The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial Multicenter Study Comparative Study
Safety and efficacy of once-daily hydromorphone extended-release versus twice-daily oxycodone hydrochloride controlled-release in chinese patients with cancer pain: a phase 3, randomized, double-blind, multicenter study.
Noninferiority of the efficacy of once-daily hydromorphone hydrochloride extended-release (hydromorphone ER) compared with twice-daily oxycodone hydrochloride controlled-release (oxycodone CR) was investigated in this randomized, double-blind study in Chinese patients with moderate to severe cancer pain requiring strong oral opioid analgesics. Randomization (1:1) to hydromorphone ER (8-32 mg) or oxycodone CR (10-40 mg) was followed by dose titration (up to 8 days) and dose maintenance (28 days, weekly visits). Primary endpoint was change from baseline to end of study in "worst pain in the past 24 hours" of Brief Pain Inventory (Short Form) score on last observation carried forward (per protocol set). A total of 137 of 260 randomized patients completed maintenance phase (hydromorphone ER: n = 70; oxycodone CR: n = 67); per protocol set: 81 patients. Mean age was 53.1 years (range: 18-70 years; males: 65.3%); most common Eastern Cooperative Oncology Group performance status = 2. Least square mean difference between 2 treatment groups for primary endpoint using analysis of covariance (baseline score, covariate) was -.1 (95% confidence interval: -1.3, 1.1), with upper bound of 95% confidence interval <1.5 (predefined noninferiority margin). Most common reason for deaths was disease progression (hydromorphone ER: 6.3%; oxycodone CR: 12.7%). Treatment-emergent adverse events were comparable between treatment groups. Hydromorphone ER was noninferior to oxycodone CR in alleviating cancer pain and was well tolerated. ⋯ This article demonstrates clinical noninferiority of the efficacy of once-daily hydromorphone ER compared with twice-daily oxycodone CR in alleviating cancer pain in Chinese patients, with comparable safety profiles between the 2 treatment groups. Thus, a treatment option with the potential for a reduced dosing frequency exists for health care providers and patients.
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Randomized Controlled Trial
Repetitive transcranial magnetic stimulation increases the corticospinal inhibition and the brain-derived neurotrophic factor in chronic myofascial pain syndrome: an explanatory double-blinded, randomized, sham-controlled trial.
Chronic myofascial pain syndrome has been related to defective descending inhibitory systems. Twenty-four females aged 19 to 65 years with chronic myofascial pain syndrome were randomized to receive 10 sessions of repetitive transcranial magnetic stimulation (rTMS) (n = 12) at 10 Hz or a sham intervention (n = 12). We tested if pain (quantitative sensory testing), descending inhibitory systems (conditioned pain modulation [quantitative sensory testing + conditioned pain modulation]), cortical excitability (TMS parameters), and the brain-derived neurotrophic factor (BDNF) would be modified. There was a significant interaction (time vs group) regarding the main outcomes of the pain scores as indexed by the visual analog scale on pain (analysis of variance, P < .01). Post hoc analysis showed that compared with placebo-sham, the treatment reduced daily pain scores by -30.21% (95% confidence interval = -39.23 to -21.20) and analgesic use by -44.56 (-57.46 to -31.67). Compared to sham, rTMS enhanced the corticospinal inhibitory system (41.74% reduction in quantitative sensory testing + conditioned pain modulation, P < .05), reduced the intracortical facilitation in 23.94% (P = .03), increased the motor evoked potential in 52.02% (P = .02), and presented 12.38 ng/mL higher serum BDNF (95% confidence interval = 2.32-22.38). No adverse events were observed. rTMS analgesic effects in chronic myofascial pain syndrome were mediated by top-down regulation mechanisms, enhancing the corticospinal inhibitory system possibly via BDNF secretion modulation. ⋯ High-frequency rTMS analgesic effects were mediated by top-down regulation mechanisms enhancing the corticospinal inhibitory, and this effect involved an increase in BDNF secretion.