Famciclovir

Generic Name: famciclovir (fam SYE klo veer)Brand Names: Famvir

What is famciclovir?

Famciclovir is an antiviral drug. It slows the growth and spread of the herpes virus so that the body can fight off the infection. Famciclovir will not cure herpes, but it can lessen the symptoms of the infections.

Famciclovir is used to treat infections caused by herpes viruses, including genital herpes, cold sores, shingles, and chicken pox.

There is no cure for herpes and famciclovir will not prevent you from developing symptoms in the future.

Famciclovir may also be used for other purposes not listed in this medication guide.

What is the most important information I should know about famciclovir?

Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated.

Treatment with famciclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

Herpes infections are contagious and you can infect other people, even while you are being treated with famciclovir. 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 passing the infection to others.

What should I discuss with my healthcare provider before taking famciclovir?

Do not take famciclovir if you are allergic to penciclovir cream (Denavir).

If you have any of these other conditions, you may need a dose adjustment or special tests to safely use this medication:

  • kidney disease;
  • a weak immune system;

  • galactose intolerance;

  • severe lactase deficiency; or

  • glucose-galactose malabsorption.

FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Your name may need to be listed on a pregnancy registry if you become pregnant while using this medication. The purpose of this registry is to track the outcome of the pregnancy and delivery to evaluate whether famciclovir had any effect on the baby.

It is not known whether famciclovir passes into breast milk, or if it could harm a nursing baby. Do not take famciclovir without telling your doctor if you are breast-feeding a baby. Do not give this medication to a child younger than 18 years old.

How should I take famciclovir?

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.

Treatment with famciclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

Take each dose with a full glass of water. Drink plenty of water while you are taking famciclovir to keep your kidneys working properly.

Famciclovir can be taken with or without food. Taking famciclovir with food may decrease stomach upset.

Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated. To prevent recurrent genital herpes, you may need to take famciclovir twice daily for up to 1 year. Follow your doctor's instructions.

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.

Store famciclovir at room temperature away from moisture and heat.

See also: Famciclovir dosage in more detail

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine. Symptoms of a famciclovir overdose are unknown.

What should I avoid while taking famciclovir?

Herpes infections are contagious and you can infect other people, even while you are being treated with famciclovir. 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 passing the infection to others.

Famciclovir will not prevent the spread of genital herpes. Avoid sexual intercourse or use a latex condom to prevent spreading the virus to others.

Famciclovir can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Famciclovir side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Less serious side effects may include:

  • nausea, vomiting, stomach pain;

  • diarrhea,

  • headache, tired feeling;

  • dizziness, sleepiness;

  • mild itching or skin rash;

  • numbness or tingly feeling; or

  • confusion.

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.

Famciclovir Dosing Information

Usual Adult Dose for Herpes Simplex -- Mucocutaneous/Immunocompetent Host:

Genital herpes:Initial episode: 250 mg orally 3 times a day for 7 to 10 days has been recommended by the US Centers for Disease Control and Prevention (CDC)Recurrent episode: 1000 mg orally twice a day for 1 day; alternatively, 125 mg orally twice a day for 5 days has been recommended by the CDCFamciclovir should be started at the first sign of genital herpes. The efficacy has not been established if started more than 6 hours after onset of symptoms or lesions.

Usual Adult Dose for Herpes Simplex -- Mucocutaneous/Immunocompromised Host:

Recurrent orolabial and genital herpes in HIV-infected patients: 500 mg orally twice a day for 7 days (5 to 10 days recommended by the CDC)

Usual Adult Dose for Herpes Simplex -- Suppression:

Suppression of recurrent genital herpes:Immunocompetent patients: 250 mg orally twice a dayHIV-infected patients: 500 mg orally twice a day has been recommended by the CDCTherapy should be continued as clinically appropriate, although the safety and efficacy of famciclovir therapy beyond 1 year have not been established.

Usual Adult Dose for Herpes Zoster:

500 mg orally every 8 hours for 7 daysFamciclovir is most effective if started within 48 hours of onset of rash. The efficacy has not been established if started more than 72 hours after onset of rash.

Usual Adult Dose for Herpes Simplex Labialis:

1500 mg orally as a single doseFamciclovir is most effective if started at the earliest sign or symptom of a cold sore (such as tingling, burning, or itching).

What other drugs will affect famciclovir?

Before taking famciclovir, tell your doctor if you are also taking probenecid (Benemid). If you are using probenecid, you may not be able to use famciclovir, or you may need dosage adjustments or special tests during treatment.

This list is not complete and there may be other drugs that can interact with famciclovir. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Where can I get more information?

  • Your pharmacist can provide more information about famciclovir.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Copyright 1996-2006 Cerner Multum, Inc. Version: 4.01. Revision Date: 05/14/2009 10:13:24 AM.
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