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Fluorouracil topical

Generic Name: fluorouracil topical (FLOOR oh URE a sil TOP i kal)
Brand Name: Carac, Efudex, Fluoroplex, Tolak, Efudex Occlusion Pack

Medically reviewed by on Sep 11, 2020 – Written by Cerner Multum

What is fluorouracil topical?

Fluorouracil interferes with the growth of skin cells. Fluorouracil works by causing the death of cells which are growing fastest, such as abnormal skin cells.

Fluorouracil topical (for the skin) is used to treat scaly overgrowths of skin (actinic or solar keratoses). Fluorouracil topical may also be used in the treatment of superficial basal cell carcinoma.

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

Important Information

This medication can harm an unborn baby or cause birth defects. Do not use fluorouracil topical if you are pregnant.

Before taking this medicine

You should not use fluorouracil topical if you are allergic to it.

To make sure fluorouracil topical is safe for you, tell your doctor if you have:

  • dihydropyrimidine dehydrogenase (DPD) enzyme deficiency.

Fluorouracil topical can harm an unborn baby or cause birth defects. Do not use if you are pregnant. If you become pregnant, stop using the medicine and tell your doctor right away. Use effective birth control to avoid pregnancy during treatment. Follow your doctor's instructions about how long to prevent pregnancy after your treatment ends.

It is not known whether fluorouracil topical passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using fluorouracil topical.

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

How should I use fluorouracil topical?

Follow all directions on your prescription label. Do not use this medicine in larger or smaller amounts or for longer than recommended.

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

Clean the area where you will apply fluorouracil topical. Rinse well and dry the area with a towel and wait ten minutes before applying the medication.

Wash your hands before and immediately after applying this medicine, unless it is being used to treat a hand condition.

Apply fluorouracil topical to the affected area with the finger tips or a non-metal applicator, smoothing it gently onto the affected skin. Use enough to cover the entire area with a thin film.

Caregivers who apply this medicine should wear rubber gloves.

Do not use fluorouracil topical on skin that is irritated, peeling, or infected or on open wounds. Wait until these conditions have fully healed before using fluorouracil topical.

Do not cover the treated skin area unless your doctor tells you to.

A moisturizer or sun screen may be applied 2 hours after fluorouracil topical has been applied.

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

What happens if I miss a dose?

Use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

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 fluorouracil topical?

Do not use fluorouracil topical 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 fluorouracil topical 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 topical unless your doctor tells you to.

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

This medicine can pass into body fluids (urine, feces, vomit). Caregivers should wear rubber gloves while cleaning up a patient's body fluids, handling contaminated trash or laundry or changing diapers. Wash hands before and after removing gloves. Wash soiled clothing and linens separately from other laundry.

Fluorouracil topical 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.

Stop using fluorouracil topical and call your doctor at once if you have:

  • severe pain or swelling of treated skin;

  • severe itching, burning, or irritation;

  • open skin sores; or

  • shedding of dead skin.

Common side effects may include:

  • skin redness, followed by dryness, tenderness, and crusting;

  • skin peeling or flaking;

  • skin darkening or scarring;

  • small blood vessels under the skin;

  • mild rash; or

  • mild irritation where the medicine was applied.

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.

Fluorouracil topical dosing information

Usual Adult Dose for Keratosis:

0.5% cream (microsphere formulation): Apply to the affected area once a day

1%, 2%, 5% cream or 2%, 5% solution: Apply 2 times a day in an amount sufficient to cover the lesions; continue until the inflammatory response reaches the erosion stage, then discontinue use
-Duration of therapy: 2 to 4 weeks; complete healing of the lesions may not be evident for 1 to 2 months following cessation of therapy

-Response starts with erythema, usually followed by vesiculation, desquamation, erosion and reepithelialization.
-Solar keratoses which do not respond to treatment should be biopsied to confirm the diagnosis.

Use: For the topical treatment of multiple actinic or solar keratoses

Usual Adult Dose for Basal Cell Carcinoma:

5% cream or solution:
-Apply 2 times a day in an amount sufficient to cover the lesions; continue until the inflammatory response reaches the erosion stage, then discontinue use
-Duration of therapy: 3 to 6 weeks; however, therapy may be required for as long as 10 to 12 weeks before lesions are obliterated

-Only the 5% cream or solution is recommended to treat superficial basal cell carcinoma.
-Response starts with erythema, usually followed by vesiculation, desquamation, erosion and reepithelialization.

Use: To treat superficial basal cell carcinomas when conventional methods are impractical, such as with multiple lesions or difficult treatment sites

What other drugs will affect fluorouracil topical?

It is not likely that other drugs you take orally or inject will have an effect on topically applied fluorouracil. But many drugs can interact with each other. Tell each of your health care providers about all medicines you use, including prescription and over-the-counter medicines, vitamins, and herbal products.

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.