Topical Analgesics

Topical analgesics are applied to the skin and produce a localized effect on sensory nerve endings to inhibit pain signaling in the periphery. This approach offers the advantage of few systemic adverse effects. There is clear evidence that topical NSAIDs produce analgesia, especially in osteoarthritis. Topical local anesthetics produce pain relief in post-herpetic neuralgia and focal neuropathies. Both classes of drug have entered treatment algorithms as early treatment options. Topical capsaicin produces analgesia in neuropathic pain, but use is limited by local adverse effects and it is considered a third-line treatment. There is less evidence for benefit from rubefacients in chronic pain. Opioids exhibit peripheral analgesia with arthroscopic knee surgery and chronic knee inflammation conditions, and topical applications appear promising for wounds and oral mucosa lesions. The realm of topical analgesics is receiving considerable attention, and several novel targets are being explored for efficacy.