Famciclovir is used to treat infections caused by certain types of viruses. It treats shingles caused by herpes zoster. It also treats outbreaks of herpes simplex that cause cold sores around the mouth, sores around the anus, and genital herpes. In people with frequent outbreaks of genital herpes, famciclovir is used to help reduce the number of future episodes.
Famciclovir is an antiviral drug. However, it is not a cure for these infections. The viruses that cause these infections continue to live in the body even between outbreaks. Famciclovir decreases the severity and length of these outbreaks. It helps the sores heal faster, keeps new sores from forming, and decreases pain/itching. This medication may also help reduce how long pain remains after the sores heal. In addition, in people with a weakened immune system, famciclovir can decrease the risk of the virus spreading to other parts of the body and causing serious infections.
Read the Patient Information Leaflet if available from your pharmacist before you start taking famciclovir and each time you get a refill. If you have any questions, ask your doctor or pharmacist.
Take this medication by mouth with or without food, usually 2 to 3 times a day or as directed by your doctor.
This medication works best when started at the first sign of an outbreak, as directed by your doctor. It may not work as well if you delay treatment.
The dosage is based on your medical condition and response to treatment.
This medication works best when the amount of drug in your body is kept at a constant level. Therefore, take this drug at evenly spaced intervals. To help you remember, take it at the same times each day.
Continue to take this medication until the full prescribed amount is finished. Do not change your dose, skip any doses, or stop this medication early without your doctor's approval.
Tell your doctor if your condition persists or worsens.
Headache, nausea, and diarrhea may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as agitation, slowed thinking, confusion, hallucinations), dizziness, drowsiness, change in the amount of urine, yellowing eyes/skin, easy bruising/bleeding.
In the US -
Before taking famciclovir, tell your doctor or pharmacist if you are allergic to it; or to penciclovir; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems.
This drug may rarely make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.
This medication may contain lactose. If you have certain conditions such as galactose intolerance, severe lactase deficiency (not lactose or milk intolerance), or glucose-galactose malabsorption that require you to restrict your intake of lactose, consult your doctor or pharmacist before taking this medication.
Do not have certain immunizations/vaccinations (such as vaccines against the varicella virus) without the consent of your doctor.
Older adults may be more sensitive to the side effects of this drug, especially dizziness, drowsiness, confusion, and change in the amount of urine.
Famciclovir does not protect against the spread of genital herpes. To lower the chance of giving herpes to your partner, do not have sexual contact during an outbreak or if you have symptoms. You can spread genital herpes even if you do not have symptoms. Therefore, always use an effective barrier method (latex or polyurethane condoms/dental dams) during all sexual activity. Consult your doctor or pharmacist for more details.
It is unknown if this medication passes into breast milk. It may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.
If overdose is suspected, contact a poison control center or emergency room right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
Do not share this medication with others.
This medication has been prescribed for your current condition only. Do not use it later for another infection unless your doctor directs you to do so. A different medication may be necessary in that case.
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.
Information last revised October 2015. Copyright(c) 2015 First Databank, Inc.
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