Famciclovir: a focus on efficacy and safety.

IMPORTANCE OF THE FIELD: Famciclovir is the prodrug of penciclovir, a guanosine analogue that inhibits viruses of the alpha sub-family of the Herpesviridae, as well as hepatitis B virus. It is indicated for management of mucocutaneous herpes simplex virus disease and acute herpes zoster, and has been investigated for management of hepatitis B virus infection. AREAS COVERED IN THIS REVIEW: Data for this review were identified by searches of papers published in English on Medline and Scopus, spanning the years 1975 through 1 February 2010 with the key words: 'famciclovir', 'famvir', 'penciclovir', 'herpes', 'oral', 'genital', 'varicella', 'zoster' and 'virus' in association with 'safety', 'toxicity', 'tolerability', 'efficacy' and 'indications'. Relevant references were also obtained from articles acquired through the search strategy. WHAT THE READER WILL GAIN: Readers are also provided with up-to-date information on the use of famciclovir for infections due to herpes simplex, varicella zoster and hepatitis B viruses. Clinical data pertaining to the safety and tolerability of famciclovir are also reviewed. TAKE HOME MESSAGE: Famciclovir is a safe, convenient, and well-tolerated drug when used for its approved indications. The most common side effects indicated in the majority of studies were headache and nausea. Data for its use in childhood and pregnancy are limited.