Famvir Reported to Reduce Pain of Shingles

A study published in Annals of Internal Medicine reportsthat early treatment with Famvir (famciclovir) significantly shortensthe duration of postherpetic neuralgia in patients with herpeszoster.

Stephen K. Tyring, MD, PhD, principal investigator of the CollaborativeFamciclovir Herpes Zoster Study Group, reports that Famvir isan effective and well-tolerated therapy for acute herpes zosterthat decreases the duration of postherpetic neuralgia, "byfar the most common complication of herpes zoster and one of themost intractable pain disorders."

"Postherpetic neuralgia is clearly the most distressing componentof the disease process for both the patient and the physician,"says Dr. Tyring, Professor of Dermatology, Microbiology/Immunologyand Internal Medicine at the University of Texas Medical Branchat Galveston. "These findings suggest that early interventionwith famciclovir offers significant benefit to the shingles patientby hastening healing of the rash and shortening the duration ofpostherpetic neuralgia."

Up to 60% of patients over age 60 with shingles may suffer frompostherpetic neuralgia, with the incidence and severity increasingwith age. The pain of postherpetic neuralgia can last for monthsor even years after the blisters disappear.

Promising Results

This placebo-controlled, double-blind study involved 419 otherwisehealthy patients with acute, uncomplicated herpes zoster who presentedwithin 72 hours of rash onset. Study patients, who averaged 50years 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 significantlyreduced the time to healing of zoster lesions (ie, time to fullcrusting, loss of vesicles, loss of ulcers and loss of crusts)versus placebo.

Most importantly, the duration of postherpetic neuralgia, definedas pain following healing, was significantly shorter in patientswho received Famvir (500 mg or 750 mg) rather than placebo, andresulted in a 2 month reduction in median duration of postherpeticneuralgia.

Famciclovir is also being tested in clinical studies for the suppressionof recurrent genital herpes and asymptomatic viral shedding, andfor the treatment of herpes labialis, herpes virus infectionsin immunocompromised patients and hepatitis B.

The raearch was supported in part by a grant from the NationalInstitute of Health and by a grant from Smithline Beecham Pharmaceuticals.