Famciclovir

The Basics

What is Famciclovir?

Used to treat infections caused by herpes viruses, including genital herpes, cold sores, and shingles and sometimes used in people with human immunodeficiency virus (HIV) who develop herpes outbreaks around the mouth, genitals, or anal area.

Brand names for Famciclovir

Famvir

How Famciclovir is classified

Anti-Infective Agents, Antiviral Agents

Famciclovir During Pregnancy

Famciclovir pregnancy category

Category BNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.

What we know about taking Famciclovir while pregnant

After oral administration, famciclovir (prodrug) is converted to penciclovir (active drug). There are no adequate and well-controlled studies of famciclovir or penciclovir use in pregnant women. No adverse effects on embryofetal development were observed in animal reproduction studies using famciclovir and penciclovir at doses higher than the maximum recommended human dose (MRHD) and human exposure. Because animal reproduction studies are not always predictive of human response, famciclovir should be used during pregnancy only if needed. In animal reproduction studies, pregnant rats and rabbits received oral famciclovir at doses (up to 1000 mg/kg/day) that provided 2.7 to 10.8 times (rats) and 1.4 to 5.4 times (rabbits) the human systemic exposure based on AUC. No adverse effects were observed on embryo-fetal development. In other studies, pregnant rats and rabbits received intravenous famciclovir at doses (360 mg/kg/day) 1.5 to 6 times (rats) and (120 mg/kg/day) 1.1 to 4.5 times (rabbits) or penciclovir at doses (80 mg/kg/day) 0.3 to 1.3 times (rats) and (60 mg/kg/day) 0.5 to 2.1 times (rabbits) the MRHD based on body surface area comparisons. No adverse effects were observed on embryo-fetal development.

Taking Famciclovir While Breastfeeding

What are recommendations for lactation if you're taking Famciclovir?

Because there is no published experience with famciclovir during breastfeeding, other agents may be preferred, especially while nursing a newborn or preterm infant.

Maternal / infant drug levels

Because there is no published experience with famciclovir during breastfeeding, other agents may be preferred, especially while nursing a newborn or preterm infant.

Possible effects of Famciclovir on milk supply

Relevant published information was not found as of the revision date.

Possible alternatives to Famciclovir

Acyclovir, Valacyclovir.