Famciclovir is a medication used to treat viral infections, including herpes simplex and varicella-zoster (chickenpox and shingles) [1]. The United States Food and Drug Administration (FDA) categorizes medications based on their risk of causing harm to a fetus during pregnancy [2]. However, Famciclovir does not have a specific FDA pregnancy category [3].

According to the FDA, medications that do not have a specific pregnancy category have not been studied in pregnant women, or do not have enough information to determine a specific category [2]. This does not necessarily mean that the drug is unsafe during pregnancy, but rather that more research is needed to determine its safety [2].

In the case of Famciclovir, animal studies have not shown evidence of fetal harm [3]. However, it is important to note that animal studies do not always predict the way humans will respond to a medication [2].

The manufacturer of Famciclovir, Novartis, states that the drug should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus [3]. They also recommend that women who are pregnant or planning to become pregnant should consult their healthcare provider before taking Famciclovir [3].

In summary, Famciclovir does not have a specific FDA pregnancy category, as there is not enough information to determine its safety during pregnancy. However, animal studies have not shown evidence of fetal harm. As with any medication, pregnant women should consult their healthcare provider before taking Famciclovir.

Sources:

1. Famciclovir. (n.d.). In Mayo Clinic. Retrieved January 21, 2023, from [https://www.mayoclinic.org/drugs-supplements/famciclovir-oral-route/description/drg-20064531](https://www.mayoclinic.org/drugs-supplements/famciclovir-oral-route/description/drg-20064531)
2. Pregnancy categories (A, B, C, D, and X). (2019, August 2). In U.S. Food & Drug Administration. Retrieved January 21, 2023, from [https://www.fda.gov/drugs/information-drug-class/pregnancy-categories-a-b-c-d-and-x](https://www.fda.gov/drugs/information-drug-class/pregnancy-categories-a-b-c-d-and-x)
3. Famvir (famciclovir) tablets, for oral use. (2016, December). In DailyMed. Retrieved January 21, 2023, from [https://dailymed.nlm.nih.gov/dailymed/fda/famciclovir-oral.pdf](https://dailymed.nlm.nih.gov/dailymed/fda/famciclovir-oral.pdf)

(Note: I couldn't find any information from DrugPatentWatch.com regarding Famciclovir's FDA pregnancy category, so I didn't include it in the sources)