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Frequently Asked Questions
Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
Famciclovir is an antiviral medicine that is used to treat infections caused by herpes viruses, including genital herpes, cold sores, and shingles.
Famciclovir is sometimes used in people with human immunodeficiency virus (HIV) who develop herpes outbreaks around the mouth, genitals, or anal area.
Famciclovir may not be effective in treating your first episode of genital herpes, but may help prevent future episodes. Famciclovir also may not be effective in Black or African-American people with genital herpes, and may not be effective in any person with shingles (herpes zoster) affecting the eyes.
There is no cure for herpes and famciclovir will not prevent you from developing symptoms in the future.
Famciclovir may also be used for purposes not listed in this medication guide.
You should not use this medicine if you are allergic to famciclovir or penciclovir cream (Denavir).
Tell your doctor if you have ever had:
- liver disease;
- kidney disease;
- a weak immune system;
- galactose intolerance;
- severe lactase deficiency; or
- glucose-galactose malabsorption.
Tell your doctor if you are pregnant or plan to become pregnant. Herpes can be passed to your baby during childbirth if you have a genital lesion when your baby is born. If you have genital herpes, it is very important to prevent herpes lesions during pregnancy. Take your medicine as directed to best control your infection.
If you are pregnant, your name may be listed on a pregnancy registry to track the effects of famciclovir on the baby.
It may not be safe to breast-feed while using this medicine. Ask your doctor about any risk.
Famciclovir is not approved for use by anyone younger than 18 years old.
Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.
Taking more famciclovir than prescribed will not make this medicine more effective
For cold sores or genital herpes, you should start taking famciclovir as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).
You may take famciclovir with or without food.
Lesions caused by herpes viruses should be kept as clean and dry as possible. Wearing loose clothing may help to prevent irritation of the lesions.
To prevent recurrent genital herpes, you may need to take famciclovir for up to 1 year. Follow your doctor's instructions.
Use this medicine for the full prescribed length of time, even if your symptoms quickly improve. Skipping doses may increase the risk of your virus becoming resistant to medication.
Store at room temperature away from moisture and heat.
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Taking this medicine will not prevent you from passing genital herpes to other people. Herpes infections are contagious and you can infect other people even while you are taking famciclovir.
Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.
Avoid sexual intercourse or use a latex condom to help keep you from spreading the virus to others. Avoid letting infected areas come into contact with other people. Avoid touching an infected area and then touching your eyes. Wash your hands frequently to prevent the spread of infection.
Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
- confusion; or
- kidney problems--little or no urination, swelling in your feet or ankles, feeling tired or short of breath.
Common side effects may include:
- headache; or
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Other drugs may affect famciclovir, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.
Your pharmacist can provide more information about famciclovir.
|Generic Examples||Supplied As||Strength|
|Famciclovir||tablet||125 mg250 mg500 mg|