Famciclovir (Famvir)

Famciclovir (Famvir) is a nucleoside analogue drug that is approved for the treatment of shingles (varicella zoster virus) and herpes simplex viruses 1 and 2. It is also active against hepatitis B virus in the test tube.

Famciclovir was derived from another anti-herpes drug, penciclovir, which was not well absorbed when taken in tablet form. Famciclovir is well absorbed by mouth. Few side-effects have been reported, apart from occasional rash, stomach upsets and headache, although in laboratory tests an increased incidence of breast tumours was seen in female rats given high doses for the duration of their lives. An independent review committee concluded that humans are not considered at increased risk of breast tumours as a result of taking famciclovir.

Famciclovir is effective in treating herpes simplex and reducing viral shedding in HIV-positive patients.1 2 Combined with 3TC (lamivudine, Epivir), it also showed promising results as a treatment for hepatitis B infection in a preliminary 48-week study of HIV-negative patients.3 However, a study assessing the impact of adding famciclovir to a failing hepatitis B regimen containing 3TC in HIV-positive patients failed to show a long-term benefit in reducing hepatitis B levels.4

Famciclovir does not interact with any of the currently available protease inhibitors or non-nucleoside reverse transcriptase inhibitors (NNRTIs).

Famciclovir is manufactured by GlaxoSmithKline. It was formerly known by the codename BRL39123A.


  1. Schacker T et al. Famciclovir for the suppression of symptomatic and asymptomatic herpes simplex virus reactivation in HIV-infected persons. A double-blind, placebo-controlled trial. Ann Intern Med 128: 21-28, 1998
  2. Romanowski B et al. Efficacy and safety of famciclovir for treating mucocutaneous herpes simplex infection in HIV-infected individuals. Collaborative Famciclovir HIV Study Group. AIDS 14: 1211-1217, 2000
  3. Shen H et al. Combination therapy with lamivudine and famciclovir for chronic hepatitis B infection. Clin Gastroenterol Hepatol 2: 330-336, 2004
  4. Matthews GV et al. Failure of combination therapy with lamivudine and famciclovir following lamivudine monotherapy for hepatitis B virus infection in patients coinfected with human immunodeficiency virus-1. Clin Infect Dis 33: 2049-2054, 2001

Community Consensus Statement on Access to HIV Treatment and its Use for Prevention

Together, we can make it happen

We can end HIV soon if people have equal access to HIV drugs as treatment and as PrEP, and have free choice over whether to take them.

Launched today, the Community Consensus Statement is a basic set of principles aimed at making sure that happens.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.