The Role of the Capsaicin 8 % Patch (Qutenza®) in the Treatment of Post-herpetic Neuralgia

Abstract

Post-herpetic neuralgia (PHN) occurs as a complication of acute herpes zoster. The capsaicin 8 % (w/w) dermal patch (Qutenza®) is a transient receptor potential vanilloid agonist that increases intracellular calcium concentration, triggering calcium-dependent protease enzymes to cause cytoskeletal breakdown. This action is thought to lead to loss of cellular integrity and defunctionalization of nociceptor epidermal nerve fibers. The capsaicin 8 % patch is indicated in the US for the treatment of neuropathic pain associated with PHN. In pivotal, randomized, doubleblind, multicenter trials in patients with PHN, a single 60-minute application of the capsaicin 8 % dermal patch reduced mean numeric pain rating scale scores between baseline and weeks 2–8 to a significantly greater extent than the low-dose comparator patch (capsaicin 0.04 % w/w). The capsaicin 8 % (w/w) dermal patch was found to be safe and generally well-tolerated. Most commonly reported side effects were local, comprising dermal irritation, erythema, and pain at the site of application. These effects were transient and mild to moderate in severity. Transient patch application-related pain was not a barrier to use and was managed with local cooling or oral analgesics in nearly all cases. Thus, the capsaicin 8 % dermal patch appears to have a good safety profile, is well tolerated, and offers effective topical therapy in some patients with PHN. This review aims to characterize the use of the capsaicin 8 % dermal patch in the treatment of PHN.