A randomized, double-blind, placebo-controlled, fixed-dose, multicenter study of pregabalin in patients with generalized anxiety disorder

Systematic review and network meta-analysis of agomelatine for the treatment of generalized anxiety disorder in adult patients

This systematic literature review aimed to assess the efficacy and tolerability of agomelatine versus approved medications for the treatment of generalized anxiety disorder (GAD) in adult patients. We selected randomized controlled trials on various medications used to treat GAD in adult patients. An existing systematic literature review (Kong et al., 2020) was used to identify relevant studies published before 2020. Outcomes of remission and discontinuation due to adverse events (AEs) were analyzed, following a random-effects network meta-analysis approach. Of 25 identified studies, 20 and 22 studies were included in the network meta-analysis for studying the remission and discontinuation (due to AEs) outcomes, respectively. A statistically significant difference in the remission rate was observed between agomelatine and pregabalin [odds ratio (OR), 2.22; 95% confidence interval (CI), 1.19-4.21]. For the other comparators, the results were nonsignificant; however, all the point estimates were in favor of agomelatine. Similarly, for discontinuation because of AEs, the point estimates leaned consistently toward agomelatine suggesting its higher tolerability. The probabilities of agomelatine having the highest remission rate and lowest discontinuation (due to AEs) rate were 67% and 68%, respectively. Based on its demonstrated effectiveness and tolerability, agomelatine can be considered as a drug of choice for the treatment of GAD.

Minor tranquillizers for short-term treatment of newly onset symptoms of anxiety and distress: a systematic review with network meta-analysis of randomized trials

Unspecific symptoms of anxiety and distress are frequently encountered in patients in both general practice and acute psychiatric services. Minor tranquillizers may be a treatment option when non-pharmacological interventions are insufficient or unavailable. We conducted a systematic review with network meta-analysis of the evidence for short-term (1-4 weeks) pharmacological treatment of newly onset symptoms of anxiety and distress. We searched the PsycInfo, MEDLINE, EMBASE and Cochrane Library databases and extracted data following a predefined hierarchy of outcomes. We assessed risk of bias using the Cochrane Risk of Bias tool and the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation framework (GRADE). We included 34 randomized trials comprising a total of 7044 patients with adjustment disorders or anxiety spectrum disorders. The network meta-analysis showed that regarding the critical outcome symptoms of anxiety within 1-4 weeks benzodiazepines (SMD - 0.58, 95% CI - 0.77 to - 0.40), quetiapine (SMD - 0.51, 95% CI - 0.90 to - 0.13) and pregabalin (SMD - 0.58, 95% CI - 0.87 to - 0.28) all performed better than placebo with no statistically significant difference between the drugs. Data on other important outcomes were inconsistently reported. Adverse effects varied, but overall, it was uncertain whether adverse effects differed between interventions. The evidence regarding the risk of dependence was uncertain, but dependence may be a concern in susceptible individuals even with short-term treatment. Overall, the certainty of the evidence according to GRADE was rated as low to very low across outcomes. Despite the limitations in the evidence, the results of this review can inform treatment guidelines, supporting clinicians in the choice of minor tranquillizer in this prevalent and help-seeking, clinically heterogeneous population.

Association between anti-seizure medication and the risk of lower urinary tract infection in patients with epilepsy

PURPOSE

The aim of this retrospective study was to analyze the incidence of lower urinary tract infections (LUTI) and antibiotic prescriptions within 12 months after initial prescription of anti-seizure medication (ASM) between January and December 2020 (index date) and to investigate the association between a broad spectrum of ASMs and the risk of LUTI in patients with epilepsy.

METHODS

This retrospective cohort study included a total of 9186 adult patients (≥18 years) with an initial diagnosis of epilepsy and a prescription of an ASM treated in 1284 general practices in Germany between January 2010 and December 2020 (index date). Six frequently prescribed ASMs with at least 1000 available patients were analyzed. Patients treated with one of six ASMs were matched to each other by propensity scores based on sex, age, and secondary diagnoses. Cox regression models were used to analyze the association between the use of ASM and LUTI risk.

RESULTS

The cumulative LUTI incidence 12 months after the start of therapy was highest in patients treated with pregabalin (16.7%), followed by valproate (11.6%) and gabapentin (10.2%). A similar trend was observed for LUTI with antibiotic prescription (9.2% pregabalin, 6.8% valproate, 6.8% gabapentin). Conditional regression analyses revealed that pregabalin therapy was significantly positively associated with LUTI (HR: 1.76; 95% CI 1.29-2.39) and LUTI-based antibiotic prescription (HR: 2.16; 95% CI 1.43-3.27). Carbamazepine was associated with a significantly lower incidence of LUTI in women (HR: 0.47; 95% CI: 0.30-0.75), but not in men. No significant associations were observed for other ASMs.

CONCLUSION

The present study identifies a significant positive association between ASM and LUTI incidence and antibiotic prescriptions in patients with epilepsy treated with pregabalin, whereas a protective effect was found for carbamazepine in women only. No significant associations were observed for the four remaining ASMs.

Role of Pregabalin to Decrease Postoperative Pain in Microdiscectomy: A Randomized Clinical Trial

Purpose The purpose of this study is to compare the effect of pregabalin in reducing the neuropathic pain in postoperative patients who have undergone single-level microdiscectomy for prolapsed intervertebral lumbar disc. Methods A randomized control clinical trial was conducted from June 2018 to April 2020 in three campuses Dr. Ziauddin University Hospital, Karachi, by two spinal surgeons. This study included 84 patients who underwent either emergency or elective microdiscectomy surgery. The patients randomized into two equal groups of 42, (group-A: pregabalin) and (group-B: placebo). Both groups also received routine analgesia along with the pregabalin and placebo capsules. In the intervention group, pregabalin was administered preoperative and postoperative defined times. The pain scores were recorded by visual analog scale (VAS) and Roland-Morris score system on the preoperative day and compared to the scores on follow-up on postoperative day seven. Results The pain scores were significantly better in group-A compared to group-B with similar baseline variables. The mean VAS scores of pains in group-A on postoperative day seven on follow-up were compared to VAS pain scores in group-B showing better pain control. The Roland-Morris scores were also significantly better for group-A. Conclusions The use of pregabalin in addition to the routine analgesia has better control of postoperative neuropathic pain in patients with single-level microdiscectomy compared to the patients who are receiving only routine analgesia. Other factors like cost, dose, side effects, and frequency should also be considered.

Trends in new prescription of gabapentinoids and of coprescription with opioids in the 4 nations of the UK, 1993-2017

We explored potential differences in time trends of gabapentinoid prescription and of opioid coprescription between 1993 and 2017 in the 4 UK nations using the Clinical Practice Research Datalink, a UK primary care database. There were distinct trends in annual rates of new gabapentin and pregabalin prescriptions in Northern Ireland. The rate of new gabapentin prescriptions rapidly increased after 2010 and exceeded that of the other nations by 2017 (rate of 836 [95% confidence interval: 787-887] per 100 000 person-years). Additionally, the rate of new pregabalin prescriptions was higher during the entire study period, reaching a peak of 1139 (95% confidence interval: 1088-1193) per 100 000 person-years in 2010, 5-fold higher than the other nations. Findings in Northern Ireland may be partly attributable to the high burden of anxiety disorders, an indication for pregabalin. Further exploration of reasons for discrepancies in gabapentinoid prescribing between UK nations is warranted.

Comparative Remission Rates and Tolerability of Drugs for Generalised Anxiety Disorder: A Systematic Review and Network Meta-analysis of Double-Blind Randomized Controlled Trials

Background: Generalized anxiety disorder (GAD) is one of the most common psychiatric disorders associated with substantial dysfunction and socioeconomic burden. Pharmacotherapy is the first choice for GAD. Remission [Hamilton Anxiety Scale (HAM-A) score ≤7] is regarded as a crucial treatment goal for patients with GAD. There is no up-to-date evidence to compare remission rate and tolerability of all available drugs by using network meta-analysis. Therefore, the goal of our study is to update evidence and determine the best advantageous drugs for GAD in remission rate and tolerability profiles.

Method: We performed a systematic review and network meta-analysis of double-blind randomized controlled trials (RCTs). We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Chinese National Knowledge Infrastructure, wanfang data, China Biology Medicine and ClinicalTrials.gov from their inception to March 2020 to identify eligible double-blind, RCTs reporting the outcome of remission in adult patients who received any pharmacological treatment for GAD. Two reviewers independently assessed quality of included studies utilizing the Cochrane Collaboration’s risk of bias tool as described in Cochrane Collaboration Handbook and extracted data from all manuscripts. Our outcomes were remission rate (proportion of participants with a final score of seven or less on HAM-A) and tolerability (treatments discontinuations due to adverse events). We calculated summary odds ratios (ORs) and 95% confidence intervals (CIs) of each outcome via pairwise and network meta-analysis with random effects.

Results: Overall, 30 studies were included, comprising 32 double-blind RCTs, involving 13,338 participants diagnosed as GAD by DSM-IV criteria. Twenty-eight trials were rated as moderate risk of bias, four trials as low. For remission rate, agomelatine (OR 2.70, 95% CI 1.74–4.19), duloxetine (OR 1.88, 95% CI 1.47–2.40), escitalopram (OR 2.03, 95% CI 1.48–2.78), paroxetine (OR 1.74, 95% CI 1.25–2.42), quetiapine (OR 1.88, 95% CI 1.39–2.55), and venlafaxine (OR 2.28, 95% CI 1.69–3.07) were superior to placebo. For tolerability, sertraline, agomelatine, vortioxetine, and pregabalin were found to be comparable to placebo. However, the others were worse than placebo in terms of tolerability, with ORs ranging between 1.86 (95% CI 1.25–2.75) for tiagabine and 5.98 (95% CI 2.41–14.87) for lorazepam. In head-to-head comparisons, agomelatine, duloxetine, escitalopram, quetiapine, and venlafaxine were more efficacious than tiagabine in terms of remission rate, ORs from 1.66 (95% CI 1.04–2.65) for duloxetine to 2.38 (95% CI 1.32–4.31) for agomelatine. We also found that agomelatine (OR 2.08, 95% CI 1.15–3.75) and venlafaxine (OR 1.76, 95% CI 1.08–2.86) were superior to vortioxetine. Lorazepam and quetiapine were poorly tolerated when compared with other drugs.

Conclusions: Of these interventions, only agomelatine manifested better remission with relatively good tolerability but these results were limited by small sample sizes. Duloxetine, escitalopram, venlafaxine, paroxetine, and quetiapine showed better remission but were poorly tolerated.

Glutamate Systems in DSM-5 Anxiety Disorders: Their Role and a Review of Glutamate and GABA Psychopharmacology

Serotonin reuptake inhibitors and benzodiazepines are evidence-based pharmacological treatments for Anxiety Disorders targeting serotonin and GABAergic systems, respectively. Although clearly effective, these medications fail to improve anxiety symptoms in a significant proportion of patients. New insights into the glutamate system have directed attention toward drugs that modulate glutamate as potential alternative treatments for anxiety disorders. Here we summarize the current understanding of the potential role of glutamate neurotransmission in anxiety disorders and highlight specific glutamate receptors that are potential targets for novel anxiety disorder treatments. We also review clinical trials of medications targeting the glutamate system in DSM-5 anxiety disorders. Understanding the role of the glutamate system in the pathophysiology of anxiety disorder may aid in developing novel pharmacological agents that are effective in treating anxiety disorders.

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.

Reproducibility of a battery of human evoked pain models to detect pharmacological effects of analgesic drugs

BACKGROUND

Although reproducibility is considered essential for any method used in scientific research, it is investigated only rarely; thus, strikingly little has been published regarding the reproducibility of evoked pain models involving human subjects. Here, we studied the reproducibility of a battery of evoked pain models for demonstrating the analgesic effects of two analgesic compounds.

METHODS

A total of 81 healthy subjects participated in four studies involving a battery of evoked pain tests in which mechanical, thermal and electrical stimuli were used to measure pain detection and tolerance thresholds. Pharmacodynamic outcome variables were analysed using a mixed model analysis of variance, and a coefficient of variation was calculated by dividing the standard deviation by the least squares means.

RESULTS

A total of 76 subjects completed the studies. After being administered pregabalin, the subjects' pain tolerance thresholds in the cold pressor and pressure stimulation tests were significantly increased compared to the placebo group. Moreover, the heat pain detection threshold in UVB-irradiated skin was significantly increased in subjects who were administered ibuprofen compared to the placebo group. Variation among all evoked pain tests ranged from 2.2% to 30.6%.

CONCLUSIONS

Four studies using a similar design showed reproducibility with respect to the included evoked pain models. The relatively high consistency and reproducibility of two analgesics at doses known to be effective in treating clinically relevant pain supports the validity of using this pain test battery to investigate the analgesic activity and determine the active dosage of putative analgesic compounds in early clinical development.

SIGNIFICANCE

The consistency and reproducibility of measuring the profile of an analgesic at clinically relevant doses illustrates that this pain test battery is a valid tool for demonstrating the analgesic activity of a test compound and for determining the optimal active dose in early clinical drug development.

Psychological and pharmacological treatments for generalized anxiety disorder (GAD): a meta-analysis of randomized controlled trials

The purpose of this meta-analysis was to provide updated pooled effect sizes of evidence-based psychotherapies and medications for generalized anxiety disorder (GAD) and to investigate potential moderators of outcomes. Seventy-nine randomized controlled trials (RCT) including 11,002 participants with a diagnosis of GAD were included in a meta-analysis that tested the efficacy of psychotherapies or medications for GAD. Psychotherapy showed a medium to large effect size (g = 0.76) and medication showed a small effect size (g = 0.38) on GAD outcomes. Psychotherapy also showed a medium effect on depression outcomes (g = 0.64) as did medications (g = 0.59). Younger age was associated with a larger effect size for psychotherapy (p < 0.05). There was evidence of publication bias in psychotherapy studies. This analysis found a medium to large effect for empirically supported psychotherapy interventions on GAD outcomes and a small effect for medications on GAD outcomes. Both groups showed a medium effect on depression outcomes. Because medication studies had more placebo control conditions than inactive conditions compared to psychotherapy studies, effect sizes between the domains should not be compared directly. Patient age should be further investigated as a potential moderator in psychotherapy outcomes in GAD.

Influence of pregabalin on post-operative pain after laparoscopic cholecystectomy: A meta-analysis of randomised controlled trials

Background:

Pregabalin may have some potential in reducing post-operative pain after laparoscopic cholecystectomy. However, the results remain controversial. We conduct a systematic review and meta-analysis to explore the influence of pregabalin on post-operative pain after laparoscopic cholecystectomy.

Materials and Methods:

PubMed, Embase, Web of science, EBSCO and Cochrane Library databases have been systematically searched. Randomised controlled trials (RCTs) assessing the effect of pregabalin versus placebo on post-operative pain after laparoscopic cholecystectomy are included. The primary outcomes are pain scores at 8–12 h and 20–24 h. Secondary outcomes include sedation score, intraoperative fentanyl requirement, post-operative analgesic requirement, operative duration, post-operative nausea and vomiting, as well as respiratory depression. This meta-analysis is performed using the random-effect model.

Results:

Eight RCTs involving 528 patients were included in the meta-analysis. Overall, compared with control intervention after laparoscopic cholecystectomy, pregabalin treatment is found to significantly reduce pain scores at 20–24 h (Standard Mean difference [Std. MD] = −0.46; 95% confidence interval [CI] = −0.82–−0.10), and post-operative analgesic requirement (Std. MD = −2.64; 95% CI = −3.94–−1.33), but cannot substantially decrease pain scores at 8–12 h (Std. MD = −0.71; 95% CI = −1.70–0.27). In addition, pregabalin results in improved sedation score (Std. MD = 0.92; 95% CI = 0.55–1.29), but has no remarkable influence on intraoperative fentanyl requirement (Std. MD = 0.04; 95% CI = −0.30–0.39), operative duration (Std. MD = 0.34; 95% CI = −0.10–0.77), post-operative nausea and vomiting (Std. MD = 0.79; 95% CI = 0.59–1.11) as well as respiratory depression (Std. MD = 0.71; 95% CI = 0.17–3.02).

Conclusions:

Compared to control intervention after laparoscopic cholecystectomy, pregabalin treatment can significantly decrease pain scores at 20–24 h and post-operative analgesic requirement, with no increase in adverse events.

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.

Pharmacotherapy for generalized anxiety disorder in adult and pediatric patients: an evidence-based treatment review

INTRODUCTION

Generalized anxiety disorder (GAD) often begins during adolescence or early adulthood and persists throughout the lifespan. Randomized controlled trials support the efficacy of selective serotonin and selective serotonin norepinephrine reuptake inhibitors (SSRIs and SNRIs, respectively), as well as benzodiazepines, azapirones, anti-adrenergic medications, melatonin analogs, second-generation antipsychotics, kava, and lavender oil in GAD. However, psychopharmacologic treatment selection requires clinicians to consider multiple factors, including age, co-morbidity, and prior treatment. Areas covered: The authors review the literature concerning pharmacotherapy for pediatric and adult patients with GAD with specific commentary on the efficacy and tolerability of selected agents in these age groups. The authors describe an algorithmic approach to the pediatric and adult patient with GAD and highlight considerations for the use of selected medications in these patients. Expert opinion: In adults with GAD, SSRIs and SNRIs represent the first-line psychopharmacologic treatment while second-line pharmacotherapies include buspirone, benzodiazepines, SGAs, and pregabalin. In pediatric patients with GAD, SSRIs should be considered the first line pharmacotherapy and psychotherapy enhances antidepressant response.

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.

Comparing the efficacy of benzodiazepines and serotonergic anti-depressants for adults with generalized anxiety disorder: a meta-analytic review

INTRODUCTION

Generalized anxiety disorder (GAD) is a common form of anxiety disorder. Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), and benzodiazepines (BZs) are the most commonly prescribed medications for GAD, but little is known about the relative efficacy of these pharmacological treatments. Areas covered: This study provides a meta-analytic review of the efficacy of these medications in the treatment of adults with GAD. A comprehensive literature search yielded 54 articles reporting 56 unique studies with 12,655 participants treated with either pill placebo (6,191 participants), SSRIs (16 trials, 2,712 participants), SNRIs (17 trials, 2,603 participants), or BZs (23 trials, 1,149 participants). The overall combined effect size was modest to moderate (Hedges' g = 0.37, p < 0.0001). Effect sizes decreased significantly over time. SSRIs (Hedges' g = 0.33) and SNRIs (Hedges' g = 0.36) demonstrated significantly lower effect sizes than BZs (Hedges' g = 0.50). These findings were not due to differences in treatment length or publication year. Expert opinion: The results of this study suggest that the most common forms of pharmacotherapy for adult GAD are moderately effective, with BZs being the most effective drug.

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.

A comparison of the effectiveness of amitriptilin and pregabalin treatment in fibromyalgia patients

OBJECTIVE

The present study is a comparison of the effectiveness of amitriptyline and pregabalin on the symptoms of fibromyalgia patients.

METHODS

A total of 71 female patients aged ≥18 years were included in this study. The patients were divided into 2 groups. Pregabalin (n=36) or amitriptyline (n=35) treatment was initiated at daily oral dose of 450 mg and 25 mg, respectively for the indicated number of patients. The patients were evaluated at the start of treatment and at the end of 12 weeks. The Fibromyalgia Impact Questionnaire, Fatigue Severity Scale, Modified Fatigue Impact Scale, Hospital Anxiety Depression Scale, Nottingham Health Profile, Mini Mental State Test, and the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) were administered to all study participants. Pain at all tender points was measured using a pressure algometer.

RESULTS

Significant improvement was observed in both groups after 12 weeks of treatment (p<0.05). Percent change in LANSS was greater in the pregabalin group compared with the amitriptyline group. Tender point pressure pain thresholds and total myalgic score improved significantly in both groups (p<0.05); however higher percentage change in these parameters was achieved in the amitriptyline group when compared with the pregabalin group (p<0.05).

CONCLUSION

Both drugs improved pain, fatigue, sleep disorder, disability, psychological evaluation, and cognitive function; however, amitriptyline was more effective at reducing experimentally measured pain than neuropathic pain. According to these results, preference for pregabalin may be recommended in fibromyalgia patients whose primary complaint is neuropathic pain.

Preventive Gabapentin versus Pregabalin to Decrease Postoperative Pain after Lumbar Microdiscectomy: A Randomized Controlled Trial

Study Design

Randomized controlled trial.

Purpose

The purpose of this study was to compare pregabalin and gabapentin for mean postoperative visual analog score (VAS) for pain in patients undergoing single-level lumbar microdiscectomy for intervertebral disc prolapse at a tertiary care hospital.

Overview of Literature

Pregabalin has a superior pharmacokinetic profile and analgesic effect at lower doses than gabapentin; however, analgesic efficacy must be established during the perioperative period after lumbar spine surgery.

Methods

This randomized controlled trial was carried out at our institute from February to October 2011 on 78 patients, with 39 participants in each study group. Patients undergoing lumbar microdiscectomy were randomized to group A (gabapentin) or group B (pregabalin) and started on trial medicines one week before surgery. The VAS for pain was recorded at 24 hours and one week postoperatively.

Results

Both groups had similar baseline variables, with mean ages of 42 and 39 years in groups A and B, respectively, and a majority of male patients in each group. The mean VAS values for pain at 24 hours for gabapentin vs. pregabalin were comparable (1.97±0.84 vs. 1.6±0.87, respectively; p=0.087) as were the results at one week after surgery (0.27±0.45 vs. 0.3±0.46, respectively; p=0.79). None of the patients required additional analgesia postoperatively. After adjusting for age and sex, the VAS value for group B patients was 0.028 points lower than for group A patients, but this difference was not statistically significant (p=0.817, R²=0.018).

Conclusions

Pregabalin is equivalent to gabapentin for the relief of postoperative pain at a lower dose in patients undergoing lumbar microdiscectomy. Therefore, other factors, such as dose, frequency, cost, pharmacokinetics, and side effects of these medicines, should be taken into account whenever it is prescribed.

Comparative clinical study of gabapentin and pregabalin for postoperative analgesia in laparoscopic cholecystectomy

Background:

Reduction in central sensitization by gabapentinoids that include gabapentin and pregabalin may reduce acute postoperative pain.

Aims:

The aim of this study is to evaluate postoperative analgesic benefit and efficacy in patients administered with oral gabapentin or pregabalin as premedication for laparoscopic cholecystectomy under general anesthesia.

Settings and Design:

Randomized, prospective, and comparative study.

Materials and Methods:

In this study, recruited patients were randomly allocated in three groups. Groups A, B, and C received 2 capsules of B complex, 3 capsules of 300 mg gabapentin each, and 2 capsules of 75 mg pregabalin, respectively, each in 30 patients of each group, 1 h before induction of anesthesia. Postoperative efficacy among these three groups was compared with respect to increase in duration of analgesia, reduction in postoperative pain scores, total postoperative requirements of analgesics and side effects.

Statistical Analysis:

Mean and standard deviation were calculated. Test of analysis between two groups was done by t-test and among three groups by analysis of variance, and then P value was calculated.

Results:

Pregabalin and gabapentin group had lower visual analog scale (VAS) score (P < 0.05), prolonged timing of first rescue analgesic (4.67 ± 14.79 vs. 158 ± 13.10 vs. 343.16 ± 9.69) min, and less opioid consumption (169.87 ± 20.32 vs. 116.13 ± 14.08 vs. 64.67 ± 16.69) mg compared to placebo group. Between the gabapentinoids, pregabalin group had lower VAS score, prolonged timing of first rescue analgesic, and less opioids consumption than the gabapentin group.

Conclusion:

It is concluded in this study that pregabalin group had lower VAS score, prolonged timing of first rescue analgesic, and less opioids consumption than the gabapentin group. Both gabapentinoids had better postoperative analgesic profile than placebo.

Treatment-refractory anxiety; definition, risk factors, and treatment challenges

A sizable proportion of psychiatric patients will seek clinical evaluation and treatment for anxiety symptoms reportedly refractory to treatment. This apparent lack of response is either due to “pseudo-resistance” (a failure to have received and adhered to a recognized and effective treatment or treatments for their condition) or to true “treatment resistance.” Pseudo-resistance can be due to clinician errors in selecting and delivering an appropriate treatment effectively, or to patient nonadherence to a course of treatment. True treatment resistance can be due to unrecognized exogenous anxiogenic factors (eg, caffeine overuse, sleep deprivation, use of alcohol or marijuana) or an incorrect diagnosis (eg, atypical bipolar illness, occult substance abuse, attention deficit-hyperactivity disorder). Once the above factors are eliminated, treatment should focus on combining effective medications and cognitive behavioral therapy, combining several medications (augmentation), or employing novel medications or psychotherapies not typically indicated as first-line evidence-based anxiety treatments.

Mechanisms of the gabapentinoids and α 2 δ-1 calcium channel subunit in neuropathic pain

The gabapentinoid drugs gabapentin and pregabalin are key front‐line therapies for various neuropathies of peripheral and central origin. Originally designed as analogs of GABA, the gabapentinoids bind to the α₂δ‐1 and α₂δ‐2 auxiliary subunits of calcium channels, though only the former has been implicated in the development of neuropathy in animal models. Transgenic approaches also identify α₂δ‐1 as key in mediating the analgesic effects of gabapentinoids, however the precise molecular mechanisms remain unclear. Here we review the current understanding of the pathophysiological role of the α₂δ‐1 subunit, the mechanisms of analgesic action of gabapentinoid drugs and implications for efficacy in the clinic. Despite widespread use, the number needed to treat for gabapentin and pregabalin averages from 3 to 8 across neuropathies. The failure to treat large numbers of patients adequately necessitates a novel approach to treatment selection. Stratifying patients by sensory profiles may imply common underlying mechanisms, and a greater understanding of these mechanisms could lead to more direct targeting of gabapentinoids.

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.

Modeling the longitudinal latent effect of pregabalin on self-reported changes in sleep disturbances in outpatients with generalized anxiety disorder managed in routine clinical practice

Background

Anxiety disorders are among the most common psychiatric illnesses, with generalized anxiety disorder (GAD) being one of the most common. Sleep disturbances are highly prevalent in GAD patients. While treatment with pregabalin has been found to be associated with significant improvement in GAD-related sleep disturbance across many controlled clinical trials, mediational analysis has suggested that a substantial portion of this effect could be the result of a direct effect of pregabalin. Thus, the objective of this study was to model the longitudinal latent effect of pregabalin or usual care (UC) therapies on changes in sleep in outpatients with GAD under routine clinical practice.

Methods

Male and female GAD outpatients, aged 18 years or above, from a 6-month prospective noninterventional trial were analyzed. Direct and indirect effects of either pregabalin or UC changes in anxiety symptoms (assessed with Hamilton Anxiety Scale) and sleep disturbances (assessed with Medical Outcomes Study-Sleep Scale [MOS-S]) were estimated by a conditional latent curve model applying structural equation modeling.

Results

A total of 1,546 pregabalin-naïve patients were analyzed, 984 receiving pregabalin and 562 UC. Both symptoms of anxiety and sleep disturbances were significantly improved in both groups, with higher mean (95% confidence interval) score reductions in subjects receiving pregabalin: −15.9 (−15.2; −16.6) vs −14.5 (−13.5; −15.5), P=0.027, in Hamilton Anxiety Scale; and −29.7 (−28.1; −31.3) vs −24.0 (−21.6; −26.4), P<0.001, in MOS-S. The conditional latent curve model showed that the pregabalin effect on sleep disturbances was significant (γ =−3.99, P<0.001), after discounting the effect on reduction in anxiety symptoms. A mediation model showed that 70% of the direct effect of pregabalin on sleep remained after discounting the mediated effect of anxiety improvement.

Conclusion

A substantial proportion of the incremental improvements in anxiety-related sleep disturbances with pregabalin vs UC were explained by its direct effect, not mediated by improvements in anxiety symptoms.

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.

Clinical and economic outcomes of adjunctive therapy with pregabalin or usual care in generalized anxiety disorder patients with partial response to selective serotonin reuptake inhibitors

BACKGROUND

This study is done to compare the effect of adjunctive therapy with pregabalin versus usual care (UC) on health-care costs and clinical and patients consequences in generalized anxiety disorder (GAD) subjects with partial response (PR) to a previous selective serotonin reuptake inhibitor (SSRI) course in medical practice in Spain.

METHODS

Post hoc analysis of patients with PR to SSRI monotherapy enrolled in a prospective 6-month naturalistic study was done. PR was defined as a Clinical Global Impression (CGI) scale score ≥3 and insufficient response with persistence of anxiety symptoms ≥16 in the Hamilton Anxiety Rating Scale (HAM-A). Two groups were analyzed: 1) adjunctive therapy (AT) with pregabalin (150-600 mg/day) to existing therapy and 2) UC (switching to a different SSRI or adding another anxiolytic different than pregabalin). Costs included GAD-related health-care resources utilization. Consequences were a combination of psychiatrist-based measurements [HAM-A, CGI, and Montgomery-Asberg Depression Rating Scale (MADRS)] and patient-reported outcomes [Medical Outcomes Study Sleep (MOS-sleep) scale, disability (World Health Organization Disability Assessment Schedule II (WHO-DAS II) and quality-of-life (Euro Qol-5D (EQ-5D)]. Changes in both health-care costs and scale scores were compared separately at end-of-trial visit by a general linear model with covariates.

RESULTS

Four hundred eighty-six newly prescribed pregabalin and 239 UC GAD patients [mean (SD) HAM-A 26.7 (6.9) and CGI 4.1 (0.5)] were analyzed. Adding pregabalin was associated with significantly higher mean (95% CI) score reductions vs. UC in HAM-A [-14.9 (-15.6; -14.2) vs. -11.2 (-12.2; -10.2), p < 0.001] and MADRS [-11.6 (-12.2; -10.9) vs. -7.8 (-8.7; -6.8), p < 0.001]. Changes in all patient-reported outcomes favored significantly patients receiving pregabalin, including quality-of-life gain; 26.4 (24.7; 28.1) vs. 19.4 (17.1; 21.6) in the EQ-VAS, p < 0.001. Health-care costs were significantly reduced in both cohorts yielding similar 6-month costs; €1,565 (1,426; 1,703) pregabalin and €1,406 (1,200; 1,611) UC, p = 0.777. The effect of sex on costs and consequences were negligible.

CONCLUSION

In medical practice, GAD patients with PR to SSRI experienced greater consequence improvements with adjunctive therapy with pregabalin versus UC, without increasing health-care cost. The effect of pregabalin was independent of patient gender.

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 reduces opioid consumption and improves outcome in chronic pain patients undergoing total knee arthroplasty

INTRODUCTION

Recently, multimodal pain control has been used to manage postoperative pain in patients undergoing total knee arthroplasty (TKA). This approach combines numerous modalities, such as opioids, nonsteroidal anti-inflammatory drugs, local anesthetics, and acetaminophen, in an effort to reduce overall opioid consumption and also to provide better pain control. Gabapentinoids are a class of drugs that have been used as part of multimodal approach, and may be effective in patients who are previous users of chronic pain medication. The hypothesis of this study was that the addition of pregabalin reduces opioid consumption and/or improves pain after TKA, even in patients who are previous users of chronic pain medications.

METHODS

Using a prospectively collected database, 262 consecutive patients undergoing primary TKA between December 2011 and April 2012 were identified who received multimodal analgesia after surgery that included pregabalin. Using the same database, these patients were compared with 268 patients undergoing TKA from January to December 2010 who also received multimodal analgesia but were not given pregabalin. The clinical records of these patients were reviewed in detail to determine the incidence and nature of postoperative complications, opioid consumption, and visual analog scale (VAS) pain scores.

RESULTS

The incidence of respiratory, renal, and hemodynamic complications was significantly lower in the patients who received pregabalin. Gastrointestinal complications, which included nausea, were not significantly different between the groups. Patients receiving pregabalin had a lower average opioid consumption, and their minimum and maximum levels of opioid consumption were also reduced. Previous users of chronic pain medications had higher VAS scores but the same opioid consumption compared with those who were not previous users of chronic pain medications. No difference was seen in the maximum VAS scores between patients who received pregabalin and those who did not.

CONCLUSION

Pregabalin in the context of multimodal pain management may be associated with reduced opioid consumption and other medical complications in patients undergoing TKA, including previous users of chronic pain medications.

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.

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.

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.

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.

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 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.

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.

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.

Do Benzodiazepines Still Deserve a Major Role in The Treatment of Psychiatric Disorders? A Critical Reappraisal

Discovered in the late 1950s by Leo Sternbach, the first benzodiazepine (BZD) chlordiazepoxide was followed by several congeners, which rapidly constituted one of the largest and most widely prescribed classes of psychotropic compounds. After 50 years, BZDs are still routinely utilized not only in psychiatry but, more generally, in the whole of medicine. Despite their high therapeutic index which makes BZDs safer than other compounds like barbiturates, as well as their rapidity of onset, psychiatrists and family physicians are well aware about the controversy that surrounds the wide use – often not adequately based on scientific evidence – of BZDs in many psychiatric disorders. In this overview of international treatment guidelines, systematic reviews and randomized clinical trials, the aim was to provide a critical appraisal of the current use and role of BZDs in psychiatric disorders and their disadvantages, with specific emphasis on anxiety and affective disorders, sleep disorders, alcohol withdrawal, violent and aggressive behaviours in psychoses, and neuroleptic-induced disorders. In addition, specific emphasis has been given to the extent of usage of BZDs and its appropriateness through the assessment of available international surveys. Finally, the entire spectrum of BZD-related adverse effects including psychomotor effects, use in the elderly, paradoxical reactions, tolerance and rebound, teratologic risk, dependence, withdrawal and abuse issues was examined in detail.

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 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.

Adjunctive pregabalin in partial responders with major depressive disorder and residual anxiety

BACKGROUND

Anxiety symptoms in depression result often in treatment resistance, residual symptoms, and persistent functional impairment.

OBJECTIVE

To assess the effectiveness and safety of adjunctive pregabalin to antidepressants for residual anxiety in patients with major depressive disorder (MDD).

METHODS

A retrospective chart review was conducted to identify partial responders among patients with MDD with residual anxiety. Twenty such patients (age, 58.4 ± 11.2 years; 15 women; baseline Hamilton Depression Rating Scale [HDRS], 17.1 ± 3.5) who received adjunctive pregabalin for residual anxiety were included. Antidepressants augmented were the selective serotonin reuptake inhibitors (n = 12), mirtazapine (n = 2), and selective serotonin-norepinephrine reuptake inhibitors (n = 6).

RESULTS

Twenty patients received at least 4 weeks of pregabalin treatment after 8 weeks of antidepressant therapy. At week 1 (9 weeks after initiating treatment), pregabalin was prescribed at a mean ± SD dose of 71.2 ± 31.7 mg, and the mean maximum pregabalin dose prescribed was 156.2 ± 76.5 mg (range, 75-300 mg). At week 8, there were 13 responders (13/20 [65%]), and 7 of these 13 patients achieved remission (HDRS17 < 8). There were significant decreases in HDRS scores (13.5 ± 3.1 vs 9.1 ± 2.9, P < 0.000), and HDRS anxiety/somatization subscale scores (6.3 ± 2 to 3.6 ± 1.7, P < 0.000). Adverse effects included somnolence (n = 7), weight gain (n = 3), dizziness (n = 4), dry mouth (n = 6), edema (n = 3), blurred vision (n = 3), difficulty with concentration/attention (n = 8), headache (n = 6), and diarrhea (n = 5).

CONCLUSIONS

The results suggest a possible augmentation role for pregabalin when used in conjunction with conventional antidepressants for residual anxiety in MDD.

The effect of a clinically effective and non-effective dose of lorazepam on 7.5% CO₂-induced anxiety

Symptoms of anxiety induced by 7.5% CO₂ inhalation can be attenuated by acute administration of GABA(A) receptor anxiolytics such as lorazepam and alprazolam. This study investigated if these effects are dose-related, by comparing a 0.5 mg dose (considered non-clinically effective) and a 2 mg dose of lorazepam (clinically effective) on 7.5% CO₂ inhalation. Eighteen healthy males (mean age 20.6 years, SD 1.29), judged physically and mentally fit, attended three visits, each one week apart, to take each treatment in a randomised double-blind crossover design. Drugs were given 60 min prior to 20 min air inhalation, followed by 20 min 7.5% CO₂ inhalation. The order of gas presentation was single blind. Subjective ratings using visual analogue scales (VAS) and questionnaires were recorded before and after each inhalation. Blood pressure (BP), heart rate (HR), respiration rate (RR) and expired CO₂ were recorded during each inhalation. Inhalation of 7.5% CO₂ significantly raised BP, HR, RR and expired CO₂. Ratings of feeling like leaving the room were significantly lower on 2 mg compared with 0.5 mg and placebo, and dose-dependent trends were seen in scores for VAS fearful, anxious, stressed, tense, and worried. Results may be indicative of dose-dependent effects of lorazepam in a CO₂ model of anxiety.

Asymmetric time-dependent activation of right central amygdala neurones in rats with peripheral neuropathy and pregabalin modulation

Neuropathic pain (NP) often presents with comorbidities, including depression and anxiety. The amygdala is involved in the processing of mood disorders, fear, and the emotional-affective components of pain. Hemispheric lateralization of pain processing in the amygdala has recently been brought to light because, independently of the side of the peripheral injury, the right central nucleus of the amygdala (CeA) showed higher neuronal activity than the left in models of inflammatory pain. Although the CeA has been called the 'nociceptive amygdala', because of its high content of nociceptive neurones, little is known about changes in its neuronal function in vivo, under NP conditions. Herein, we quantified CeA spontaneous and evoked activity in rats subjected to spinal nerve ligation (SNL), under isoflurane anaesthesia, following application of mechanical and thermal stimuli to widespread body areas. We found that spontaneous and stimulus-evoked neuronal activity was higher in the left CeA at 2 and 6 days after SNL induction and declined afterwards, whereas activity in the right CeA became dominant at 14 days after surgery, independently of the side of surgery. We also observed that systemic injection of pregabalin, which is widely used in patients with NP, reduced CeA spontaneous and stimulus-evoked neuronal activity. Overall, we observed that peripheral nerve injury produced asymmetric plasticity in ongoing and evoked activity in the left and right CeA. Remarkably, at 14 days after SNL induction, enhanced evoked activity in the right CeA persisted compared to short-term increases in activity in the left CeA. The plasticity found in ongoing and evoked activity was inhibited by pregabalin.