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Generic name: fluorouracil topicalFLOOR-oh-URE-a-sil-TOP-i-kal ]
Brand names: Carac, Efudex, Fluoroplex, Tolak
Drug class: Topical antineoplastics

Medically reviewed by on Aug 30, 2022. Written by Cerner Multum.

What is Efudex?

Efudex (for the skin) is used to treat scaly overgrowths of skin (actinic or solar keratosis).

Efudex is also used to treat superficial basal cell carcinoma.

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

Efudex side effects

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

Efudex may cause serious side effects. Stop using Efudex and call your doctor at once if you have:

Before your skin begins to heal it will become red, dry, tender, and crusty. This is a normal skin reaction, even if these symptoms get worse for a short time. Gradually, the dead skin will begin to shed off and you'll see raw skin appear. Ask your doctor when to stop using the medicine after you notice signs of healing.

Common side effects of Efudex may include:

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.


Do not use if you are pregnant. Use effective birth control, and tell your doctor if you become pregnant during treatment.

Before taking this medicine

You should not use Efudex if you are allergic to fluorouracil, or if you have:

Do not use Efudex if you are pregnant. It could harm the unborn baby or cause birth defects. Use effective birth control to prevent pregnancy while you are using this medicine.

You should not breastfeed while using Efudex.

Efudex is not approved for use by anyone younger than 18 years old.

How should I use Efudex?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Do not take by mouth. Topical medicine is for use only on the skin.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

Wash your hands before and immediately after applying this medicine, unless it is being used to treat a hand condition. Caregivers who apply this medicine should wear rubber gloves.

Apply only enough medicine to cover the affected skin with a thin film. Do not cover the treated skin area with bandaging or plastic unless your doctor tells you to.

Do not apply Efudex to skin that is irritated, peeling, or infected or on open wounds. Wait until these conditions have fully healed before using this medicine.

You may need to use Efudex for up to 6 weeks. Treated skin may have an undesirable appearance as it heals, which may take several weeks.

Store at room temperature away from moisture and heat. Do not freeze. Keep the medicine container tightly closed when not in use. Keep out of the reach of children and pets.

Do not use Efudex to treat a skin condition that has not been checked by your doctor.

What happens if I miss a dose?

Apply the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not apply two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using Efudex?

Do not use Efudex on your eyelids or in your eyes, nose, or mouth. Rinse with water or saline if this medicine gets in your eyes.

Do not let Efudex build up in the skin folds around your mouth, nose, or eyes. Use caution when applying the medicine around these areas.

Avoid using other medications on the areas you treat with fluorouracil unless your doctor tells you to.

Avoid exposure to sunlight or tanning beds. Efudex can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

What other drugs will affect Efudex?

Medicine used on the skin is not likely to be affected by other drugs you use. But many drugs can interact. Tell your doctor about all your current medicines, including prescription and over-the-counter medicines, vitamins, and herbal products.

Popular FAQ

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Further information

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.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.