Other treatments for postherpetic neuralgia have been investigated, but not all are effective. Aspirin cream has been helpful in a few small studies, but the benefit is not considered significant. 20 No recommendations can be made for the anticonvulsants valproate (Depakote) 19 and carbamazepine (Tegretol) 20 because of limited data. Anesthetic agents such as N -methyl- d -aspartate receptor antagonists play a role in processing pain signals and could potentially benefit patients with postherpetic neuralgia. Ketamine (Ketalar), dextromethorphan, and memantine (Namenda) have not been shown to improve pain compared with placebo. 20
Herpes zoster and postherpetic neuralgia are relatively common conditions, primarily in elderly and immunocompromised patients. Although the diagnosis of the conditions is generally straightforward, treatment can be frustrating for the patient and physician. Approaches to management include treatment of the herpes zoster infection and associated pain, prevention of postherpetic neuralgia, and control of the neuropathic pain until the condition resolves. Primary treatment modalities include antiviral agents, corticosteroids, tricyclic antidepressants and anticonvulsants.
When it comes to research, itch and the treatment of itch has been sidelined, with most of the effort going to understanding and alleviating pain. In spite of some similarities between itch and pain pathways, medications that alleviate pain are not as effective in relieving itch . Research is currently being conducted on potential targets including cholecystokinin , PAR2 and GRPR antagonists, as well as a new oral kappa-opiod receptor agonist, nalfurafine , which is in clinical trial . 12 But much more research is needed to investigate the neural circuitry and mechanisms of itch and eventually find innovative treatments for chronic itch.