In this Article

• What is famciclovir (Famvir)?
• What are the possible side effects of famciclovir (Famvir)?
• What is the most important information I should know about famciclovir (Famvir)?
• What should I discuss with my healthcare provider before taking famciclovir (Famvir)?
• How should I take famciclovir (Famvir)?
• What happens if I miss a dose (Famvir)?
• What happens if I overdose (Famvir)?
• What should I avoid while taking famciclovir (Famvir)?
• What other drugs will affect famciclovir (Famvir)?
• Where can I get more information?

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

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 (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 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.