Topical analgesics for neuropathic pain: Preclinical exploration, clinical validation, future development

摘要: Topical analgesics applied locally to skin or specialized compartments modify pain by actions on sensory nerve endings and/or adjacent cellular elements. With this approach, there are low systemic drug levels, good tolerability and few interactions, combination with oral formulations is feasible. The goal of review provide an overview the potential for topical contribute improved management neuropathic pain. Mechanistic preclinical studies indicate much development novel In humans, two approved use in post-herpetic neuralgia (lidocaine 5% medicated plaster, capsaicin 8% patch), evidence efficacy other conditions. Comparative trials similar between analgesics. Not all individuals respond analgesics, interest determining factors (patient factors, characteristics) which might predict responsiveness There a growing number controlled case reports investigational agents (vasodilators, glutamate receptor antagonists, α2-adrenoreceptor agonists, antidepressants, centrally acting drugs), including combinations several agents, indicating these produce relief compounding pain, but challenges remain approach. have be valuable additional approach