Pregabalin long-term treatment and assessment of discontinuation in patients with generalized anxiety disorder.

Discontinuation effects following cessation of 12 and 24 wk of pregabalin treatment for generalized anxiety disorder (GAD) were evaluated in a placebo- and lorazepam-controlled, randomized, double-blind, multicentre trial conducted in 16 countries. The study design consisted of two 12-wk treatment periods (periods 1 and 2), each followed by a 1-wk taper and two post-discontinuation assessments, one immediately following the taper and one 1-wk post-taper. Patients were assigned to receive an initially flexible dose of pregabalin 450-600 mg/d, pregabalin 150-300 mg/d, or lorazepam 3-4 mg/d for 6 wk; responders continued fixed-dose therapy for 6 additional weeks. Patients entering period 2 continued on the same fixed dose or switched to placebo. Discontinuation effects were evaluated with the Physician Withdrawal Checklist (PWC) and reported discontinuation-emergent signs and symptoms. Rebound anxiety was measured with the Hamilton Anxiety Rating Scale. GAD symptoms improved with all treatments and improvements were maintained over 12 and 24 wk. Low levels of discontinuation symptoms were evident in all treatment groups. For patients who received active treatment during both periods, mean (95% confidence interval) increases on the PWC from last visit on active treatment to the second post-discontinuation assessment were: pregabalin 450-600 mg/d: 2.8 (1.6-3.9), pregabalin 150-300 mg/d: 1.7 (0.7-2.8), lorazepam 3-4 mg/d: 2.2 (1.0-3.5). Rates of rebound anxiety were also low at both 12 and 24 wk (0-6%). This suggests that risk of discontinuation symptoms and rebound anxiety are low for pregabalin after 12 and 24 wk of treatment.

Efficacy and safety of pregabalin versus levetiracetam as adjunctive therapy in patients with partial seizures: a randomized, double-blind, noninferiority trial.

OBJECTIVES: To assess the comparative efficacy and safety of pregabalin and levetiracetam for the reduction of seizure frequency in patients with partial seizures. METHODS: This was a randomized, double-blind, flexible-dose, parallel-group noninferiority study of pregabalin and levetiracetam (randomized 1:1) as adjunctive treatment in adult patients with refractory partial seizures. The study included a 6-week baseline phase, 4-week dose-escalation phase, and 12-week maintenance phase. The primary endpoint was the proportion of patients with a ≥ 50% reduction in 28-day seizure rate during the 12-week maintenance phase, as compared with baseline. Noninferiority of pregabalin was declared if the lower limit of the 95% confidence interval (CI) for the difference in responder rates was greater than the prespecified noninferiority margin of -12%. A key secondary endpoint was the percent change from baseline in 28-day seizure rate during the dose-escalation and maintenance phases. RESULTS: Five hundred nine patients were randomized to pregabalin (n = 254) or levetiracetam (n = 255) and 418 (208 pregabalin, 210 levetiracetam) completed the maintenance phase. With both pregabalin and levetiracetam, the proportion of patients with a ≥ 50% reduction in 28-day seizure rate was 0.59 (difference between groups [95% CI], 0.00 [-0.08 to 0.09]). Because the lower bound of the 95% CI was greater than the prespecified noninferiority margin of -12%, pregabalin was not inferior to levetiracetam. There was no significant difference between pregabalin and levetiracetam in the percent change in 28-day seizure rate (median difference [95% CI], 4.1 [-2.6 to 10.9], p = 0.3571). In a post hoc analysis, the proportion of patients who were seizure-free for the maintenance phase was lower with pregabalin (8.4%) than with levetiracetam (16.2%), p = 0.0155. Safety profiles were similar and consistent with prior trials. SIGNIFICANCE: These results indicate that pregabalin is noninferior, and has a similar tolerability, to levetiracetam as adjunctive therapy in reducing seizure frequency in patients with partial seizures.

Safety, tolerability, and pharmacokinetics of pregabalin in children with refractory partial seizures: a phase 1, randomized controlled study.

OBJECTIVE: To evaluate the safety, tolerability, and pharmacokinetics (PK) of pregabalin as adjunctive therapy in children with refractory partial seizures. METHODS: This was a phase 1, randomized, placebo-controlled, parallel-group, escalating-dose, multiple-dose study comprising a 7-day, double-blind treatment period and a single-blind, single dose of pregabalin administered to all children on day 8. Children in four age cohorts (1-23 months, 2-6, 7-11, and 12-16 years) received one of four doses of pregabalin (2.5, 5, 10, or 15 mg/kg/day) or placebo. Safety and tolerability were assessed throughout the study. Steady-state and single-dose PK parameters on day 8 were analyzed using standard noncompartmental procedures. RESULTS: Sixty-five children received at least one dose of treatment. Four pregabalin-treated children discontinued treatment, three of whom received 15 mg/kg/day. Two children experienced serious adverse events, one of whom received pregabalin 15 mg/kg/day. During double-blind treatment, the most common adverse events reported in the pregabalin-treated population were somnolence (27.1%) and dizziness (12.5%). Steady-state pregabalin peak and total exposure in each age cohort appeared to increase linearly with dose. Apparent oral clearance (CL/F) was directly related to creatinine clearance, consistent with adults. CL/F normalized for body weight was 43% higher in patients weighing <30 kg. Steady-state and single-dose PK were consistent. SIGNIFICANCE: Pregabalin at doses up to 10 mg/kg/day in children aged 1 month to 16 years, and at doses up to 15 mg/kg/day in those aged <6 years, demonstrated acceptable safety and tolerability. For children weighing <30 kg, a dose increase of 40% (mg/kg dosing) is required to achieve comparable exposure with adults or children weighing ≥30 kg. These data will inform dose selection in phase 3 trials of the efficacy and safety of adjunctive pregabalin in children with refractory partial seizures.

Adjunctive use of controlled-release pregabalin in adults with treatment-resistant partial seizures: a double-blind, randomized, placebo-controlled trial.

OBJECTIVES: To assess the efficacy and tolerability of add-on pregabalin controlled-release formulation (PGB-CR) (doses of 165 or 330 mg/day) in patients with partial-onset seizures (POS). METHODS: This was a randomized, double-blind (DB), parallel-group study of PGB-CR once-daily as adjunctive treatment in adults with treatment-resistant partial seizures. After an 8-week baseline period, eligible patients were randomized (1:1:1) to placebo, PGB-CR 165 mg, or PGB-CR 330 mg for 14 weeks, including a 2-week dose escalation. Primary endpoint was the loge -transformed 28-day seizure rate for all POS with observable component during the full 14-week double-blind treatment phase. Secondary endpoints included the 50% responder rate and percent change from baseline in 28-day POS rate. RESULTS: Three hundred twenty-three patients were randomized and received treatment; placebo (n = 110), PGB-CR 330 mg (n = 100), PGB-CR 165 mg (n = 113); and 287 (88.9%) completed the trial. The primary efficacy analysis result, expressed as percent reduction from placebo, was 13.1% and 1.0% for PGB-CR 330 mg and PGB-CR 165 mg, respectively, and was not statistically significant (p = 0.091, 0.908). The proportion of 50% responders was similar for placebo (35.8%) and 165 mg PGB-CR (37.8%) and nominally higher for 330 mg PGB-CR (45.9%, p = 0.125 compared to placebo). The LS mean estimates of the percent change from baseline for placebo (-5.7%) was nominally smaller than 165 mg PGB-CR (-15.0%, p = 0.540) and 330 mg PGB-CR (-31.5%, p = 0.079); however, the median percent changes from baseline were not as well differentiated (placebo, -35.4%; 165 mg PGB-CR, -38.0%; 330 mg PGB-CR -43.4%). Rates of adverse events (AEs) were low for placebo and study drug; the most frequent reported AEs were dizziness, somnolence, and fatigue, consistent with the immediate-release formulation. SIGNIFICANCE: Results from this trial did not demonstrate that PGB-CR is effective in reducing seizure frequency below that of placebo. Both doses of PGB-CR were shown to be safe and well-tolerated.

Assessment of sleep in patients with fibromyalgia: qualitative development of the fibromyalgia sleep diary.

OBJECTIVES: Sleep disturbance is a common experience in fibromyalgia (FM). The field lacks a sleep specific patient reported outcome (PRO) measure developed and validated in a FM population. The study objective is to gain an in-depth understanding of sleep in FM and to develop a PRO measure of it. METHODS: Research involved the following stages: 1) A literature review conducted to identify key concepts associated with FM patient experience of sleep and PRO measures that have been used to assess this; 2) Qualitative interviews with therapeutic area experts; 3) Focus groups with FM patients who experienced sleep disturbance; 4) Development of a conceptual framework and the Fibromyalgia Sleep Diary (FMSD); and 5) Cognitive interviews with patients to explore content validity of the FMSD. RESULTS: The literature review and expert interviews supported sleep disturbance being an important aspect of the FM patient experience, and underscored the need for a new FM specific sleep PRO measure. Results from the focus groups demonstrated that FM patients experience sleep disturbances that they attribute to their FM symptoms, such as pain and stiffness, confirming the importance of understanding more about sleep changes. Aspects of sleep raised by FM patients included poor sleep quality and insufficient quantity including difficulty with falling asleep, getting comfortable, and staying asleep; restlessness; light sleep; not feeling rested upon awakening; and difficulty starting the day. Cognitive interview results showed that the 8-item FMSD, developed to reflect the concepts identified above, was relevant to FM patients with content that was interpreted as intended. CONCLUSIONS: The FMSD was developed in line with the recommendations of the FDA PRO guidance and ISPOR PRO Task Force. The qualitative evidence generated thus far strongly supports the content validity of the FMSD as a PRO measure of sleep disturbance in FM populations. Psychometric evaluation of the FMSD to demonstrate reliability, validity and sensitivity to change is recommended as a next step.

Nonrestorative sleep as a distinct component of insomnia.

STUDY OBJECTIVES: Explore characteristics of nonrestorative sleep (NRS) in prospectively defined subgroups of individuals with NRS symptoms, investigate whether NRS can occur independently of difficulties initiating and maintaining sleep (DIS/DMS), and determine its effect on waking function. DESIGN: Cross-sectional and longitudinal population-based study comparing patterns of daytime symptoms, and their persistence, in cohorts of subjects with NRS symptoms grouped according to presence or absence of DIS and DMS. SETTING: 28 sleep centers in the US. PARTICIPANTS: Subjects reporting awakening unrestored or unrefreshed at least 3 times weekly over the previous 3 months were classified, based on self-reported sleep problems, to DIS (n = 138), DMS (n = 44), DIS+DMS (n = 125), and NRS-only (no DIS or DMS; n = 192) cohorts. Eighty healthy volunteers formed a control group. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Polysomnography confirmed DIS and/or DMS in 56/138 (41%), 18/44 (41%), and 37/125 (30%) subjects in DIS, DMS, and DIS+DMS cohorts, respectively; and absence of DIS or DMS in 115/192 (60%) NRS-only subjects and 52/80 (65%) healthy volunteers. Multiple subject-reported endpoints including the Endicott Work Productivity Scale, Pittsburgh Insomnia Rating Scale, Restorative Sleep Questionnaire, and SF-36, showed that NRS-only subjects had significantly impaired daytime function relative to healthy volunteers, comparable to impairment affecting subjects with DIS and/or DMS. Symptoms persisted over 3 months. CONCLUSIONS: This study confirms that NRS can occur independently of other components of insomnia. Daytime symptoms were as severe in individuals with NRS-only as those whose NRS symptoms were combined with DIS or DMS.

Quantifying the return of headache in triptan-treated migraineurs: an observational study.

To improve understanding of secondary treatment failure in migraine patients, we evaluated 'headache return' as a novel endpoint to assess returning headaches according to their severity, expanding on current standard assessments of overall recurrence or relapse rates, in a six-month observational study of triptan-treated migraineurs. A total of 359 patients (91% female; mean age, 42.5 years) recorded data for 2168 headaches in electronic diaries. Two-thirds of headaches responded to triptan treatment (improved-to-mild or no pain two hours post-dose); 34% of headaches had a pain-free response. By 48 hours post-dose, 19% of all responding headaches returned; 24% of headaches achieving a pain-free response returned, predominantly to mild pain. More severe baseline headache, short duration since diagnosis of migraine, and female gender were associated with increased likelihood of headache return. Treatment satisfaction declined with increasing severity of headache return, demonstrating the value of assessing headache return by severity to fully evaluate its impact.

Reframing chronic pain as a disease, not a symptom: rationale and implications for pain management.

Chronic pain is a common public health problem that has a detrimental impact on patient health, quality of life (QoL), and function, and poses a substantial socioeconomic burden. Evidence supports the redefinition of chronic pain as a distinct disease entity, not simply a symptom of injury or illness. Chronic pain conditions are characterized by three types of pain pathophysiology (i.e. nociceptive, neuropathic, and centralized pain/central sensitization) influenced by a cluster of coexisting psychosocial factors. Negative risk/vulnerability factors (e.g. mood or sleep disturbances) and positive resilience/protective factors (e.g. social/interpersonal relationships and active coping) interact with pain neurobiology to determine patients' unique pain experience. Viewing chronic pain through a biopsychosocial lens, instead of a purely biomedical one, clinicians need to adopt a practical integrated management approach. Thorough assessment focuses on the whole patient (not just the pain), including comorbidities, cognitive/emotional/behavioral characteristics, social environment, and QoL/functional impairment. As for other complex chronic illnesses, the treatment plan for chronic pain can be developed based on pain subtype and psychosocial profile, incorporating pharmacotherapy and self-management modalities. Preferred pharmacologic treatment of conditions primarily associated with nociception (e.g. osteoarthritis) includes acetaminophen and non-steroidal anti-inflammatory drugs, whereas preferred pharmacologic treatment of conditions primarily associated with neuropathy or central sensitization (e.g. fibromyalgia) includes tricyclic compounds, serotonin-norepinephrine reuptake inhibitors, and α2δ ligands. Education, exercise, cognitive behavioral therapy, and many other non-pharmacological approaches, alone or combined with pharmacotherapy, have been shown to be effective for any type of pain, although they remain underutilized due to lack of awareness of their benefits and reimbursement obstacles.

Pregabalin as Adjunctive Treatment for Focal Onset Seizures in Pediatric Patients: A Randomized Controlled Trial.

Efficacy and safety of pregabalin as adjunctive treatment for children (aged 4-16 years) with partial-onset seizures, hereafter termed focal onset seizures for this study, was evaluated. This double-blind, randomized, placebo-controlled, international study had 3 phases: 8-week baseline, 12-week double-blind treatment (2-week dose escalation; 10-week fixed dose), and 1-week taper. Selection criteria included experiencing focal onset seizures and receiving a stable regimen of 1 to 3 antiepileptic drugs. Study treatments were pregabalin 2.5 mg/kg/d, 10 mg/kg/d, or placebo; doses were increased to 3.5 or 14 mg/kg/d for subjects weighing <30 kg. The key endpoints were change in loge(28-day seizure rate), achieving a ≥50% seizure responder rate, safety, and tolerability during double-blind treatment. Subjects (n = 295; mean age 10.2 years, 55% male, 69% white) were randomized to pregabalin 2.5 mg/kg/d (n = 104), 10 mg/kg/d (n = 97), or placebo (n = 94). A statistically significant reduction in loge(28-day seizure rate) was demonstrated with pregabalin 10 mg/kg/d (a 19.9% improvement over placebo; P = .0185). Seizure frequency was numerically improved (statistically nonsignificant) with pregabalin 2.5 mg/kg/d ( P = .2577). Responder rate significantly favored pregabalin 10 mg/kg/d (40.6%, P = .0068) compared with placebo (22.6%) and was numerically improved with pregabalin 2.5 mg/kg/d (29.1%, P = .2600). Common adverse events (≥10% of any group) in 10 mg/kg/d, 2.5 mg/kg/d, and placebo groups, respectively, included somnolence (25.8%, 17.3%, 13.8%), increased weight (13.4%, 3.8%, 4.3%), and increased appetite (10.3%, 6.7%, 4.3%). Pregabalin 10 mg/kg/d demonstrated efficacy in seizure frequency reduction in children with focal onset seizures compared with placebo, and both pregabalin doses were generally safe and well tolerated. www.clinicialtrials.gov identifier NCT01389596; EudraCT #2010-020852-79.

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.

Adjunctive pregabalin vs gabapentin for focal seizures: Interpretation of comparative outcomes.

OBJECTIVE: To evaluate the comparative safety and adjunctive efficacy of pregabalin and gabapentin in reducing seizure frequency in patients with partial-onset seizures based on prestudy modeling showing superior efficacy for pregabalin. METHODS: The design of this comparative efficacy and safety study of pregabalin and gabapentin as adjunctive treatment in adults with refractory partial-onset seizures was randomized, flexible dose, double blind, and parallel group. The study included a 6-week baseline and a 21-week treatment phase. The primary endpoint was the percentage change from baseline in 28-day seizure rate to the treatment phase. RESULTS: A total of 484 patients were randomized to pregabalin (n = 242) or gabapentin (n = 242). Of these, 359 patients (187 pregabalin, 172 gabapentin) completed the treatment phase. The observed median and mean in percentage change from baseline was -58.65 and -47.7 (SD 48.3) for pregabalin and -57.43 and -45.28 (SD 60.6) for gabapentin. For the primary endpoint, there was no significant difference between treatments. The Hodges-Lehman estimated median difference was 0.0 (95% confidence interval -6.0 to 7.0). Safety profiles were comparable and consistent with prior trials. CONCLUSIONS: The absence of the anticipated efficacy difference based on modeling of prior, nearly identical trials and the larger-than-expected response rates of the 2 antiepileptic drugs were unexpected. These findings raise questions that are potentially important to consider in future comparative efficacy trials. CLINICALTRIALSGOV IDENTIFIER: NCT00537940. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with partial seizures enrolled in this study, pregabalin is not superior to gabapentin in reducing seizure frequency. Because of the atypical response rates, the results of this study are poorly generalizable to other epilepsy populations.

Effect of the gastrointestinal prokinetic agent erythromycin on the pharmacokinetics of pregabalin controlled-release in healthy individuals: a phase I, randomized crossover trial.

BACKGROUND AND OBJECTIVES: The controlled-release (CR) formulation of pregabalin is designed to remain in the stomach for a prolonged period while slowly releasing pregabalin for absorption in the small intestine. This study evaluated the effect of the gastrointestinal prokinetic agent, erythromycin, on the pharmacokinetics of a single dose of pregabalin CR 330 mg administered following an evening meal and the safety and tolerability of a single dose of pregabalin CR 330 mg when administered with and without multiple doses of erythromycin 500 mg. METHODS: This was a phase I, open-label, randomized, two-period, two-treatment crossover study. Participants received (in a randomized sequence) a single oral dose of pregabalin CR 330 mg alone and pregabalin CR 330 mg co-administered with multiple doses of erythromycin 500 mg. The CR formulation was administered immediately following a standardized 600-750 calorie 30 % fat evening meal. Erythromycin 500 mg was administered orally approximately 1 h prior to pregabalin CR, as well as 6 and 12 h following the first erythromycin dose. Blood samples were collected up to 48 h post-pregabalin CR dose. Pharmacokinetic parameters were estimated from concentration-time data using standard noncompartmental methods. Adverse events were monitored throughout. RESULTS: Eighteen healthy participants (aged 19-52 years) received pregabalin CR. Co-administration of pregabalin CR with erythromycin resulted in a 17 % decrease in total exposure [area under the plasma concentration-time curve from zero to infinity (AUC∞)] and a 13 % decrease in peak plasma concentrations (C max) relative to pregabalin CR administered alone. The 90 % CI for the ratio of the adjusted geometric mean AUC∞ was 76.5-89.2 % (outside the 80-125 % range prespecified for bioequivalence). Adverse events were of mild to moderate severity and the adverse event profile was similar for pregabalin CR administered with and without erythromycin. CONCLUSION: Co-administration of multiple high doses of erythromycin resulted in 17 % lower pregabalin exposure for a single dose of pregabalin CR 330 mg than for pregabalin CR 330 mg administered alone. Although the two treatments did not achieve formal bioequivalence, the impact of co-administered erythromycin treatment was small and not considered clinically relevant.

Pregabalin monotherapy in patients with partial-onset seizures: a historical-controlled trial.

OBJECTIVE: To assess pregabalin monotherapy for partial-onset seizures using a historical-controlled conversion-to-monotherapy design. METHODS: Adults with inadequately controlled partial-onset seizures while receiving 1 or 2 antiepileptic drugs during an 8-week prospective baseline were randomized to double-blind monotherapy with pregabalin 600 or 150 mg/d (4:1) for 20 weeks (8-week conversion and 12-week monotherapy period). The primary endpoint was the seizure-related exit rate for pregabalin 600 mg/d, based on discontinuations due to predefined criteria. Efficacy was declared if the upper limit of the 95% confidence interval for the exit rate was below a historical-control threshold of 74%, with stepwise evaluation using a threshold of 68%. RESULTS: The trial was stopped early for positive efficacy after an interim analysis in 125 patients. The full study population included 161 patients, with 148 evaluable for efficacy. The mean time since epilepsy diagnosis was 14 years. Overall, 54.3% (600 mg/d) and 46.9% (150 mg/d) of patients completed 20 weeks of double-blind treatment. Seizure-related exit rate in the 600 mg/d group (27.5%; 95% confidence interval, 17.8%-37.2%) was significantly below the 74% and 68% thresholds (p < 0.001 for both). Eight patients on 600 mg/d and 2 on 150 mg/d were seizure-free throughout pregabalin monotherapy. Pregabalin's overall safety profile was consistent with prior trials. CONCLUSIONS: Pregabalin monotherapy was safe and efficacious for patients with inadequately controlled partial-onset seizures. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that patients with inadequately controlled partial-onset seizures switched to pregabalin monotherapy have fewer seizure-related exit events compared with historical controls switched to pseudo-placebo monotherapy.

Pharmacokinetics of pregabalin controlled-release in healthy volunteers: effect of food in five single-dose, randomized, clinical pharmacology studies.

BACKGROUND: The pharmacokinetic properties of the immediate-release (IR) and the recently developed controlled-release (CR) formulation of pregabalin are dose proportional. Pregabalin IR can be taken with or without food. OBJECTIVES: This analysis characterizes the effect of food on pregabalin CR. The objectives of this analysis were: (1) to evaluate the effect of administration time and fat or caloric content of an accompanying meal on the pharmacokinetic properties of a single dose of pregabalin CR (330 mg) relative to a single dose of pregabalin IR (300 mg); (2) to evaluate the pharmacokinetic properties of a single dose of pregabalin CR administered fasted relative to a single dose of pregabalin CR administered immediately after food; and (3) to determine the safety and tolerability of single-dose administration of pregabalin CR and IR with and without food. METHODS: The effect of food on the pharmacokinetic properties of pregabalin CR was determined in five phase I, open-label, single-dose, crossover studies (24-28 participants/study). Caloric and fat content of meals were varied and treatments were administered in the morning, at midday, or in the evening. Blood samples were collected up to 48 h post-dose. Pharmacokinetic parameters were estimated from plasma concentration-time data using standard noncompartmental methods. Adverse events were monitored throughout all studies. RESULTS: One hundred and twenty-eight healthy participants (19-54 years of age) received pregabalin. Peak plasma concentrations (C max) were lower for CR than the respective pregabalin IR doses, and time to C max occurred later. When pregabalin CR was administered with food at midday or in the evening, total exposures [area under the plasma concentration-time curve from time zero extrapolated to infinite time (AUC∞)] were equivalent for pregabalin CR and IR formulations regardless of fat or caloric content. When pregabalin CR was administered with an 800-1,000 calorie medium-fat breakfast, AUC∞ was equivalent for pregabalin CR and IR. Bioequivalence criteria for comparison of pregabalin CR after a low- or medium-calorie breakfast relative to pregabalin IR were not met; however, bioavailability of the pregabalin CR vs. IR formulation was relatively high (75-86 %). When pregabalin CR was administered fasted, the AUC∞ was 70-78 % of the AUC∞ of pregabalin CR administered with food and bioequivalence criteria were not met. Additionally, the AUC∞ of the pregabalin CR formulation administered fasted was 62-69 % of that of pregabalin IR administered fasted and bioequivalence criteria were not met. Single-dose pregabalin CR and IR were well tolerated in all studies, with no serious or severe adverse events reported. CONCLUSION: Time of day of administration and the fat and caloric content of the accompanying meal had minimal overall effect on the pharmacokinetic properties and bioavailability of the pregabalin CR formulation.

Pregabalin controlled-release pharmacokinetics in healthy volunteers: analysis of four multiple-dose randomized clinical pharmacology studies.

BACKGROUND: Pregabalin (Lyrica(®)) is approved as an immediate-release (IR) formulation for administration twice (BID) or three times (TID) a day depending on indication. Once daily (QD) dosing may be appropriate for ease of clinical use and patient convenience. OBJECTIVES: The objectives of this analysis were: (1) to evaluate the pharmacokinetics of pregabalin controlled-release (CR) administered with food relative to the pregabalin IR formulation administered fasted; (2) to evaluate the pharmacokinetics of a two-tablet dose of pregabalin CR compared with the equivalent one-tablet dose of pregabalin CR; and (3) to determine the safety and tolerability of multiple-dose administration of pregabalin CR and IR. METHODS: The pharmacokinetic properties of pregabalin CR were determined in four phase I, open-label, multiple-dose crossover studies (18-24 participants/study). Pregabalin CR (82.5, 165, 330 or 660 mg/day) administered QD was compared with pregabalin IR (75, 150, 300 or 600 mg/day, respectively) administered either BID or TID. Blood samples were collected up to 24 h post-dose. Pharmacokinetic parameters were estimated from plasma concentration-time data using standard noncompartmental methods. Adverse events were monitored throughout all studies. RESULTS: Eight-four healthy participants (19-55 years of age) received pregabalin. For all pregabalin CR doses, total exposure was equivalent to the corresponding pregabalin IR dose. Relative bioavailability of pregabalin CR was 93-97 % of pregabalin IR, and bioequivalence criteria with respect to the 24-h steady-state exposure (area under the plasma concentration-time curve from 0 to 24 h [AUC24]) were met. Administration of a two-tablet dose of pregabalin CR was bioequivalent to one-tablet pregabalin CR. The relative bioavailability of two-tablet pregabalin CR was 97-102 % of one-tablet pregabalin CR, and bioequivalence criteria with respect to AUC24 and peak plasma concentrations were met. Pregabalin CR pharmacokinetic parameters were dose proportional following administration of 82.5-660 mg/day pregabalin CR. Pregabalin was well tolerated across studies, with no serious or severe adverse events. CONCLUSION: Total daily exposure with multiple-dose pregabalin CR is equivalent to the corresponding pregabalin IR dose.

Eletriptan for the acute treatment of migraine in adolescents: results of a double-blind, placebo-controlled trial.

BACKGROUND: Eletriptan is a potent 5-HT(1B/1D) agonist with proven efficacy in the acute treatment of migraine in adults. OBJECTIVE: To evaluate the efficacy and tolerability of eletriptan 40 mg versus placebo in adolescent patients (aged 12-17). METHODS: A multicenter, double-blind, parallel-group, placebo-controlled trial was conducted comparing 40 mg of oral eletriptan with placebo for the treatment of migraine in adolescent patients. The primary efficacy endpoint was 2-hour headache response, and a number of secondary endpoints were also evaluated. An exploratory analysis evaluated which clinical and demographic characteristics might be correlated with high placebo response. RESULTS: Of 274 patients who treated a migraine attack, 267 were evaluated for efficacy (n = 138 eletriptan; n = 129 placebo) at 2 hours post-dose. There was no significant difference in 2-hour headache response for eletriptan 40 mg versus placebo (57% vs 57%), and no significant improvements were observed for any of the outcomes at 1 or 2 hours post-dose. By contrast, there was a significant advantage for eletriptan 40 mg in reducing headache recurrence within 24 hours post-dose (11% vs 25%, P= .028), and post hoc analyses showed statistically significant differences for sustained headache response rates (52% vs 39%; P= .04) and sustained pain-free response rates (22% vs 10%; P= .013). The strongest clinical predictor of placebo response was triptan-naïve status (i.e., no previous use of any triptan). Eletriptan 40 mg was well tolerated in this population, and the profile of adverse events was similar to that observed in Phase III trials in adult patients. CONCLUSIONS: The high placebo response rates reported here for 1- and 2-hour outcomes are in accordance with other studies of triptans in adolescent patients. The evaluation of treatment effect in adolescent migraine might benefit from use of more stringent outcome measures, such as headache recurrence, sustained headache response, and sustained pain-free response at 24 hours post-dose.

Efficacy, safety, and tolerability of oral eletriptan for treatment of acute migraine: a multicenter, double-blind, placebo-controlled study conducted in the United States.

OBJECTIVE: To investigate the efficacy, consistency, safety, and tolerability of oral eletriptan in the acute treatment of three migraine attacks. BACKGROUND: Eletriptan is a selective 5-HT1B/1D agonist member of a class of agents known to be effective in the acute treatment of migraine. METHODS: Thirteen hundred thirty-four patients were randomized to 20 mg, 40 mg, or 80 mg of eletriptan, or placebo and could treat up to three attacks. The primary efficacy endpoint was 2-hour headache response for the first attack. Secondary endpoints included associated symptom relief, and pain-free, sustained pain-free, and consistency of response. RESULTS: Eletriptan 20 mg, 40 mg, and 80 mg achieved significantly (P <.0001) better headache response rates than placebo at 2 hours (47%, 62%, and 59%, respectively, versus 22%) and 4 hours (64%, 76%, and 79%, respectively, versus 25%). Headache response was observed to be rapid, showing improvement at 0.5 hour and 1 hour. Two-hour pain-free response rates for eletriptan 20 mg, 40 mg, and 80 mg were 14%, 27%, and 27%, respectively, compared with 4% for placebo. Sustained pain-free response rates were significantly (P <.001) better for eletriptan 20 mg (10%), 40 mg (20%), and 80 mg (18%) compared with placebo (3%). Eletriptan had a higher consistency of intrapatient response than placebo in two of three (68% to 82%) and three of three attacks (32% to 60%) versus 16% and 8%, respectively. All eletriptan doses yielded significant functional improvement at 2 hours. Adverse events were generally mild or moderate and transient, with eletriptan 20 mg having an adverse event profile comparable to placebo. CONCLUSIONS: Eletriptan is efficacious, displaying high consistency of response over multiple attacks, and is well tolerated for the acute treatment of migraine.