Does treatment of acute herpes zoster prevent or shorten postherpetic neuralgia?

Our goal was to determine if any treatment of acute herpes zoster alters the incidence or duration of postherpetic neuralgia (PHN), a common sequela in elderly patients.

We systematically searched MEDLINE and The Cochrane Library. We also examined the reference lists of identified trials and reviews.

We included all randomized controlled trials of treatments of zoster published in English that included assessment of pain at any time after rash healing.

Forty-two trials met inclusion criteria, and 2 reviewers independently evaluated them for methodologic quality and the statistical and clinical significance of results.

Four placebo-controlled trials of oral acyclovir with 692 patients provided marginal evidence for reduction in pain incidence at 1 to 3 months following zoster onset. Famciclovir significantly reduced duration but not incidence of PHN in one placebo-controlled trial of 419 patients. Valacyclovir significantly reduced duration but not incidence of PHN in one acyclovir-controlled trial of 1141 patients. Steroids had no effect on PHN. Amitriptyline for 90 days reduced pain incidence at 6 months in one placebo-controlled trial of 80 patients. A single trial of percutaneous electrical nerve stimulation (PENS) in 50 patients suggested a decrease in pain incidence at 3 and 6 months compared with famciclovir.

There is limited evidence that current interventions prevent or shorten PHN. Famciclovir and valacyclovir have been shown to reduce the duration of PHN in single published trials. Well-designed and larger trials of amitriptyline and PENS should be conducted.