Treatment of patients with herpes zoster by epidural injection of steroids and local anaesthetics: less pain after 1 month, but no effect on long-term postherpetic neuralgia--a randomised trial

OBJECTIVE: To assess the effectiveness of a single epidural injection of steroids and local anaesthetics, as a supplement to the standard treatment, for the prevention ofpostherpetic neuralgia in older patients with herpes zoster. DESIGN: Open randomised trial. METHOD: In the period September 2001-February 2004, 598 patients, aged > 50 years, with acute herpes zoster (rash for < 7 days) below dermatome C6, were randomly assigned to receive either standard therapy (oral antiviral agents and analgesics) alone or standard therapy plus an additional single epidural injection of 80 mg methylprednisolone and 10 mg bupivacaine. The primary endpoint was the proportion of patients with zoster-associated pain one month after inclusion. The presence and severity of zoster-associated pain at other time points were secondary endpoints. RESULTS: At one month, pain was reported by 137 (48%) patients in the injection group versus 164 (58%) in the control group (relative risk; RR: 0.83; 95% CI: 0.71-0.97; p = 0.02). After three months, these values were 58 (21%) and 63 (24%), respectively (RR: 0.89; 95% CI: 0.65-1-21; p = 0.47), and at 6 months: 39 (15%) and 44 (17%) (RR: 0.85; 95% CI: 0.57-1-13; p = 0.43). No subgroups were detectable in which the relative risk for pain at one month after inclusion substantially differed from the overall estimate. At one month, the median severity of pain in the injection group was 2 (on a 100-points scale) versus 6 in the control group (p = 0.02). At later follow-up, there was no longer any statistically significant difference in the severity of pain between the two groups. No patient had major adverse events related to the epidural injection. CONCLUSION: A single epidural injection of steroids and local anaesthetics in the acute phase of herpes zoster resulted in a modest decrease in zoster-associated pain in the first month. This treatment did not, however, prevent long-term postherpetic neuralgia.