosed with generalized anxiety disorder, social anxiety disorder or panic disorder, with moderate to severe anxiety symptoms. The trial was registered in the Dutch Trial Registration (NTR28143).

RESULTS

Fifty-nine women were included, of which 47 completed the trial. Both per-protocol and intention-to treat analyses demonstrated effectiveness of AT compared to WL, showing a reduction in anxiety, an increase in subjective quality of life (both with large effects) and an improvement in accessibility of emotion regulation strategies (medium effect). Treatment effects remained after 3 months follow-up. Improved acceptance of emotions and improved goal-oriented action are aspects of emotion regulation that are associated with the decrease in anxiety level.

CONCLUSION

AT is effective in reducing anxiety symptoms, improving quality of life and aspects of emotion regulation. Future RCTs should use active controls (treatment as usual) and study cost-effectiveness.

Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the treatment of panic disorder, social anxiety disorder and generalised anxiety disorder

Objective:

To provide practical clinical guidance for the treatment of adults with panic disorder, social anxiety disorder and generalised anxiety disorder in Australia and New Zealand.

Method:

Relevant systematic reviews and meta-analyses of clinical trials were identified by searching PsycINFO, Medline, Embase and Cochrane databases. Additional relevant studies were identified from reference lists of identified articles, grey literature and literature known to the working group. Evidence-based and consensus-based recommendations were formulated by synthesising the evidence from efficacy studies, considering effectiveness in routine practice, accessibility and availability of treatment options in Australia and New Zealand, fidelity, acceptability to patients, safety and costs. The draft guidelines were reviewed by expert and clinical advisors, key stakeholders, professional bodies, and specialist groups with interest and expertise in anxiety disorders.

Results:

The guidelines recommend a pragmatic approach beginning with psychoeducation and advice on lifestyle factors, followed by initial treatment selected in collaboration with the patient from evidence-based options, taking into account symptom severity, patient preference, accessibility and cost. Recommended initial treatment options for all three anxiety disorders are cognitive–behavioural therapy (face-to-face or delivered by computer, tablet or smartphone application), pharmacotherapy (a selective serotonin reuptake inhibitor or serotonin and noradrenaline reuptake inhibitor together with advice about graded exposure to anxiety triggers), or the combination of cognitive–behavioural therapy and pharmacotherapy.

Conclusion:

The Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the treatment of panic disorder, social anxiety disorder and generalised anxiety disorder provide up-to-date guidance and advice on the management of these disorders for use by health professionals in Australia and New Zealand.

Effect of valproate and pregabalin on human anxiety-like behaviour in a randomised controlled trial

Valproate is an anticonvulsant drug with strong preclinical evidence for reducing anxiety behaviour in rodents but no clear clinical evidence. To motivate clinical trials, we here investigate the use of valproate in a translational human model of anxiety behaviour. In a double-blind, randomised, placebo-controlled trial, n = 118 healthy participants played a previously validated approach/avoidance conflict computer game to measure anxiety-like behaviour, while under 400 mg valproate, under 200 mg of the established anxiolytic/anticonvulsant pregabalin, or under placebo. Saccadic peak velocity and subjective ratings were assessed to control for drug-induced sedation. Compared to placebo, valproate and pregabaline were anxiolytic in the primary outcome, and several secondary outcomes. Bayesian model comparison decisively demonstrated no differences between the two drugs. Subjective and objective sedation was significantly more pronounced under pregabalin than valproate, but did not explain anxiolytic effects. We demonstrate acute anxiolytic properties of valproate in healthy humans. Both drugs have similar anxiolytic properties at the doses used. Valproate is less sedative than pregabalin. Our results suggest clinical trials on the use of valproate in anxiolytic treatment. More generally, we propose a strategy of screening drugs in human preclinical models that can directly be compared across species, such as the approach/avoidance conflict computer game used here. This approach could thus facilitate translational anxiety research.

Pregabalin for anxiety in patients with schizophrenia - A randomized, double-blind placebo-controlled study

INTRODUCTION

Anxiety is frequent in patients with schizophrenia and poses a major impact on patients perceived quality of life, daily functioning and risk of suicide. Pregabalin has shown effective in the treatment of generalized anxiety disorder and has been suggested for the treatment of anxiety in patients with schizophrenia. As evidence is sparse regarding treatment of anxiety in this patient group, we aimed to investigate the use of pregabalin for anxiety in patients with schizophrenia.

METHODS

A randomized, double-blind placebo controlled study was used. Patients were randomized to either placebo or pregabalin (≤600mg/d) as add-on treatment. Primary analyses were intention-to-treat based with change in Hamilton Anxiety Scale after 4 and 8weeks of treatment as primary outcome. Secondary outcomes were change in psychopathology, quality-of-life, cognitive functioning and sleep. The study used centralized raters to increase accuracy and minimize baseline inflation.

RESULTS

A total of 54 patients were included with 46 completing the study. Pregabalin reduced the HAM-A₆ score significantly compared to placebo and with a medium effect size 0.72 (p=0.01). No significant between-group difference was found for the overall HAM-A₁₄. Most common side-effects were weight gain, dizziness, sedation and increased duration of sleep.

CONCLUSIONS

Although no effect was found on overall HAM-A₁₄, pregabalin might be effective in the treatment of psychic anxiety symptoms in patients with schizophrenia with a medium effect size.

Pregabalin for generalized anxiety disorder: an updated systematic review and meta-analysis

Generalized anxiety disorder (GAD), characterized by pervasive and highly distressing anxiety and worries, is associated with severe impairment. Although numerous agents from various drug classes are available to treat GAD, as many as 50% of patients have inadequate response, constituting an important medical frontier. In the face of this challenge, new pharmacological alternatives need to be further studied aiming at clinical improvement and better quality of life for patients. To assess the efficacy of pregabalin (PGB) compared with placebo for amelioration of anxiety symptoms in patients with GAD. A systematic literature search was performed using databases such as MEDLINE and EMBASE and other sources. The main outcome was Hedges' g for continuous scores. We used a random-effects model. Heterogeneity was evaluated with the I (moderate heterogeneity was assumed if I was >50% and high heterogeneity if I was >75%) and the χ-test (P<0.10 for heterogeneity). Publication bias was evaluated using the funnel plot. Meta-regression was performed using the random-effects model. For safety evaluation, we compared patients' dropout rates. We included eight randomized-controlled trials (n=2299) in our study, comparing the use of PGB in different dosages and placebo. In terms of the main outcome, PGB was found to be superior to the placebo group (Hedges' g=0.37; 95% confidence interval 0.30-0.44). The funnel plot assessment showed a low risk of publication bias. Between-study heterogeneity was not significant (I=0%), strengthening our results. Meta-regression showed no particular influence of any variable on the results. A categorical analysis of safety, using dropout as the most severe possible outcome, was carried out. No difference between PGB and placebo groups was observed in terms of the dropout rates. PGB was superior to placebo for the amelioration of GAD symptoms. In addition, the dropout rate was not significantly higher than that of the placebo groups. PGB was comparable to benzodiazepines in clinical response, but had lower dropout rates than benzodiazepine.

Early improvement with pregabalin predicts endpoint response in patients with generalized anxiety disorder: an integrated and predictive data analysis

Generalized anxiety disorder (GAD), a common mental disorder, has several treatment options including pregabalin. Not all patients respond to treatment; quickly determining which patients will respond is an important treatment goal. Patient-level data were pooled from nine phase II and III randomized, double-blind, short-term, placebo-controlled trials of pregabalin for the treatment of GAD. Efficacy outcomes included the change from baseline in the Hamilton Anxiety Scale (HAM-A) total score and psychic and somatic subscales. Predictive modelling assessed baseline characteristics and early clinical responses to determine those predictive of clinical improvement at endpoint. A total of 2155 patients were included in the analysis (1447 pregabalin, 708 placebo). Pregabalin significantly improved the HAM-A total score compared with the placebo at endpoint, treatment difference (95% confidence interval), -2.61 (-3.21 to -2.01), P<0.0001. Pregabalin significantly improved HAM-A psychic and somatic scores compared with placebo, -1.52 (-1.85 to -1.18), P<0.0001, and -1.10 (-1.41 to -0.80), P<0.0001, respectively. Response to pregabalin in the first 1-2 weeks (≥20 or ≥30% improvement in HAM-A total, psychic or somatic score) was predictive of an endpoint greater than or equal to 50% improvement in the HAM-A total score. Pregabalin is an effective treatment option for patients with GAD. Patients with early response to pregabalin are more likely to respond significantly at endpoint.

Psychological factors and treatment effectiveness in resistant anxiety disorders in highly comorbid inpatients

BACKGROUND

Anxiety disorders are a group of various mental syndromes that have been related with generally poor treatment response. Several psychological factors may improve or hinder treatment effectiveness. Hope has a direct impact on the effectiveness of psychotherapy. Also, dissociation is a significant factor influencing treatment efficiency in this group of disorders. Development of self-stigma could decrease treatment effectiveness, as well as several temperamental and character traits. The aim of this study was to explore a relationship between selected psychological factors and treatment efficacy in anxiety disorders.

SUBJECTS AND METHODS

A total of 109 inpatients suffering from anxiety disorders with high frequency of comorbidity with depression and/or personality disorder were evaluated at the start of the treatment by the following scales: the Mini-International Neuropsychiatric Interview, the Internalized Stigma of Mental Illness scale, the Adult Dispositional Hope Scale, and the Temperament and Character Inventory - revised. The participants, who sought treatment for anxiety disorders, completed the following scales at the beginning and end of an inpatient-therapy program: Clinical Global Impression (objective and subjective) the Beck Depression Inventory - second edition, the Beck Anxiety Inventory, and the Dissociative Experiences Scale. The treatment consisted of 25 group sessions and five individual sessions of cognitive behavioral therapy or psychodynamic therapy in combination with pharmacotherapy. There was no randomization to the type of group-therapy program.

RESULTS

Greater improvement in psychopathology, assessed by relative change in objective Clinical Global Impression score, was connected with low initial dissociation level, harm avoidance, and self-stigma, and higher amounts of hope and self-directedness. Also, individuals without a comorbid personality disorder improved considerably more than comorbid patients. According to backward-stepwise multiple regression, the best significant predictor of treatment effectiveness was the initial level of self-stigma.

CONCLUSION

The initial higher levels of self-stigma predict a lower effectiveness of treatment in resistant-anxiety-disorder patients with high comorbidity with depression and/or personality disorder. The results suggest that an increased focus on self-stigma during therapy could lead to better treatment outcomes.

Abuse Potential of Pregabalin: A Systematic Review

BACKGROUND

Several case reports and epidemiological studies have raised concern about the abuse potential of pregabalin, the use of which has increased substantially over the last decade. Pregabalin is, in some cases, used for recreational purposes and it has incurred attention among drug abusers for causing euphoric and dissociative effects when taken in doses exceeding normal therapeutic dosages or used by alternative routes of administration, such as nasal insufflation or venous injection. The magnitude of the abuse potential and the mechanism behind it are not fully known.

OBJECTIVE

The aim of this study was to present a systematic review of the data concerning the abuse potential of pregabalin.

METHODS

We performed a systematic literature search and reviewed the preclinical, clinical and epidemiological data on the abuse potential of pregabalin.

RESULTS

We included preclinical (n = 17), clinical (n = 19) and epidemiological (n = 13) studies addressing the abuse potential of pregabalin. We also reviewed case reports (n = 9) concerning abuse of pregabalin. The preclinical studies indicated that pregabalin possesses modulatory effects on the GABA and glutamate systems, leaving room for an abuse potential. Further, clinical studies reported euphoria as a frequent side effect in patients treated with pregabalin. The majority of case reports concerning abuse of pregabalin involved patients with a history of substance abuse and, similarly, epidemiological studies found evidence of abuse, especially among opiate abusers.

CONCLUSIONS

Overall, the available literature suggests an important clinical abuse potential of pregabalin and prescribers should pay attention to signs of abuse, especially in patients with a history of substance abuse.

Efficacy and safety of pregabalin in generalised anxiety disorder: A critical review of the literature

The aim of this review is to summarise the literature on the efficacy and safety of pregabalin for the treatment of generalised anxiety disorder (GAD). Of 241 literature citations, 13 clinical trials were identified that were specifically designed to evaluate the efficacy and safety of pregabalin in GAD, including 11 randomised double-blind trials and two open-label studies. Pregabalin efficacy has been consistently demonstrated across the licensed dose range of 150-600 mg/day. Efficacy has been reported for pregabalin monotherapy in elderly patients with GAD, patients with severe anxiety, and for adjunctive therapy when added to a selective serotonin reuptake inhibitor or serotonin-norepinephrine reuptake inhibitor in patients who have failed to respond to an initial course of antidepressant therapy. The two most common adverse events with pregabalin are somnolence and dizziness, both of which appear to be dose-related. Pregabalin appears to have a low potential for causing withdrawal symptoms when long-term therapy is discontinued; however, tapering over the course of at least one week is recommended. A review of available evidence indicates that pregabalin is a well-tolerated and consistently effective treatment for GAD, with a unique mechanism of action that makes it a useful addition to the therapeutic armamentarium.

Pregabalin for the treatment of patients with generalized anxiety disorder with inadequate treatment response to antidepressants and severe depressive symptoms

To evaluate the effectiveness of pregabalin in patients with resistant generalized anxiety disorder (GAD) and severe depressive symptoms, we carried out a post-hoc analysis of a multicenter, prospective, and observational 6-month study. We included patients who were at least 18 years old, fulfilled the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) criteria for GAD, showed inadequate responses to previous courses of antidepressant treatment, had Montgomery-Asberg Rating Scale scores of at least 35, had not received pregabalin previously, and were prescribed pregabalin upon entry into this study. We included 1815 patients fulfilling the DSM-IV criteria for GAD, and 133 (7.3%) fulfilled the selection criteria for these analyses. Ninety-seven percent of the patients received pregabalin (mean dose: 222 mg/day) in combination with other psychotropics. The Hamilton Anxiety Scale total score was reduced by a mean of 20.3 points (95% confidence interval, 22.1-18.4) (57.2% reduction) at month 6. Pregabalin also ameliorated comorbid depressive symptoms, with a reduction in the mean score of the Montgomery-Asberg Rating Scale of 22.3 points (95% confidence interval, 24.2-20.4) (56.6% reduction). Our results suggest that pregabalin, as part of a combination regimen with antidepressants and/or benzodiazepines, might be effective for the treatment of patients with GAD who have shown inadequate response to previous antidepressants and have severe depressive symptoms.

Conversion from thrice- to twice-daily pregabalin dosing for pain: Economic and clinical outcomes in a veteran population

PURPOSE

Results of a study analyzing economic and clinical outcomes one year after conversion from thrice- to twice-daily pregabalin dosing for pain are presented.

METHODS

A retrospective chart review was conducted at two Veterans Affairs facilities. The analyzed population included all patients receiving pregabalin for pain whose dosing was converted from thrice- to twice-daily pregabalin dosing during a one-year period. The primary endpoint was the economic impact of the conversion. Secondary endpoints included reversion to thrice-daily pregabalin dosing, pregabalin discontinuation, addition of medications for pain, and unscheduled neuropathy-related visits.

RESULTS

Among the 57 patients included in the data analysis, 41 continued to take pregabalin twice daily, 10 had pregabalin discontinued, and 6 had dosing reverted to thrice daily. The mean age of patients and the distribution of add-on pain medications did not differ significantly between patients whose pregabalin dosing frequency remained at twice daily and patients whose frequency reverted to thrice daily. The costs associated with pregabalin therapy differed significantly between the preconversion and postconversion periods. A savings of $115,867 was realized from this conversion for both facilities combined over the course of one year.

CONCLUSION

In patients receiving pregabalin for pain, conversion from thrice- to twice-daily pregabalin dosing-while maintaining the same daily dose-resulted in substantial cost savings while having little effect on clinical outcomes.

Pharmacotherapy for anxiety and comorbid alcohol use disorders

BACKGROUND

Anxiety disorders are a potentially disabling group of disorders that frequently co-occur with alcohol use disorders. Comorbid anxiety and alcohol use disorders are associated with poorer outcomes, and are difficult to treat with standard psychosocial interventions. In addition, improved understanding of the biological basis of the conditions has contributed to a growing interest in the use of medications for the treatment of people with both diagnoses.

OBJECTIVES

To assess the effects of pharmacotherapy for treating anxiety in people with comorbid alcohol use disorders, specifically: to provide an estimate of the overall effects of medication in improving treatment response and reducing symptom severity in the treatment of anxiety disorders in people with comorbid alcohol use disorders; to determine whether specific medications are more effective and tolerable than other medications in the treatment of particular anxiety disorders; and to identify which factors (clinical, methodological) predict response to pharmacotherapy for anxiety disorders.

SEARCH METHODS

Review authors searched the specialized registers of The Cochrane Collaboration Depression, Anxiety and Neurosis Review Group (CCDANCTR, to January 2014) and the Cochrane Drugs and Alcohol Group (CDAG, to March 2013) for eligible trials. These registers contain reports of relevant randomized controlled trials (RCT) from: the Cochrane Central Register of Controlled Trials (CENTRAL, all years), MEDLINE (1950 to date), EMBASE (1974 to date) and PsycINFO (1967 to date). Review authors ran complementary searches on EMBASE, PubMed, PsycINFO and the Alcohol and Alcohol Problems Science Database (ETOH) (to August 2013). We located unpublished trials through the National Institutes of Health (NIH) RePORTER service and the World Health Organization (WHO) International Clinical Trials Registry Platform (to August 2013). We screened reference lists of retrieved articles for additional studies.

SELECTION CRITERIA

All true RCTs of pharmacotherapy for treating anxiety disorders with comorbid alcohol use disorders. Trials assessing drugs administered for the treatment of drinking behaviour, such as naltrexone, disulfiram and acomprosate were not eligible for inclusion in this systematic review.

DATA COLLECTION AND ANALYSIS

A systematic review is a standardised evaluation of all research studies that address a particular clinical issue.Two review authors independently assessed RCTs for inclusion in the review, collated trial data and assessed trial quality. We contacted investigators to obtain missing data. We calculated categorical and continuous treatment effect estimates and their 95% confidence intervals (CI) for treatment using a random-effects model with effect-size variability expressed using Chi(2) and I(2) heterogeneity statistics.

MAIN RESULTS

We included five placebo-controlled pharmacotherapy RCTs (with 290 participants) in the review. Most of the trials provided little information on how randomization was performed or on whether both participants and study personnel were blinded to the intervention. Two of the three trials reporting superiority of medication compared with placebo on anxiety symptom outcomes were industry funded. We regarded one trial as being at high risk of bias due to selective reporting.Study participants had Diagnostic and Statistical Manual (DSM) III- and DSM IV-diagnosed alcohol use disorders and post-traumatic stress disorder (two studies), social anxiety disorder (SAD; two studies) or generalized anxiety disorder (GAD; one study). Four trials assessed the efficacy of the selective serotonin re-uptake inhibitors (SSRIs: sertraline, paroxetine); one RCT investigated the efficacy of buspirone, a 5-hydroxytryptamine (5-HT) partial agonist. Treatment duration lasted between eight and 24 weeks. Overall, 70% of participants included in the review were male.There was very low quality evidence for an effect of paroxetine on global clinical response to treatment, as assessed by the Clinical Global Impressions - Improvement scale (CGI-I). Global clinical response was observed in more than twice as many participants with paroxetine than with placebo (57.7% with paroxetine versus 25.8% with placebo; risk ratio (RR) 2.23, 95% CI 1.13 to 4.41; 2 trials, 57 participants). However, there was substantial uncertainty regarding the size of the effect of paroxetine due to the small number of studies providing data on clinically diverse patient samples. The second primary outcome measure was reduction of anxiety symptom severity. Although study investigators reported that buspirone (one trial) was superior to placebo in reducing the severity of anxiety symptoms over 12 weeks, no evidence of efficacy was observed for paroxetine (mean difference (MD) -14.70, 95% CI -33.00 to 3.60, 2 trials, 44 participants) and sertraline (one trial). Paroxetine appeared to be equally effective in reducing the severity of post-traumatic stress disorder (PTSD) symptoms as the tricyclic antidepressant desipramine in one RCT. The maximal reduction in anxiety disorder symptom severity was achieved after six weeks with paroxetine (two RCTs) and 12 weeks with buspirone (one RCT), with maintenance of medication efficacy extending to 16 with paroxetine and 24 weeks with buspirone. There was no evidence of an effect for any of the medications tested on abstinence from alcohol use or depression symptoms. There was very low quality evidence that paroxetine was well tolerated, based on drop-out due to treatment-emergent adverse effects. Nevertheless, levels of treatment discontinuation were high, with 43.1% of the participants in the studies withdrawing from medication treatment. Certain adverse effects, such as sexual problems, were commonly reported after treatment with paroxetine and sertraline.

AUTHORS' CONCLUSIONS

The evidence-base for the effectiveness of medication in treating anxiety disorders and comorbid alcohol use disorders is currently inconclusive. There was a small amount of evidence for the efficacy of medication, but this was limited and of very low quality. The majority of the data for the efficacy and tolerability of medication were for SSRIs; there were insufficient data to establish differences in treatment efficacy between medication classes or patient subgroups. There was a small amount of very low quality evidence that medication was well tolerated. There was no evidence that alcohol use was responsive to medication.Large, rigorously conducted RCTs would help supplement the small evidence-base for the efficacy and tolerability of pharmacotherapy for anxiety and comorbid alcohol use disorders. Further research on patient subgroups who may benefit from pharmacological treatment, as well as novel pharmacological interventions, is warranted.

Coping strategies, hope, and treatment efficacy in pharmacoresistant inpatients with neurotic spectrum disorders

BACKGROUND

Approximately 30%-60% of patients with neurotic spectrum disorders remain symptomatic despite treatment. Identifying the predictors of good response to psychiatric and psychotherapeutic treatment may be useful for increasing treatment efficacy in neurotic patients. The objective of this study was to investigate the influence of hope, coping strategies, and dissociation on the treatment response of this group of patients.

METHODS

Pharmacoresistant patients, who underwent a 6-week psychotherapeutic program, were enrolled in the study. All patients completed the Clinical Global Impression (CGI) - both objective and subjective forms, Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI)-II at baseline and after 6 weeks. The COPE Inventory, the Adult Dispositional Hope Scale (ADHS), and the Dissociative Experiences Scale (DES) were completed at the start of the treatment.

RESULTS

Seventy-six patients completed the study. The mean scores for all scales measuring the severity of the disorders (BAI, BDI-II, subjective and objective CGI) significantly decreased during the treatment. Several subscores of the COPE Inventory, the overall score of ADHS, and the overall score of DES significantly correlated with the treatment outcome. Multiple regression was used to find out which factors were the most significant predictors of the therapeutic outcomes. The most important predictors of the treatment response were the overall levels of hope and dissociation.

CONCLUSION

According to our results, a group of patients with a primary neurotic disorder, who prefer the use of maladaptive coping strategies, feel hopelessness, and have tendencies to dissociate, showed poor response to treatment.

Pregabalin: a review of its use in adults with generalized anxiety disorder

Pregabalin (Lyrica(®)), a well established anxiolytic agent, has been approved in the EU for the treatment of generalized anxiety disorder (GAD) in adults. It has a distinct mechanism of action relative to other anti-anxiety agents (α2δ binding at presynaptic voltage dependent calcium channels leading to inhibition of excitatory neurotransmission), a rapid onset of effect (typically ≤1 week) and broad spectrum activity against both the psychic and somatic symptoms of GAD. In long-term studies, pregabalin maintained improvements in anxiety symptoms that occurred in response to short-term treatment and delayed the time to relapse of GAD compared with placebo. Common comorbidities of GAD, such as insomnia, gastrointestinal symptoms and subsyndromal depression, have no effect on the anxiolytic efficacy of, and moreover are specifically improved by, pregabalin. Treatment with pregabalin is generally well tolerated; the drug has an adverse event profile that includes dizziness, somnolence and weight gain. The potential for abuse of pregabalin is low; the risk of withdrawal symptoms is generally low when the drug is discontinued gradually (over 1 week). Alongside selective serotonin reuptake inhibitors (SSRIs) and serotonin-noradrenaline reuptake inhibitors (SNRIs), pregabalin is considered a first-line agent for the long-term treatment of GAD by the World Federation of Societies of Biological Psychiatry. It should be stressed, however, that definitive head-to-head studies comparing pregabalin with SSRI/SNRIs, including in patients with GAD and co-morbid major depressive disorder, are currently lacking. Recently, a study of SSRI/SNRI augmentation with pregabalin yielded positive results, while another study of switching from long-term benzodiazepine therapy to pregabalin was inconclusive; further investigations on these topics are warranted.

Pregabalin abuse for enhancing sexual performance: case discussion and literature review

Pregabalin is a γ-aminobutyric acid analogue that is primarily prescribed in psychiatry for management of generalized anxiety disorder. The belief in its low potential for abuse has placed it in a superior position to other anxiolytic agents. However, more recent, concerns have been raised about the addictive potential of pregabalin. This problem has not received much attention nor has the mechanism of its development. There is also a lack of understanding of the difference in the experience of abusing pregabalin in contrast to abusing other illicit drugs. We report the case of a 55-year-old patient with a background history of multiple psychoactive substances misuse who elaborated on his own personal experience of pregabalin abuse. He consumed a month’s supply of this medication over 2 days and realized an enhancement in sexual desire and excitement. This effect should be considered when prescribing pregabalin.

Pregabalin long-term treatment and assessment of discontinuation in patients with generalized anxiety disorder

Discontinuation effects following cessation of 12 and 24 wk of pregabalin treatment for generalized anxiety disorder (GAD) were evaluated in a placebo- and lorazepam-controlled, randomized, double-blind, multicentre trial conducted in 16 countries. The study design consisted of two 12-wk treatment periods (periods 1 and 2), each followed by a 1-wk taper and two post-discontinuation assessments, one immediately following the taper and one 1-wk post-taper. Patients were assigned to receive an initially flexible dose of pregabalin 450-600 mg/d, pregabalin 150-300 mg/d, or lorazepam 3-4 mg/d for 6 wk; responders continued fixed-dose therapy for 6 additional weeks. Patients entering period 2 continued on the same fixed dose or switched to placebo. Discontinuation effects were evaluated with the Physician Withdrawal Checklist (PWC) and reported discontinuation-emergent signs and symptoms. Rebound anxiety was measured with the Hamilton Anxiety Rating Scale. GAD symptoms improved with all treatments and improvements were maintained over 12 and 24 wk. Low levels of discontinuation symptoms were evident in all treatment groups. For patients who received active treatment during both periods, mean (95% confidence interval) increases on the PWC from last visit on active treatment to the second post-discontinuation assessment were: pregabalin 450-600 mg/d: 2.8 (1.6-3.9), pregabalin 150-300 mg/d: 1.7 (0.7-2.8), lorazepam 3-4 mg/d: 2.2 (1.0-3.5). Rates of rebound anxiety were also low at both 12 and 24 wk (0-6%). This suggests that risk of discontinuation symptoms and rebound anxiety are low for pregabalin after 12 and 24 wk of treatment.

Pregabalin: latest safety evidence and clinical implications for the management of neuropathic pain

Used mainly for the management of neuropathic pain, pregabalin is a gabapentinoid or anticonvulsant that was initially developed as an antiepileptic agent. After more than a decade of experience with pregabalin, experience and studies have shown that the adverse effect profile of pregabalin is well tolerated for the management of neuropathic pain and other conditions. Its use is associated with benign central nervous system and systemic adverse effects, and there are very limited metabolic, idiosyncratic or known teratogenic adverse effects. Along with its efficacy in particular neuropathic pain conditions, pregabalin's safety led it to be one of the first pharmacotherapies considered for the management of neuropathic pain. This review discusses the use of pregabalin as well as its potential adverse effects, including the most commonly noted features of sedation, dizziness, peripheral edema and dry mouth. Although other adverse effects may occur, these appear to be uncommon. The review also discusses the clinical implications of pregabalin's use for the clinician.

Pregabalin in acute treatment of anxious depression: a case series

Symptoms of anxiety are common in patients with depression. In this retrospective case series we investigated the effect of Pregabalin as an add-on medication in unipolar depressed patients with high levels of anxiety. The therapeutic effect of Pregabalin showed a fast onset and was comparable to the anxiolytic effect of benzodiazepines.

How well do randomized controlled trial data generalize to 'real-world' clinical practice settings? A comparison of two generalized anxiety disorder studies

The aim of this post-hoc comparison is to compare efficacy and tolerability results from two generalized anxiety disorder (GAD) studies: a placebo-controlled, randomized controlled trial (RCT) and a study conducted in the clinical practice setting, and to evaluate the extent to which results from RCTs in GAD patients can be generalized to clinical practice. In the clinical practice study, GAD outpatients (n=578) were treated with 4 weeks of pregabalin 150-600mg/day. In the double-blind placebo-controlled RCT, GAD outpatients (n=249) were randomized to 8 weeks of pregabalin (300-600mg/day), or placebo (only the first 4 weeks are included in the current analysis). Efficacy measures included the Hospital Anxiety and Depression Scale - Anxiety and Depression subscales (HADS-A; HADS-D), a visual analogue anxiety scale (VAS-Anxiety), and the Medical Outcomes Study Sleep Problems Index (MOS-SPI). Baseline HADS-A and HADS-D scores were both higher in the clinical practice study vs. the RCT. In the RCT, treatment with pregabalin resulted in significantly greater Week 4 change vs. placebo in the HADS-A (-5.3 vs. -3.9; P<0.005), VAS-Anxiety (-24.0 vs. -13.3; P<0.02), MOS-SPI (-19.1 vs. -9.5; P<0.01), and HADS-D (-2.7 vs. -1.4; P<0.05). The magnitude of Week 4 improvement on pregabalin in the clinical practice study was numerically larger on the HADS-A (-5.9), VAS-Anxiety (-36.0), MOS-SPI (-22.7), and HADS-D (-5.1), despite use of lower doses. These results suggest that clinical practice patients with GAD may achieve comparable efficacy on lower doses of pregabalin than tested in RCTs, despite having comparable levels of anxiety symptom severity at baseline. The current exploratory comparison also suggests that results from RCTs in patients with GAD may not be directly generalizable to clinical practice.

Long-term treatment of anxiety disorders with pregabalin: a 1 year open-label study of safety and tolerability

OBJECTIVE

Short-term clinical trials have demonstrated the efficacy and safety of pregabalin in the treatment of generalized anxiety disorder (GAD). This study examined long-term safety and tolerability of pregabalin in patients with GAD, social anxiety disorder (SAD), or panic disorder (PD).

RESEARCH DESIGN AND METHODS

Patients (n = 528) completing one of four randomized, double-blind, placebo-controlled trials of pregabalin for GAD, SAD, or PD were treated, open label, with flexible-dose pregabalin (150-600 mg/day) for 1 year.

CLINICAL TRIAL REGISTRATION

NCT00150449.

MAIN OUTCOME MEASURES

The primary outcomes were safety and tolerability. Illness severity was assessed at baseline and Weeks 27/52 using the Clinical Global Impression of Severity (CGI-S) scale. Patients were characterized as 'responders' or 'non-responders' based on CGI-S scores ≤2 and >2, respectively. Analyses were performed on the total anxiety (GAD, SAD and PD) and GAD groups.

RESULTS

During 1 year of treatment with pregabalin, dizziness (12.5%) was the only treatment-related adverse event (AE) occurring ≥10%. Somnolence, weight gain, headache and insomnia occurred at 7.6%, 5.5%, 5.3% and 4.7%, respectively. Few treatment-related AEs were rated as severe in the total anxiety (5.1%) or GAD (3.6%) groups. Discontinuation rates due to AEs were similar (9.7% and 10.6%, respectively). No clinically significant laboratory, electrocardiogram, or other treatment-related safety findings were noted, except for treatment-related weight gain, which occurred in both the total (24.4%) and GAD (19.4%) groups. Mean CGI-S scores were similar at baseline in the total (n = 528; score, 3.4) and GAD groups (n = 330; score, 3.6), and CGI-S responder rates were similar at last-observation-carried-forward endpoint (51.3% and 48.1%, respectively).

CONCLUSIONS

Pregabalin was generally well tolerated in the long-term treatment of anxiety disorders. Improvement in illness severity was maintained over time. The key limitations of this study were that it was not randomized and neither placebo- nor active-comparator-controlled.

Pregabalin reduces cocaine self-administration and relapse to cocaine seeking in the rat

Pregabalin (Lyrica™) is a structural analog of γ-aminobutyric acid (GABA) and is approved by the FDA for partial epilepsy, neuropathic pain and generalized anxiety disorders. Pregabalin also reduces excitatory neurotransmitter release and post-synaptic excitability. Recently, we demonstrated that pregabalin reduced alcohol intake and prevented relapse to the alcohol seeking elicited by stress or environmental stimuli associated with alcohol availability. Here, we sought to extend these findings by examining the effect of pregabalin on cocaine self-administration (0.25 mg/infusion) and on cocaine seeking elicited by both conditioned stimuli and stress, as generated by administration of yohimbine (1.25 mg/kg). The results showed that oral administration of pregabalin (0, 10 or 30 mg/kg) reduced self-administration of cocaine over an extended period (6 hours), whereas it did not modify self-administration of food. In cocaine reinstatement studies, pregabalin (10 and 30 mg/kg) abolished the cocaine seeking elicited by both the pharmacological stressor yohimbine and the cues predictive of cocaine availability. Overall, these results demonstrate that pregabalin may have potential in the treatment of some aspects of cocaine addiction.

Pregabalin for the treatment of generalized anxiety disorder: an update

A PREVIOUS REVIEW SUMMARIZED WHAT WAS THEN KNOWN ABOUT THE POTENTIAL ROLE OF PREGABALIN IN THE TREATMENT OF PATIENTS WITH GENERALIZED ANXIETY DISORDER (GAD): this review provides an update on its pharmacological properties and presumed mechanism of action, the liability for abuse, and efficacy and tolerability in patients with GAD. Pregabalin has a similar molecular structure to the inhibitory neurotransmitter gamma amino butyric acid (GABA) but its mechanism of action does not appear to be mediated through effects on GABA. Instead, its anxiolytic effects may arise through high-affinity binding to the alpha-2-delta sub-unit of the P/Q type voltage-gated calcium channel in "over-excited" presynaptic neurons, thereby reducing the release of excitatory neurotransmitters such as glutamate. The findings of randomized controlled trials and meta-analyses together indicate that pregabalin is efficacious in both acute treatment and relapse prevention in GAD, with some evidence of an early onset of effect, and broad efficacy in reducing the severity of psychological and physical symptoms of anxiety. It also has efficacy as an augmenting agent after non-response to antidepressant treatment in GAD. Continuing vigilance is needed in assessing its potential abuse liability but the tolerability profile of pregabalin may confer some advantages over other pharmacological treatments in the short term for treatment in patients with GAD.

Effects of pregabalin on sleep in generalized anxiety disorder

Sleep disturbance is a cardinal symptom in both DSM-IV and ICD-10 criteria for generalized anxiety disorder (GAD). This review summarizes the results of clinical trials and pooled analyses that provide data on pregabalin's effect on sleep disturbance in patients diagnosed with GAD. The hypothesized mechanism of action of pregabalin is distinctly different from other anxiolytics. Pregabalin binds to a membrane α2δ subunit protein to inhibit release in excited central nervous system neurons of neurotransmitters implicated in pathological anxiety. Treatment with pregabalin has been found to be associated with significant improvement in GAD-related sleep disturbance across seven placebo-controlled clinical trials. Treatment with pregabalin is associated with improvement in all forms of insomnia and improvement in sleep has been found to be correlated with reduction in functional impairment and improvement in quality of life on subjective global measures. Results of a mediational analysis suggest that 53% of the effect of pregabalin on sleep disturbance was due to a direct effect and 47% was due to an indirect effect, mediated through prior reduction in anxiety symptom severity. In patients with GAD, improvement in sleep has been found to be associated with a reduction in daytime sleepiness. However, dose-related sedation is reported, typically in the first 2 wk of treatment, in approximately 10-30% of patients, depending on the dose used and the speed of titration. Insomnia is a common component of the clinical presentation of GAD and pregabalin appears to be an efficacious treatment for this often chronic and disabling symptom.

A cost-utility analysis of pregabalin versus venlafaxine XR in the treatment of generalized anxiety disorder in Portugal

Background

Generalized anxiety disorder is characterized by excessive anxiety and worry about several events and activities. The estimated 1-year prevalence for adults is around 2% and the lifetime prevalence could reach more than 6%. The disease is associated with reduced quality of life, being comparable to that of major depressive disorder and to chronic illnesses such as diabetes and arthritis, and high consumption of health care resources.

Methods

A previously published patient-level simulation cost-utility model was adapted to the Portuguese context in order to evaluate clinical and economic consequences of using pregabalin in place of venlafaxine XR in the treatment of generalized anxiety disorder. The model predicts the evolution of 1,000 patients with generalized anxiety disorder, simulating their pathway in weekly cycles over one year treatment. This is done by setting a pre-treatment Hamilton Anxiety Scale score and projecting the weekly impact of the pharmacotherapy on this score. The model uses clinical data from an 8-week flexible dose direct comparison clinical trial between the two drugs; utility values based on a Spanish study; and Portuguese economic data, being the resource consumption obtained via an expert panel.

Results

Pregabalin patients benefited from 0.738 quality adjusted life years while those on venlafaxine XR achieved 0.712. Moreover, the number of weeks with no or minimal anxiety symptoms was estimated to be 12.9 for pregabalin and only 3.8 for venlafaxine XR. Those clinical gains were achieved at the expense of an extra 715€ per patient, implying an incremental cost per quality adjusted life year of 27,199€ and an incremental cost per week with no or minimal symptoms of 79€. Sensitivity analysis shows that results are robust to main assumptions.

Conclusions

Assuming a threshold of 30,000€ per quality adjusted life year, pregabalin is cost-effective in comparison with venlafaxine XR in the treatment of generalized anxiety disorder in Portugal.

The cost effectiveness of pharmacological treatments for generalized anxiety disorder

BACKGROUND

Generalized anxiety disorder (GAD) is one of the most prevalent anxiety disorders, with important implications for patients and healthcare resources. However, few economic evaluations of pharmacological treatments for GAD have been published to date, and those available have assessed only a limited number of drugs.

OBJECTIVE

To assess the cost effectiveness of pharmacological interventions for patients with GAD in the UK.

METHODS

A decision-analytic model in the form of a decision tree was constructed to compare the costs and QALYs of six drugs used as first-line pharmacological treatments in people with GAD (duloxetine, escitalopram, paroxetine, pregabalin, sertraline and venlafaxine extended release [XL]) and 'no pharmacological treatment'. The analysis adopted the perspective of the NHS and Personal Social Services (PSS) in the UK. Efficacy data were derived from a systematic literature review of double-blind, randomized controlled trials and were synthesized using network meta-analytic techniques. Two network meta-analyses were undertaken to assess the comparative efficacy (expressed by response rates) and tolerability (expressed by rates of discontinuation due to intolerable side effects) of the six drugs and no treatment in the study population. Cost data were derived from published literature and national sources, supplemented by expert opinion. The price year was 2011. Probabilistic sensitivity analysis was conducted to evaluate the underlying uncertainty of the model input parameters.

RESULTS

Sertraline was the best drug in limiting discontinuation due to side effects and the second best drug in achieving response in patients not discontinuing treatment due to side effects. It also resulted in the lowest costs and highest number of QALYs among all treatment options assessed. Its probability of being the most cost-effective drug reached 75 % at a willingness-to-pay threshold of £20,000 per extra QALY gained.

CONCLUSION

Sertraline appears to be the most cost-effective drug in the treatment of patients with GAD. However, this finding is based on limited evidence for sertraline (two published trials). Sertraline is not licensed for the treatment of GAD in the UK, but is commonly used by primary care practitioners for the treatment of depression and mixed depression and anxiety.

The diagnosis and treatment of generalized anxiety disorder

BACKGROUND

Generalized anxiety disorder (GAD) is a common and serious disease with a lifetime prevalence of 4.3% to 5.9%. It is underdiagnosed in primary care.

METHODS

Recommendations on the treatment of GAD are given on the basis of all available findings from pertinent randomized trials, retrieved by a selective search of the literature.

RESULTS

Among psychotherapeutic techniques, various kinds of cognitive behavioral therapy (CBT) have been found useful in controlled trials. The drugs of first choice include selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephine reuptake inhibitors (SNRIs), and the calcium-channel modulator pregabalin. Tricyclic antidepressants are also effective but have more adverse effects than SSRIs. Although benzodiazepines are effective anxiolytic agents for short-term use, they should not be given over the long term because of the danger of addiction. Buspirone, an azapirone, was found to be effective in a small number of trials, but the findings across trials are inconsistent. The response rate of GAD to CBT in published studies lies between 47% and 75%, while its response rate to drug treatment lies between 44% and 81%.

CONCLUSION

The treatment of GAD with CBT and drugs is evidence-based and has a good chance of improving the manifestations of the disorder.

Evaluation of the effects of venlafaxine and pregabalin on the carbon dioxide inhalation models of Generalised Anxiety Disorder and panic

Previous studies have shown that subjective and objective symptoms of anxiety induced by 7.5% CO(2) inhalation can be attenuated by anxiolytics such as lorazepam and, to a lesser extent, paroxetine. Venlafaxine and pregabalin, two other licensed treatments for Generalised Anxiety Disorder, were used to further investigate the 7.5% and 35% CO(2) models of anxiety in healthy volunteers. Fifty-four participants were randomised to receive either placebo, venlafaxine or pregabalin. Study treatments were dosed incrementally over a three week period, to reach daily doses of 150 mg venlafaxine and 200mg pregabalin by the CO(2) challenge test day. Participants inhaled air 7.5% CO(2) for 20 minutes (single-blind presentation), and a non-blinded single vital capacity of 35% CO(2). Subjective ratings were recorded before and after each inhalation. Both 7.5% and 35% CO(2) inhalations produced the expected effects of increased ratings of symptoms of panic and anxiety, with increased blood pressure and heart rate. No significant treatment effects were found, although there were trends towards a reduction in feeling tense and nervous by both drugs compared with placebo during the 7.5% CO(2) challenge, and a reduction in alertness generally in the venlafaxine group compared with the pregabalin group. In contrast with the clear anxiolytic effects of benzodiazepines reported in several previous CO(2) studies, these findings suggest that the anxiogenic effects of CO(2) challenges are not significantly influenced by these serotonergic and GABAergic anxiolytics. This may be due to a lack of sensitivity of the CO(2) challenges in healthy volunteers to these drug types.

Evidence-based review of clinical outcomes of guideline-recommended pharmacotherapies for generalized anxiety disorder

OBJECTIVE

To quantify the rates of clinical outcomes of Canadian Psychiatric Association (CPA) guideline-recommended pharmacotherapies for generalized anxiety disorder (GAD) by drug classification within each treatment line.

METHODS

Evidence from original research cited by the CPA was included. Pooled analyses, duplicates, and studies with nonextractable data were excluded. Response, remission, and baseline-endpoint or mean reductions scores of the Hamilton Anxiety Rating Scale (HARS) were extracted. The Cochrane Collaboration's computer program, Review Manager, version 5, with a random effects model, was used to pool results.

RESULTS

A total of 50 articles were cited as evidence for managing GAD by the CPA. There was sufficient evidence of remission with first- or third-line agents to pool reported rates, and with agents from all 3 treatment lines to pool response rates and reduction in HARS scores. The mean range of effect size varied considerably from study to study within each treatment line. Comparison of pooled remission rates between first- and second-line agents was not possible. While the range of values by drug and drug class overlapped, the summary results for the probability of response and reduction in HARS scores was greater for first-line, compared with second-line, treatments. Drug components for third-line treatments were heterogeneous and produced mixed results.

CONCLUSION

Despite the abundance of evidence in its totality presented in the CPA guidelines, there is inadequate evidence to formulate recommendations based on the pooled results from this study alone. However, such analysis provides an additional resource for clinicians to make more effective treatment decisions for individual patients with GAD.

Elucidating the mechanism of action of pregabalin: α(2)δ as a therapeutic target in anxiety

This review provides a brief summary of what is known about the anxiolytic mechanism of action of pregabalin, a highly selective, high-affinity ligand of the P/Q type of voltage-gated calcium channel (CaV). Evidence from in vivo models of neuronal hyperexcitability suggests that pregabalin reduces synaptic release of neurotransmitters in selected CNS regions including the cortex, olfactory bulb, hypothalamus, amygdala, hippocampus, cerebellum and dorsal horn of the spinal cord. Release of neurotransmitters from the synaptic vesicle, and propagation of neurotransmission, requires the vesicle to fuse with the presynaptic membrane. Pregabalin binding to the α(2)δ type 1 protein of the P/Q type CaV reduces the availability of Ca2+ required for membrane fusion and exocytosis of neurotransmitters. Evidence that the anxiolytic mechanism of action of pregabalin is mediated by binding to the α(2)δ type 1 protein comes from animal models, which have demonstrated a structure-activity relationship between the affinity of ligands for the α(2)δ type 1 protein and their potency in models of anxiety such as the Vogel conflict test. Furthermore, the anxiolytic activity of pregabalin is lost in transgenic mice with specific point mutations in the CaV α(2)δ type 1 protein. Pregabalin-mediated reduction in calcium currents has also been shown to result in a significant inhibition of the release of neurotransmitters implicated in pathological anxiety such as glutamate and monoamine neurotransmitters. However, further research is needed to confirm that these effects contribute to the anxiolytic mechanism of action of pregabalin. Finally, pregabalin may also act by inhibiting synaptogenesis of excitatory neurons formed in response to chronic stress or anxiety, or more acutely inhibit the trafficking of CaV to the plasma membrane.

Pregabalin effects on neural response to emotional faces

Pregabalin has shown promise in the treatment of anxiety disorders. Previous functional magnetic resonance imaging (fMRI) studies indicate agents used to treat anxiety, e.g., SSRIs and benzodiazepines, attenuate amygdala, insula, and medial prefrontal cortex (mPFC) activation during emotional processing. Our prior study has shown that during anticipation of an emotional stimulus, pregabalin attenuates amygdala and insula activation but increases medial PFC activation. In this study, we examined whether, similar to SSRIs and benzodiazepines, pregabalin attenuates amygdala, insula, and medial PFC during emotional face processing. Sixteen healthy volunteers underwent a double-blind within-subjects fMRI study investigating effects of placebo, 50 mg, and 200 mg pregabalin on neural activation during an emotional face-matching task. Linear mixed model analysis revealed that pregabalin dose-dependently attenuated left amygdala activation during fearful face-matching and left anterior insula activation during angry face-matching. The 50 mg dose exhibited more robust effects than the 200 mg dose in the right anterior insula and ventral ACC. Thus, pregabalin shares some similarity to SSRIs and benzodiazepines in attenuating anger and fear-related insula and amygdala activation during emotional face processing. However, there is evidence that a subclinical 50 mg dose of pregabalin produced more robust and widespread effects on neural responses in this paradigm than the more clinically relevant 200 mg dose. Taken together, pregabalin has a slightly different effect on brain activation as it relates to anticipation and emotional face processing, which may account for its unique characteristic as an agent for the treatment of anxiety disorders.

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.

Does early improvement predict endpoint response in patients with generalized anxiety disorder (GAD) treated with pregabalin or venlafaxine XR?

Many patients with generalized anxiety disorder (GAD) only respond to pharmacological treatment after a delay of some weeks, and approximately 35% of patients do not respond. Therefore, early identification of potential responders may have important implications for clinical decision-making. In order to identify early improvement criteria that optimally predict eventual response during short-term treatment of GAD with pregabalin or venlafaxine XR, data were pooled from four double-blind, placebo-controlled GAD treatment studies. A range of measures were analyzed using logistic regression models and receiver operator characteristic (ROC) curve analysis, to predict endpoint response. Results showed that early improvement (≥ 20% reduction from baseline score) on the Hamilton Anxiety Scale (HAM-A) was associated with a high probability of achieving an endpoint response at Weeks 1 and 2 among patients treated with pregabalin (~67%), and at Week 2 with venlafaxine XR (60%). A Clinical Global Impression - Improvement (CGI-I) score ≤ 3 at Week 2 was a reliable predictor of achieving endpoint response for pregabalin and venlafaxine XR (odds ratio [OR], 5.33 and 2.47, respectively) with high sensitivity (pregabalin, 0.91; venlafaxine XR, 0.86) and relatively low specificity (pregabalin, 0.33; venlafaxine XR, 0.29), indicating a high true positive rate, but relatively low true negative rate. These findings indicate that improvement by Week 2 on the single item CGI may be a simple and reliable way to predict treatment response with pregabalin or venlafaxine XR in patients with GAD, but a less reliable way to predict non-responders.

Post hoc analysis of pregabalin vs. non-pregabalin treatment in patients with cancer-related neuropathic pain: better pain relief, sleep and physical health

BACKGROUND AND PURPOSE

A previous study of cancer-related neuropathic pain (NP) found that a 10-fold increase in pregabalin (PGB) use increased patients' satisfaction with treatment. Further research of PGB vs. non-pregabalin (non-PGB) treatment was carried out to assess if the use of more specific NP-targeting drugs, such as PGB, in combined therapy, in patients with cancer-related NP, provides better health outcomes.

PATIENTS AND METHODS

Post hoc analysis of PGB- vs. non- PGB-treated patients in a 2-month epidemiological, prospective, multicentre study to assess NP prevalence and management in cancer pain patients visiting radiotherapy oncologic units. Patients undertook the Brief Pain Inventory (BPI), Hospital Anxiety and Depression Scale (HADS), the Medical Outcomes Sleep Scale (MOS-Sleep) and the short form (SF-12) Health Survey.

RESULTS

A total of 273 patients with no previous PGB treatment: 162 were treated with PGB polytherapy and 111 with other treatments. At 8 weeks, satisfaction with treatment was 92.6% (PGB) vs. 78.9% (non-PGB), p=0.0024, and benzodiazepine use 37.8% (non-PGB) vs. 19.8% (PGB), p=0.0009. The decreases in BPI total pain intensity and total interference with activities and in MOS overall sleep problems index were significantly larger in the PGB group.

CONCLUSIONS

The addition of more specific NP-targeting drugs to usual treatment, such as PGB, in NP cancer patients provides more satisfaction with treatment and better outcomes in terms of pain intensity, interference with activities and sleep than treatments without specific NP-targeting drugs. Anxiolytic profile of PGB could allow for less use of benzodiazepines.

Treatment of generalized anxiety disorder: a comprehensive review of the literature for psychopharmacologic alternatives to newer antidepressants and benzodiazepines

OBJECTIVE

Generalized anxiety disorder (GAD) is common, chronic, and debilitating. Treatment with benzodiazepines and newer antidepressants is often inadequate. This article reviews the effectiveness of alternative and augmenting medications, such as older antidepressants, antipsychotics, anticonvulsants, and β-blockers.

DATA SOURCES

A search using MEDLINE (1980 to week 4 of May 2010) with the key words generalized anxiety disorder or GAD and therapeutics or treatment was conducted. Articles included adult patients with a GAD diagnosis that established chronicity of illness. These included a small number of studies that used DSM-III criteria but added a chronicity of symptoms and included all studies that used DSM-III-R and DSM-IV criteria. Articles that did not include medications or that exclusively focused on newer antidepressants (selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, bupropion, and mirtazapine), buspirone, benzodiazepines, or herbal or investigational medications were excluded. Review articles and non-English-language articles were also excluded.

RESULTS

Thirty-six studies were reviewed. All of the references were then analyzed, and key portions were extracted. Many studies were open trials. Double-blind, placebo-controlled studies with imipramine, risperidone, olanzapine, hydroxyzine, ondansetron, tiagabine, valproate, and pregabalin had been conducted. Imipramine, hydroxyzine, valproate, and pregabalin were the most effective, although risperidone, olanzapine, ziprasidone, and aripiprazole may also reduce symptoms.

CONCLUSIONS

Several medication strategies can be considered as promising alternatives or augmenting to antidepressant or benzodiazepine therapy in GAD.

A meta-analysis of the efficacy of pregabalin in the treatment of generalized anxiety disorder

OBJECTIVE

Generalized anxiety disorder (GAD) is a chronic anxiety disorder that leads to significant functional impairment and reduced quality of life. Pregabalin is a novel analogue of the inhibitory neurotransmitter gamma amino butyric acid, which has been proposed as a treatment for a range of conditions including GAD. This study examined the efficacy of pregabalin for GAD across published trials, using a meta-analytic method.

METHOD

This study examined the 7 published placebo-controlled trials of GAD using pregabalin, and, using meta-analytic techniques, we calculated the effect size of treatment with pregabalin (compared with placebo) on a total of 1352 people.

RESULTS

The overall effect size of pregabalin in the treatment of GAD was Hedges' g = 0.364, with an effect size of 0.349 on psychic anxiety symptoms and of 0.239 on somatic anxiety symptoms.

CONCLUSION

Pregabalin is an efficacious therapy for GAD, although effect sizes are smaller than those from earlier studies. Limitations and future research directions are discussed.

Pregabalin influences insula and amygdala activation during anticipation of emotional images

Pregabalin (PGB) has shown potential as an anxiolytic for treatment of generalized and social anxiety disorder. PGB binds to voltage-dependent calcium channels, leading to upregulation of GABA inhibitory activity and reduction in the release of various neurotransmitters. Previous functional magnetic resonance imaging (fMRI) studies indicate that selective serotonin reuptake inhibitors and benzodiazepines attenuate amygdala, insula, and medial prefrontal cortex activation during anticipation and emotional processing in healthy controls. The aim of this study was to examine whether acute PGB administration would attenuate activation in these regions during emotional anticipation. In this double-blind, placebo-controlled, randomized crossover study, 16 healthy controls completed a paradigm involving anticipation of negative and positive affective images during fMRI approximately 1 h after administration of placebo, 50, or 200 mg PGB. Linear mixed model analysis revealed that PGB was associated with (1) decreases in left amygdala and anterior insula activation and (2) increases in anterior cingulate (ACC) activation, during anticipation of positive and negative stimuli. There was also a region of the anterior amygdala in which PGB dose was associated with increased activation during anticipation of negative and decreased activation during anticipation of positive stimuli. Attenuation of amygdala and insula activation during anticipatory or emotional processing may represent a common regional brain mechanism for anxiolytics across drug classes. PGB induced increases in ACC activation could be a unique effect related to top-down modulation of affective processing. These results provide further support for the viability of using pharmaco-fMRI to determine the anxiolytic potential of pharmacologic agents.