Birol Emir

Efficacy, Safety, and Tolerability of Pregabalin Treatment for Painful Diabetic Peripheral Neuropathy: Findings from seven randomized, controlled trials across a range of doses

OBJECTIVE—To evaluate the efficacy, safety, and tolerability of pregabalin across the effective dosing range, to determine differences in the efficacy of three times daily (TID) versus twice daily (BID) dosage schedules, and to use time-to-event analysis to determine the time to onset of a sustained therapeutic effect using data from seven trials of pregabalin in painful diabetic peripheral neuropathy (DPN). RESEARCH DESIGN AND METHODS—Data were pooled across seven double-blind, randomized, placebo-controlled trials using pregabalin to treat painful DPN with dosages of 150, 300, and 600 mg/day administered TID or BID. Only one trial included all three of these dosages, and TID dosing was used in four. All studies shared fundamental selection criteria, and treatment durations ranged from 5 to 13 weeks. RESULTS—Pooled analysis showed that pregabalin significantly reduced pain and pain-related sleep interference associated with DPN (150, 300, and 600 mg/day administered TID vs. placebo, all P ≤ 0.007). Only the 600 mg/day dosage showed efficacy when administered BID (P ≤ 0.001). Pain and sleep interference reductions associated with pregabalin appear to be positively correlated with dosage; the greatest effect was observed in patients treated with 600 mg/day. Kaplan-Meier analysis revealed that the median time to onset of a sustained (≥30% at end point) 1-point improvement was 4 days in patients treated with pregabalin at 600 mg/day, 5 days in patients treated with pregabalin at 300 mg/day, 13 days in patients treated with pregabalin at 150 mg/day, and 60 days in patients receiving placebo. The most common treatment-emergent adverse events were dizziness, somnolence, and peripheral edema. CONCLUSIONS—Treatment with pregabalin across its effective dosing range is associated with significant, dose-related improvement in pain in patients with DPN.

Efficacy of donepezil on behavioral symptoms in patients with moderate to severe Alzheimer's disease.

OBJECTIVE This subanalysis of a large, double-blind, placebo-controlled trial examined the prevalence of behavioral symptoms in moderate to severe Alzheimers disease (AD), and the effect of treatment with donepezil. METHODS Two hundred ninety patients with moderate to severe AD (standardized Mini-Mental State Examination scores 5-17) were randomized to receive 24 weeks of once-daily doses of donepezil 5 mg/day for 28 days, and 10 mg/day thereafter per the clinicians judgment (n = 144), or placebo (n = 146). The outcome measure of interest was the 12-item Neuropsychiatric Inventory (NPI). RESULTS Baseline demographics were similar between the treatment groups. Least squares mean (+/- SE) baseline NPI 12-item total scores were 19.55 +/- 1.48 and 19.30 +/- 1.45, respectively. At baseline, the most common symptoms were apathy/indifference (67%), aberrant motor behavior (53%), depression/dysphoria (52%), anxiety (49%), and agitation/aggression (45%). NPI individual item change from baseline scores at Week 24 using a last observation carried forward (LOCF) analysis showed benefits with donepezil treatment compared with placebo for all items, with significant treatment differences for depression/dysphoria, anxiety, and apathy/indifference (p < .05). Symptoms present at baseline that improved significantly for donepezil- compared with placebo-treated patients at Week 24 LOCF included anxiety, apathy/indifference, and irritability/lability (p < .05). When patients who were not receiving psychoactive medications at baseline were analyzed separately, significant improvements in NPI (continued) 12-item total score were observed with donepezil compared with placebo at most visits and at Week 24 LOCF (p < .05). CONCLUSIONS Behavioral symptoms of the magnitude observed in this moderate to severe AD population improved with donepezil.

efficacy of Donepezil on maintenance of activities of daily living in patients with moderate to severe Alzheimer's disease and the effect on Caregiver burden

OBJECTIVES: This study investigated the efficacy of donepezil treatment on activities of daily living (ADLs) and social functioning in patients with moderate to severe Alzheimers disease (AD) and the possible benefits of this treatment on caregiving time and stress levels.

Pregabalin for painful HIV neuropathy: a randomized, double-blind, placebo-controlled trial.

Objective: Pregabalin is effective in several neuropathic pain syndromes. This trial evaluated its efficacy, safety, and tolerability for treatment of painful HIV-associated neuropathy. Methods: This randomized, double-blind, placebo-controlled, parallel-group trial included a 2-week double-blind dose-adjustment (150–600 mg/day BID) phase, a 12-week double-blind maintenance phase, and an optional 3-month open label extension phase. The primary efficacy measure was the mean Numeric Pain Rating Scale (NPRS) score, an 11-point numeric rating scale. Secondary measures included Patient Global Impression of Change (PGIC) and sleep measurements. Results: Baseline mean NPRS score was 6.93 for patients randomized to pregabalin (n = 151) and 6.72 for those to placebo (n = 151). Pregabalin average daily dosage (SD) was 385.7 (160.3) mg/d. At endpoint, pregabalin and placebo showed substantial reductions in mean NPRS score from baseline: −2.88 vs −2.63, p = 0.3941. Pregabalin had greater improvements in NPRS score relative to placebo at weeks 1 (−1.14 vs −0.69, p = 0.0131) and 2 (−1.92 vs −1.43, p = 0.0393), and at weeks 7 (−3.22 vs −2.53 p = 0.0307) and 8 (−3.33 vs −2.53, p = 0.0156). At all other time points, differences between groups were not significant. Sleep measurements and 7-item PGIC did not differ among treatment groups; however, collapsed PGIC scores showed 82.8% of pregabalin and 66.7% of placebo patients rated themselves in 1 of the 3 “improved” categories (p = 0.0077). Somnolence and dizziness were the most common adverse events with pregabalin. Conclusions: Pregabalin was well-tolerated, but not superior to placebo in the treatment of painful HIV neuropathy. Factors predicting analgesic response in HIV neuropathy warrant additional research. Classification of Evidence: This Class II trial showed that pregabalin is not more effective than placebo in treatment of painful HIV neuropathy.

Sensory profiles of patients with neuropathic pain based on the neuropathic pain symptoms and signs

Summary It is suggested that there are several distinct pain sensory profiles across various neuropathic pain disorders that may reflect distinct pathophysiological mechanisms. ABSTRACT This manuscript aimed to characterize the clinical profile of various neuropathic pain (NeP) disorders and to identify whether patterns of sensory symptoms/signs exist, based on baseline responses on the Neuropathic Pain Symptom Inventory (NPSI) questionnaire and the quantitative sensory testing (QST). These post hoc analyses were based on data from 4 randomized, double‐blind, placebo‐controlled clinical studies of pregabalin (150–600 mg/day) in patients with NeP syndromes: central poststroke pain, posttraumatic peripheral pain, painful HIV neuropathy, and painful diabetic peripheral neuropathy. The NPSI questionnaire includes 10 different pain symptom descriptors. QST was used to detect sensory thresholds of accurately calibrated sensory stimuli and to quantify the intensity of evoked sensation. To identify symptoms/signs clusters and select the number of clusters, a principal component analysis (PCA) and hierarchical clustering methods with clinical input were used. Analysis of the NPSI pain qualities and individual QST measures at baseline indicated no clear association between particular symptoms/signs profiles and etiologies. Based on NPSI symptoms, PCA identified 3 pain dimensions: provoked, deep, and pinpoint. A hierarchical cluster analysis identified 3 clusters with distinct pain characteristics profiles independent of NeP syndrome. Based on QST signs, PCA identified 2 pain dimensions: evoked by cold and evoked by touch. A hierarchical cluster analysis identified 4 clusters with distinct pain characteristics profiles. These “trans‐etiological” profiles may reflect distinct pathophysiological mechanisms and therefore, potential differential responses to treatment.

Functional, Cognitive and Behavioral Effects of Donepezil in Patients with Moderate Alzheimer's Disease

Summary Objective: To investigate the efficacy and safety of donepezil in a subgroup of patients with Alzheimers disease (AD) of moderate severity from a previous trial. Methods: Two hundred and seven patients with moderate AD (standardized Mini-Mental State Examination [sMMSE] score 10-17) were randomized to treatment in this 24-week, double-blind, placebo-controlled trial. Patients received either donepezil, 5mg/day for the first 28 days and 10mg/day thereafter according to the clinicians judgement (n = 102), or placebo (n = 105). The primary outcome measure was the Clinicians Interview-Based Impression of Change with caregiver input (CIBIC-plus) at week 24 using a last observation carried forward (LOCF) analysis. Results: Baseline patient demographics were similar between treatment groups. Mean age was 74.3 years (range 48–92). Least-squares (LS) mean sMMSE scores at baseline were 13.6 ± 0.3 for the donepezil group and 13.9 ± 0.3 for the placebo group. LS mean CIBIC-plus scores for donepezil-treated patients were improved from, or close to, baseline severity at all visits, and were significantly different from placebo at weeks 8,12,18, and 24 (week 24 LOCF mean difference = 0.53, p = 0.0003). LS mean change from baseline scores on the sMMSE and Severe Impairment Battery (SIB) for the donepezil group improved throughout the study, and were significantly different from placebo at each visit for the sMMSE (week 24 LOCF mean difference = 2.06, p = 0.0002) and from week 8 for the SIB (week 24 LOCF mean difference = −4.44, p = 0.0026). LS mean change scores on the Disability Assessment for Dementia remained at or above baseline levels throughout the study for the donepezil group, while the placebo group showed a steady decline; treatment differences were significant at each visit (week 24 LOCF mean difference = −9.25, p < 0.0001). LS mean change scores on the Neuropsychiatric Inventory 12-item total improved throughout the study for the donepezil group and were significantly different from placebo at weeks 4 and 24 (week 24 LOCF mean difference = 5.92, p = 0.0022). Eighty-one per cent of donepezil-treated and 89% of placebo-treated patients completed the trial, with 9% and 5%, respectively, discontinuing due to adverse events (AEs). Eighty-two per cent of donepezil-treated and 80% of placebo-treated patients experienced AEs, the majority of which were rated mild in severity and, in general, were similar between treatment groups. Conclusion:The significant treatment responses observed with donepezil in these patients reinforce the findings from earlier studies that show donepezil to have important benefits, compared with placebo, across functional, cognitive, and behavioral symptoms, with good tolerability, in patients with AD of moderate severity.

Comparative efficacy of antidepressants in preventing relapse in anxiety disorders — A meta-analysis

BACKGROUND We assessed the efficacy of continuation treatment with antidepressants in a meta-analysis of relapse prevention studies in the five principal anxiety disorders, to explore the benefit of continuation treatment in each disorder, and their relative efficacy across these disorders. METHOD Double-blind placebo-controlled studies with relapse prevention designs in Panic Disorder, Generalized Anxiety Disorder, Social Phobia, Post-Traumatic Stress Disorder and Obsessive-Compulsive Disorder were identified in a systematic literature search. The primary efficacy comparison was relapse rates between active and placebo arms calculated as odds ratios (ORs) using Review Manager version 5.0. Relapse data were also used to calculate relative risk (RR), risk difference (RD) and number needed to treat (NNT). RESULTS Twenty-two relapse prevention trials were identified for these 5 disorders. Continuation antidepressant treatment produced robust treatment effects for each disorder, however the magnitude varied by indication. The greatest treatment effect was noted for GAD (pooled OR 0.20), whereas the pooled ORs for PD and OCD were for almost 2-fold higher (0.35 and 0.38 respectively). RR, RD and NNT showed similar statistically significant trends. LIMITATIONS This study cannot identify an optimal duration of therapy. This analysis only examined studies testing monoamine reuptake inhibiting antidepressants, and therefore these results might not be generalizable to other classes of antianxiety agents. CONCLUSIONS This meta-analysis underscores the importance of continuation treatment following acute response in all 5 anxiety disorders, however the relative efficacy of continuation antidepressant treatment appears to vary by disorder.

Evaluation of the safety and efficacy of pregabalin in older patients with neuropathic pain: results from a pooled analysis of 11 clinical studies

BackgroundOlder patients are typically underrepresented in clinical trials of medications for chronic pain. A post hoc analysis of multiple clinical studies of pregabalin in patients with painful diabetic peripheral neuropathy (DPN) or postherpetic neuralgia (PHN) was conducted to evaluate the efficacy and safety of pregabalin in older patients.MethodsData from 11 double-blind, randomized, placebo-controlled clinical studies of pregabalin in patients with DPN or PHN were pooled. Efficacy outcomes included change in Daily Pain Rating Scale score, ≥30% and ≥50% responders, and endpoint pain score ≤3. Safety was based on adverse events (AEs). Primary efficacy was analyzed by analysis of covariance with terms for treatment, age category, protocol, baseline pain, and treatment-by-age category interaction.Results2516 patients (white, n = 2344 [93.2%]; men, n = 1347 [53.5%]; PHN, n = 1003 [39.9%]; pregabalin, n = 1595) were included in the analysis. Patients were grouped by age: 18 to 64 years (n = 1236), 65 to 74 years (n = 766), and ≥75 years (n = 514). Baseline mean pain and sleep interference scores were comparable across treatment and age groups. Significant improvements in endpoint mean pain were observed for all pregabalin dosages versus placebo in all age groups (p ≤ 0.0009), except for the lowest dosage (150 mg/day) in the youngest age group. Clinically meaningful pain relief, defined as ≥30% and ≥50% pain response, was observed in all age groups. The most common AEs were dizziness, somnolence, peripheral edema, asthenia, dry mouth, weight gain, and infections. The relative risks for these AEs increased with pregabalin dose, but did not appear related to older age or type of neuropathic pain.ConclusionsPregabalin (150-600 mg/day) significantly reduced pain in older patients (age ≥65 years) with neuropathic pain and improvements in pain were comparable to those observed in younger patients. Titration of pregabalin to the lowest effective dose should allow for effective pain relief while minimizing AEs in older patients with neuropathic pain. Given the common use of polypharmacy in older patients, the absence of known drug-drug interactions makes pregabalin an important treatment option for older patients with pain of neuropathic origin.

Time to onset of neuropathic pain reduction: A retrospective analysis of data from nine controlled trials of pregabalin for painful diabetic peripheral neuropathy and postherpetic neuralgia.

These retrospective analyses of daily mean pain scores from nine placebo-controlled trials of pregabalin at 150, 300, or 600 mg/day (pregabalin, n = 1205; placebo, n = 772) examined time to significant reduction of pain during the first 2 weeks of treatment of painful diabetic peripheral neuropathy and postherpetic neuralgia. Time to onset of reduction in pain-defined as the first day for which patients treated with pregabalin had significant reductions (P < 0.05) in mean pain score compared with the placebo group for that day and the subsequent day-was calculated for all treatment groups demonstrating statistically significant reduction in pain at trial end point. The time to a 1-point or greater improvement in mean pain score was measured for each patient who was a responder at end point (30% or greater improvement in mean pain score). In seven of the nine trials (representing 11 of 14 pregabalin arms), significant reduction in pain was achieved at end point. The time to onset for reduction in pain was treatment Day 1 or 2 in nine of these successful treatment arms. Individual responder analysis confirmed that responders in the pregabalin groups reported a 1-point or greater pain reduction earlier than responders in placebo groups (P < 0.0001). However, this analysis is not a direct estimate of the likelihood that an individual patient would experience noticeable pain relief by the end of the second day. Overall, for patients who will respond to pregabalin, statistically significant and sustained reduction of pain associated with diabetic peripheral neuropathy and posttherapeutic neuralgia occurs early, usually by the end of 2 days of pregabalin treatment.

Relationship Between Pain Relief and Improvements in Patient Function/Quality of Life in Patients With Painful Diabetic Peripheral Neuropathy or Postherpetic Neuralgia Treated With Pregabalin

BACKGROUND In patients with chronic pain due to diabetic peripheral neuropathy (DPN) or postherpetic neuralgia (PHN), pregabalin treatment results in pain relief and improved patient function/quality of life (QoL). Few studies, however, have examined the exact relationship between pain relief and improvements in patient function/QoL. It is unclear, for example, whether pregabalin has a direct independent effect on patient function/QoL or whether improvements in function/QoL are an indirect consequent of pain relief. OBJECTIVES To determine whether improvements in function/QoL in response to pregabalin treatment are related to the extent of pain relief in patients with neuropathic pain due to DPN or PHN and to determine whether pregabalin has a direct independent effect on patient function/QoL that is distinct from its effects on pain. METHODS Data from 11 randomized, double-blind, placebo-controlled trials of pregabalin for the treatment of DPN or PHN were pooled for this analysis. Changes in patient function/QoL scores were plotted according to the extent of pain relief to assess whether greater levels of pain relief were associated with greater improvement in function/QoL. A novel mediation analysis was used to asses to what extent the effects of pregabalin on function/QoL scores are a direct treatment effect as opposed to an indirect effect mediated through improvements in pain or sleep. RESULTS Moderate-to-substantial pain relief (a ≥30% decrease in pain) in response to pregabalin treatment was associated with significant (P < 0.05) improvements in 36-Item Short Form Health Survey (SF-36) scores (used to assess patient function/QoL). In many patients, greatest improvement in SF-36 scores was reported by patients achieving ≥50% decrease in pain. Analysis of Patient Global Impression of Change scores revealed a similar trend, where >80% of patients who achieved substantial pain relief also reported their status as much or very much improved. A substantial direct pregabalin treatment effect was evident for many SF-36 domains that could not be explained by pain relief or improvement in sleep. CONCLUSIONS In patients with chronic pain due to DPN or PHN, improvements in patient function/QoL in response to pregabalin treatment are correlated with the extent of pain relief. However, such improvements in function/QoL are not mediated entirely through pain relief but are the result of a combination of pregabalins effects on pain and sleep disturbance and a direct effect on patient function itself.