Famciclovir is commonly prescribed to treat cold sores, genital herpes, and shingles. The antiviral medication is typically used at the first signs of an outbreak to help reduce symptoms and prevent outbreaks from occurring again. Depending on the condition being treated, the tablets can be taken every day, for just one day, or for a week. Side effects may include headaches, vomiting, fatigue, and diarrhea.
Famciclovir (Famvir®) is a prescription antiviral medication used to treat the following conditions:
- Shingles in people with normal immune systems
- Recurring genital herpes in people with normal immune systems
- Recurring cold sores in people with normal immune systems
- Herpes simplex infections (including cold sores and genital herpes) in people with HIV or other conditions that weaken the immune system.
You should talk with your healthcare provider prior to taking famciclovir if you have:
- Kidney disease, including kidney failure (renal failure)
- Severe lactose intolerance
- Galactose intolerance
- Any allergies, including allergies to food, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant (see Famvir and Pregnancy)
- Breastfeeding (see Famvir and Breastfeeding).
Make sure to tell your healthcare provider about all other medicines you are currently taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
(Click Precautions and Warnings With Famciclovir to learn more, including information on who should not take the drug.)