What is this medication for?
Famciclovir belongs to the family of medications known as antivirals. It is used to treat herpes labialis (cold sores), shingles (a painful rash caused by some herpes viruses; also known as herpes zoster), and to treat or prevent recurrent episodes of genital herpes.
Famciclovir prevents the virus from making DNA (genetic material) and copying itself, and so leads to lower levels of virus in the blood. It does not cure herpes infections.
Your doctor may have suggested this medication for conditions other than those listed here. As well, some forms of this medication may not be used for all of the conditions discussed here. If you are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.
Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.
Some medications may have other generic brands available. Always ask your doctor or pharmacist about the safety of switching between brands of the same medication.
How should I use this medication?
Herpes labialis (cold sores): The recommended adult dose is 1,500 mg as a single dose. Start treatment during the prodromal period (the period during which early symptoms such as tingling, itching, or burning occur).
Shingles: The recommended adult dose of famciclovir is 500 mg 3 times daily for 7 days. Start treatment within 72 hours of the onset of the rash.
Genital herpes: The recommended adult dose of famciclovir is 1,000 mg twice daily for 1 day. Start treatment during the prodromal period (the period during which early symptoms warn of a herpes flare-up) or within 6 hours of onset of the rash.
For prevention of recurrent episodes, the recommended dose is 250 mg twice a day for up to 1 year.
For people with HIV, the recommended adult dose of famciclovir is 500 mg twice a day for 7 days to treat herpes infection.
The tablets should be swallowed whole and may be taken with or without food. Finish all this medication, even if you have started to feel better.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.
It is important to take this medication exactly as prescribed by your doctor. Take this medication for the full duration of the prescription even if you feel better. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.
Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.
Who should NOT take this medication?
Do not take this medication if you are allergic to famciclovir, penciclovir, or any ingredients of the medication.