Generic name: FluorouracilBrand names: Carac, Efudex

Why is Carac prescribed?

Efudex and Carac are prescribed for the treatment of actinic or solar keratoses (small red horny growths or flesh-colored wartlike growths caused by overexposure to ultraviolet radiation or the sun). Such growths may develop into skin cancer. When conventional methods are impractical—as when the affected sites are hard to get at—the 5 percent strength of Efudex is useful in the treatment of superficial basal cell carcinomas, or slow-growing malignant tumors of the face usually found at the edge of the nostrils, eyelids, or lips. Efudex is available in cream and solution forms. Carac comes in cream form only.

Most important fact about Carac

If you use an airtight dressing to cover the skin being treated, there may be inflammatory reactions in the normal skin around the treated area. If it is necessary to cover the treated area, use a porous gauze dressing to avoid skin reactions.

How should you take Carac?

Use care when applying these products around the eyes, nose, and mouth. Wash your hands immediately after applying Carac.

  • If you miss a dose...Apply it as soon as you remember. If more than a few hours have passed, skip the dose you missed and go back to your regular schedule. If you miss more than 1 dose, contact your doctor.
  • Storage instructions...Store away from heat, light, and moisture.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue using Efudex.

  • Side effects may include:Burning, discoloration of the skin, itching, pain

If you develop symptoms of a severe allergic reaction—including abdominal pain, bloody diarrhea, vomiting, fever, and chills—stop taking Efudex and contact your doctor immediately. You may have a condition known as DPD enzyme deficiency.

Why should Carac not be prescribed?

If you are sensitive to or have ever had an allergic reaction to Efudex, Carac or similar drugs, you should not take Carac. Make sure your doctor is aware of any drug reactions you have experienced.

People with a condition called DPD enzyme deficiency should also avoid these products. The active ingredient can give them a life-threatening reaction marked by abdominal pain, bloody diarrhea, vomiting, fever, and chills.

Special warnings about Carac

Avoid prolonged exposure to ultraviolet rays while you are under treatment with these products.

Skin may be unsightly during treatment with Carac and, in some cases, for several weeks after treatment has ended.

If your solar keratoses do not clear up with use of Carac, your doctor will probably order a biopsy (removal of a small amount of tissue to be examined under a microscope) to confirm the skin disease.

Your doctor will perform follow-up biopsies if you are being treated for superficial basal cell carcinoma.

Possible food and drug interactions when taking Carac

There are no reported food or drug interactions.

Special information if you are pregnant or breastfeeding

Efudex can harm a developing baby, and should not be used by women who are—or even may become—pregnant. If you do become pregnant while using Efudex, check with your doctor immediately.

Because it's not known whether Efudex could find its way into breast milk and harm a nursing infant, you'll need to choose between nursing your baby or undergoing treatment with Efudex.

Recommended dosage for Carac

When Efudex is applied to affected skin, the skin becomes abnormally red, blisters form, and the surface skin wears away. A lesion or sore forms at the affected site, and the diseased or cancerous skin cells die before a new layer of skin forms.


Actinic or Solar Keratosis

Apply Efudex cream or solution 2 times a day, or Carac cream once a day, in an amount sufficient to cover the affected area. Continue using the medication until the inflammatory response reaches the stage where the skin wears away, a sore or lesion forms, and the skin cells die; your doctor will then have you stop using the medication. The usual length of treatment is from 2 to 4 weeks. You may not see complete healing of the affected area for 1 to 2 months after ending the treatment.

Superficial Basal Cell Carcinomas

For this condition, use only the 5% strength of Efudex. Twice a day, apply enough cream or solution to cover the affected area. Continue the treatment for at least 3 to 6 weeks; it may take 10 to 12 weeks of application before the lesions are gone.

Your doctor will want to monitor your condition to make sure it has been cured.


Although no specific information is available on Efudex overdosage, any medication used in excess can have serious consequences. If you suspect an overdosage, seek medical attention immediately.

  • Carac Prescribing Information (FDA)
  • Carac Cream MedFacts Consumer Leaflet (Wolters Kluwer)
  • Carac Concise Consumer Information (Cerner Multum)
  • Carac Topical Advanced Consumer (Micromedex) - Includes Dosage Information
  • Fluoroplex Prescribing Information (FDA)