Treatment of post herpetic neuralgia in the elderly

Abstract

The incidence of acute herpes zoster and post herpetic neuralgia (PHN) increases with age. PHN resolves spontaneously within three months in approximately 50% of cases, although 22% experience discomfort for more than a year. There is little good evidence that treatment with antiviral agents, corticosteroids, local and regional anaesthesia, amantadine or levodopa in the acute stage can prevent the development of PHN. However, few studies have sufficient statistical power to allow firm conclusions to be drawn. Amitriptyline is beneficial in patients with established PHN and has an analgesic effect which is independent of its antidepressant action. Anticonvulsants and neuroleptics are of unproven efficacy and should be avoided in the elderly as side effects are common. Various local anaesthetic and surgical techniques may provide temporary relief in individual patients although none has been shown to produce consistent benefit. Transcutaneous electrical nerve stimulation (TENS) is free from adverse effects and appears to benefit some patients. Intractable pain often results in over-prescribing with the risk of adverse drug reactions. Drug therapy should be minimized with careful assessment of the risk/benefit ratio for any additional medication.