Safety and Efficacy of Different Systemic Treatment Modalities for Acute Pain of Herpes Zoster: A Pilot Study.

Background: Herpes zoster is a viral infection of skin caused by Varicella Zoster virus. The most important symptom for which the patient seeks medical advice is pain, which is perceived before the development of rash and lasts even after its resolution. The pain during the first 30 days after onset of herpes zoster is known as acute herpetic neuralgia. The aim of this study was to compare the efficacy and side-effects of different systemic treatment modalities for acute herpes zoster neuralgia.

Materials and Methods: This was a randomized, single-blind, parallel control study. Forty-five patients of herpes zoster within 72 hours of onset were enrolled after considering various inclusion and exclusion criteria over a duration of 1 year. Pain severity was assessed after sequential distribution and allotment of patients in three groups using verbal rating scale (VRS). Patients in Group A (control group), were treated with Tab.valacyclovir (1 g tds × 7 days), Group B-Tab.valacyclovir (1 g tds × 7 days) + Cap. Pregabalin (75 mg bd × 1 month), and Group C -Tab.valacyclovir (1 g tds × 7 days) +Cap. Pregabalin (75 mg bd × 1 month) + Tab.methylprednisolone (0.64 mg/kg body weight in two divided doses × 7 days). Patients were followed up at 1, 4, 6 weeks. Complete resolution of acute pain and side-effects were noted.

Results: At the end of 4 weeks, reduction in acute pain was statistically significant ( P < 0.05) in all the three groups individually compared to the baseline value. At the end of 6 weeks, percentage of patients with persistence of pain was more in Group A and B compared to Group C, which was statistically significant ( P = 0.0001). In group A, postherpetic neuralgia was observed in more patients compared to group B and C. No significant side-effects were observed in any group except vomiting, somnolence, and dizziness.

Limitations: Sample size of this study was limited. Further studies with large sample size are required to further validate the findings of the present study.

Conclusions: Combination therapy with valacyclovir, methylprednisolone, and pregabalin has better efficacy compared to valacyclovir and pregabalin and valacyclovir alone in the management of acute herpes zoster neuralgia. No significant side-effects were observed.