Predictors of Treatment Response to Capsaicin Patch

Abstract

Neuropathic pain is a very difficult to treat chronic condition. One of the most promising treatments developed in recent years is the capsaicin 8% patch. But given the high cost of treatment, the patch should be applied only to those most likely to benefit from improve- ment. There have been several studies that have tried to look for predictors of treatment response. Three of them found correlation with pain and response to treatment. The pre- dictors found were: baseline pain scores, variability of pain prior to treatment, pain response for lidocaine pretreatment, and time with preexisting pain. Four studies found that sensory abnormalities used for prediction of response to treatment seems to be useful as well. Though the correct sensory sensations are not clear there seems to be a tendency for the burning or heat-pain sensations and the pressure-pain sensations to be taken into account. From this findings, it seems that patients with exclusively peripheral damage and with no central plastic changes are the most suitable for treatment. There must be some more research to be done, where a combination of the predictors already found could give a very high predictability of treatment response, lowering de NNT to almost 1.