Long-term open-label safety study of rizatriptan acute treatment in pediatric migraineurs.

OBJECTIVE: To evaluate the safety/tolerability of rizatriptan in the long-term acute treatment of migraine in pediatric patients. BACKGROUND: Acute migraine treatment options for children are limited. A recent single-attack trial demonstrated that rizatriptan is effective in eliminating migraine headache pain in this population. We evaluated the long-term safety and efficacy of rizatriptan when used for intermittent acute treatment. METHODS: Open-label study in pediatric migraineurs ages 12-17 years. Patients weighing <40 kg received rizatriptan (orally disintegrating tablet) 5 mg, and those weighing ≥40 kg received 10 mg. Patients could treat up to 8 mild/moderate/severe migraine attacks per month for up to 12 months. One dose of study medication was allowed in a 24-hour period. RESULTS: A total of 674 patients were enrolled, and 606 patients were treated with study medication (N = 583 for 10 mg, N = 23 for 5 mg). The mean duration in the study was 292 days, and the mean number of doses of study medication taken was 20. Over the course of the study within 14 days post-any-dose, 66.0% (400) of the 606 treated patients had any adverse event, 2.3% (14) discontinued due to an adverse event, 2.6% (16) had a serious adverse event, and 23.4% (142) had a triptan-related adverse event. Of the 16 patients with serious adverse events within 14 days post-any-dose, the adverse events in 3 were considered drug-related; all 3 patient's adverse events were classified as serious only because they were associated with an overdose (use of >1 dose of study medication in a 24-hour period). The mean percentage of patient's attacks with pain freedom at 2-hours post-dose was 46.3%; this was relatively consistent over time (Months 1-3 = 43.7%, Months 4-6 = 51.9%, Months 7-9 = 49.9%, Months 10-12 = 49.5%). CONCLUSION: Rizatriptan was generally safe and well tolerated in the long-term acute treatment of migraine in pediatric patients aged 12-17 years and demonstrated a consistent treatment effect over time.

Predicting response to pregabalin from pretreatment pain quality: clinical applications of the pain quality assessment scale.

OBJECTIVE: The aim of this study is to assess the Pain Quality Assessment Scale (PQAS) in predicting pregabalin in peripheral neuropathic pain (NP). STUDY DESIGN: Post hoc analysis of a double-blind, placebo-controlled, enriched enrollment, randomized withdrawal trial evaluating pregabalin in 99 patients with NP who completed the PQAS, which comprises 20 questions regarding individual pain domains and qualities that are scored into three scales: paroxysmal, deep, and surface. METHODS: Patients rated the average pain intensity and pain quality using the PQAS at baseline; average pain intensity was assessed again after 40 days of treatment with pregabalin. Associations between pretreatment PQAS scores and treatment response were estimated using Pearson's r. Logistic regression was used to identify pretitration PQAS scores contributing unique variance to predicting treatment response. RESULTS: Fifty participants provided baseline PQAS scores and received pregabalin for the entire length of the study. Nine of 23 PQAS baseline scales and items were significantly associated with treatment response to pregabalin: the paroxysmal and deep scales, and the items assessing the following pain domains and qualities: intensity, electric, tingling, cramping, radiating, throbbing, and deep (P values range, 0.002-0.045; rs range, 0.28-0.43). The PQAS items assessing sharp, hot, and unpleasant pain items demonstrated nonsignificant trends (P < 0.10) to be associated with treatment response. In the logistic regression analysis, pretitration PQAS scores had 77% sensitivity and 83% specificity to correctly identify pregabalin responders. Significantly correlated PQAS items had a sensitivity of 85% and specificity of 76%. CONCLUSION: Pretitration PQAS scores reliably predicted pregabalin responders in patients with NP.

Efficacy and tolerability of rizatriptan in pediatric migraineurs: results from a randomized, double-blind, placebo-controlled trial using a novel adaptive enrichment design.

BACKGROUND: Treatment options for children and adolescents with migraine are limited. This study evaluated rizatriptan for the acute treatment of migraine in children and adolescents. METHODS: Randomized, double-blind, placebo-controlled, parallel-group trial in migraineurs 6-17 years old with unsatisfactory response to nonsteroidal anti-inflammatory drugs or acetaminophen/paracetamol. The trial included a double-blind run-in with weight-based rizatriptan dosing (5 mg for < 40 kg, 10 mg for ≥ 40 kg). In the Stage 1 run-in, patients were randomized in a ratio of 20:1 placebo:rizatriptan and were instructed to treat within 30 minutes of a moderate/severe migraine. Patients with mild/no pain after 15 minutes of treatment (responders) took no further study medication, whereas patients with moderate/severe pain (non-responders) proceeded to take study medication in Stage 2. Non-responders who received placebo in Stage 1 were randomized 1:1 to rizatriptan:placebo, whereas non-responders who received rizatriptan in Stage 1 were allocated to placebo in Stage 2. The primary efficacy endpoint was pain freedom at 2 hours after Stage 2 dose in 12-17-year-olds. RESULTS: A higher proportion of 12-17-year-olds on rizatriptan had pain freedom at 2 hours compared with those on placebo: 87/284 (30.6%) versus 63/286 (22.0%), odds ratio = 1.55 [95% CI: 1.06 to 2.26], p = 0.025. Adverse events within 14 days of dose in 12-17-year-olds were similar for rizatriptan and placebo. The pattern of findings was similar in 6-17-year-olds. CONCLUSION: Rizatriptan demonstrated a statistically significant improvement over placebo in eliminating pain and was generally well tolerated in migraineurs aged 12-17 and 6-17 years. TRIAL REGISTRATION: ClinicalTrials.gov NCT01001234.

Randomized controlled trial of the CGRP receptor antagonist MK-3207 in the acute treatment of migraine.

BACKGROUND: This study evaluated the CGRP receptor antagonist MK-3207 for acute treatment of migraine. METHODS: Multicenter, double-blind, randomized, placebo-controlled, parallel-group, two-stage adaptive study with two interim efficacy analyses to facilitate optimal dose selection. Migraine patients were initially randomized to MK-3207 2.5, 5, 10, 20, 50 and 100 mg or placebo to treat a moderate/severe migraine. One or more doses were to be discontinued based on the first interim analysis and a lower or higher dose could be added based on the second interim analysis. The primary endpoint was two-hour pain freedom. RESULTS: A total of 547 patients took study medication. After the first interim analysis, the two lowest MK-3207 doses (2.5, 5 mg) were identified as showing insufficient efficacy. Per the pre-specified adaptive design decision rule, only the 2.5-mg group was discontinued and the five highest doses (5, 10, 20, 50, 100 mg) were continued into the second stage. After the second interim efficacy analysis, a 200 mg dose was added due to insufficient efficacy at the top three (20, 50, 100 mg) doses. A positive dose-response trend was demonstrated when data were combined across all MK-3207 doses for two-hour pain freedom (p < .001). The pairwise difference versus placebo for two-hour pain freedom was significant for 200 mg (p < .001) and nominally significant for 100 mg and 10 mg (p < .05). The incidence of adverse events appeared comparable between active treatment groups and placebo, and did not appear to increase with increasing dose. CONCLUSIONS: MK-3207 was effective and generally well tolerated in the acute treatment of migraine.

Randomized controlled study of telcagepant plus ibuprofen or acetaminophen in migraine.

OBJECTIVE: To evaluate the efficacy and tolerability of telcagepant when co-administered with ibuprofen or acetaminophen for the acute treatment of migraine. BACKGROUND: Telcagepant is an oral calcitonin gene-related peptide receptor antagonist which is being evaluated for the acute treatment of migraine. Combining telcagepant with analgesics that have a different mechanism of action could produce greater efficacy. METHODS: Randomized, double-blind, placebo-controlled study. Patients were randomized to treat a moderate or severe migraine headache with either telcagepant 280 mg + ibuprofen 400 mg (N = 171), telcagepant 280 mg + acetaminophen 1000 mg (N = 171), telcagepant 280 mg (N =170), or placebo (N = 171). The primary efficacy endpoint was 2-hour pain freedom. The study had approximately 88% power to detect an additive effect of at least 15 percentage points (telcagepant combination vs telcagepant monotherapy) and 48% power to detect an additive effect of at least 10 percentage points. Safety and tolerability were assessed by adverse events and laboratory tests. RESULTS: The percentages of patients with 2-hour pain freedom were greater in each active treatment group compared to placebo (P < .001): telcagepant + ibuprofen = 35.2%, telcagepant + acetaminophen = 38.3%, telcagepant = 31.2%, placebo = 10.9%. No significant differences were seen for either of the combination groups vs telcagepant monotherapy, but both were numerically larger than telcagepant monotherapy. All the active treatments were generally well tolerated. The percentage of patients reporting any adverse event within 48 hours was higher in the active treatment groups than placebo: telcagepant + ibuprofen = 30.3%, telcagepant + acetaminophen = 31.6%, telcagepant = 24.8%, placebo = 18.2%. The most common adverse events reported by ≥ 4 patients in one or more of the treatment groups that included telcagepant were fatigue, nausea, dizziness, somnolence, dry mouth, and tremor. CONCLUSIONS: The combination of telcagepant 280 mg with either ibuprofen 400 mg or acetaminophen 1000 mg did not show a statistically significant difference from telcagepant alone. Numerically greater treatment effects in the combination treatment groups over the telcagepant 280 mg monotherapy suggest that telcagepant combination treatments may merit further evaluation in studies powered to detect smaller additive benefits. (Clinicaltrials.gov; NCT00758836).

Can Reactive Airways Dysfunction Syndrome (RADS) be iatrogenic?

Reactive airways dysfunction syndrome (RADS) is an asthma-like illness that develops after a single high-level exposure to a pulmonary irritant. Two different cases are reviewed, in which the exposure circumstances were not sufficient to result in adverse health effects yet resulted in persistent respiratory symptoms and a clinical diagnosis of RADS. Potential explanations for an erroneous diagnosis of RADS included an incomplete exposure assessment, medication adverse effects that can contribute to respiratory symptoms, and alternative explanations for respiratory symptoms or test findings. In particular, the empirical use of bronchodilator medications without a clear indication appeared to contribute to continued respiratory symptoms. Without a clear understanding of the patient's exposure, a RADS diagnosis should be carefully considered. The possibility of an iatrogenic sequence of events in which medication adverse effects facilitate respiratory symptoms and a mistaken RADS diagnosis should be considered, particularly in patients who have a poorly defined exposure history.

The value of HAZWOPER medical surveillance.

Medical surveillance is mandated for workers with potential exposure to hazardous materials. However, little guidance is provided regarding the components of a medical surveillance testing program for these individuals. This article describes the medical surveillance program for a group of 72 employees who respond to hazardous material releases throughout the United States. Conditions related to chemical exposures were not identified in this group. However, several non-occupational health conditions were identified, including a relatively high prevalence of one or more signs of metabolic syndrome. Medical surveillance may provide valuable information regarding an individual's underlying health status and non-occupational health conditions to be addressed at an early stage.

Comparison of the efficacy and tolerability of preservative-free and preservative-containing formulations of the dorzolamide/timolol fixed combination (COSOPT™) in patients with elevated intraocular pressure in a randomized clinical trial.

BACKGROUND: The aim of this study was to compare the efficacy and tolerability of preservative-free (PF) and preservative-containing (PC) formulations of the dorzolamide/timolol fixed combination (COSOPT™) in patients with elevated intraocular pressure (IOP). METHODS: A parallel, randomized, double-masked study was conducted. After a 3-week run-in on timolol, patients with ocular hypertension, as confirmed by an IOP ≥22 mmHg, were randomized 1:1 to receive PF or PC dorzolamide/timolol twice daily for 12 weeks. IOP was measured at hour 0 (drug trough) and hour 2 (drug peak) at baseline (last day of 3-week timolol run-in), and weeks 2, 6 and 12. RESULTS: A total of 261 patients were randomized. Mean baseline IOPs were 23.7 mmHg for both treatments at hour 0 and 21.2 mmHg for PF dorzolamide/timolol and 21.4 mmHg for PC dorzolamide/timolol at hour 2. At all study time points (trough and peak at weeks 2, 6, and 12), the difference between treatments in mean change from baseline IOP was <0.5 mmHg. The 95% confidence intervals for the estimated treatment difference (PF minus PC) in mean change from baseline IOP at week 12 was -0.86 to 0.23 mmHg for trough (primary endpoint) and -0.39 to 0.67 mmHg for peak (secondary endpoint). The most common adverse events were ocular burning/stinging, reported by 16.0% and 21.5% of patients receiving PF and PC dorzolamide/timolol respectively, and taste perversion, reported by 3.1% and 5.4% of patients receiving PF and PC dorzolamide/timolol respectively. CONCLUSIONS: In patients with elevated IOP, PF and PC dorzolamide/timolol were equivalent in efficacy for change in trough and peak IOP, and had generally similar tolerability.

Characterization of a fatal methyl bromide exposure by analysis of the water cooler.

BACKGROUND: A suspected inhalation exposure to methyl bromide (MeBr) in the packaging and shipping area of a chemical manufacturer resulted in a worker fatality and several symptomatic cases. However, air testing was negative for MeBr resulting in uncertainty regarding the potential chemical exposure. Methods of quickly confirming the exposure and magnitude were sought. METHODS: Head space air and water samples were obtained from the breakroom water cooler in the facility and tested for MeBr. RESULTS: Increased levels of MeBr were identified in the air and water samples from the cooler and used to calculate the MeBr concentration of air entering the cooler. The MeBr air concentration within the breakroom was estimated as 1,200-2,100 ppm depending on assumptions regarding the amount of water dispensed from the cooler both before and during the incident. CONCLUSIONS: Estimated MeBr air concentrations in the breakroom were consistent with those known to be associated with reported health effects among the involved workers. The water cooler analysis represented a unique method of retrospectively verifying and quantifying exposure to MeBr.

Patients' assessment of the convenience of fentanyl HCl iontophoretic transdermal system (ITS) versus morphine intravenous patient-controlled analgesia (IV PCA) in the management of postoperative pain after major surgery.

The patient-controlled fentanyl HCl iontophoretic transdermal system (ITS) is a compact, self-contained, needle-free system that has been approved for acute postoperative pain management in hospitalized adults. The objective of the present analysis was to evaluate patients' assessment of fentanyl ITS and morphine intravenous patient-controlled analgesia (IV PCA) convenience on 7 different subscales, using a validated patient ease of care (EOC) questionnaire in 2 prospective, open-label, randomized, phase IIIb clinical trials. Patients received fentanyl ITS or morphine IV PCA (N = 1,305) for up to 72 h after total hip replacement surgery (THR study) or abdominal or pelvic surgery (APS study). For the majority of items on the patient EOC questionnaire, trends suggest that greater percentages of patients reported the most positive response for fentanyl ITS than they did for morphine IV PCA in both studies; differences were particularly noteworthy for items on the Movement subscale. In the THR study, more patients in the fentanyl ITS group were responders compared with those in the morphine IV PCA group for the subscales Confidence with Device, Pain Control, Knowledge/Understanding, and Satisfaction. In the APS study, responder rates for these subscales did not differ between treatment groups. These findings indicate that patients assessed the EOC associated with fentanyl ITS higher compared with morphine IV PCA for the management of acute postoperative pain and suggest that fentanyl ITS has the potential to improve acute postoperative pain care for patients and nurses.

Interpretation of the "positive" methacholine challenge.

BACKGROUND: A methacholine challenge may be used in confirming the diagnosis of asthma, occupational asthma, or reactive airways dysfunction syndrome (RADS) through identification of bronchial hyperreactivity (BHR). While sensitivity of the test in diagnosing clinically significant asthma is excellent, specificity of the test is poor. Since there are many conditions which have been associated with BHR, a positive test must be interpreted cautiously. METHODS: This paper reviews potential causes of a positive methacholine challenge other than asthma or RADS which have been reported in the medical literature. RESULTS: Factors which may be associated with a positive methacholine test include test methodology, normal variation of BHR in the general population, and numerous medical conditions. CONCLUSIONS: In cases of inhalation exposure evaluations, alternative explanations must be considered when determining whether a causal association exists between the exposure and a positive methacholine test result.

Tramadol/acetaminophen or hydrocodone/acetaminophen for the treatment of ankle sprain: a randomized, placebo-controlled trial.

STUDY OBJECTIVE: This randomized, multicenter study compares the analgesic efficacy and safety of tramadol/acetaminophen versus hydrocodone/acetaminophen versus placebo for the treatment of acute musculoskeletal pain caused by ankle sprain. METHODS: Adults were enrolled with ankle sprain with a diagnosis of partial ligament tear, pain visual analog scale score of 50 to 100 mm (0="no pain," 100="extreme pain"), and pain numeric rating scale score of 2 to 3 (0="none," 3="severe"). Patients reported pain intensity on these scales and pain relief (-1="pain worse," 4="complete relief") hourly for 4 hours after the first dose of tramadol/acetaminophen 75 mg/650 mg, hydrocodone/acetaminophen 7.5 mg/650 mg, or placebo, and daily for 5 days, with as-needed dosing. RESULTS: Tramadol/acetaminophen (n=192) and hydrocodone/acetaminophen (n=204) provided greater total pain relief than placebo (n=207; P<.001) during the first 4 hours (mean scores [95% confidence interval (CI)] 6.6 [95% CI 6.1 to 7.1], 6.8 [95% CI 6.3 to 7.3], and 5.4 [95% CI 4.9 to 5.9], respectively; possible range -4 to 16), decreased pain intensity during the first 4 hours, and increased average pain relief on days 1 to 5. No efficacy measure was significantly different between the tramadol/acetaminophen and hydrocodone/acetaminophen groups. Common adverse events included somnolence, nausea, dizziness, and vomiting. CONCLUSION: One or 2 capsules of 37.5 mg tramadol/325 mg acetaminophen and 1 capsule of 7.5 mg hydrocodone/650 mg acetaminophen were well tolerated, had comparable clinical utility, and were more effective than placebo in the management of acute musculoskeletal pain caused by ankle sprain.

The safety and efficacy of fentanyl iontophoretic transdermal system compared with morphine intravenous patient-controlled analgesia for postoperative pain management: an analysis of pooled data from three randomized, active-controlled clinical studies.

BACKGROUND: Postoperative pain is often managed using IV patient-controlled analgesia (PCA). In this analysis of pooled data, we compared the safety and efficacy of the fentanyl iontophoretic transdermal system (ITS) with morphine IV PCA. METHODS: Data were obtained from three multicenter, randomized, active-controlled trials (N = 1941). The primary efficacy measure was success ("good"/"excellent" ratings) on the 24-h patient global assessment of the method of pain control. Pain intensity, relative dosing ratios, discontinuation rates, and adverse events were assessed. Efficacy was evaluated across age, surgery type, and body mass index (BMI). RESULTS: Comparable percentages of patients reported success on the 24-h patient global assessment of the method of pain control (fentanyl ITS, 80.5%; morphine IV PCA, 81.0%; difference = -0.5%; 95% confidence interval, -4.0% to 3.0%). Mean last pain intensity scores in the first 24 h were comparable (fentanyl ITS, 3.1; morphine IV PCA, 3.0; difference = 0.07; 95% confidence interval, -0.14 to 0.29). Relative dosing ratios of fentanyl to morphine overall and in subpopulations (age, BMI) were comparable over 6, 12, and 24 h. Fentanyl ITS was equally effective when compared with morphine IV PCA for patient subpopulations (age, surgery type, and BMI). Discontinuation rates and the incidence of adverse events were similar between groups. CONCLUSIONS: These pooled data represent one of the largest head-to-head comparisons of fentanyl versus morphine in a postoperative acute pain setting. Results suggest that fentanyl ITS is effective across subpopulations defined by age and BMI, and support a consistent safety and efficacy profile of fentanyl delivered by fentanyl ITS for postoperative pain management.

System-related events and analgesic gaps during postoperative pain management with the fentanyl iontophoretic transdermal system and morphine intravenous patient-controlled analgesia.

BACKGROUND: Analgesic gaps (interruptions in analgesic delivery) contribute to ineffective postoperative pain management. In this analysis, we evaluated the incidence of analgesic gaps resulting from system-related events (SREs) for patients using the fentanyl iontophoretic transdermal system (ITS), a noninvasive patient-controlled analgesia (PCA) system, or morphine IV PCA for postoperative pain management. METHODS: Data were pooled from two open-label, randomized, active-controlled trials that evaluated the efficacy and safety of fentanyl ITS and morphine IV PCA after total hip replacement, abdominal, or pelvic surgery. The incidence and duration of analgesic gaps resulting from SREs were assessed, along with SRE resolution times. RESULTS: A total of 1305 patients received fentanyl ITS (n = 647) or morphine IV PCA (n = 658). Fentanyl ITS was associated with a significantly lower incidence of analgesic gaps per 100 patients compared with morphine IV PCA (5.87 vs 12.01, respectively; P < 0.001). Compared with patients receiving morphine IV PCA, patients receiving fentanyl ITS had both a numerically lower median total analgesic gap time (15.0 min vs 20.0 min) and a numerically lower median total SRE resolution time (11.0 min vs 20.0 min). Most fentanyl ITS SREs were resolved by applying a new system, whereas many different SRE resolution methods were used for morphine IV PCA. CONCLUSIONS: Fentanyl ITS was associated with a significantly lower incidence of analgesic gaps relative to morphine IV PCA. Fentanyl ITS may provide patients with fewer interruptions and more continuous analgesic delivery.

Randomized trial of preladenant, given as monotherapy, in patients with early Parkinson disease.

OBJECTIVE: To evaluate the adenosine 2a receptor antagonist preladenant as a nondopaminergic drug for the treatment of Parkinson disease (PD) when given as monotherapy. METHODS: This was a randomized, 26-week, placebo- and active-controlled, parallel-group, multicenter, double-blind trial conducted in adults diagnosed with PD for <5 years who were not yet receiving l-dopa or dopamine agonists. Patients with a Unified Parkinson's Disease Rating Scale (UPDRS) part 3 (motor function) score ≥10 and Hoehn & Yahr score ≤3 were randomized 1:1:1:1:1 to preladenant 2, 5, or 10 mg twice daily, rasagiline 1 mg (active-control) once daily, or placebo. The primary endpoint was the change from baseline at week 26 in the sum of UPDRS parts 2 (activities of daily living) and 3 scores (UPDRS2+3). RESULTS: The number of patients treated was 1,007. Neither preladenant nor rasagiline was superior to placebo after 26 weeks. The differences vs placebo (95% confidence interval) in UPDRS2+3 scores (with a negative difference indicating improvement vs placebo) were preladenant 2 mg = 2.60 (0.86, 4.30), preladenant 5 mg = 1.30 (-0.41, 2.94), preladenant 10 mg = 0.40 (-1.29, 2.11), and rasagiline 1 mg = 0.30 (-1.35, 2.03). Post hoc analyses did not identify a single causal factor that could explain the finding of a failed trial. Preladenant was generally well-tolerated with few patients discontinuing due to adverse events (preladenant 7%, rasagiline 3%, placebo 4%). CONCLUSIONS: No evidence supporting the efficacy of preladenant as monotherapy was observed in this phase 3 trial. The lack of efficacy of the active control rasagiline makes it difficult to interpret the results. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov: NCT01155479. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for patients with early PD, preladenant is not effective as monotherapy at the doses studied (2, 5, 10 mg).

Fentanyl iontophoretic transdermal system for acute-pain management after orthopedic surgery: a comparative study with morphine intravenous patient-controlled analgesia.

BACKGROUND AND OBJECTIVES: The fentanyl HCl iontophoretic transdermal system (ITS) has been demonstrated in clinical trials to be safe and effective for acute-pain management after several types of major surgery. The current study compared the efficacy, safety, and convenience of fentanyl ITS with morphine intravenous patient-controlled analgesia (IV PCA) for acute-pain management after unilateral total-hip replacement (THR). METHODS: In this multicenter (52 sites), randomized, open-label, active-controlled, phase IIIb study, patients (n = 799) received fentanyl ITS (40 mug fentanyl [10-minute infusion/lockout], up to 6 doses/h) or morphine IV PCA (1-mg morphine bolus [5-minute lockout], up to 10 mg/h) after unilateral THR. The primary efficacy measure was success ratings ("excellent" or "good") on the patient global assessment (PGA) of the method of pain control in the first 24 hours. Pain intensity and adverse events were also assessed. RESULTS: The PGA success ratings (83.0% v 82.2%; difference = 0.9%; 95% CI: -4.4% to 6.1%) and the mean last pain-intensity scores (3.0 v 3.0; difference = 0.0; 95% CI: -0.33 to 0.33) in the first 24 hours were statistically equivalent between fentanyl ITS and morphine IV PCA groups, respectively. The incidence of adverse events was similar between the groups. CONCLUSIONS: Results of this study demonstrate fentanyl ITS and a standard regimen of morphine IV PCA were comparable methods of pain control for management of acute postoperative pain after THR, on the basis of the PGA success ratings and pain intensity in the first 24 hours of treatment.

Safety and effectiveness of topiramate for the management of painful diabetic peripheral neuropathy in an open-label extension study.

OBJECTIVE: The aim of this study was to further assess the long-term safety and effectiveness of open-label topiramate therapy in subjects with moderately to severely painful diabetic peripheral neuropathy (DPN). METHODS: Adults aged 18 to 75 years received open-label topiramate (25-600 mg/d for 26 weeks) in an extension of a previously published randomized, double-blind trial comparing topiramate with placebo. Safety analyses included adverse event (AE) reports and clinical laboratory tests. Metabolic end points included body weight and glycosylated hemoglobin (HbA(1c)). Effectiveness analyses included a 100-mm pain visual analog (PVA) scale, worst and current pain severity, and sleep disruption. RESULTS: Two hundred five subjects participated in this open-label extension study (118 formerly treated with topiramate and 87 who formerly received placebo). The groups did not differ in baseline demographics or disease characteristics. One hundred twenty-four (60.5%) subjects (68.6% of former topiramate recipients and 49.4% of former placebo recipients) completed the extension study; the most common reason for discontinuation was an AE (27.3% of subjects). AEs among subjects who received > or =1 dose of topiramate (n = 298) included upper respiratory tract infection (16.1%), anorexia (15.1%), diarrhea (12.8%), nausea (12.8%), paresthesia (10.7%), and headache (10.1%). Baseline pain scores were lower in those formerly treated with topiramate (n = 117) than in the former placebo group (n = 86) (PVA: 43.3 vs 52.5, P = 0.014; worst pain: 1.9 vs 2.5, P < 0.001; current pain: 1.6 vs 1.9, P = 0.026; sleep disruption: 3.6 vs 4.6, P = 0.021). At the final visit, PVA, current pain, and sleep disruption scores were not significantly different between the former topiramate and former placebo groups, but worst pain differed significantly (1.4 vs 1.8; P = 0.025). Mean weight loss from the start of topiramate therapy was 5.2 and 5.3 kg in the former topiramate and former placebo groups, respectively (P < 0.001 vs baseline). Mean HbA(1c) values before and after topiramate treatment were 7.7% and 7.4%, respectively, in the former topiramate group (P = 0.004 vs baseline), and 7.6% and 7.1%, respectively, in the former placebo group (P < 0.001 vs baseline). CONCLUSION: Although 39.5% of subjects discontinued, most often due to AEs, the results of this 26-week, open-label extension study with topiramate (up to 600 mg/d) in subjects with moderately to severely painful DPN suggest that pain relief was effective and durable.

Advances in neuropathic pain: diagnosis, mechanisms, and treatment recommendations.

Chronic neuropathic pain, caused by lesions in the peripheral or central nervous system, comes in many forms. We describe current approaches to the diagnosis and assessment of neuropathic pain and discuss the results of recent research on its pathophysiologic mechanisms. Randomized controlled clinical trials of gabapentin, the 5% lidocaine patch, opioid analgesics, tramadol hydrochloride, and tricyclic antidepressants provide an evidence-based approach to the treatment of neuropathic pain, and specific recommendations are presented for use of these medications. Continued progress in basic and clinical research on the pathophysiologic mechanisms of neuropathic pain may make it possible to predict effective treatments for individual patients by application of a pain mechanism-based approach.

A double-blind placebo-controlled comparison of tramadol/acetaminophen and tramadol in patients with postoperative dental pain.

The objective of this study was to compare the analgesic efficacy of tramadol/acetaminophen (APAP) (total dose 75 mg/650 mg) and tramadol (total dose 100 mg) for the control of pain after oral surgery. A total of 456 patients with moderate-to-severe pain within 5 h after extraction of two or more third molars were randomized to receive two identical encapsulated tablets containing tramadol/APAP 37.5 mg/325 mg, tramadol 50 mg, or placebo. Tramadol/APAP was superior to tramadol (P < 0.001) or placebo (P < 0.001) on all efficacy measures: total pain relief (PAR) over 6 h (7.4, 2.5, and 1.5, respectively, on a scale of 0-24); sum of pain intensity differences (PIDs) (3.1, 0.6, and 0.1, respectively, on a scale of -6 to 18); and sum of PAR and PID (10.5, 3.1, and 1.6, respectively, on a scale of -6 to 42). Median times to onset of perceptible and meaningful PAR were 37.6 and 126.5 min, respectively, for the tramadol/APAP group (P < 0.001) for each, compared with tramadol and placebo arms). The most common adverse events with active treatment were nausea, dizziness, and vomiting; these events occurred more frequently in the tramadol group than in the tramadol/APAP group. This study established the superiority of tramadol/APAP 75 mg/650 mg over tramadol 100 mg in the treatment of acute pain following oral surgery.

Core outcome domains for chronic pain clinical trials: IMMPACT recommendations.

OBJECTIVE: To provide recommendations for the core outcome domains that should be considered by investigators conducting clinical trials of the efficacy and effectiveness of treatments for chronic pain. Development of a core set of outcome domains would facilitate comparison and pooling of data, encourage more complete reporting of outcomes, simplify the preparation and review of research proposals and manuscripts, and allow clinicians to make informed decisions regarding the risks and benefits of treatment. METHODS: Under the auspices of the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT), 27 specialists from academia, governmental agencies, and the pharmaceutical industry participated in a consensus meeting and identified core outcome domains that should be considered in clinical trials of treatments for chronic pain. CONCLUSIONS: There was a consensus that chronic pain clinical trials should assess outcomes representing six core domains: (1) pain, (2) physical functioning, (3) emotional functioning, (4) participant ratings of improvement and satisfaction with treatment, (5) symptoms and adverse events, (6) participant disposition (e.g. adherence to the treatment regimen and reasons for premature withdrawal from the trial). Although consideration should be given to the assessment of each of these domains, there may be exceptions to the general recommendation to include all of these domains in chronic pain trials. When this occurs, the rationale for not including domains should be provided. It is not the intention of these recommendations that assessment of the core domains should be considered a requirement for approval of product applications by regulatory agencies or that a treatment must demonstrate statistically significant effects for all of the relevant core domains to establish evidence of its efficacy.