A study published in Annals of Internal Medicine reports that early treatment with Famvir (famciclovir) significantly shortens the duration of postherpetic neuralgia in patients with herpes zoster.
Stephen K. Tyring, MD, PhD, principal investigator of the Collaborative Famciclovir(Drug information on famciclovir) Herpes Zoster Study Group, reports that Famvir is an effective and well-tolerated therapy for acute herpes zoster that decreases the duration of postherpetic neuralgia, "by far the most common complication of herpes zoster and one of the most intractable pain disorders."
"Postherpetic neuralgia is clearly the most distressing component of the disease process for both the patient and the physician," says Dr. Tyring, Professor of Dermatology, Microbiology/Immunology and Internal Medicine at the University of Texas Medical Branch at Galveston. "These findings suggest that early intervention with famciclovir offers significant benefit to the shingles patient by hastening healing of the rash and shortening the duration of postherpetic neuralgia."
Up to 60% of patients over age 60 with shingles may suffer from postherpetic neuralgia, with the incidence and severity increasing with age. The pain of postherpetic neuralgia can last for months or even years after the blisters disappear.
This placebo-controlled, double-blind study involved 419 otherwise healthy patients with acute, uncomplicated herpes zoster who presented within 72 hours of rash onset. Study patients, who averaged 50 years of age, were randomized to receive Famvir (500mg ot 750mg) or placebo three time daily for 7 days.
Famvir was well tolerated, with a safety profile similar to placebo. The most common side effects with placebo and Famvir respectively, include diarrhea (4.8% vs 7.7%), nausea (11.6% vs 12.5%) and headache (17.8% vs 22.7%).
Famvir (500 mg and 750 mg) given three times daily significantly reduced the time to healing of zoster lesions (ie, time to full crusting, loss of vesicles, loss of ulcers and loss of crusts) versus placebo.
Most importantly, the duration of postherpetic neuralgia, defined as pain following healing, was significantly shorter in patients who received Famvir (500 mg or 750 mg) rather than placebo, and resulted in a 2 month reduction in median duration of postherpetic neuralgia.
Famciclovir is also being tested in clinical studies for the suppression of recurrent genital herpes and asymptomatic viral shedding, and for the treatment of herpes labialis, herpes virus infections in immunocompromised patients and hepatitis B.
The raearch was supported in part by a grant from the National Institute of Health and by a grant from Smithline Beecham Pharmaceuticals.