Drug information
What is famciclovir?
Famciclovir is an antiviral prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of herpes simplex virus (HSV) and varicella zoster virus (VZV) infections.
In adults with normal immune systems, famciclovir is FDA-approved:
- To treat recurrent outbreaks of cold sores (also known as herpes labialis or orolabial herpes) caused by HSV
- To treat recurrent outbreaks of genital herpes caused by HSV and to prevent outbreaks from reoccurring (called chronic suppressive therapy)
- To treat shingles (also known as herpes zoster) caused by VZV
In adults with HIV, famciclovir is FDA-approved:
- To treat recurrent outbreaks of orolabial or genital herpes caused by HSV
HSV and VZV infections are opportunistic infections (OIs) of HIV. An OI is an infection that occurs more frequently or is more severe in people with weakened immune systems—such as people with HIV—than in people with healthy immune systems. To learn more about OIs, read the HIVinfo What is an Opportunistic Infection? fact sheet.
How is famciclovir used in people with HIV?
The Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents include recommendations on the uses of famciclovir in people with HIV.
Using a medicine as indicated on the medicine label is called on-label use; using the medicine in a different way is called off-label use. Off-label use, for example, can include using a drug for a different disease or medical condition. Good medical practice and the best interests of a patient sometimes require that a medicine be used off-label.
The guidelines include recommendations on the following uses of famciclovir:
On-label uses:
- To treat recurrent outbreaks of orolabial or genital herpes caused by HSV
- To treat an initial outbreak of orolabial or genital herpes
- To prevent recurrent outbreaks of genital herpes (chronic suppressive therapy)
- To treat shingles and chicken pox (a VZV infection also known as primary varicella infection)
What should I tell my health care provider before taking famciclovir?
Before taking famciclovir, tell your health care provider:
- If you are allergic to famciclovir or any other medicines.
- About any medical conditions you have or have had, for example, kidney or liver problems.
- About anything that could affect your ability to take medicines, such as difficulty swallowing or remembering to take pills.
- If you are pregnant or plan to become pregnant. Whether famciclovir can harm an unborn baby is unknown. Talk to your health care provider about possible risks with taking famciclovir when pregnant.
- If you are breastfeeding or plan to breastfeed. Do not breastfeed if you have HIV.
- About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Famciclovir may affect the way other medicines or products work, and other medicines or products may affect how famciclovir works. Ask your health care provider if there are interactions between famciclovir and the other medicines you take.
Ask your health care provider about possible side effects from famciclovir. Your health care provider will tell you what to do if you have side effects.
How should I take famciclovir?
Take famciclovir according to your health care provider’s instructions. Your health care provider will tell you how much famciclovir to take and when to take it. Before you start famciclovir and each time you get a refill, read any printed information that comes with your medicine.
How should famciclovir be stored?
- Store famciclovir at room temperature, 68°F to 77°F (20°C to 25°C).
- Do not use famciclovir if the original seal over the container opening is broken or missing.
- Throw away famciclovir that is no longer needed or expired (out of date). Follow FDA guidelines on how to safely dispose of unused medicine.
- Keep famciclovir and all medicines out of reach of children.
Where can I find more information about famciclovir?
More information about famciclovir is available:
- Recommendations on the HIV-related uses of famciclovir, from the Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents, prepared by the Centers for Disease Control and Prevention, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America
- Famciclovir-related research studies, from ClinicalTrials.gov
The above Patient Version drug summary is based on the following FDA label(s): Tablet (film coated).
Last Reviewed: March 18, 2019