Does Famciclovir Cause Post-Herpetic Neuralgia?
Objectives: To determine the efficacy and effectiveness of famciclovir versus placebo for the treatment of herpes zoster. Critical appraisal: Key issues include: 1) loss of blinding as to treatment allocation is strongly suggested by differential loss of patients with mild herpes zoster (as measured by number of lesions) from patients receiving placebo; 2) the report has an incongruous value for the “median duration” of post-herpetic neuralgia (PHN) in patients over age 50 in the placebo group as 163 days. This total, 163 days, exceeds the total defined PHN study period by 11 days; 3) pain severity not reported; and 4) data analysis was incomplete and incongruous. Data extraction: Data for calculation of incidence and patient-days of neuralgia were extracted from the trial report. Data analysis: Tyring et al neglected to report that famciclovir increased the incidence of PHN, particularly for patients over age 50, arguably the patients most likely to suffer severe or protracted PHN. Wh
