Background: The treatment of postherpetic neuralgia (PHN) continues to be a challenge in clinical pain management. In this randomized, controlled study, we assessed the effectiveness of repetitive paravertebral injections with local anesthetics and steroids for the prevention of PHN in patients with acute herpes zoster.
Methods: One hundred thirty-two patients with acute herpes zoster diagnosed 1-7 days after the onset of the rash were randomly assigned to receive either standard therapy (oral antivirals and analgesics) or standard therapy with additional repetitive paravertebral injections of a mixture of 10 mL 0.25% bupivacaine and 40 mg methylprednisolone acetate every 48 h for a week. Efficacy was evaluated at 1, 3, 6, and 12 mo after the end of the treatments. The primary end point was the proportion of patients with zoster-associated pain and/or allodynia 1 mo after inclusion. Statistical analysis was performed based on the intent-to-treat population.
Results: One hundred thirteen patients completed the 1-yr follow-up. At 1 mo posttherapy, 13% of patients in the paravertebral group reported zoster-related pain, compared with 45% in the standard group (P < 0.001). At 3, 6, and 12 mo posttherapy, the incidence of PHN was still significantly lower in the paravertebral group than in the standard group. The quality of life improved in both groups at each follow-up time point with no significant difference between groups.
Conclusion: Repetitive paravertebral anesthetic block in combination with steroids plus standard treatment with acyclovir and analgesics significantly reduced the incidence of PHN than the standard treatment alone.