Pain
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Randomized Controlled Trial Multicenter Study
A multicenter, placebo-controlled, double-blind, multiple-crossover study of Fentanyl Pectin Nasal Spray (FPNS) in the treatment of breakthrough cancer pain.
This randomized, double-blind, crossover study assessed the efficacy and tolerability of a new rapid onset nasal fentanyl formulation (Fentanyl Pectin Nasal Spray; FPNS) for breakthrough cancer pain (BTCP). Eighty-three of 114 patients experiencing one to four BTCP episodes/day while taking ≥60 mg/day of oral morphine or equivalent successfully identified an effective dose of FPNS during a titration phase and entered a double-blind phase in which 10 BTCP episodes were treated with this effective dose (7) or placebo (3). Compared with placebo, FPNS significantly improved mean summed pain intensity difference (SPID) from 10 min (P<0.05) until 60 min (P<0.0001), including the primary endpoint at 30 min (P<0.0001). ⋯ Approximately 70% of patients were satisfied or very satisfied with the convenience and ease of use of FPNS. Only 5.3% of patients withdrew from treatment due to adverse events, no significant nasal effects were reported, and 87% of patients elected to continue open-label treatment post-study. In this short-term study, FPNS was safe, well tolerated, and rapidly efficacious for BTCP.
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The clinical diagnosis of Complex Regional Pain Syndrome (CRPS) is a dichotomous (yes/no) categorization necessary for clinical decision-making. However, such dichotomous diagnostic categories do not convey an individual's subtle and temporal gradations in severity of the condition, and have poor statistical power when used as an outcome measure in research. This study evaluated the validity and potential utility of a continuous type score to index severity of CRPS. ⋯ In an archival prospective dataset, increases in anxiety and depression from pre-surgical baseline to 4 weeks post-knee arthroplasty were found to predict significantly higher CSS at 6- and 12-month follow-up (p's<.05). Results indicate the CSS corresponds with and complements currently accepted dichotomous diagnostic criteria for CRPS, and support its validity as an index of CRPS severity. Its utility as an outcome measure in research studies is also suggested, with potential statistical advantages over dichotomous diagnostic criteria.
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Widespread pain and pain hypersensitivity are the hallmark of fibromyalgia, a complex pain condition linked to central sensitization. In this study the painDETECT questionnaire (PDQ), validated to identify neuropathic pain and based on pain quality items, was applied in a cross-sectional sample of patients with chronic widespread pain (CWP). The aims of the study were to assess the patient-reported sensory neuropathic symptoms by PDQ and to correlate these with tender point (TP) count and pressure-pain thresholds. ⋯ The study indicates that pain in CWP has neuropathic features, and that the presence and number of tender points are associated with neuropathic pain symptoms. A high mean PDQ score was found to correlate with TP count and pressure-pain thresholds. The PDQ may become a useful tool assisting in the identification of central sensitization in patients with CWP and in the future diagnostic assessment fibromyalgia.
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Widespread central hypersensitivity is present in chronic pain and contributes to pain and disability. According to animal studies, expansion of receptive fields of spinal cord neurons is involved in central hypersensitivity. We recently developed a method to quantify nociceptive receptive fields in humans using spinal withdrawal reflexes. ⋯ This study provides for the first time evidence for widespread expansion of reflex receptive fields in chronic pain patients. It thereby identifies a mechanism involved in central hypersensitivity in human chronic pain. Reverting the expansion of nociceptive receptive fields and exploring the prognostic meaning of this phenomenon may become future targets of clinical research.
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Numbers-needed-to-treat (NNT) are useful for presenting treatment response, conveying the clinical relevance of results. NNTs are typically calculated at a landmark endpoint (end of trial), but often using the last observation carried forward (LOCF), which ignores patient discontinuations. We compared NNTs in chronic low back pain (CLBP) using three separate imputation methods, using data from two identical 12-week trials comparing etoricoxib 60 mg (N=210), 90 mg (N=212), and placebo (N=217). ⋯ Landmark NNTs at week 12 were generally similar or slightly lower (better) than those from a longitudinal approach, but results were inconsistent. Landmark analyses provide no information on response variability, as is obtained with longitudinal analysis. Outcome, imputation method, and reporting method are intimately connected and need to be considered alongside trial quality and validity to make sensible comparisons between treatments.