The journal of pain : official journal of the American Pain Society
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Chronic pain is a major health concern in the United States. Several guidelines have been developed for clinicians to promote effective management and provide an analytical framework for evaluation of treatments for chronic pain. This study explores sample population demographics and the utilization of various therapeutic modalities in an adult population with common nonmalignant chronic pain (NMCP) indications in U.S. outpatient settings. A cross-sectional study using the National Ambulatory Medical Care Survey (NAMCS) data from 2000 to 2007 was used to analyze various treatment practices for the management of NMCP and evaluate the results in comparison with guidelines. The study population of 690,205,290 comprised 63% females, with 45.17% of patient visits occurring in primary care settings. Treatment with at least 1 chronic pain medication was reported in 99.7% of patients. Nonsteroidal anti-inflammatory agents were the most common treatment prescribed, with use reported in approximately 95% of the patient visits. No other pain medication drug class or nonmedication therapy was prescribed more than 26.4%. These results point to a potential underutilization of many recommended NMCP treatments including combination therapies and the need for enhanced education of chronic pain guidelines. ⋯ This study, representing over 690 million patient visits, contributes to the relative paucity of data on the use of therapeutic modalities in the management of NMCP. These results may assist clinicians and healthcare policymakers in identifying areas where practices are at odds with guidelines with the goal to improve care.
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Repeated injections of the antibiotic ceftriaxone cause analgesia in rodents by upregulating the glutamate transporter, GLT-1. No evidence is available in humans. We studied the effect of a single intravenous administration of ceftriaxone in patients undergoing decompressive surgery of the median or ulnar nerves. Forty-five patients were randomized to receive saline, ceftriaxone (2 g), or cefazolin (2 g), 1 hour before surgery. Cefazolin, which is structurally related to ceftriaxone, was used as a negative control. Pain thresholds were measured 10 minutes before drug injections and then 4 to 6 hours after surgery. Ceftriaxone caused analgesia in all patients, whereas cefazolin was inactive. We also performed animal studies to examine whether a single dose of ceftriaxone was sufficient to induce analgesia. A single intraperitoneal injection of ceftriaxone (200 mg/kg), but not cefazoline (200 mg/kg), caused analgesia in mouse models of inflammatory or postsurgical pain, and upregulated GLT-1 in the spinal cord. Ceftriaxone-induced analgesia was additive to that produced by blockade of mGlu5 receptors, which are activated by extrasynaptic glutamate. These data indicate that a single dose of ceftriaxone causes analgesia in humans and mice and suggest that ceftriaxone should be used for preoperative antimicrobial prophylaxis when a fast relief of pain is desired. ⋯ The study reports for the first time that a single preoperative dose of ceftriaxone causes analgesia in humans. A single dose of ceftriaxone could also relieve inflammatory and postsurgical pain and upregulate GLT-1 expression in mice. Ceftriaxone should be preferred to other antibiotics for antimicrobial prophylaxis to reduce postoperative pain.
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CXBH mice, known as an "opioid receptor-rich" strain, are a recombinant inbred mouse strain established by crossing the C57BL/6By and BALB/cBy strains. In the present study, we investigated nociceptive and antinociceptive sensitivity in CXBH mice and elucidated the underlying molecular mechanisms. CXBH mice exhibited slightly higher morphine-induced antinociception compared with C57BL/6J and BALB/cBy mice in the hot-plate test but not tail-flick test. CXBH mice exhibited a marked reduction of nociceptive sensitivity, regardless of the type of nociceptive stimulus, with the exception of tail stimulation. Changes in gene expression that corresponded to reduced nociceptive sensitivity in the brains of CXBH mice were observed in 62 transcripts, including pain- and analgesia-related transcripts, in a whole-genome expression assay. The total mRNA expression of opioid receptors was higher in CXBH mice than in C57BL/6J and BALB/cBy mice. However, the expression levels of MOR-1 mRNA, a major transcript of the μ opioid receptor gene, were not different among the C57BL/6J, BALB/cBy, and CXBH strains. In conclusion, supraspinal nociceptive responses were reduced in the CXBH mouse strain, and the expression levels of transcripts were altered in the brain of this strain. ⋯ This article presents the nociceptive and antinociceptive properties of CXBH recombinant inbred mice and gene expression differences that may underlie nociceptive tolerance in the strain. The CXBH mouse strain may be a useful animal model to investigate the molecular basis of individual differences in supraspinal pain sensitivity.
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Randomized Controlled Trial
A randomized controlled pilot study of a cognitive-behavioral therapy approach for painful diabetic peripheral neuropathy.
The purpose of the present pilot study was to assess the efficacy of cognitive-behavioral therapy (CBT) for painful diabetic peripheral neuropathy. This was a randomized, treatment as usual (TAU), controlled, nonblinded intervention pilot study with a 4-month follow-up conducted in a VA medical center. It was hypothesized that participants who received CBT, as compared to those who received TAU, would report significant decreases on self-report measures of pain severity, interference, and depressive symptoms from pretreatment to 4-month follow-up. Participants meeting inclusion criteria were randomly assigned to 1 of the study conditions. Of the 20 eligible participants, 12 were randomized to CBT and 8 were randomized to TAU. Participants randomized to CBT showed significant decreases on measures of pain severity (B = -.54) and pain interference (B = -.77) from pretreatment to 4-month follow-up. There were no significant changes in the TAU participants' scores on measures of pain severity (B = .00) or pain interference (B = -.09). Neither CBT nor TAU participants showed significant changes in their levels of depressive symptoms from pretreatment to 4-month follow-up. CBT may be an effective treatment approach for reducing pain severity and interference associated with painful diabetic peripheral neuropathy. ⋯ The results of this study suggest that engaging patients in CBT for painful diabetic peripheral neuropathy may provide them the skills to become more active and experience less pain.
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The study of complex regional pain syndrome (CRPS) in humans is complicated by inhomogeneities in available study cohorts. We hoped to characterize early CRPS-like features in patients undergoing hand surgery. Forty-three patients were recruited from a hand surgery clinic that had elective surgeries followed by cast immobilization. On the day of cast removal, patients were assessed for vasomotor, sudomotor, and trophic changes, and edema and pain sensitization using quantitative sensory testing. Pain intensity was assessed at the time of cast removal and after 1 additional month, as was the nature of the pain using the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS). Skin biopsies were harvested for the analysis of expression of inflammatory mediators. We identified vascular and trophic changes in the surgical hands of most patients. Increased sensitivity to punctate, pressure, and cold stimuli were observed commonly as well. Moreover, levels of IL-6, TNF-alpha, and the mast cell marker tryptase were elevated in the skin of hands ipsilateral to surgery. Moderate-to-severe pain persisted in the surgical hands for up to 1 month after cast removal. Exploratory analyses suggested interrelationships between the physical, quantitative sensory testing, and gene expression changes and pain-related outcomes. ⋯ This study has identified CPRS-like features in the limbs of patients undergoing surgery followed by immobilization. Further studies using this population may be useful in refining our understanding of CRPS mechanisms and treatments for this condition.