Pregabalin for the treatment of generalised anxiety disorder

Efficacy and Safety of Single-Dose Pregabalin in Preoperative Pediatric Sedation

INTRODUCTION

This study aimed to investigate the anxiolytic and sedative effects of a single oral dose of 5 mg/kg pregabalin in pediatric patients undergoing elective surgery. It also assessed potential adverse effects and its impact on bispectral index (BIS) responses.

MATERIALS AND METHODS

This prospective randomized clinical trial enrolled 60 pediatric patients undergoing minor elective surgery. Patients were randomly assigned to receive either oral pregabalin (5 mg/kg) or a placebo one hour before induction of anesthesia. Anxiety levels were assessed using the Visual Analog Scale for Anxiety (VAS-A), and sedation levels were evaluated using the Ramsay Sedation Scale (RSS).

RESULTS

Pregabalin premedication significantly reduced preoperative anxiety, as indicated by lower VAS-A scores compared to the control group. Sedation levels, measured using the RSS, were significantly higher in the pregabalin group at various time points post-dose. During intubation, skin incision, and recovery, BIS responses were significantly lower in the pregabalin group.

CONCLUSION

The use of single-dose pregabalin preoperatively in children recorded a significant decrease in anxiety and achieved a state of sedation without an increase in adverse effects.

Pregabalin for the discontinuation of long-term benzodiazepines use: An assessment of its effectiveness in daily clinical practice

Purpose

To evaluate the effectiveness and tolerability of pregabalin in the management of the discontinuation of benzodiazepines in long-term users.

Subjects and methods

We performed a 12-week, prospective, uncontrolled, non-interventional, and observational study in patients aged 18 years old or above, who met DSM-IV-TR criteria for benzodiazepine dependence without other major psychiatry disorder. Evaluations included the Benzodiazepine Withdrawal Symptom Questionnaire, the Hamilton Anxiety Rating Scale, the Clinical Global Impression Scale, and the Sheehan Disability Scale. A urine drug screen for benzodiazepines was performed at baseline and every 4 weeks thereafter. The primary effectiveness variable was success rate, defined as achievement of benzodiazepine-free status at week 12 according to the urine drug screen.

Results and discussion

The mean dose at week 12 was 315 (±166) mg/day. The success rate of the benzodiazepine taper in the primary efficacy population (n = 282) was 52% (95% confidence interval [CI], 46–58). Success rates for women and men were 58% (95% CI, 49–67) and 46% (95% CI, 38–55), respectively. The success rates did not differ according to either the benzodiazepine of abuse or the presence of other substance use disorders. Significant and clinically relevant improvements were observed in withdrawal and anxiety symptoms, as well as in patients’ functioning. At week 12, tolerability was rated as good or excellent by 90% and 83% of the clinicians and patients, respectively.

Conclusion

Our results suggest that pregabalin is an efficacious and well-tolerated adjunctive treatment for benzodiazepine withdrawal.

Structure elucidation and formation mechanistic study of a methylene-bridged pregabalin dimeric degradant in pregabalin extended-release tablets

During the pharmaceutical development of pregabalin extended-release tablets, an unknown degradant at a relative retention time (RRT) of 11.7 was observed and its nominal amount exceeded the ICH identification threshold in an accelerated stability study. The aim of this study is to identify the structure and investigate the formation mechanism of this impurity for the purpose of developing a chemically stable pharmaceutical product. By utilizing multi-stage LC-MS analysis in conjunction with mechanism-based stress study, the structure of the RRT 11.7 impurity was rapidly identified as a dimeric degradant that is caused by dimerization of two pregabalin molecules with a methylene bridging the two pregabalin moieties. The structure of the dimer was confirmed by 1D and 2D NMR measurement. The formation pathway of the dimeric degradant was also inferred from the mechanism-based stress study, which implicated that the bridging methylene could originate from formaldehyde which might be the culprit that triggers the dimerization in the first place. The subsequent API-excipients compatibility study indicated that the degradant was indeed formed in the compatibility experiments between pregabalin API and two polymeric excipients (PEO and PVPP) that are known to contain residual formaldehyde, but only in the co-presence of another excipient, colloidal silicon dioxide (SiO₂). The kinetic behavior of the degradant formation was also investigated and two kinetic models were utilized based on the Arrhenius and Eyring equations, respectively, to calculate the activation energy (E_a) as well as the enthalpy of activation (△H^‡), entropy of activation (△S^‡), and Gibbs free energy (△G^‡) of the degradation reaction. The results of this study would be useful for the understanding of similar dimeric degradant formation in finished products of drug substances containing primary or secondary amine moieties.

Anxiolytic effects of the novel α2δ ligand mirogabalin in a rat model of chronic constriction injury, an experimental model of neuropathic pain

RATIONALE

Psychiatric disorders such as anxiety and depression are frequently observed in neuropathic pain patients, and negatively impact their quality of life. Mirogabalin is a novel ligand for the α₂δ subunit of voltage-gated calcium channels and has unique binding characteristics to α₂δ subunits and potent and long-lasting analgesic effects in neuropathic pain models.

OBJECTIVES

To provide further information on the pharmacological profile of mirogabalin and its utility for chronic pain therapy, we investigated its anxiolytic effects in an experimental animal model for neuropathic pain.

METHODS

In chronic constriction injury (CCI) model rats, mechanical hypersensitivity was determined by the von Frey test. Anxiety- and depression-related behaviours were evaluated using the elevated plus maze test and forced swimming test, respectively.

RESULTS

CCI model rats showed sustained tactile allodynia followed by anxiety-related behaviours, not depression-related behaviours. The tactile allodynia (significant decreases in paw withdrawal threshold) developed within 2 weeks after model preparation, whereas the anxiety-related behaviours (significant decreases in the number of entries and time spent in open arms and significant increases in time spent in closed arms) were observed at 5 weeks but not 4 weeks after model preparation. Single oral administration of mirogabalin (3 or 10 mg/kg) dose-dependently alleviated the above-mentioned anxiety-related behaviours and tactile allodynia.

CONCLUSIONS

CCI model rats showed anxiety-related behaviours in a time-dependent manner in the elevated plus maze test. Mirogabalin alleviated both the anxiety-related behaviours and tactile allodynia in CCI model rats. Mirogabalin may provide effective anxiety relief as well as pain relief in patients with neuropathic pain.

A Validated Fluorometric Method for the Rapid Determination of Pregabalin in Human Plasma Applied to Patients With Pain

BACKGROUND

Pregabalin has been used for the treatment of pain. A clinically accepted method applied to patients with pain has not been published for the determination of pregabalin in human plasma. This study developed a fluorometric ultrahigh-performance liquid chromatography (UHPLC) method to measure pregabalin concentration in patients with pain.

METHODS

After plasma pretreatment involving protein precipitation, pregabalin and gabapentin as an internal standard were derivatized with 4-fluoro-7-nitrobenzofurazan (NBD-F) under the following reaction conditions: 1 minute, pH 10, and 60°C. The UHPLC separation was performed using a 2.3-μm particle size octadecylsilyl column. The fluorescence detector was set at excitation and emission wavelengths of 470 and 530 nm, respectively. The predose blood samples were collected from 40 patients with pain who have been treated with 75 mg of pregabalin twice daily.

RESULTS

The chromatographic run time was 1.25 minutes. No interfering peaks were observed in the blank plasma at the retention times of NBD derivatives. The calibration curve of pregabalin was linear at a range of 0.05-10 mcg/mL (r > 0.999). The lower limit of quantification was 0.05 mcg/mL. The intra-assay accuracy and precision were 98.3%-99.8% and within 4.3%, respectively. The inter-assay accuracy and precision were 103.2%-107.1% and within 4.1%, respectively. The predose plasma concentration of pregabalin in patients with pain ranged from 0.14 to 8.5 mcg/mL.

CONCLUSIONS

This study provides a validated fluorometric UHPLC method with fast analytical performance for the determination of pregabalin in human plasma. The present method could be applied to patients with pain and be used for the clinical research or therapeutic drug monitoring of pregabalin.

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

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

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.

Anti-anxiety efficacy of Sudarshan Kriya Yoga in general anxiety disorder: A multicomponent, yoga based, breath intervention program for patients suffering from generalized anxiety disorder with or without comorbidities

BACKGROUND

Surdashan Kriya Yoga (SKY) is a procedure that in various studies, has shown evidences of efficacy in alleviating Depression and Anxiety disorders, but in Europe and USA it has not been studied yet on a Caucasian population as an adjunct therapy for psychiatric Disorders.

METHODS

The study involved a sample of consenting women and men (n = 69) who received SKY therapy for a six-month time period. They were assessed at recruitment, after two weeks, after three months and after six months using Hamilton Rating Scale for Anxiety (HRSA), Hamilton Rating Scale for Depression (HRSD), Zung Self-Rating Anxiety Scale (ZSAS), Zung Self-Rating Depression Scale (ZSDS) and Symptom Checklist-90 (SCL-90).

RESULTS

All the analyses have shown that SKY therapy significantly reduces the scores of Anxiety and Depression. This is plain, especially after the initial SKY treatment, which is followed by a long plateau phase that seems to verge on no Anxiety/Depression scores. It was found that SKY effects lead to a significant convergence between the self-assessment (Zung Self-Rating Scale) and hetero-assessment (Hamilton Rating Scale).

LIMITATIONS

The study should be replicated on a larger clinical sample in a controlled trial to learn more about the effectiveness of SKY Protocol.

CONCLUSIONS

Participation in SKY adjunct therapy ten days intense workshop and follow-ups, coupled with daily individual and independent practice of a simplified protocol of breathing techniques (30 min), can lead to significant reduction in levels of Anxiety and Depression.

Efficacy of once-daily extended release quetiapine fumarate in patients with different levels of severity of generalized anxiety disorder

This study is a pooled, post-hoc analysis evaluating once-daily extended release quetiapine fumarate (quetiapine XR) monotherapy in patients with generalized anxiety disorder (GAD). Three previously reported positive, 8-week, randomized, double-blind, placebo-controlled studies evaluated quetiapine XR therapy (50, 150, 300 mg/day) in patients with GAD [Hamilton Anxiety Rating Scale (HAM-A) total score ≥ 20]. Patients were stratified by baseline severity: HAM-A total score ≥ 22, ≥ 24, < 26, ≥ 26, ≥ 28. We report HAM-A total score change, response (≥ 50% reduction in HAM-A total score), and remission (HAM-A total score ≤ 7 and ≤ 9). Quetiapine XR significantly improved HAM-A total scores compared with placebo at Weeks 1 and 8 in the HAM-A ≥ 22, ≥ 24, and ≥ 26 cohorts (all doses), at Week 1 (all doses) and Week 8 (quetiapine XR 150 mg/day) in the < 26 cohort, and at Week 1 (all doses) and Week 8 (quetiapine XR 50 and 150 mg/day) in the HAM-A ≥ 28 group (P<0.05). Week 8 effect sizes for 50, 150, and 300 mg/day were as follows: 0.29, 0.47, 0.17 (HAM-A ≥ 22); 0.35, 0.55, 0.22 (HAM-A ≥ 24); 0.18, 0.32, 0.10 (HAM-A < 26); 0.41, 0.59, 0.24 (HAM-A ≥ 26); 0.60, 0.64, 0.22 (HAM-A ≥ 28), respectively. Acute quetiapine XR monotherapy significantly improves anxiety compared with placebo in patients with moderate or severe GAD, with symptom improvements seen as early as Week 1.

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 is increasingly prescribed for neuropathic pain, generalised anxiety disorder and epilepsy but many patients discontinue treatment

AIM

To assess prescribing patterns, sociodemographic characteristics and previous disease history in patients receiving pregabalin.

METHODS

An observational study using register data on dispensed drugs and recorded diagnoses for all patients in Stockholm, Sweden, who filled at least one prescription of pregabalin between July 2005 and December 2009. Analyses focused on prevalence, incidence, diagnosis patterns, prior dispensing of other analgesics/psychotropics and persistence to treatment over time.

RESULT

A total of 18,626 patients (mean age 55 years, 63% women) were initiated on treatment between July 2006 and December 2009. Approved indications were recorded in hospital and/or primary care within 1 year prior to the first dispensing for 40% of the patients (epilepsy 1.3%, neuropathic pain 35.5% and generalised anxiety disorder (GAD) 3.6%). Antidepressants were used by 55%, opioids by 49% and sedatives by 48% prior to initiation of pregabalin. One-third (34%) only purchased one prescription and the proportion purchasing pregabalin 1 year after initiation was 42.1% for epilepsy, 36.3% for GAD, 21.5% for neuropathic pain and 25.6% for those without any of the included diagnoses.

CONCLUSION

Pregabalin was mainly used as a second-line drug for the treatment of GAD or neuropathic pain and to a lesser extent as add-on therapy in epilepsy. However, a large proportion of all patients only purchased one prescription and the persistence declined rapidly over time. The issue of potential off-label prescribing or poor registration of diagnoses should also be noted as a high proportion had been prescribed the drug without a record of any of the approved indications.

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.

Understanding the pharmacokinetics of anxiolytic drugs

INTRODUCTION

Anxiety disorders are considered the most common mental disorders and they can increase the risk for comorbid mood and substance use disorders, significantly contributing to the global burden of disease. For this reason, anxiolytics are the most prescribed psychoactive drugs, particularly in the Western world.

AREAS COVERED

This review aims to analyze pharmacokinetic profile, plasma level variations so as the metabolism, interactions and possible relation to clinical effect of several drugs which are used primarily as anxiolytics. The drugs analyzed include benzodiazepines, anticonvulsants (pregabalin, gabapentin), buspirone, β-blockers and antihistamines (hydroxyzine). Regarding the most frequently used anxiolytic benzodiazepines, data on alprazolam, bromazepam, chlordesmethyldiazepam, chlordiazepoxide, clotiazepam, diazepam, etizolam, lorazepam, oxazepam, prazepam and clonazepam have been detailed.

EXPERT OPINION

There is a need for a more balanced assessment of the benefits and risks associated with benzodiazepine use, particularly considering pharmacokinetic profile of the drugs to ensure that patients, who would truly benefit from these agents, are not denied appropriate treatment. An optimal pharmacological approach involving an integrative pharmacokinetic and pharmacodynamic optimization strategy would ensure better treatment and personalization of anxiety disorders. So it would be desirable for the development of new anxiolytic drug(s) that are more selective, fast acting and free from the unwanted effects associated with the traditional benzodiazepines as tolerance or dependence.

A multicomponent yoga-based, breath intervention program as an adjunctive treatment in patients suffering from generalized anxiety disorder with or without comorbidities

Objectives:

The aim of this study is to evaluate the efficacy and tolerability of Sudarshan Kriya Yoga (SKY) course in generalized anxiety disorder (GAD) outpatients, who after eight weeks of an appropriate dose of traditional therapy had not yet achieved remission.

Subjects:

The adult participants (18-65 years) were outpatients with a primary diagnosis of GAD with or without comorbidities on the Mini-International Neuropsychiatric Interview (MINI). Participants had a minimum of eight weeks standard treatment with an appropriate dose of a standard prescription anxiolytic, a clinician global impression-severity (CGI-S) score of 5-7, a Hamilton anxiety scale (HAM-A) total score ≥20 including a score of >2 on the anxious mood and tension items.

Materials and Methods:

Forty-one patients were enrolled in an open-label trial of the SKY course as an adjunct to standard treatment of GAD at the START Clinic for Mood and Anxiety Disorders, a tertiary care mood and anxiety disorder clinic in Toronto. The SKY course was administered over five days (22 h total). Subjects were encouraged to practice the yoga breathing techniques at home for 20 min per day after the course and were offered group practice sessions for 2 h once a week led by certified yoga instructors. The primary outcome measure was the mean change from pre-treatment on the HAM-A scale. Psychological measures were obtained at baseline and four weeks after completing the intervention.

Results:

Thirty-one patients completed the program (mean age 42.6 ± 13.3 years). Among completers, significant reductions occurred in the pre- and post-intervention mean HAM-A total score (t=4.59; P<0.01) and psychic subscale (t=5.00; P≤0.01). The response rate was 73% and the remission rate 41% as measured on the HAM-A.

Conclusion:

The results of this small pilot trial suggest that the SKY course represents a potentially valuable adjunct to standard pharmacotherapy in patients with GAD or treatment-resistant GAD, and warrants further investigation. In particular, changes in worry and body symptoms showed significant improvements that may further our understanding of the mechanism of change in the tolerance of anxiety and worry.

Efficacy and safety of pregabalin in the treatment of alcohol and benzodiazepine dependence

INTRODUCTION

Both alcohol and benzodiazepine dependence (AD, BD) are severe and chronic conditions with devastating physical and mental health effects. The relative scarcity and controversial evidential status of available pharmacological interventions for the treatment of patients' acute withdrawal syndrome and/or relapse prevention call for the clinical investigation of novel safe and efficacious agents.

AREAS COVERED

We review published studies of pregabalin as monotherapy in the treatment of AD and BD in more than 450 patients. Available evidence includes four RCTs, two in AD with active comparator drugs (naltrexone, tiapride, and lorazepam) and one placebo-controlled, and one placebo-controlled in BD. We also review other available studies on pregabalin's potential to reduce benzodiazepine consumption, its side effects, especially cognitive, as well as extant reports on its liability for abuse.

EXPERT OPINION

Available evidence suggests that monotherapy with pregabalin, within the dosage range of 150 - 600 mg/d, is a promising "novel" option for the safe and efficacious relapse prevention of both AD and BD. However, its efficacy as monotherapy in the acute treatment of AD withdrawal syndrome is still controversial. Clinicians should be cautious in prescribing pregabalin to patients with a history of multiple substance recreational use, and monitor its effects on cognition at dosages above 450 mg/d. Further, well-designed clinical research is still needed for the eventual consolidation of pregabalin's place in the treatment of AD and BD.

Switching from long-term benzodiazepine therapy to pregabalin in patients with generalized anxiety disorder: a double-blind, placebo-controlled trial

To evaluate the efficacy of pregabalin in facilitating taper off chronic benzodiazepines, outpatients (N = 106) with a lifetime diagnosis of generalized anxiety disorder (current diagnosis could be subthreshold) who had been treated with a benzodiazepine for 8-52 weeks were stabilized for 2-4 weeks on alprazolam in the range of 1-4 mg/day. Patients were then randomized to 12 weeks of double-blind treatment with either pregabalin 300-600 mg/day or placebo while undergoing a gradual benzodiazepine taper at a rate of 25% per week, followed by a 6-week benzodiazepine-free phase during which they continued double-blind study treatment. Outcome measures included ability to remain benzodiazepine-free (primary) as well as changes in Hamilton Anxiety Rating Scale (HAM)-A and Physician Withdrawal Checklist (PWC). At endpoint, a non-significant higher proportion of patients remained benzodiazepine-free receiving pregabalin compared with placebo (51.4% vs 37.0%). Treatment with pregabalin was associated with significantly greater endpoint reduction in the HAM-A total score versus placebo (-2.5 vs +1.3; p < 0.001), and lower endpoint mean PWC scores (6.5 vs 10.3; p = 0.012). Thirty patients (53%) in the pregabalin group and 19 patients (37%) in the placebo group completed the study, reducing the power to detect a significant difference on the primary outcome. The results on the anxiety and withdrawal severity measures suggest that switching to pregabalin may be a safe and effective method for discontinuing long-term benzodiazepine therapy.

Modulation of ion channels in clinical psychopharmacology: adults and younger people

This review focuses on the use of Na(+), Ca(2+) and Cl(-) channel modulators in psychiatric disease. Drugs that modulate ion channels have been used in psychiatry for more than a century, and in this review we critically evaluate clinical research that reports the therapeutic effects of drugs acting on GABA(A), voltage-gated Na(+) and voltage-gated Ca(2+) channels in pediatric and adult patients. As in other fields, the evidence underpinning the use of medicines in younger people is far less robust than for adults. In addition, we discuss some current developments and highlight clinical disorders in which current molecules could be further tested. Notable success stories, such as benzodiazepines (in sleep and anxiety disorders) and antiepileptics (in bipolar disorder), have been the result of serendipitous discoveries or refinements of serendipitous discoveries, as in all other major treatments in psychiatry. Genomic, high-throughput screening and molecular pharmacology discoveries may, however, guide further developments in the future. This could include increased research in promising targets that have been perceived as commercially risky, such as selective α-subunit GABA(A) receptors.

Management of generalized anxiety disorder in primary care: identifying the challenges and unmet needs

BACKGROUND

Generalized anxiety disorder (GAD) is one of the most common psychiatric disorders in primary care, although it is often underrecognized and undertreated. GAD is chronic, disabling, and associated with other health problems. Treatment response is often unsatisfactory, but the clinical evidence base for new treatments has expanded substantially in the past decade and suggests a growing range of options for reducing the burden of GAD. The objective of this article was to review current literature on GAD and its management to provide an overview of the clinical importance of GAD in primary care and available treatments.

DATA SOURCES

Recent studies (ie, over the past decade) on the epidemiology and treatment of GAD were identified by searching Medline using the term generalized anxiety disorder only and in combination with the terms epidemiology and treatment and for each drug class (benzodiazepines, azapirones, antidepressants, antihistamines, alpha-2-delta ligands, and antipsychotics) and for named drugs (buspirone, venlafaxine, duloxetine, fluoxetine, escitalopram, olanzapine, paroxetine, pregabalin, quetiapine, and risperidone in addition to psychological therapies and cognitive-behavioral therapy. The literature search was conducted in August 2008 for the period 1987-2009.

STUDY SELECTION

Studies were included if judged to be relevant to a review of the epidemiology and management of GAD. Articles were excluded if they were not written in English or were published more than 10 years before the literature search was conducted. A few older studies were included for which more recent research evidence was not available. Recent national and international guidelines for the management of GAD were also reviewed.

DATA EXTRACTION/SYNTHESIS

Most currently available interventions have similar overall efficacy, and treatment choices should reflect the situation of individual patients. Important unmet needs exist for treatments (1) that work rapidly, with (2) broad spectrum benefits, (3) that can improve rates of remission and well-being, (4) are devoid of risk for withdrawal symptoms, and (5) have few if any adverse interactions with other drugs. Additional needs include (6) safer drugs for the elderly, (7) safe and effective drugs for children with GAD, (8) further evaluation of psychotherapy, and (9) understanding the appropriate circumstances for, and optimal choices of, drug combination.

CONCLUSION

While the development of novel treatments evolves, current management approaches can focus on improving identification and defining optimal use of available therapies for GAD.

Extended-release quetiapine fumarate (quetiapine XR): a once-daily monotherapy effective in generalized anxiety disorder. Data from a randomized, double-blind, placebo- and active-controlled study

The efficacy and tolerability of extended-release quetiapine fumarate (quetiapine XR) once-daily monotherapy in generalized anxiety disorder (GAD) was assessed. This multicentre, double-blind, randomized, placebo- and active-controlled, phase III trial consisted of a 1- to 4-wk enrolment/wash-out period and a 10-wk (8-wk active treatment, 2-wk post-treatment drug-discontinuation) study period; 873 patients were randomized to 50 mg or 150 mg quetiapine XR, 20 mg paroxetine, or placebo. Primary endpoint was change from randomization at week 8 in Hamilton Rating Scale for Anxiety (HAMA) total score. At week 8, all active agents produced significant improvements in HAMA total and psychic subscale scores vs. placebo; HAMA somatic subscale scores were significantly reduced only by 150 mg quetiapine XR. Significant separation from placebo (-2.90) in HAMA total score was observed at day 4 for 50 mg quetiapine XR (-4.43, p<0.001) and 150 mg quetiapine XR (-3.86, p<0.05), but not for paroxetine (-2.69). Remission (HAMA total score 7) rates at week 8 were significantly higher for 150 mg quetiapine XR (42.6%, p<0.01) and paroxetine (38.8%, p<0.05) vs. placebo (27.2%). The most common adverse events (AEs) were dry mouth, somnolence, fatigue, dizziness, and headache, for quetiapine XR, and nausea, headache, dizziness for paroxetine. A lower proportion of patients reported sexual dysfunction with quetiapine XR [0.9% (50 mg), 1.8% (150 mg)] than with placebo (2.3%) or paroxetine (7.4%). The incidence of AEs potentially related to extrapyramidal symptoms was: quetiapine XR: 50 mg, 6.8%, 150 mg, 5.0%; placebo, 1.8%; and paroxetine, 8.4%. Once-daily quetiapine XR is an effective and generally well-tolerated treatment for patients with GAD, with symptom improvement seen as early as day 4.

Pharmacotherapy Update: Pregabalin in the Treatment of Generalized Anxiety Disorder

Generalized anxiety disorder (GAD) is a common disorder that is chronic, disabling, and often goes undiagnosed. Currently, four distinct classes of medications have demonstrated efficacy in the treatment of GAD: benzodiazepines, serotonin and/or norepinephrine reuptake inhibitors (SSRIs/SNRIs), histamine H1 receptor blockers (hydroxyzine), and pregabalin. Pregabalin acts via binding to an α2-δ subunit presynaptic membrane protein that inhibits neurotransmitter release in excited neurons. Pregabalin is renally excreted and undergoes minimal (<2%) hepatic metabolism, thus limiting the risk of drug–drug interactions. The efficacy of pregabalin for the treatment of GAD has been established based on the results of 8 double-blind, placebo-controlled, short-term led trials, and one 6-month relapse prevention study. The current review summarizes data showing that pregabalin has a significantly different safety profile from the benzodiazepines (eg, less sedation, less cognitive and psychomotor impairment, less risk of dependence and withdrawal), and SSRI/SNRI anxiolytics (eg, less gastrointestinal side effects and sexual dysfunction). The review also summarizes efficacy data showing that pregabalin is a broad spectrum anxiolytic that with a speed of onset similar to the benzodiazepines.

Pregabalin in the treatment of alcohol and benzodiazepines dependence

We review all available studies on the use of the newer anticonvulsant drug pregabalin (PGB) in the treatment of both alcohol dependence (AD) and benzodiazepine dependence (BD). In AD, the available evidence includes one open-label and one double-blind randomized studies, whereas in BD, only a few case reports and one open-label study are as yet available. In both conditions, PGB was found efficacious with significant improvement in withdrawal symptoms at the dosage ranges of 150-450 mg/day (AD) and 225-900 mg/day (BD). Moreover, its side effects were mild and transient. Despite the limited quality of the studies design, their findings suggest that PGB might constitute a novel efficacious and safe option in the treatment of both AD and BD.

Pregabalin in the treatment of post-traumatic peripheral neuropathic pain: a randomized double-blind trial

BACKGROUND

Pregabalin is effective in the treatment of peripheral and central neuropathic pain. This study evaluated pregabalin in the treatment of post-traumatic peripheral neuropathic pain (including post-surgical).

METHODS

Patients with a pain score >or=4 (0-10 scale) were randomized and treated with either flexible-dose pregabalin 150-600 mg/day (n = 127) or placebo (n = 127) in an 8-week double-blind treatment period preceded by a 2-week placebo run-in.

RESULTS

Pregabalin was associated with a significantly greater improvement in the mean end-point pain score vs. placebo; mean treatment difference was -0.62 (95% CI -1.09 to -0.15) (P = 0.01). The average pregabalin dose at end-point was approximately 326 mg/day. Pregabalin was also associated with significant improvements from baseline in pain-related sleep interference, and the Medical Outcomes Study sleep scale sleep problems index and sleep disturbance subscale (all P < 0.001). In the all-patient group (ITT), pregabalin was associated with a statistically significant improvement in the Hospital Anxiety and Depression Scale anxiety subscale (P < 0.05). In total, 29% of patients had moderate/severe baseline anxiety; treatment with pregabalin in this subset did not significantly improve anxiety. More patients reported global improvement at end-point with pregabalin than with placebo (68% vs. 43%; overall P < 0.01). Adverse events led to discontinuation of 20% of patients from pregabalin and 7% from placebo. Mild or moderate dizziness and somnolence were the most common adverse events in the pregabalin group.

CONCLUSION

Flexible-dose pregabalin 150-600 mg/day was effective in relieving neuropathic pain, improving disturbed sleep, improving overall patient status, and was generally well tolerated in patients with post-traumatic peripheral neuropathic pain.

Pregabalin, tiapride and lorazepam in alcohol withdrawal syndrome: a multi-centre, randomized, single-blind comparison trial

INTRODUCTION

The aim of this trial was to compare lorazepam with non-benzodiazepine medications such as pregabalin and tiapride in the treatment of alcohol withdrawal syndrome (AWS). These drugs were chosen for their inhibitorial effects on the hypersecretion of neurotransmitters usually observed in AWS. Craving reduction and improvement of psychiatric symptoms were the secondary end-points.

METHODS

One hundred and ninety subjects affected by current alcohol dependence were considered consecutively: 111 were enrolled and divided into three groups of 37 subjects each. Within a treatment duration of 14 days, medication was given up to the following maximum doses (pregabalin 450 mg/day; tiapride 800 mg/day; lorazepam 10 mg/day). Withdrawal (CIWA-Ar), craving [visual analogue scale (VAS); Obsessive and Compulsive Drinking Scale (OCDS)], psychiatric symptoms [Symptom Check List 90 Revised (SCL-90-R)] and quality of life (QL-index) rating scales were applied.

RESULTS

On the CIWA-Ar score, all the groups showed a significant reduction between times (P < 0.001) with a higher reduction for the pregabalin group (P < 0.01) on items regarding headache and orientation. Retention in treatment was lower in the tiapride group (P < 0.05), while the number of subjects remaining alcohol free was higher in the pregabalin group (P < 0.05). Significant reduction between baseline and the end of the treatment was found in all the groups at the OCDS and the VAS for craving, at the SCL-90-R and QL-index (P < 0.001).

DISCUSSION

All the medications in the trial showed evidence of safety and efficacy in the treatment of uncomplicated forms of AWS, with some particular differences. The efficacy of pregabalin was superior to that of tiapride, used largely in research trials and, for some measures, to that of the 'gold standard', lorazepam. Accordingly, pregabalin may be considered as a potentially useful new drug for treatment of AWS, deserving further investigation.

Early onset anxiolytic efficacy after a single dose of pregabalin: double-blind, placebo- and active-comparator controlled evaluation using a dental anxiety model

To evaluate acute onset of anxiolytic activity using a dental anxiety model, 89 patients were randomised to double-blind single dose pregabalin 150 mg, alprazolam 0.5 mg or placebo 4 h before a scheduled dental procedure. A Dental Anxiety Total score >12 (moderate-to-severe) without meeting Diagnostic and Statistical Manual of Mental Disorders (Fourth edition) (DSM-IV) anxiety disorder criteria was required. Efficacy and safety, assessed 2, 2.5, 3, 3.5 and 4 h postdose, included 100 mm Visual Analogue Scale for Anxiety (VAS-Anxiety; primary outcome), 100 mm VAS-Sedation and Time-to-Onset of Action Scale (TOAS), a patient-rated anti-anxiety drug-benefit scale (no [0] to full benefit [10]). Mixed model analysis found significantly greater VAS-A improvement slopes for pregabalin (t = -2.47; P = 0.014) and alprazolam (t = -2.39; P = 0.018). There was a significant improvement versus placebo in the TOAS from 2 h through endpoint in alprazolam patients and from 3 h onward in pregabalin patients. Pregabalin produced significantly greater increases in VAS-Sedation versus placebo from 2.5 h through 4 h (2 h onward for alprazolam). Notably, there was a higher correlation between TOAS and VAS-Sedation (r = +0.58) than VAS-Anxiety (r = -0.50) on Spearman's analysis. The majority of Adverse Effects (AEs) were mild, and the most frequent for pregabalin, alprazolam, and placebo, respectively, were fatigue (N = 7, 7, 3), dizziness (N = 6, 3, 3), attention disturbance (N = 3, 1, 0), somnolence (N = 3, 0, 0), feeling abnormal (N = 0, 2, 0) and balance disorder (N = 0, 2, 0). These results suggest that onset of clinically meaningful anxiolytic effect after single-dose pregabalin occurs within the first 3-4 h. Additional research is needed to determine whether anxiolytic effect occurs in generalized anxiety disorder populations by day 1 or within 3-4 h post-first dose.

Efficacy of pregabalin and venlafaxine-XR in generalized anxiety disorder: results of a double-blind, placebo-controlled 8-week trial

The objective of this study was to evaluate the anxiolytic efficacy, and speed of onset of efficacy, of pregabalin (PGB) and venlafaxine-XR (VXR) in patients with generalized anxiety disorder (GAD). In this double-blind trial, outpatients, ages 18-65 years, who met Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria for GAD were randomized to 8 weeks of flexible-dose treatment with PGB (300-600 mg/day), VXR (75-225 mg/day), or placebo (PBO). The intent-to-treat sample consisted of 121 patients on PGB [least square (LS) mean ± SE baseline Hamilton Anxiety Rating Scale (HAM-A), 27.6 ± 0.4], 125 patients on VXR (baseline HAM-A, 27.4 ± 0.4), and 128 patients on PBO (baseline HAM-A, 26.8 ± 0.4). Treatment with PGB was associated with a significantly greater LS mean change in the HAM-A total score at last observation carried forward endpoint versus PBO (-14.5 ± 0.9 vs. -11.7 ± 0.9; P = 0.028). Treatment with VXR was not significant versus PBO at endpoint (-12.0 ± 0.9; -11.7 ± 0.9; P =0.968). Treatment with PGB showed an early onset of improvement, with significantly greater LS mean change in the HAM-A by day 4 versus both PBO (-5.3 ± 0.5 vs. -3.4± 0.5; P = 0.008) and VXR (-2.9 ± 0.5; P = 0.0012). The proportion of patients reporting a severe adverse event was similar for PGB (9.1%) and PBO (7.8%), but higher for VXR (20.0%; P < 0.05). In conclusion, PGB was a safe and effective treatment of GAD, with a significantly earlier onset of anxiolytic activity than VXR.

[Cognition and perception deficits in fibromyalgia and rheumatoid arthritis]

INTRODUCTION

Cognitive disturbance in patients with fibromyalgia and rheumatoid arthritis is today a topic of a great clinical interest, largely due to the fact that these persons often complain about cognitive problems.

OBJECTIVE

This study is aimed to assess the visuospatial memory, attention and perceptive capacities in chronic pain patients.

MATERIAL AND METHODS

Groups were constituted by fibromyalgia patients and rheumatoid arthritis patients, as well as a control group. All the subjects completed a battery of visual and spa-tial memory, speed of processing, working memory, attention, orientation and visuoperceptive abilities. A cognitive reserve measurement was obtained.

RESULTS

Results show that chronic pain patients displayed worse cognitive performance than controls. Moreover, arthritis patients execute poorly when compared to the group of fibromyalgia in tasks that demand visuoperceptive integration and visuomotor processing. Patients suffering fibromyalgia obtained worse punctuations than those with arthritis in spatial memory and spatial orientation tasks.

CONCLUSIONS

Both groups developed important cognitive deficits, which cannot be explained by the collateral effects of such pathologies, because cognitive profiles are not similar and appear from the beginning of the disease.

Quetiapine as an adjunctive pharmacotherapy for the treatment of non-remitting generalized anxiety disorder: a flexible-dose, open-label pilot trial

BACKGROUND

Generalized anxiety disorder (GAD) is a chronic disorder associated with significant morbidity and disability. Traditional therapies are associated with poor levels of remission, and often result in troublesome side effects.

METHODS

This was a 12-week, open-label, flexible-dose study to assess the efficacy and tolerability of quetiapine as an adjunctive treatment to traditional medication. 40 outpatients with GAD who had not achieved remission following at least 8 weeks of an adequate dose of traditional therapy were enrolled. The primary endpoint was the mean change from pre-treatment to week 12 in the Hamilton Anxiety Rating Scale (HAM-A) total scores. Secondary endpoints included: the proportion of patients achieving remission (HAM-A total score of < or =10 at week 12), Clinical Global Impressions-Severity of Illness (CGI-S), Clinical Global Impressions-Global Improvement (CGI-I), Pittsburgh Sleep Quality Index (PSQI) and Penn State Worry Questionnaire (PSWQ).

RESULTS

Adjunctive quetiapine (mean dose 386mg/day at week 12) significantly reduced the HAM-A total scores from pre-treatment (29.8+/-9.0) to week 12 (9.0+/-10.2) (-20.6; p<0.001). The HAM-A remission rate was 72.1% at week 12. Adjunctive quetiapine resulted in a significant reduction in all efficacy measures by study end. Quetiapine was well tolerated: the most common adverse event (AE) was sedation, with no incidence of serious AEs and no clinically significant changes in vital signs, weight (mean gain 0.5kg at week 12) or laboratory assessments.

CONCLUSION

The results of this small pilot trial suggest that quetiapine adjunctive to traditional therapy may be a useful treatment in patients with GAD or treatment-resistant GAD, and warrant further investigation.

Pregabalin in the discontinuation of long-term benzodiazepines' use

OBJECTIVE

Tolerance, dependence, and adverse effects on cognitive functions are well-known consequences of long-term use of benzodiazepines (BDZ), especially at high doses, raising thorny therapeutic problems in their discontinuation. One promising pharmacological agent in BDZ discontinuation might be the newer anti-epileptic pregabalin, already successfully tested in the treatment of anxiety disorders.

METHODS

We report on a sample of 15 patients with long-term, mostly high-dose dependence from BDZ, treated with pregabalin in an open-label study at doses 225-900 mg.

RESULTS

All patients discontinued successfully BDZ in 3-14 weeks, moreover with a significant reduction of their previous anxiety levels under BDZ. In addition, patients showed also a significant amelioration in their cognitive functioning. Pregabalin's side-effects were mild and transient, lasting only during the first 2 weeks of treatment.

CONCLUSION

Although preliminary, our findings suggest that pregabalin may be one new promising agent in the treatment of BDZ dependence.

Efficacy of pregabalin in depressive symptoms associated with generalized anxiety disorder: a pooled analysis of 6 studies

Epidemiological evidence supports comorbidity of generalized anxiety disorder (GAD) and major depressive disorder (MDD) or dysthymia, and its association with significant disability. As pregabalin, a new alpha(2)-delta anxiolytic treatment for GAD, unlike most other licensed treatments for GAD has not undergone investigation in patients with MDD, we examined its efficacy in depressive symptoms associated with GAD, through a post-hoc analysis of the existing clinical trial database. The results provide consistent evidence that in patients with GAD pregabalin reduced associated symptoms of depression. This was seen in the 150 mg/day, 300-450 mg/day and 600 mg/day dosing groups. Even in subjects with more prominent depressive symptoms, pregabalin remained effective for both sub-syndromal depression and GAD symptoms, with pregabalin 300-450 mg/day demonstrating the most beneficial response. In conclusion, pregabalin, an alternative treatment option for GAD with a novel mechanism of action, also demonstrated efficacy in treating depressive symptoms typically encountered in GAD patients.

Pregabalin in the discontinuation of long-term benzodiazepine use: a case-series

Tolerance, dependence, and adverse effects on cognitive functions are well known consequences of long-term use of benzodiazepines (BDZ), especially at high doses; this raises thorny therapeutic problems in their discontinuation. One promising pharmacological agent in BDZ discontinuation might be the newer antiepileptic, pregabalin (PGB), which has already successfully been tested in the treatment of anxiety disorders. We report on a series of four women with long-term, high-dose dependence on BDZ, who were treated with PGB at doses of 225-600 mg. All four patients discontinued BDZ successfully in 3-7 weeks. Moreover, they had an impressive reduction of their previous anxiety levels under BDZ. In addition, the patients showed a clinically significant amelioration in their cognitive functioning. The side effects of PGB were mild and transient, persisting only during the first 2 weeks of treatment. Although our findings are preliminary, they suggest that PGB might be one of the most promising of the newer agents in the treatment of BDZ dependence.

Pregabalin in the management of central neuropathic pain

Central neuropathic pain is a painful condition, often severe, that occurs in a person who is already affected by an injury or disease of the brain or spinal cord. This dual insult is especially threatening to the quality of life of a person and their ability to perform even the most basic of tasks. Despite this high level of suffering there are relatively few trials investigating the management of central neuropathic pain. However, two randomised placebo-controlled studies have recently emerged demonstrating efficacy of pregabalin in reducing central neuropathic pain due to spinal cord injury and central poststroke pain. Pregabalin, an anticonvulsant, has been shown to be efficacious in the management of peripheral neuropathic pain of various causes and now may have a role to play in central neuropathic pain.

Pregabalin for the treatment of generalized anxiety disorder: a novel pharmacologic intervention

Pregabalin is the first anxiolytic pharmacologic alternative for the treatment of generalized anxiety disorder (GAD) to be introduced in more than 10 years. GAD is a significant psychiatric condition with lifetime prevalence rates ranging between 5.7 and 6.4%. It causes significant impairment in quality of life and functional abilities equivalent to those associated with major depression. Randomized, controlled trials confirm that pregabalin is superior to placebo and comparable with lorazepam, alprazolam and venlafaxine for the treatment of patients with moderate-to-severe GAD. The onset of anxiolytic activity for pregabalin is apparent within 1 week following initiation of treatment, which is more rapid than that obtained with paroxetine and venlafaxine. Additionally, pregabalin has demonstrated potential for the prevention of relapse of GAD. Recently, the efficacy, safety and tolerability of pregabalin were also shown in a placebo-controlled study with elderly patients. Safety and tolerability profiles are favorable, with transient dizziness and somnolence of mild-to-moderate severity being the most commonly reported adverse events. Pregabalin has minimal potential for drug-drug interactions and does not provoke a clinically significant withdrawal response. Furthermore, pregabalin has low potential for abuse and dependence, unlike other classes of medications used for the treatment of GAD. Clinicians may consider the use of pregabalin in lieu of benzodiazepines as an alternative therapy for their patients with GAD.