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

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

Start the treatment with Famvir 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 Famvir. 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 is Famvir?

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

Famvir is used to treat infections caused by herpes viruses. Illnesses caused by herpes viruses include genital herpes, cold sores, shingles and chicken pox.

Famvir may also be used for purposes other than those listed in this medication guide.

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

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

Before taking this medication, tell your doctor if you have:

kidney disease;

galactose intolerance;

severe lactase deficiency; or

glucose-galactose malabsorption.

If you have any of these conditions, you may not be able to use Famvir, or you may need a dosage adjustment or special tests during treatment.

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.

Do not take Famvir without telling your doctor if you are breast-feeding a baby. It is not known whether Famvir passes into breast milk, or if it could harm a nursing baby.

Do not give this medication to a child younger than 18 years old.

How should I take Famvir?

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts or take it for longer than the duration recommended by your doctor.

Start treatment with Famvir as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

Each dose should be taken with a full glass of water. In order to keep your kindneys working properly drink plenty of water while you are taking Famvir.

Take Famvir with or without food. Taking Famvir 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. Famvir will not treat a viral infection such as the common cold or flu.

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 Famvir at room temperature away from moisture and heat.

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?

If you think you have used too much of this medicine, seek emergency medical attention. Symptoms of a Famvir overdose are unknown.

What should I avoid while taking Famvir?

Herpes infections are contagious and you can infect other people, even while you are being treated with Famvir. 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.

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

What are the possible side effects of Famvir?

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.

Continue taking Famvir and talk to your doctor if you have any of these less serious side effects:

nausea, vomiting, stomach pain;

headache;

diarrhea,

dizziness, sleepiness;

mild itching or skin rash; or

confusion.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What other drugs will affect Famvir?

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

There may be other drugs that can affect Famvir. 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.