Lidocaine patch (5%) is no more potent than placebo in treating chronic back pain when tested in a randomised double blind placebo controlled brain imaging study.
A 5% lidocaine patch is a patch containing 5% lidocaine, which is applied to the affected area. It is used in conditions such as neuropathic pain, CRPS, diabetic neuropathy and chronic back pain (CBP). Except for its minimal side effects, the mechanism and potential efficacy of the patches in reducing pain are not clearly understood.
In this study, the effectiveness of the 5% lidocaine patch was compared with a placebo (patch with no pharmacological components) in reducing pain of CBP in a total of 30 CBP patients.
Results show that there was no significant difference between the two groups in either pain intensity (measured by numerical and visual pain scales), sensory and affective qualities of pain (measured by questionnaires) or pain in related activated brain areas (measured by fMRI). These results suggest that 5% lidocaine wasn’t more effective than placebo in CBP. However, results indicate a significant reduction in clinical pain after treatment in both groups compared to an untreated group receiving no treatment. Application of the patch two times a day for two weeks may have acted as a potent placebo analgesic by expectation of pain relief > From Hashmi et al., Mol Pain 8 (2012) 29. All rights reserved to BioMed Central Ltd.
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