Long-term efficacy of pregabalin in generalized anxiety disorder

A multicenter, randomized, placebo-controlled, double-blind study was conducted to evaluate the efficacy of pregabalin in preventing relapse of generalized anxiety disorder (GAD) after response to short-term treatment. Outpatients (n=624) with GAD for > or =1 year received open-label pregabalin (450 mg/day) for 8 weeks and, if a clinical response was observed, were randomized to receive either pregabalin (450 mg/day; n=168) or placebo (n=170) for 24 weeks. The primary efficacy parameter was time to relapse. Among responders to open-label acute treatment with pregabalin, time to relapse of GAD was significantly longer for patients treated with pregabalin compared with placebo (P<0.0001). Fifty per cent of the placebo group had relapsed by day 23, and at study endpoint, 65% had relapsed. In the pregabalin group, only 42% had relapsed by study end. Total attrition during double-blind treatment was somewhat higher on pregabalin compared with placebo (21.4 vs. 15.3%); attrition owing to adverse events (AEs) was also somewhat higher on pregabalin (6.0 vs. 2.4%). AEs were relatively low in the double-blind phase; only three AEs occurred with an incidence of more than 5% on pregabalin and placebo, respectively: infection (14.9 vs. 11.2%), headache (10.1 vs. 11.2%), and somnolence (6.0 vs. 0%). No safety concerns were identified with long-term treatment. The study indicates that pregabalin is an effective treatment for the prevention of relapse in patients with GAD.     

Efficacy of pregabalin in generalized social anxiety disorder: results of a double-blind, placebo-controlled, fixed-dose study

The objective of this study was to evaluate the efficacy and tolerability of pregabalin for the treatment of generalized social anxiety disorder (SAD). Patients with generalized SAD, who met the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) criteria (total N=329), were randomly assigned to 11 weeks of double-blind treatment with fixed daily doses of either pregabalin (300, 450, and 600(mg) or placebo. The treatment with pregabalin (600(mg) was associated with a significantly greater mean reduction in the Liebowitz Social Anxiety Scale total score, from baseline to endpoint, compared with placebo (-29.8 vs. -19.7; P= 0.0099), whereas reduction on pregabalin (300(mg, -20.2) and pregabalin (450(mg, -25.5) was not significant Treatment with pregabalin (600(mg) was also associated with a significantly greater improvement than placebo on the fear and avoidance subscales of the Liebowitz Social Anxiety Scale, as well as the majority of other secondary measures. Onset of improvement occurred by week 1 in the pregabalin 600-mg dose group. The most common adverse events on all three doses of pregabalin were somnolence and dizziness. Consistent with a previous study, the results of this study suggest that the 600-mg dose of pregabalin per day may be efficacious in the treatment of SAD.     

Efficacy of pregabalin in preventing relapse in patients with generalized social anxiety disorder: results of a double-blind, placebo-controlled 26-week study

The objective of this study was to evaluate the efficacy and safety of pregabalin in preventing relapse in generalized social anxiety disorder (SAD). Patients with Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) generalized SAD, who met responder criteria after 10 weeks of open-label treatment with fixed-dose pregabalin (450 mg/day; n=153), were randomly assigned to 26 weeks of double-blind treatment with pregabalin (450 mg/day) or placebo. The primary a-priori outcome of time to relapse was analyzed using the Kaplan-Meier method and the log-rank test. Double-blind treatment with pregabalin was associated with significant delay in time to relapse versus placebo (P=0.035), and with significantly greater maintenance of symptomatic improvement over 26 weeks on the Liebowitz Social Anxiety Scale total (P=0.012) and subscale scores and on the Marks Fear Questionnaire total phobia (P=0.010) and social phobia (P=0.014) subscales. Pregabalin was generally well tolerated. During the double-blind phase, the adverse events that occurred more frequently with pregabalin compared with placebo were dizziness (11.3 vs. 4.1%) and infection (21.3 vs. 16.4%). The results of this study suggest that pregabalin (450 mg/day) is safe, well tolerated, and has significant relapse-prevention efficacy over 26 weeks in patients with SAD who responded to an initial course of the pregabalin treatment.     

Adjunctive therapy with pregabalin in generalized anxiety disorder patients with partial response to SSRI or SNRI treatment

This study evaluated the efficacy of adjunctive pregabalin versus placebo for treatment of patients with generalized anxiety disorder (GAD) who had not optimally responded to previous or prospective monotherapies. This was a phase 3, randomized, double-blind, placebo-controlled study. Patients diagnosed with GAD who had a historical and current lack of response to pharmacotherapy [Hamilton Anxiety Rating Scale (HAM-A) of ≥ 22 at screening] were randomized to adjunctive treatment with either pregabalin (150-600 mg/day) or placebo. The primary outcome measure was the change in HAM-A total scores after 8 weeks of combination treatment. Adverse events were regularly monitored. Randomized patients (N=356) were treated with pregabalin (n=180) or placebo (n=176). Mean baseline HAM-A scores were 20.7 and 21.4, respectively. After treatment, the mean change in HAM-A was significantly greater for pregabalin compared with placebo (-7.6 vs. -6.4, respectively; P<0.05). HAM-A responder rates (≥ 50% reduction) were significantly higher for pregabalin (47.5%) versus placebo (35.2%; P=0.0145). The time-to-sustained response favored pregabalin over placebo (P=0.014). Adverse events were consistent with previous studies and discontinuations were infrequent for pregabalin (4.4%) and placebo (2.3%). The study was discontinued early after an interim analysis. The results indicate that adjunctive pregabalin is an efficacious therapy for patients with GAD who experience an inadequate response to established treatments.     

Efficacy of the novel anxiolytic pregabalin in social anxiety disorder: a placebo-controlled, multicenter study

Pregabalin is a novel compound in development for the treatment of anxiety disorders. The safety and efficacy of pregabalin for the treatment of social anxiety disorder was evaluated in a double-blind, multicenter clinical trial in which 135 patients were randomized to 10 weeks of double-blind treatment with either pregabalin 150 mg/d. pregabalin 600 mg/d, or placebo. The primary efficacy parameter was change from baseline to end point in the Liebowitz Social Anxiety Scale (LSAS) total score. Safety was assessed through clinical and laboratory monitoring, and recording spontaneously reported adverse events. Ninety-four patients (70%) completed the 11-week double-blind treatment phase. LSAS total score was significantly decreased by pregabalin 600 mg/d treatment compared with placebo (P = 0.024, analysis of covariance). Significant differences (P < or = 0.05) between pregabalin 600 mg/d and placebo were seen on several secondary measures including the LSAS subscales of total fear, total avoidance, social fear, and social avoidance, and the Brief Social Phobia Scale fear subscale. Pregabalin 150 mg/d was not significantly better than placebo on any measures. Somnolence and dizziness were the most frequently occurring adverse events among patients receiving pregabalin 600 mg/d. In conclusion, pregabalin 600 mg/d was an effective and well-tolerated treatment of social anxiety disorder.     

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

Pregabalin is a novel compound under development for the treatment of several types of anxiety disorders. To obtain an initial evaluation of the efficacy and safety of pregabalin in the treatment of generalized anxiety disorder (GAD), we conducted a double-blind, fixed-dose, parallel-group, placebo and active-controlled multicenter 4-week study that compared 271 patients randomized to receive pregabalin 50 mg tid (N = 70), pregabalin 200 mg tid (N = 66), placebo (N = 67), or lorazepam 2 mg tid (N = 68), followed by a 1-week double-blind taper. The primary efficacy parameter was change from baseline to endpoint (last observation carried forward) in the Hamilton Anxiety Scale (HAM-A) total score; adjusted mean change scores on the HAM-A were significantly improved for pregabalin 200 mg tid (difference of 3.90 between drug and placebo; p = 0.0013 [ANCOVA], df = 252) and for lorazepam (difference of 2.35; p = 0.0483 [ANCOVA], df = 252), with the significant difference between the pregabalin 200 mg tid and placebo groups seen at week 1 of treatment (p = 0.0001 [ANCOVA], df = 238). Safety analysis, which included assessment of spontaneously reported adverse events, laboratory monitoring, and withdrawal symptoms, showed pregabalin to be generally well-tolerated. The most common adverse events seen with pregabalin 200 mg tid were somnolence and dizziness. They were usually mild or moderate in intensity and were often transient. Pregabalin-treated patients had a higher completion rate than lorazepam-treated patients. This study supports the hypothesis that pregabalin is effective and safe in short-term therapy for GAD. More studies are needed to determine the best dosing regimen to optimize efficacy and tolerability.     

Efficacy and tolerability of twice-daily pregabalin for treating pain and related sleep interference in postherpetic neuralgia: a 13-week, randomized trial

OBJECTIVE: This trial evaluated the efficacy and safety of pregabalin dosed twice daily (BID) for relief of neuro-pathic pain associated with postherpetic neuralgia (PHN). RESEARCH DESIGN AND METHODS: The 13-week, double-blind, placebo-controlled study randomized 370 patients with PHN to pregabalin (150, 300, or 600 mg/day BID) or placebo. MAIN OUTCOME MEASURES: Primary efficacy measure was endpoint mean pain score from daily pain diaries. Secondary efficacy measures included endpoint mean sleep-interference score from daily sleep diaries and Patient Global Impression of Change (PGIC). Safety evaluations included adverse events (AEs), physical and neurologic examinations, 12-lead ECG, vital signs, and laboratory testing. RESULTS: Pregabalin provided significant, dose-proportional pain relief at endpoint: difference from placebo in mean pain score, 150 mg/day, -0.88, p = 0.0077; 300 mg/day, -1.07, p = 0.0016; 600 mg/day, -1.79, p = 0.0003. Weekly mean pain scores significantly improved as early as week 1. Sleep interference in all pregabalin groups was also significantly improved at endpoint, compared with placebo (p < 0.001), beginning at week 1 (p < 0.01). At study termination, patients in the 150 (p = 0.02) and 600 mg/day (p = 0.003) groups were more likely to report global improvement than were those in the placebo group.Most AEs were mild or moderate. Among pregabalin-treated patients, 13.5% withdrew due to AEs, most commonly for dizziness (16 patients, 5.8%), somnolence (8, 2.9%), or ataxia (7, 2.5%). CONCLUSIONS: Pregabalin, dosed BID, reduced neuropathic pain associated with PHN and was well tolerated. It also reduced the extent to which pain interfered with sleep. Pregabalin's effects were seen as early as week 1 and were sustained throughout the 13-week study.     

Pregabalin: in the treatment of generalised anxiety disorder

Pregabalin, the pharmacologically active S-enantiomer of 3-aminomethyl-5-methyl-hexanoic acid, is a structural analogue of GABA, although it is not active at GABA receptors, nor does it acutely alter GABA uptake or degradation.black triangle Pregabalin binds with high affinity to the alpha2-delta subunit protein of voltage-gated calcium channels in CNS tissues and acts as a presynaptic modulator of the excessive release, in hyperexcited neurons, of various excitatory neurotransmitters. Binding of pregabalin to the alpha2-delta subunit appears necessary for its demonstrable anxiolytic, analgesic and anticonvulsant activities in animal models.black triangle Oral pregabalin, typically at dosages of 300-600 mg/day, was superior to placebo and similar to lorazepam 6 mg/day, alprazolam 1.5 mg/day and venlafaxine 75 mg/day in improving anxiety and depressive symptoms in patients with moderate-to-severe generalised anxiety disorder (GAD). Pregabalin had a rapid onset of anxiolytic activity relative to alprazolam and venlafaxine, which was evident after 1 week. Additionally, pregabalin (initial dosage 450 mg/day) was effective for the prevention of relapse of GAD over 34 weeks. Pregabalin was well tolerated during dosage escalation to fixed dosages (maximum 600 mg/day) over 7 days. Dizziness and somnolence, usually of mild to moderate severity, were the most common adverse events.black triangle The drug was not associated with a clinically significant medication withdrawal syndrome during a 1-week taper following 4 or 6 weeks' double-blind treatment.     

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.     

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 150–600 mg/day. In the double-blind placebo-controlled RCT, GAD outpatients (n=249) were randomized to 8 weeks of pregabalin (300–600 mg/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.     

Lu AA21004, a multimodal psychotropic agent, in the prevention of relapse in adult patients with generalized anxiety disorder

The purpose of this study was to investigate the long-term maintenance of the efficacy of Lu AA21004 5 or 10 mg/day in the prevention of relapse in patients with generalized anxiety disorder (GAD). Patients (n = 687) with a primary diagnosis of GAD (DSM-IV criteria) and a baseline Hamilton Anxiety (HAM-A) total score of at least 20 underwent a 20-week, open-label Lu AA21004 treatment. In all, 459 patients responded and were randomized to 24-56 weeks of a double-blind treatment with Lu AA21004 (n = 229) or placebo (n = 230). The predefined primary efficacy endpoint was time to relapse (HAM-A total score ≥ 15) using a Cox model; the key secondary efficacy endpoint under multiplicity control was time to relapse for patients responding to treatment for at least 12 weeks. The primary analysis showed a statistically significant effect of Lu AA21004 relative to the placebo on the time to relapse of GAD, with a hazard ratio of 2.71 (P < 0.001). There was a statistically significant effect of Lu AA21004 in the stable responders (hazard ratio = 3.06, P < 0.001). Lu AA21004 was well tolerated, with withdrawal rates due to adverse events of 9% (open-label) and 3% (placebo) and 4% (Lu AA21004) in the double-blind period. In this study, Lu AA21004 5 or 10 mg/day was efficacious in preventing relapse and was well tolerated in the maintenance treatment of GAD.     

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.     

Buspirone in depressed outpatients: a controlled study

One hundred fifty-five outpatients suffering from major depression with significant anxiety entered a double-blind study comparing 8 weeks of treatment with buspirone or placebo. Twenty-nine percent of buspirone and 40 percent of placebo patients discontinued treatment before 8 weeks. Major efficacy measures were the Hamilton Rating Scale for Depression (HAM-D) total score, the HAM-D retardation and anxiety factors, the HAM-D Rickels and Bech core depression clusters, the Clinical Global Impressions (CGI), and the Hopkins Symptom Checklist (HSCL). Results were consistent across all outcome measures, including the two core depression clusters, with treatment response to buspirone significantly better than to placebo at treatment endpoint. Seventy percent of buspirone and 35 percent of placebo patients (p less than .01) were rated moderately or markedly improved after 8 weeks of therapy. Buspirone was found to be safe and well-tolerated by patients with major depression and concomitant anxiety at doses of up to 90 mg/day.     

Remission rates with venlafaxine extended release in Greek outpatients with generalized anxiety disorder. A double-blind, randomized, placebo controlled study

The primary endpoints in this study were the remission rates [final Hamilton Rating Scale for Anxiety (HAM-A) total score < or =7] and reduction from baseline in the HAM-A total score in patients with generalized anxiety disorder (GAD) and no associated depression. Patients with GAD (DSM-IV and HAM-A total score >18) were randomly assigned to treatment with venlafaxine XR or placebo for 8 weeks. A 1-week placebo run-in period preceded the double-blind phase. Patients with a >20% drop in their total HAM-A score during the run-in period, were excluded from the double-blind phase. All patients started therapy with 75 mg/day venlafaxine XR or matched placebo. Patients with less than 30% decrease in their HAM-A total score at the end of the second week, doubled their dose. Patients on the 150 mg/day dose underwent a 1-week taper period. Of the 24 patients in the venlafaxine XR group, 62.5% achieved remission versus 9.1% in the placebo group (P=0.0006). The mean decrease from baseline in HAM-A total score was 19.2 points for the venlafaxine XR group and 10.8 points for the placebo group (P<0.001). Eleven placebo-treated patients and seven venlafaxine XR treated patients doubled their dose at the end of the second week of double-blind treatment. No patient interrupted therapy because of side-effects. No changes in systolic or diastolic blood pressure were observed. Venlafaxine XR 75-150 mg/day was well tolerated. The remission rates achieved with venlafaxine 75-150 mg/day in non-depressed GAD patients were high with good tolerability.     

A double-blind, placebo-controlled trial of abecarnil and diazepam in the treatment of patients with generalized anxiety disorder

In a multicenter, double-blind trial, 310 patients who had received a diagnosis of generalized anxiety disorder were treated for 6 weeks with either abecarnil, diazepam, or placebo at mean daily doses of 12 mg of abecarnil or 22 mg of diazepam administered three times daily. Patients who were improved at 6 weeks could volunteer to continue double-blind treatment for a total of 24 weeks. The maintenance treatment phase allowed the comparison of taper results for the three treatments at several study periods (0-6 weeks, 7-12 weeks, and more than 12 weeks). Slightly more diazepam (77%) and placebo (75%) patients completed the 6-week study than abecarnil patients (66%). At intake and baseline, after a 1-week placebo washout, the patient was required to have a Hamilton Rating Scale for Anxiety score of > or =20. Major adverse events for both abecarnil and diazepam were drowsiness, dizziness, fatigue, and coordination difficulties. Clinical improvement data showed that both abecarnil and diazepam produced statistically significantly more symptom relief than did placebo after 1 week of treatment. At 6 weeks treatment (using last observation carried forward analysis), however, only diazepam still differed significantly (p < 0.01) from placebo. High placebo response (56% moderate to marked global improvement) at 6 weeks, as well as a slightly lower nonsignificant improvement rate observed with abecarnil, a partial y-aminobutyric acid (GABA) agonist, when compared with diazepam, a full GABA agonist, most likely contributed to our findings. Finally, taper results showed that only diazepam and not abecarnil caused the presence of temporary discontinuation symptoms, but only in patients who had been treated for at least 12 weeks.     

Duloxetine as an SNRI treatment for generalized anxiety disorder: results from a placebo and active-controlled trial

This study examined the efficacy and tolerability of duloxetine 60-120 mg/day for the treatment of patients with generalized anxiety disorder. This was a multicenter, randomized, double-blind, flexible-dose, placebo and active-controlled (venlafaxine extended-release 75-225 mg/day) trial designed to assess duloxetine 60-120 mg/day during 10 weeks of treatment in adults with Diagnostic and statistical manual of mental disorders-IV-defined generalized anxiety disorder. The primary efficacy outcome measure was mean change from baseline to endpoint in the Hamilton Anxiety Rating Scale total score assessed using analysis of covariance. A total of 487 patients were randomly assigned to duloxetine (n=162), venlafaxine XR (n=164), or placebo (n=161). Significantly greater improvement on the Hamilton Anxiety Rating Scale total score occurred in the duloxetine (P=0.007) and venlafaxine XR (P<0.001) groups compared with the placebo group. Overall discontinuation rates did not differ among the three groups, but adverse event-related discontinuation was significantly higher in the duloxetine (14.2%, P<0.001) and venlafaxine XR (11.0%, P=0.001) groups than in the placebo group (1.9%). During the 2-week drug-tapering phase, discontinuation-emergent adverse events were significantly greater in the venlafaxine XR group (26.9%, P=0.04), but not in the duloxetine group (19.4%, P=0.448) compared with placebo (15.8%). Duloxetine 60-120 mg/day and venlafaxine XR 75-225 mg/day were each efficacious treatments for patients with generalized anxiety disorder.     

Imipramine and buspirone in patients with panic disorder who are discontinuing long-term benzodiazepine therapy

Pretreatment with imipramine, buspirone, or placebo was compared in 40 patients meeting the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition criteria for panic disorder and in patients who were discontinuing long-term benzodiazepine use. The average duration of benzodiazepine use was 75 +/- 64 months, and the average benzodiazepine intake expressed as diazepam equivalents was 25.7 +/- 19 mg/d. We hypothesized that pretreatment with either imipramine or buspirone, in contrast to pretreatment with placebo, would lead to a significant decrease of symptoms of anxiety and depression before tapering benzodiazepines, thus making the taper process easier to complete. All 3 treatments (imipramine, buspirone, and placebo) caused a reduction in anxiety and depression symptoms as measured by changes in the Hamilton Anxiety Rating Scale and Hamilton Depression Rating Scale. Neither discontinuation severity nor taper-free status 12 weeks posttaper differed between the 3 treatment groups.     

Eight-week, placebo-controlled, double-blind comparison of the antidepressant efficacy and tolerability of bupropion XR and venlafaxine XR

The efficacy, safety and tolerability of bupropion XR and venlafaxine XR was assessed and compared with placebo in adult outpatients with major depressive disorder (MDD). Adults meeting DSM-IV criteria for MDD with a minimum Hamilton Depression Rating Scale (HAMD) 17-Item total score of > or =18 were randomized to eight weeks of double-blind treatment with either bupropion XR (150 mg/day), venlafaxine XR (75 mg/day) or placebo. At the end of the fourth week of treatment, a dosage increase to bupropion XR 300 mg/day or venlafaxine XR 150 mg/day was allowed if, in the opinion of the investigator, response was inadequate. The primary efficacy endpoint was mean change from baseline at week 8 in the Montgomery-Asberg Depression Rating Scale (MADRS) total score last observation carried forward (LOCF). Mean changes from baseline at week 8 (LOCF) in MADRS total score were statistically significant for bupropion XR and venlafaxine XR patients compared to the placebo group: -16.0 for bupropion XR (P = 0.006 vs placebo), -17.1 for venlafaxine XR (P < 0.001 vs placebo) and -13.5 for placebo. Secondary outcomes (including CGI-S, HAM-A, MEI, Q-LES-Q-SF, responder and remitter analyses) also improved significantly for both active treatment groups compared with placebo. The most frequently reported adverse events were dry mouth and insomnia for bupropion XR, and nausea, hyperhidrosis, fatigue, and insomnia for venlafaxine XR. In this double-blind, placebo-controlled trial, bupropion XR at doses up to 300 mg/day and venlafaxine XR at doses up to 150 mg/day demonstrated comparable antidepressant efficacy.     

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

Pregabalin is a new anxiolytic that acts as a presynaptic inhibitor of the release of excessive levels of excitatory neurotransmitters by selectively binding to the alpha2-delta subunit of voltage-gated calcium channels. The current study evaluated the anxiolytic efficacy of BID versus TID dosing of pregabalin in patients with generalized anxiety disorder. Outpatients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition generalized anxiety disorder and having baseline Hamilton Anxiety (HAM-A) total scores > or =20 were randomized to 6 weeks of double-blind treatment with pregabalin 200 mg/d (BID; N = 78), 400 mg/d (BID; N = 89), or 450 mg/d (TID; N = 88) or placebo (N = 86). Mean improvement in HAM-A total score at last observation carried forward end point was significantly greater on pregabalin 200 (P = 0.006), 400 (P = 0.001), and 450 mg/d (P = 0.005) compared with placebo. Pairwise comparisons of BID versus TID dosing found no difference in HAM-A change score at end point. All 3 pregabalin dosage groups showed significantly greater efficacy versus placebo at end point on the HAM-A psychic and somatic anxiety factor scores. Improvement on both factors was rapid: significance versus placebo was achieved as early as the first assessment at week 1, with > or =30% reduction in HAM-A severity and equal or greater improvement for every subsequent visit in > or =38% of patients in all 3 pregabalin dosage groups (P < or = 0.001). Pregabalin was well tolerated, and despite the fixed-dose study design, discontinuations caused by adverse events ranged from 9% to 13%--comparable with that observed with placebo (8%). This study demonstrates that pregabalin is an effective treatment of generalized anxiety disorder, with BID dosing showing similar efficacy and comparable tolerability with TID dosing.     

Efficacy and tolerability of twice-daily pregabalin for treating pain and related sleep interference in postherpetic neuralgia: a 13‐week,randomized trial

ABSTRACT

Objective: This trial evaluated the efficacy and safety of pregabalin dosed twice daily (BID) for relief of neuro-pathic pain associated with postherpetic neuralgia (PHN).

Research design and methods: The 13‐week, double-blind, placebo-controlled study randomized 370 patients with PHN to pregabalin (150, 300, or 600?mg/day BID) or placebo.

Main outcome measures: Primary efficacy measure was endpoint mean pain score from daily pain diaries. Secondary efficacy measures included endpoint mean sleep-interference score from daily sleep diaries and Patient Global Impression of Change (PGIC). Safety evaluations included adverse events (AEs), physical and neurologic examinations, 12-lead ECG, vital signs, and laboratory testing.

Results: Pregabalin provided significant, dose-proportional pain relief at endpoint: difference from placebo in mean pain score, 150?mg/day, –0.88, p = 0.0077; 300?mg/day, –1.07, p = 0.0016; 600?mg/day, –1.79, p = 0.0003. Weekly mean pain scores significantly improved as early as week 1. Sleep interference in all pregabalin groups was also significantly improved at endpoint, compared with placebo (?p < 0.001), beginning at week 1 (?p < 0.01). At study termination, patients in the 150 (p = 0.02) and 600?mg/day (p = 0.003) groups were more likely to report global improvement than were those in the placebo group.

Most AEs were mild or moderate. Among pregabalin-treated patients, 13.5% withdrew due to AEs, most commonly for dizziness (16 patients, 5.8%), somnolence (8, 2.9%), or ataxia (7, 2.5%).

Conclusions: Pregabalin, dosed BID, reduced neuropathic pain associated with PHN and was well tolerated. It also reduced the extent to which pain interfered with sleep. Pregabalin's effects were seen as early as week 1 and were sustained throughout the 13‐week study.