85 resultados para Double-blind Crossover
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Abstract Background Carbohydrate (CHO) ingestion may be an interesting approach to avoid significant decrement to the tennis match performance. The aim of the present investigation was to assess the effects of CHO supplementation on tennis match play performance. Methods Twelve young tennis players (18.0 ± 1.0 years; 176 ± 3.4 cm; 68.0 ± 2.3 kg; body fat: 13.7 ± 2.4%) with national rankings among the top 50 in Brazil agreed to participate in this study, which utilized a randomized, crossover, double blind research design. The experiment was conducted over a 5-day period in which each player completed two simulated tennis matches of a 3-hour duration. The players received either a CHO or a placebo (PLA) drinking solution during simulated tennis matches. Athlete’s performance parameters were determined by filming each match with two video cameras. Each player was individually tracked for the entire duration of the match to measure the following variables: (1) games won; (2) rally duration; (3) strokes per rally; (4) effective playing time (%); (5) aces; (6) double faults; (7) first service in; (8) second service in; (9) first return in and (10) second return in. Results There were no differences between trials in any of the variables analyzed. Conclusions CHO supplementation did not improve tennis match play performance under the present experimental conditions.
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Noninvasive brain stimulation (NIBS) techniques are being increasingly investigated as a therapeutic approach for neuropsychiatric disorders. One method is to combine NIBS with pharmacotherapy to enhance the clinical effects or avoid an increase in drug dosages to decrease the incidence of side effects. However, few studies to date have investigated the relative and combined efficacy of NIBS with pharmacotherapy. Based on a literature review of previous studies and meta-analyses for major depression, we identified four randomized, controlled trials that tested the combination of NIBS with a new drug and two trials that directly compared NIBS versus pharmacotherapy. There was no study designed to address the relative efficacy of each intervention against placebo and against combined therapy. We discuss the methods and rationale of NIBS-pharmacotherapy trials, addressing some methodological aspects, including factorial design, recruitment, blinding, blinding assessment, placebo effect and quantitative aspects, such as power analysis, statistics and interaction effects. Our review of the methodology underlying NIBS-drug trials provides insights for the further clinical research development of NIBS in major depression.
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Major depressive disorder (MDD) trials - investigating either non-pharmacological or pharmacological interventions - have shown mixed results. Many reasons explain this heterogeneity, but one that stands out is the trial design due to specific challenges in the field. We aimed therefore to review the methodology of non-invasive brain stimulation (NIBS) trials and provide a framework to improve clinical trial design. We performed a systematic review for randomized, controlled MDD trials whose intervention was transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) in MEDLINE and other databases from April 2002 to April 2008. We created an unstructured checklist based on CONSORT guidelines to extract items such as power analysis, sham method, blinding assessment, allocation concealment, operational criteria used for MDD, definition of refractory depression and primary study hypotheses. Thirty-one studies were included. We found that the main methodological issues can be divided in to three groups: (1) issues related to phase II/small trials, (2) issues related to MDD trials and, (3) specific issues of NIBS studies. Taken together, they can threaten study validity and lead to inconclusive results. Feasible solutions include: estimating the sample size a priori; measuring the degree of refractoriness of the subjects; specifying the primary hypothesis and statistical tests; controlling predictor variables through stratification randomization methods or using strict eligibility criteria; adjusting the study design to the target population; using adaptive designs and exploring NIBS efficacy employing biological markers. In conclusion, our study summarizes the main methodological issues of NIBS trials and proposes a number of alternatives to manage them. Copyright (C) 2011 John Wiley & Sons, Ltd.
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Objectives: The use of noninvasive cortical electrical stimulation with weak currents has significantly increased in basic and clinical human studies. Initial, preliminary studies with this technique have shown encouraging results; however, the safety and tolerability of this method of brain stimulation have not been sufficiently explored yet. The purpose of our study was to assess the effects of direct current (DC) and alternating current (AC) stimulation at different intensities in order to measure their effects on cognition, mood, and electroencephalogram. Methods: Eighty-two healthy, right-handed subjects received active and sham stimulation in a randomized order. We conducted 164 ninety-minute sessions of electrical stimulation in 4 different protocols to assess safety of (1) anodal DC of the dorsolateral prefrontal cortex (DLPFC); (2) cathodal DC of the DLPFC; (3) intermittent anodal DC of the DLPFC and; (4) AC on the zygomatic process. We used weak currents of 1 to 2 mA (for DC experiments) or 0.1 to 0.2 mA (for AC experiment). Results: We found no significant changes in electroencephalogram, cognition, mood, and pain between groups and a low prevalence of mild adverse effects (0.11% and 0.08% in the active and sham stimulation groups, respectively), mainly, sleepiness and mild headache that were equally distributed between groups. Conclusions: Here, we show no neurophysiological or behavioral signs that transcranial DC stimulation or AC stimulation with weak currents induce deleterious changes when comparing active and sham groups. This study provides therefore additional information for researchers and ethics committees, adding important results to the safety pool of studies assessing the effects of cortical stimulation using weak electrical currents. Further studies in patients with neuropsychiatric disorders are warranted.
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Aims To describe, in the context of DSM-V, how a focus on addiction and compulsion is emerging in the consideration of pathological gambling (PG). Methods A systematic literature review of evidence for the proposed re-classification of PG as an addiction. Results Findings include: (i) phenomenological models of addiction highlighting a motivational shift from impulsivity to compulsivity associated with a protracted withdrawal syndrome and blurring of the ego-syntonic/ego-dystonic dichotomy; (ii) common neurotransmitter (dopamine, serotonin) contributions to PG and substance use disorders (SUDs); (iii) neuroimaging support for shared neurocircuitries between behavioural and substance addictions and differences between obsessivecompulsive disorder (OCD), impulse control disorders (ICDs) and SUDs; (iv) genetic findings more closely related to endophenotypic constructs such as compulsivity and impulsivity than to psychiatric disorders; (v) psychological measures such as harm avoidance identifying a closer association between SUDs and PG than with OCD; (vi) community and pharmacotherapeutic trials data supporting a closer association between SUDs and PG than with OCD. Adapted behavioural therapies, such as exposure therapy, appear applicable to OCD, PG or SUDs, suggesting some commonalities across disorders. Conclusions PG shares more similarities with SUDs than with OCD. Similar to the investigation of impulsivity, studies of compulsivity hold promising insights concerning the course, differential diagnosis and treatment of PG, SUDs, and OCD.
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Aims: This study aimed to classify alcohol-dependent outpatients on the basis of clinical factors and to verify if the resulting types show different treatment retention. Methods: The sample comprised 332 alcoholics that were enrolled in three different pharmacological trials carried out at Sao Paulo University, Brazil. Based on four clinical factors problem drinking onset age, familial alcoholism, alcohol dependence severity, and depression - K-means cluster analysis was performed by using the average silhouette width to determine the number of clusters. A direct logistic regression was performed to analyze the influence of clusters, medication groups, and Alcoholics Anonymous ( AA) attendance in treatment retention. Results: Two clusters were delineated. The cluster characterized by earlier onset age, more familial alcoholism, higher alcoholism severity, and less depression symptoms showed a higher chance of discontinuing the treatment, independently of medications used and AA attendance. Participation in AA was significantly related to treatment retention. Discussion: Health services should broaden the scope of services offered to meet heterogeneous needs of clients, and identify treatment practices and therapists which improve retention. Information about patients' characteristics linked to dropout should be used to make treatment programs more responsive and attractive, combining pharmacological agents with more intensive and diversified psychosocial interventions. Copyright (C) 2012 S. Karger AG, Basel
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This long-term extension of an 8-week randomized, naturalistic study in patients with panic disorder with or without agoraphobia compared the efficacy and safety of clonazepam (n = 47) and paroxetine (n = 37) over a 3-year total treatment duration. Target doses for all patients were 2 mg/d clonazepam and 40 mg/d paroxetine (both taken at bedtime). This study reports data from the long-term period (34 months), following the initial 8-week treatment phase. Thus, total treatment duration was 36 months. Patients with a good primary outcome during acute treatment continued monotherapy with clonazepam or paroxetine, but patients with partial primary treatment success were switched to the combination therapy. At initiation of the long-term study, the mean doses of clonazepam and paroxetine were 1.9 (SD, 0.30) and 38.4 (SD, 3.74) mg/d, respectively. These doses were maintained until month 36 (clonazepam 1.9 [ SD, 0.29] mg/d and paroxetine 38.2 [SD, 3.87] mg/d). Long-term treatment with clonazepam led to a small but significantly better Clinical Global Impression (CGI)-Improvement rating than treatment with paroxetine (mean difference: CGI-Severity scale -3.48 vs -3.24, respectively, P = 0.02; CGI-Improvement scale 1.06 vs 1.11, respectively, P = 0.04). Both treatments similarly reduced the number of panic attacks and severity of anxiety. Patients treated with clonazepam had significantly fewer adverse events than those treated with paroxetine (28.9% vs 70.6%, P < 0.001). The efficacy of clonazepam and paroxetine for the treatment of panic disorder was maintained over the long-term course. There was a significant advantage with clonazepam over paroxetine with respect to the frequency and nature of adverse events.
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NEWEST (Neoadjuvant Endocrine Therapy for Women with Estrogen-Sensitive Tumors) is the first study to compare biological and clinical activity of fulvestrant 500 versus 250 mg in the neoadjuvant breast cancer setting. We hypothesized that fulvestrant 500 mg may be superior to 250 mg in blocking estrogen receptor (ER) signaling and growth. A multicenter, randomized, open-label, Phase II study was performed to compare fulvestrant 500 mg (500 mg/month plus 500 mg on day 14 of month 1) versus fulvestrant 250 mg/month for 16 weeks prior to surgery in postmenopausal women with ER+ locally advanced breast cancer. Core biopsies at baseline, week 4, and surgery were assessed for biomarker changes. Primary endpoint: change in Ki67 labeling index (LI) from baseline to week 4 determined by automated computer imaging system (ACIS). Secondary endpoints: ER protein expression and function; progesterone receptor (PgR) expression; tumor response; tolerability. ER and PgR were examined retrospectively using the H score method. A total of 211 patients were randomized (fulvestrant 500 mg: n = 109; 250 mg: n = 102). At week 4, fulvestrant 500 mg resulted in greater reduction of Ki67 LI and ER expression versus 250 mg (-78.8 vs. -47.4% [p < 0.0001] and -25.0 vs. -13.5% [p = 0.0002], respectively [ACIS]); PgR suppression was not significantly different (-22.7 vs. -17.6; p = 0.5677). However, H score detected even greater suppression of ER (-50.3 vs. -13.7%; p < 0.0001) and greater PgR suppression (-80.5 vs. -46.3%; p = 0.0018) for fulvestrant 500 versus 250 mg. At week 16, tumor response rates were 22.9 and 20.6% for fulvestrant 500 and 250 mg, respectively, with considerable decline in all markers by both ACIS and H score. No detrimental effects on endometrial thickness or bone markers and no new safety concerns were identified. This provides the first evidence of greater biological activity for fulvestrant 500 versus 250 mg in depleting ER expression, function, and growth.
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Purpose Sorafenib is a multikinase inhibitor with antiangiogenic/antiproliferative activity. A randomized, double-blind, placebo-controlled phase IIB trial assessed sorafenib with capecitabine for locally advanced or metastatic human epidermal growth factor receptor 2 (HER2) -negative breast cancer. Patients and Methods Patients were randomly assigned to first-or second-line capecitabine 1,000 mg/m(2) orally twice a day for days 1 to 14 of every 21-day cycle with sorafenib 400 mg orally twice a day or placebo. The primary end point was progression-free survival (PFS). Results In total, 229 patients were enrolled. The addition of sorafenib to capecitabine resulted in a significant improvement in PFS versus placebo (median, 6.4 v 4.1 months; hazard ratio [HR], 0.58; 95% CI, 0.41 to 0.81; P = .001) with sorafenib favored across subgroups, including first-line (HR, 0.50; 95% CI, 0.30 to 0.82) and second-line (HR, 0.65; 95% CI, 0.41 to 1.04) treatment. There was no significant improvement for overall survival (median, 22.2 v 20.9 months; HR, 0.86; 95% CI, 0.61 to 1.23; P = .42) and overall response (38% v 31%; P = .25). Toxicities (sorafenib v placebo) of any grade included rash (22% v 8%), diarrhea (58% v 30%), mucosal inflammation (33% v 21%), neutropenia (13% v 4%), hypertension (18% v 12%), and hand-foot skin reaction/hand-foot syndrome (HFSR/HFS; 90% v 66%); grade 3 to 4 toxicities were comparable between treatment arms except HFSR/HFS (44% v 14%). Reasons for discontinuation in the sorafenib and placebo arms included disease progression (63% v 82%, respectively), adverse events (20% v 9%, respectively), and death (0% v 1%, respectively). Conclusion Addition of sorafenib to capecitabine improved PFS in patients with HER2-negative advanced breast cancer. The dose of sorafenib used in this trial resulted in unacceptable toxicity for many patients. A phase III confirmatory trial has been initiated with a reduced sorafenib dose.
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Introduction: Patients undergoing mechanical ventilation (MV) are frequently administered prolonged and/or high doses of opioids which when removed can cause a withdrawal syndrome and difficulty in weaning from MV. We tested the hypothesis that the introduction of enteral methadone during weaning from sedation and analgesia in critically ill adult patients on MV would decrease the weaning time from MV. Methods: A double-blind randomized controlled trial was conducted in the adult intensive care units (ICUs) of four general hospitals in Brazil. The 75 patients, who met the criteria for weaning from MV and had been using fentanyl for more than five consecutive days, were randomized to the methadone (MG) or control group (CG). Within the first 24 hours after study enrollment, both groups received 80% of the original dose of fentanyl, the MG received enteral methadone and the CG received an enteral placebo. After the first 24 hours, the MG received an intravenous (IV) saline solution (placebo), while the CG received IV fentanyl. For both groups, the IV solution was reduced by 20% every 24 hours. The groups were compared by evaluating the MV weaning time and the duration of MV, as well as the ICU stay and the hospital stay. Results: Of the 75 patients randomized, seven were excluded and 68 were analyzed: 37 from the MG and 31 from the CG. There was a higher probability of early extubation in the MG, but the difference was not significant (hazard ratio: 1.52 (95% confidence interval (CI) 0.87 to 2.64; P = 0.11). The probability of successful weaning by the fifth day was significantly higher in the MG (hazard ratio: 2.64 (95% CI: 1.22 to 5.69; P < 0.02). Among the 54 patients who were successfully weaned (29 from the MG and 25 from the CG), the MV weaning time was significantly lower in the MG (hazard ratio: 2.06; 95% CI 1.17 to 3.63; P < 0.004). Conclusions: The introduction of enteral methadone during weaning from sedation and analgesia in mechanically ventilated patients resulted in a decrease in the weaning time from MV.
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Background: This randomized, placebo-controlled, double-blind pilot study evaluated the impact of repetitive transcranial magnetic stimulation (rTMS) on clinical, cognitive, and social performance in women suffering with postpartum depression. Methods: Fourteen patients were randomized to receive 20 sessions of sham rTMS or active 5 Hz rTMS over the left dorsolateral prefrontal cortex. Psychiatric clinical scales and a neuropsychological battery were applied at baseline (pretreatment), week 4 (end of treatment), and week 6 (follow-up, posttreatment week 2). Results: The active rTMS group showed significant improvement 2 weeks after the end of rTMS treatment (week 6) in Hamilton Depression Rating Scale (P = 0.020), Global Assessment Scale (P = 0.037), Clinical Global Impression (P = 0.047), and Social Adjustment Scale-Self Report-Work at Home (P = 0.020). Conclusion: This study suggests that rTMS has the potential to improve the clinical condition in postpartum depression, while producing marginal gains in social and cognitive function.
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BACKGROUND Vorapaxar is a new oral protease-activated receptor 1 (PAR-1) antagonist that inhibits thrombin-induced platelet activation. METHODS In this multinational, double-blind, randomized trial, we compared vorapaxar with placebo in 12,944 patients who had acute coronary syndromes without ST-segment elevation. The primary end point was a composite of death from cardiovascular causes, myocardial infarction, stroke, recurrent ischemia with rehospitalization, or urgent coronary revascularization. RESULTS Follow-up in the trial was terminated early after a safety review. After a median follow-up of 502 days (interquartile range, 349 to 667), the primary end point occurred in 1031 of 6473 patients receiving vorapaxar versus 1102 of 6471 patients receiving placebo (Kaplan-Meier 2-year rate, 18.5010 vs. 19.9%; hazard ratio, 0.92; 95% confidence interval [CI], 0.85 to 1.01; P=0.07). A composite of death from cardiovascular causes, myocardial infarction, or stroke occurred in 822 patients in the vorapaxar group versus 910 in the placebo group (14.7% and 16.4%, respectively; hazard ratio, 0.89; 95% CI, 0.81 to 0.98; P=0.02). Rates of moderate and severe bleeding were 7.2% in the vorapaxar group and 5.2% in the placebo group (hazard ratio, 1.35; 95% CI, 1.16 to 1.58; P<0.001). Intracranial hemorrhage rates were 1.1% and 0.2%, respectively (hazard ratio, 3.39; 95% CI, 1.78 to 6.45; P<0.001). Rates of nonhemorrhagic adverse events were similar in the two groups. CONCLUSIONS In patients with acute coronary syndromes, the addition of vorapaxar to standard therapy did not significantly reduce the primary composite end point but significantly increased the risk of major bleeding, including intracranial hemorrhage. (Funded by Merck; TRACER ClinicalTrials.gov number, NCT00527943.)
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Objective: To compare the efficacy of metformin with that of lifestyle changes in patients with polycystic ovary syndrome (PCOS). Design: Prospective, randomized clinical trial of 40 women with PCOS to analyze the effects of metformin and lifestyle intervention treatments on menstrual pattern and hormone and metabolic profile. The duration of treatment was 6 months. Statistical analysis was done using Student's t-test. Results: Fifteen women in the metformin group and 12 in the lifestyle changes group completed the study. The menstrual pattern improved by similar to 67% in both groups. There was a significant decrease in waist circumference in the lifestyle changes group (101.8 +/- 3.9 and 95.1 +/- 3.6, at baseline and at 6 months of treatment, respectively; p<0.001) and in body mass index (BMI) in both groups. The predictor of menstrual pattern improvement was BMI. Conclusions: Both metformin and lifestyle changes may increase the number of menstrual cycles in PCOS. This effect was related to a decrease in BMI.
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New drugs for type 2 diabetes that act on incretin metabolism have been shown to improve glycemic control, reduce body weight and have a low risk for hypoglycemia. Among these, liraglutide is the first glucagon-like peptide 1 (GLP-1) analogue approved for subcutaneous, once-daily administration. According to results from clinical trials, liraglutide is on attractive alternative for the early treatment of type 2 diabetes. The results of the LEAD (Liraglutide Effect and Action in Diabetes) study program demonstrated the efficacy and safety of liraglutide in terms of reduction of glycated hemoglobin (HbA(tc)) levels, significant loss of body weight that was maintained over the long term, better control of the lipid profile and systolic arterial pressure, reduction of the risk for hypoglycemia and reduction of cardiovascular risk. Moreover, the drug was demonstrated to be safe and can be co-administered with oral antidiabetic agents. The product's tolerability has been demonstrated, with nausea as the most common adverse event, which waned from the fourth week of treatment.
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Background The effect of intensified platelet inhibition for patients with unstable angina or myocardial infarction without ST-segment elevation who do not undergo revascularization has not been delineated. Methods In this double-blind, randomized trial, in a primary analysis involving 7243 patients under the age of 75 years receiving aspirin, we evaluated up to 30 months of treatment with prasugrel (10 mg daily) versus clopidogrel (75 mg daily). In a secondary analysis involving 2083 patients 75 years of age or older, we evaluated 5 mg of prasugrel versus 75 mg of clopidogrel. Results At a median follow-up of 17 months, the primary end point of death from cardiovascular causes, myocardial infarction, or stroke among patients under the age of 75 years occurred in 13.9% of the prasugrel group and 16.0% of the clopidogrel group (hazard ratio in the prasugrel group, 0.91; 95% confidence interval [CI], 0.79 to 1.05; P = 0.21). Similar results were observed in the overall population. The prespecified analysis of multiple recurrent ischemic events (all components of the primary end point) suggested a lower risk for prasugrel among patients under the age of 75 years (hazard ratio, 0.85; 95% CI, 0.72 to 1.00; P = 0.04). Rates of severe and intracranial bleeding were similar in the two groups in all age groups. There was no significant between-group difference in the frequency of nonhemorrhagic serious adverse events, except for a higher frequency of heart failure in the clopidogrel group. Conclusions Among patients with unstable angina or myocardial infarction without ST- segment elevation, prasugrel did not significantly reduce the frequency of the primary end point, as compared with clopidogrel, and similar risks of bleeding were observed. (Funded by Eli Lilly and Daiichi Sankyo; TRILOGY ACS ClinicalTrials.gov number, NCT00699998.)