The Efficacy of Ultrasound-Guided Thoracic Paravertebral Blocks Using a Novel Analgesic Regimen for Thoracic Herpes Zoster-Associated Pain: A Randomized Controlled Trial

The main symptom of herpes zoster (HZ) is pain. While numerous antiviral agents, administered either orally or intravenously, have been recommended for treating this symptom in clinical practice, the optimal strategy for preventing HZ-associated pain remains uncertain.

This study aimed to evaluate the efficiency and safety of a novel analgesic mixture containing parecoxib for treating thoracic HZ neuralgia through ultrasound (US)-guided paravertebral blockades.

An open-label, prospective, randomized clinical trial.

A university hospital.

Sixty patients with thoracic HZ neuralgia receiving appropriate antiviral therapy and pregabalin treatment were randomly divided into 2 equally sized groups. Group C (the control group) received a conventional mixture (0.25% lidocaine + 1/4 betamethasone + 0.1% ropivacaine + saline, 15 mL volume). Group N received the experimental mixture (the above components + 1000 µg of methylcobalamin + 20 mg of parecoxib, 15 mL in volume). Under US-guidance, 15 mL of the assigned mixture was injected below the costotransverse ligament at the affected thoracic segment. The scores on the numeric rating scale (NRS) and Pittsburgh Sleep Quality Index (PSQI) were assessed at baseline and at 12 hours and then 7 days after treatment. Safety parameters (nausea, vomiting, constipation, injection site reactions, pneumothorax, local anesthetic toxicity, and respiratory depression) were monitored.

Both groups showed significant reductions in their NRS scores and improvements to their sleep (P < 0.001). Compared to the control mixture, the novel drug combination was associated with superior NRS scores (P < 0.001) and significantly improved PSQI scores (P < 0.001) at 7 days after treatment. Side effects and complications (nausea, vomiting, constipation, injection site reactions, pneumothorax, local anesthetic toxicity, and respiratory depression) were not observed in either group of patients.

The sample size of this study was relatively small. Study section and publication bias might have affected the general findings.

Compared to conventional treatment, US-guided paravertebral blocks that used the novel drug combination provided more sustained analgesia and greater sleep quality enhancement without additional safety concerns. This optimized formulation represents a promising therapeutic approach for treating thoracic HZ-associated neuralgia.