Neuroscience letters
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Neuroscience letters · Apr 2002
Clinical Trial Controlled Clinical TrialThe addition of glyceryltrinitrate to capsaicin cream reduces the thermal allodynia associated with the application of capsaicin alone in humans.
The aim of this study was to determine whether topical application of capsaicin cream causes thermal allodynia and the extent to which this is attenuated by the addition of glyceryltrinitrate (GTN). This was a double blind placebo controlled study of 40 consenting adult subjects. Each of four cream combinations (GTN, capsaicin, GTN/capsaicin and vehicle) were applied to the subjects with at least a 1 day interval between each application. ⋯ Thermal allodynia is usually apparent when warm water is applied to skin containing capsaicin. The thermal allodynia caused by the topical application of capsaicin was significantly reduced by the addition of GTN. The addition of GTN to capsaicin cream significantly reduces the thermal allodynia associated with the application of capsaicin cream alone.
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Neuroscience letters · Apr 2002
Increased production of nitric oxide stimulated by interferon-gamma from peripheral blood monocytes in patients with complex regional pain syndrome.
This study examines immediate nitric oxide (NO) release from monocytes following interleukin-1beta (IL-1beta), interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) challenge in patients with complex regional pain syndrome (CRPS). Study patients exhibited the following: (1), mechanical allodynia; (2), evidence of either vasomotor or sudomotor disturbance; and (3), concordant painful allodynia documented with quantitative sensory testing that was temporarily abolished with sympathetic block. ⋯ Subjects with CRPS exhibited a statistically significant increase in NO release in response to IFN-gamma (P<0.012) compared with controls. The NO responses to IFN-gamma in excess of NS (P<0.025) and as the ratio IFN-gamma/NS (P<0.022) were also significantly increased.