Pain
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Inflammatory diseases associated with pain are often difficult to treat in the clinic due to insufficient understanding of the nociceptive pathways involved. Recently, there has been considerable interest in the role of reactive oxygen species (ROS) in inflammatory disease, but little is known of the role of hydrogen peroxide (H(2)O(2)) in hyperalgesia. In the present study, intraplantar injection of H(2)O(2)-induced a significant dose- and time-dependent mechanical and thermal hyperalgesia in the mouse hind paw, with increased c-fos activity observed in the dorsal horn of the spinal cord. ⋯ Thermal, but not mechanical, hyperalgesia in response to H(2)O(2) (i.pl.) was longer lasting in TRPV1 wild type mice compared to TRPV1 knockouts. It is unlikely that downstream lipid peroxidation was increased by H(2)O(2). In conclusion, we demonstrate a notable effect of H(2)O(2) in mediating inflammatory hyperalgesia, thus highlighting H(2)O(2) removal as a novel therapeutic target for anti-hyperalgesic drugs in the clinic.
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Randomized Controlled Trial Multicenter Study Comparative Study
Efficient assessment of neuropathic pain drugs in patients with small fiber sensory neuropathies.
We sought to develop an enrichment crossover study design that would allow us to efficiently evaluate and compare promising candidate neuropathic pain drugs. We evaluated the efficacy of gabapentin or tramadol vs. active placebo (diphenhydramine) in subjects with biopsy-proven painful idiopathic small fiber neuropathy (SFN) who were self-reported gabapentin responders. Eligible subjects entered two single blind run-in phases. ⋯ Eighteen subjects were randomized into the double-blind, crossover phase. There was a significant treatment effect of gabapentin vs. diphenhydramine (p=0.001) and tramadol vs. diphenhydramine (p=0.018) by the before-bed daily pain score averaged over the final 7 days of each treatment period. We conclude that gabapentin and tramadol were effective in the treatment of painful SFN and that this experimental enrichment paradigm is attractive to screen potential neuropathic pain compounds for efficacy in proof-of-concept studies.
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Randomized Controlled Trial Comparative Study Clinical Trial
A randomized clinical trial for women with vulvodynia: Cognitive-behavioral therapy vs. supportive psychotherapy.
Many treatments used for women with vulvodynia are based solely upon expert opinion. This randomized trial aimed to test the relative efficacy of cognitive-behavioral therapy (CBT) and supportive psychotherapy (SPT) in women with vulvodynia. Of the 50 participants, 42 (84%) completed 10-week treatments and 47 (94%) completed one-year follow-up assessments. ⋯ Participants in the CBT condition reported significantly greater treatment improvement, satisfaction and credibility than participants in the SPT condition (p's<0.05). Findings from the present study suggest that psychosocial treatments for vulvodynia are effective. CBT, a directed treatment approach that involves learning and practice of specific pain-relevant coping and self-management skills, yielded better outcomes and greater patient satisfaction than a less directive approach.
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Chronic widespread pain (CWP) is associated with poor health-related quality of life (HRQoL). It is unclear whether pain itself is the cause of poor HRQoL or other factors play a role. We hypothesised that new onset of CWP was associated with poor physical and mental HRQoL but that psychosocial risk markers for CWP onset would explain this relationship. ⋯ After adjusting for baseline psychosocial status, the relationship between CWP onset and SF12-MCS was attenuated (RRR=1.2; 95% CI 0.8-1.8), although the association with SF12-PCS remained (RRR=4.8% CI 3.1-7.47). New onset of CWP is associated with poor mental and physical HRQoL. However, the relationship with mental HRQoL is explained by psychosocial risk markers.