When This Medicine Should Not Be Used:
You should not use this medicine if you have had an allergic reaction to famciclovir or penciclovir (Denavir®), or if you have a severe lactose absorption problem.

How to Use This Medicine:
Tablet

• Your doctor will tell you how much medicine to use. Do not use more than directed.
• You may take this medicine with or without food.
• Take this medicine at the first sign of a herpes breakout or as soon as possible. The medicine might not work as well if you start treatment too late.

Drugs and Foods to Avoid:
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Make sure your doctor knows if you are also using probenecid (Benemid®, Probalan®).

Warnings While Using This Medicine:

• Make sure your doctor knows if you are pregnant or breastfeeding, or if you have kidney disease.
• This medicine may make you dizzy or drowsy. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert.
• Famciclovir will not stop the spread of herpes during sex. Avoid having sex while you have herpes sores.
• Even if you have no signs of a herpes infection, it is still possible to spread the virus to others during sex. Talk with your doctor about ways to keep from spreading the virus.
• Call your doctor if your symptoms do not improve or if they get worse.

Possible Side Effects While Using This Medicine:
Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Confusion, dizziness, or drowsiness.
• Numbness, tingling, or burning pain in your hands, arms, legs, or feet.
• Seeing or hearing things which are not really there.
• Unusual bleeding, bruising, or weakness.
• Yellowing of your skin or the whites of your eyes.

If you notice these less serious side effects, talk with your doctor:

• Headache.
• Nausea, vomiting, diarrhea, upset stomach, or stomach pain.
• Painful or irregular menstrual periods (in women).
• Skin rash or itching.
• Tiredness.

If you notice other side effects that you think are caused by this medicine, tell your doctor.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088