Why is this medication prescribed?

Penciclovir is used on the lips and faces of adults to treat cold sores caused by herpes simplex virus. Penciclovir does not cure herpes infections but decreases pain and itching if applied when the earliest symptoms first appear.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Penciclovir comes as a cream. It is usually used externally every 2 hours while you are awake for 4 days. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist or doctor to explain any part you do not understand. Use penciclovir exactly as directed. Do not use more or less of it or use it more often than prescribed by your doctor. Use this medication as soon as possible after symptoms appear.

Clean and dry the area before applying the cream to avoid spreading the infection. Rub the cream in gently, using enough cream to cover all sores completely.

Continue to use penciclovir even if you feel well. Do not stop using penciclovir without talking to your doctor.

What special precautions should I follow?

Before using penciclovir,

• tell your doctor and pharmacist if you are allergic to penciclovir, acyclovir (Zovirax), or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, including vitamins.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking penciclovir, call your doctor.

What should I do if I forget a dose?

Apply the missed dose as soon as you remember it and apply any remaining doses for that day at evenly spaced intervals. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not apply a double dose to make up for a missed one.

What side effects can this medication cause?

Although side effects from penciclovir are not common, they can occur. Tell your doctor if any of these symptoms are severe or do not go away:

• headache
• irritation at the site of application

What storage conditions are needed for this medicine?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

What other information should I know?

Keep all appointments with your doctor. Penciclovir should only be used on the lips and face. Avoid getting it in your eyes. Keep the infected area clean and dry.

Do not let anyone else use your medication. Ask your pharmacist any questions you have about refilling your prescription. If you still have symptoms of infection after you finish the penciclovir, call your doctor.