This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Dworkin, R. H. Articles by Craig, W. F. Search for Related Content PubMed PubMed Citation Articles by Dworkin, R. H. Articles by Craig, W. F.

---

LETTERS TO THE EDITOR

No Alternative to Antiviral Drugs for Acute Herpes Zoster

Department of Anesthesiology University of Rochester School of Medicine and Dentistry Rochester, NY 14642

The results of recent studies and meta-analyses demonstrate that the antiviral drugs acyclovir, famciclovir, and valacyclovir reduce the risk of developing postherpetic neuralgia (PHN) and the overall duration of herpes zoster pain (1–5). Indeed, routine use of antiviral drugs has been recommended for herpes zoster patients who are at increased risk of prolonged pain and other complications—those who are older, have moderate or severe rash, have moderate or severe pain, or have ophthalmic involvement (6–9). Ahmed et al. (10) recently reported the results of a trial of percutaneous electrical nerve stimulation (PENS) versus famciclovir treatment in 50 patients with acute herpes zoster. In view of the data on the efficacy of antiviral therapy and current treatment guidelines, Ahmed et al.’s (10) conclusion that the results of their trial suggest that PENS "may be a viable alternative to antiviral drugs for the treatment of acute herpes zoster lesions" must be critically evaluated.

In immunocompetent patients, acute zoster is most often an uncomplicated infection that lasts 2–3 wk. What makes herpes zoster a clinical concern is not the lesions, but the unfortunate minority of patients who develop PHN (8,11). Ahmed et al. (10) reported that PENS was "more effective than famciclovir in preventing PHN-related pain symptoms 3 and 6 mo after resolution of the cutaneous lesions." This conclusion was based on comparing the mean pain severity in the antiviral and PENS groups of the few patients with persisting pain in the subset of patients over 50 years of age. But the differences between the two treatments in the percentages of patients with pain at these follow-up times were not statistically significant. There was no evidence, therefore, that PENS prevented PHN, although it may have reduced the intensity of pain in older patients.

Given the very limited evidence provided by Ahmed et al.’s (10) data that PENS significantly attenuated PHN, their conclusion that PENS provides a viable alternative to antiviral drugs must be rejected, and antiviral therapy must remain the standard of care for patients with acute herpes zoster. However, a substantial number of patients with herpes zoster still suffer from prolonged pain, despite adequate antiviral therapy. Although it is possible that new antivirals with greater efficacy will be developed, another strategy for preventing PHN involves supplementing antiviral treatment. The appropriate design in such research on the prevention of PHN is to compare an antiviral agent combined with an investigational treatment (e.g., PENS) with the antiviral agent combined with a placebo matching the investigational treatment (12).

References

1. Beutner KR, Friedman DJ, Forszpaniak C, et al. Valaciclovir compared with acyclovir for improved therapy for herpes zoster in immunocompetent adults. Antimicrob Agents Chemother 1995;39:1546–53.[Abstract]
2. Tyring S, Barbarash RA, Nahlik JE, et al. Famciclovir for the treatment of acute herpes zoster: effects on acute disease and postherpetic neuralgia: a randomized, double-blind, placebo-controlled trial. Ann Intern Med 1995;123:89–96.[Abstract/Free Full Text]
3. Wood MJ, Kay R, Dworkin RH, et al. Oral acyclovir therapy accelerates pain resolution in patients with herpes zoster: a meta-analysis of placebo-controlled trials. Clin Infect Dis 1996;22:341–7.[Web of Science][Medline]
4. Jackson JL, Gibbons R, Meyer G, Inouye L. The effect of treating herpes zoster with oral acyclovir in preventing postherpetic neuralgia: a meta-analysis. Arch Intern Med 1997;157:909–12.[Abstract/Free Full Text]
5. Dworkin RH, Boon RJ, Griffin DRG, Phung D. Postherpetic neuralgia: impact of famciclovir, age, rash severity, and acute pain in herpes zoster patients. Infect Dis 1998;178 (Suppl 1):S76–80.
6. Guidelines for the management of shingles. Report of a working group of the British Society for the Study of Infection. J Infection 1995;30:193–200.
7. Wood MJ, Kroon S, eds. Management strategies in herpes: reducing the burden of zoster-associated pain-update. Worthing, UK: PPS Europe, 1995.
8. Kost RG, Straus SE. Postherpetic neuralgia: pathogenesis, treatment, and prevention. N Engl J Med 1996;335:32–42.[Free Full Text]
9. Dworkin RH, Carrington D, Cunningham A, et al. Assessment of pain in herpes zoster: lessons learned from antiviral trials. Antiviral Res 1997;33:73–85.[Web of Science][Medline]
10. Ahmed HE, Craig WF, White PF, et al. Percutaneous electrical nerve stimulation: an alternative to antiviral drugs for acute herpes zoster. Anesth Analg 1998;87:911–4.[Free Full Text]
11. Dworkin RH, Portenoy RK. Pain and its persistence in herpes zoster. Pain 1996;67:241–51.[Web of Science][Medline]
12. Dworkin RH. Prevention of postherpetic neuralgia. Lancet 1999;353:1636–7.[Web of Science][Medline]

Response

Department of Anesthesiology, and Pain Management University of Texas Southwestern Medical Center at Dallas, TX 75235

Dr. Dworkin argues that percutaneous electrical nerve stimulation (PENS) is not a viable alternative to antiviral drugs. Although the results of this preliminary study require validation in a larger series of patients, the fact remains that PENS compared favorably to an antiviral drug in this immunocompetent patient population (1). As pointed out by Dr. Dworkin, "a substantial number of herpes zoster patients still suffer from prolonged pain despite ‘adequate’ antiviral therapy." Therefore, it would be logical to perform a follow-up study evaluating the effects of combining antiviral therapy with PENS therapy (as we had suggested in our manuscript) (1).

Rather than reject a potentially useful new therapy for postherpetic neuralgia, the impressive findings in this Brief Communication will hopefully encourage other investigators to pursue studies with novel modalities like PENS for preventing postherpetic neuralgia. Electroanalgesia is proving to be a useful therapeutic modality for a wide variety of acute and chronic pain syndromes. In many cases, these nonpharmacologic techniques can also "complement" standard pharmacologic therapies. We encourage Dr. Dworkin and his colleagues to support research of promising new therapies rather than simply rejecting them "out of hand" because the numbers are necessarily small in the initial trials.

References

1. Ahmed HE, Craig CF, White PF, et al. Percutaneous electrical nerve stimulation: an alternative to antiviral drugs for acute herpes zoster. Anesth Analg 1998;87:911–4.

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Dworkin, R. H. Articles by Craig, W. F. Search for Related Content PubMed PubMed Citation Articles by Dworkin, R. H. Articles by Craig, W. F.