After reading “Stop shingles in its tracks,” (J Fam Pract. 2009;58:531-534), I would like to make the following comments:
Antiviral drugs may indeed lessen both the severity of acute pain and the duration of skin lesions in patients with herpes zoster (HZ), and some studies have shown that famciclovir and valacyclovir shorten the duration of postherpetic neuralgia (PHN). There is no convincing evidence, however, that antiviral medication significantly reduces the incidence of PHN.1,2
Treatment with acyclovir within 72 hours after rash onset reduces the incidence of eye disorders in ophthalmic zoster patients (from 50% to 20%-30%). Famciclovir and valacyclovir appear to be equally effective, but their efficacy in reducing eye disorders associated with HZ has not been studied. In clinical practice, however, these second generation antivirals may be more effective than acyclovir because compliance with the treatment regimen (3 daily doses, vs 5) is likely to be higher.3 The evidence suggests that oral antiviral drugs should be prescribed only for elderly HZ patients at high risk for PHN and all patients with ophthalmic zoster, regardless of age or severity of symptoms.1
Finally, the definition of PHN used in the vaccine trial was pain associated with HZ that was rated ≥3 on a 0-to-10 pain scale, persisting or appearing >90 days after the onset of rash4—not any pain continuing 1 month after the rash healed. As the incidence and severity of PHN decline gradually, the effectiveness of vaccination is even greater than Lang et al suggested.
Wim Opstelten, MD, PhD
University Medical Center, Utrecht,
The Netherlands