Sensory profiles: A new strategy for selecting patients in treatment trials for neuropathic pain

Unlike the plethora of drugs available to treat epilepsy, depression, or migraine, comparatively few and insufficiently effective drugs are available for neuropathic pain. Neuropathic pain syndromes are traditionally classified according to etiology. Randomized controlled trials investigating drugs for neuropathic pain customarily assess drug efficacy in patients whose pain has a defined etiology, for example painful diabetic neuropathy or postherpetic neuralgia, and often report poor responder rates. Even in trials testing the best new drugs for neuropathic pain no more than 30–50% of patients achieve decent pain relief (P50%). One reason why so many patients with neuropathic pain are non-responders is probably that in the same disease, and even in the same patient, pain may originate from various pathophysiological mechanisms whereas drugs for pain relief often act on one mechanism alone.