The relationship between the reporting of euphoria events and early treatment responses to pregabalin: an exploratory post-hoc analysis.

BACKGROUND: Euphoria is a complex, multifactorial problem that is reported as an adverse event in clinical trials of analgesics including pregabalin. The relationship between the reporting of euphoria events and pregabalin early treatment responses was examined in this exploratory post-hoc analysis. METHODS: Data were from patients with neuropathic or non-neuropathic chronic pain enrolled in 40 randomized clinical trials, who received pregabalin (75-600 mg/day) or placebo. Reports of treatment-emergent euphoria events were based on the Medical Dictionary of Regulatory Activities preferred term "euphoric mood". Prevalence rates of euphoria events overall and by indication were assessed. Post-treatment endpoints included ≥30% improvements in pain and sleep scores up to 3 weeks as well as a ≥1-point improvement in daily pain score up to 11 days after treatment. RESULTS: 13,252 patients were analyzed; 8,501 (64.1%) and 4,751 (35.9%) received pregabalin and placebo, respectively. Overall, 1.7% (n=222) of patients reported euphoria events. Among pregabalin-treated patients, a larger proportion who reported euphoria events achieved an early pain response compared with those who did not report euphoria (30% pain responders in week 1 with euphoria events [43.0%], without euphoria events [24.2%]). Results were similar for weeks 2 and 3. For Days 2-11, a larger proportion of pregabalin-treated patients with (relative to without) euphoria events were 1-point pain responders. Findings were similar in pregabalin-treated patients for sleep endpoints (30% sleep responders in week 1 with euphoria events [50.7%], without euphoria events [36.1%]). Similar results were found for weeks 2 and 3. Patients who received placebo showed similar patterns, although the overall number of them who reported euphoria events was small (n=13). CONCLUSION: In patients who received pregabalin for neuropathic or non-neuropathic chronic pain, those who experienced euphoria events may have better early treatment responses than those who did not report euphoria events.

A randomized study of the efficacy and safety of parecoxib for the treatment of pain following total knee arthroplasty in Korean patients.

PURPOSE: Parecoxib is an injectable cyclooxygenase-2 inhibitor with proven postoperative analgesic efficacy in a variety of settings, including total knee arthroplasty (TKA). The effect of ethnicity on the efficacy of parecoxib for post-TKA pain has not been studied. PATIENTS AND METHODS: This was a parallel-group, double-blind, randomized, placebo- controlled study of ethnically Korean patients aged ≥18 years who had unilateral TKA. Patients who reported moderate or severe pain 6 hours after the end of postoperative opioid analgesia were randomized to receive a single intravenous dose of parecoxib sodium 40 mg or placebo. Patients were evaluated for 24 hours postdose. The primary efficacy endpoints included time-specific pain intensity difference (PID), time-specific pain relief (PR), and time to rescue medication. The incidence and nature of adverse events (AEs) assessed safety. RESULTS: Of the 116 patients randomized, 58 received parecoxib and 58 placebo. Mean (SD) PID was significantly greater for parecoxib vs placebo 1 hour postdose (0.69 [0.67] vs 0.40 [0.59], respectively; p<0.05), and for each time point up to 24 hours. Similarly, mean (SD) PR was significantly greater for parecoxib vs placebo 1.5 hours postdose (1.63 [0.85] vs 1.07 [0.90], respectively; p=0.001), and for each time point up to 24 hours. The median time (hours:minutes) to rescue medication was significantly longer for parecoxib vs placebo (21:30 vs 4:08, respectively; p<0.001). Generally, fewer AEs were reported with parecoxib than placebo, and the AE profile was consistent with previous studies. These results are comparable to the findings from a similarly designed study in a Caucasian patient population. CONCLUSION: Parecoxib 40 mg significantly improved postoperative pain vs placebo in Korean patients after TKA. The efficacy and safety of parecoxib in Korean patients is similar to that seen in Caucasian patients.

Effect of Baseline Characteristics on the Pain Response to Pregabalin in Fibromyalgia Patients with Comorbid Depression.

Objective: To evaluate the effect of baseline characteristics on the treatment response to pregabalin in fibromyalgia (FM) patients with depression. Design: Post hoc analysis from a randomized, double-blind, placebo-controlled, two-way crossover study of pregabalin (300 or 450 mg/day, twice daily). Subjects: A total of 193 FM patients taking an antidepressant for comorbid depression. Methods: The effect of patient baseline characteristics on the treatment response to pregabalin vs placebo was assessed for the primary efficacy end point (mean pain score on an 11-point numeric rating scale). Variables were analyzed using a linear mixed effects model with sequence, period, and treatment as fixed factors, and subject within sequence and within subject error as random factors. Results: Pregabalin significantly improved mean pain scores vs placebo irrespective of age, duration of FM, number of prior FM medications, depression diagnosis, shorter-term depression (<10 years), prior or no prior opioid use, pain severity, anxiety severity, and sleep disruption severity (all P < 0.05). Compared with placebo, pregabalin did not significantly affect mean pain scores in patients with comorbid insomnia, irritable bowel syndrome, or gastroesophageal reflux disease; severe FM; a diagnosis of depression before FM, longer-term depression (≥ 10 years), more severe depression, or who were taking a high dose of antidepressant. Conclusions: Pregabalin significantly improved mean pain scores when compared with placebo for the majority of baseline characteristics assessed in FM patients taking an antidepressant for comorbid depression.

Safety and efficacy of pregabalin in adolescents with fibromyalgia: a randomized, double-blind, placebo-controlled trial and a 6-month open-label extension study.

BACKGROUND: Fibromyalgia (FM) is a common pain condition characterized by widespread musculoskeletal pain and tenderness. Pregabalin is an approved treatment for adults in the United States, but there are no approved treatments for adolescents with FM. METHODS: This was a 15-week, randomized, double-blind, placebo-controlled study and 6-month open-label safety trial of flexible-dose pregabalin (75-450 mg/day) for the treatment of adolescents (12-17 years) with FM. Primary outcome was change in mean pain score at endpoint (scored from 0-10, with 24-h recall). Secondary outcomes included global assessments and measures of pain, sleep, and FM impact. RESULTS: A total of 107 subjects were randomized to treatment (54 pregabalin, 53 placebo) and 80 completed the study (44 pregabalin, 36 placebo). Improvement in mean pain score at endpoint with pregabalin versus placebo was not statistically significant, treatment difference (95 % CI), -0.66 (-1.51, 0.18), P = 0.121. There were significant improvements with pregabalin versus placebo in secondary outcomes of change in pain score by week (P < 0.05 for 10 of 15 weeks); change in pain score at week 15 (1-week recall), treatment difference (95 % CI), -0.87 (-1.68, -0.05), P = 0.037; and patient global impression of change, 53.1 % versus 29.5 % very much or much improved (P = 0.013). Trends toward improvement with pregabalin in other secondary outcomes measuring pain, sleep, and FM impact were not significant. Safety was consistent with the known profile of pregabalin in adults with FM. CONCLUSION: Pregabalin did not significantly improve the mean pain score in adolescents with FM. There were significant improvements in secondary outcomes measuring pain and impression of change. TRIAL REGISTRATIONS: NCT01020474 ; NCT01020526 .

Burden of illness in fibromyalgia patients with comorbid depression.

OBJECTIVES: To assess the burden of fibromyalgia (FM) in patients with FM taking antidepressant medication for comorbid depression. METHODS: Symptom burden, impact on work and activity, and healthcare resource utilisation (HCRU) was examined at randomisation in patients enrolled in a clinical trial. Symptom burden was estimated based on self-reported health status measures. The Work Productivity and Activity Impairment: Specific Health Problem scale adapted to FM and a separate HCRU questionnaire were completed. The relationship between FM severity and burden was evaluated. RESULTS: The total population analysed comprised 193 patients; 71 (36.8%) had moderate FM and 119 (61.7%) severe FM. Patients had moderate pain, severe impairment in functioning due to FM, sleep disruption, mild anxiety, and mild depression. In the 7 days preceding randomisation, an average of 58.0% overall work impairment was reported, with 15.2% of working hours missed and 54.0% productivity while at work. In the 3 months preceding randomisation, on average, 5.0 visits per patient were made to healthcare professionals. Physical treatments were used by 34.7% and supplements by 31.6% of patients. Prescription and non-prescription medications, as well as professional services providing help with activities of daily living (ADL) that are impacted by FM, were used by >75% of patients. In addition, 50.4 hours of unpaid help was provided for ADL assistance. Total out-of-pocket expenditures were US$307.1, €410.4, or C$211.3, depending on location. FM burden worsened with increasing FM severity. CONCLUSIONS: This study demonstrates the significant burden of FM in patients with comorbid depression treated with an antidepressant.

Pregabalin Improves Fibromyalgia-related Sleep Disturbance.

OBJECTIVE: To investigate the effect of pregabalin on wake and sleep bout parameters. MATERIALS AND METHODS: A post hoc analysis of polysomnography data from a randomized, placebo-controlled, crossover study investigating the effect of pregabalin (150 to 450 mg/d) and placebo on sleep in fibromyalgia (FM). Eligible patients had FM and sleep-maintenance problems, including wake after sleep onset ≥45 minutes and total sleep time (TST) 3.0 to 6.5 hours, but no other sleep/circadian rhythm disorders. Polysomnography was performed for 2 consecutive nights (screening, post-treatment). Wake and sleep bout duration and frequency were derived; a "bout"=consecutive 30-s epochs of sleep or wake. RESULTS: Of 119 patients randomized (103 [87%] female), data were available for 103 treated with pregabalin and 106 with placebo. Pregabalin versus placebo treatment decreased mean±SD number of wake/sleep bouts (33.24±1.33 vs. 36.85±1.32; difference: -3.61 [95% confidence interval, -6.03, -1.18]; P=0.0039) and increased sleep bout duration (15.25±0.63 vs. 11.58±0.62 min; +3.67 min [2.22, 5.12 min]; P<0.0001). Pregabalin decreased mean duration of wake bouts versus placebo (3.41±0.55 vs. 3.94±0.55 min; -0.53 min [-1.06, -0.002 min]; P=0.0493). An exploratory correlation analysis of treatment effects found stage 1 sleep was negatively correlated with wake and sleep bout duration and positively with wake/sleep bout number; slow wave sleep (%total sleep time) was positively correlated with wake and sleep bout duration and negatively with wake/sleep bout number. CONCLUSIONS: Pregabalin improved sleep parameters characteristic of disturbed sleep in FM, by preventing awakenings and increasing sleep bout duration. These effects are reflected in, and correlated with, a decrease in "light sleep" (stage 1) and an increase in "deep sleep" (slow wave sleep).

Characteristics of Disturbed Sleep in Patients With Fibromyalgia Compared With Insomnia or With Pain-Free Volunteers.

OBJECTIVE: To investigate the differential nature of disturbed sleep in patients with fibromyalgia (FM) reporting sleep difficulties versus patients with primary insomnia (PI) and patients who do not report disturbed sleep (pain-free controls). MATERIALS AND METHODS: Patients (FM: n=132; PI: n=109; normals: n=52) were recruited for different studies. FM and PI patients were preselected to meet the sleep disturbance criteria. Patients with sleep or circadian disorders were excluded from all groups. Polysomnography was conducted at screening, during 2 consecutive nights. For this post hoc analysis of polysomnographies, length and frequency (duration, number) of wake and sleep bouts were analyzed, together with traditional sleep measures; a "bout"=consecutive 30-second epochs of sleep or wake. Data are mean±SD. RESULTS: FM and PI patients had decreased total sleep time and slow-wave sleep (SWS), and increased latency to persistent sleep (LPS) and wake time after sleep onset (WASO) versus controls (P<0.05 for each). FM versus PI patients had more SWS (48.1±32.4 vs. 27.2±23.6 min; P<0.0001) and shorter LPS (58.2±29.8 vs. 70.7±31.3 min; P=0.0055), but comparable WASO (107.7±32.8 vs. 108.6±31.5 min). Despite comparable WASO, FM patients had shorter (4.64±2.42 vs. 5.87±3.15 min; P=0.0016) but more frequent wake bouts versus PI patients (41.6±16.7 vs. 35.7±12.6; P=0.0075). Sleep bout duration was similar for FM (9.32±0.35 min) and PI patients (10.1±0.37 min); both populations had shorter sleep bout duration versus controls (15.7±0.7 min; P<0.0001 both). CONCLUSIONS: Increased frequency of wake and sleep bouts and decreased wake bout duration, together with decreased LPS and increased SWS, suggests that sleep in FM is characterized by an inability to maintain continuous sleep but a greater sleep drive compared with PI.

Efficacy and Safety of Pregabalin in Patients with Fibromyalgia and Comorbid Depression Taking Concurrent Antidepressant Medication: A Randomized, Placebo-controlled Study.

OBJECTIVE: To assess pregabalin efficacy and safety in patients with fibromyalgia (FM) with comorbid depression taking concurrent antidepressant medication. METHODS: This randomized, placebo-controlled, double-blind, 2-period, 2-way crossover study was composed of two 6-week treatment periods separated by a 2-week taper/washout phase. Patients with FM (aged ≥ 18 yrs) taking a stable dose of a selective serotonin reuptake inhibitor (SSRI) or a serotonin/norepinephrine reuptake inhibitor (SNRI) for depression were randomized 1:1 to receive pregabalin/placebo or placebo/pregabalin (optimized to 300 or 450 mg/day). Antidepressant medication was continued throughout the study. The primary efficacy outcome was the mean pain score on an 11-point numerical rating scale. Secondary efficacy outcomes included measures of anxiety, depression, patient function, and sleep. RESULTS: Of 197 patients randomized to treatment, 181 and 177 received ≥ 1 dose of pregabalin and placebo, respectively. At baseline, 52.3% of patients were taking an SSRI and 47.7% an SNRI, and mean pain score was 6.7. Mean pain scores at endpoint were statistically significantly reduced with pregabalin (least squares mean difference from placebo -0.61, 95% CI -0.91 - -0.31, p = 0.0001). Pregabalin significantly improved Hospital Anxiety and Depression Scale-Anxiety (difference -0.95, p < 0.0001) and -Depression (difference -0.88, p = 0.0005) scores, Fibromyalgia Impact Questionnaire total score (difference -6.60, p < 0.0001), and sleep quality (difference 0.57, p < 0.0001), but not EuroQol 5-Dimensions score (difference 0.02, p = 0.3854). Pregabalin safety was consistent with previous studies and current product labeling. CONCLUSION: Compared with placebo, pregabalin statistically significantly improved FM pain and other symptoms in patients taking antidepressant medication for comorbid depression. ClinicalTrials.gov identifier: NCT01432236.