(flure-oh-YOOR-a-sil)

Trade names: Carac^TM, Efudex^®, Fluoroplex^®
Other names: 5-fluorouracil, 5-FU

Chemocare.com uses generic names in all descriptions of drugs. Carac is the trade name for fluorouracil cream. 5-FU cream and efudex and fluoroplex are other names for fluorouracil cream. In some cases, health care professionals may use the trade name carac or other names 5-FU cream or efudex or fluoroplex when referring to the generic drug name fluorouracil cream.

Drug type:  Fluorouracil is an anti-cancer ("antineoplastic" or "cytotoxic") chemotherapy drug.  This medication is classified as an "antimetabolite."  (For more detail, see "How this drug works" section below).

What Fluorouracil Cream Is Used For:

• Basal cell cancer of the skin.
• Actinic keratoses (a pre-cancerous skin condition).

Note:  If a drug has been approved for one use, physicians may elect to use this same drug for other problems if they believe it may be helpful.

How Fluorouracil Cream Is Given:

• As a topical cream or solution, a thin coating is applied to the affected skin lesions, treatment may continue over several weeks. 
• Use non-metal applicator or fingertips to apply cream.
• Use care when applying cream or solution around the eyes, nose, and mouth.  
• Wash your hands immediately after applying this medication. 
• The amount of fluorouracil (cream) that you will receive depends on many factors, such as the type of cancer or condition being treated.  Your doctor will determine your dose and schedule.

Side Effects:

Important things to remember about the side effects of fluorouracil (cream):

• Most people do not experience all of the side effects listed.
• Side effects are often predictable in terms of their onset and duration.
• Side effects are almost always reversible and will go away after treatment is complete.
• There are many options to help minimize or prevent side effects.
• There is no relationship between the presence or severity of side effects and the effectiveness of the medication.

The following side effects are common (occurring in greater than 30%) for patients taking flurouracil(cream):

• Pain, itching, burning, irritation, inflammation, dryness, swelling, tenderness at the site of application.  This will heal once the treatment is complete.

These side effects are less common side effects (occurring in about 10-29%) of patients receiving flurouracil(cream):

• Discoloration of the skin or scarring
• Increased sensitivity to sunlight

Not all side effects are listed above. Some that are rare (occurring in less than 10% of patients) are not listed here.  However, you should always inform your health care provider if you experience any unusual symptoms.

When to contact your doctor or health care provider:

Always inform your health care provider if you experience any unusual symptoms.

Precautions: 

• Before starting fluorouracil (cream) treatment, make sure you tell your doctor about any other medications you are taking (including prescription, over-the-counter, vitamins, herbal remedies, etc).
• Do not take aspirin, products containing aspirin unless your doctor specifically permits this.
• Inform your health care professional if you are pregnant or may be pregnant prior to starting this treatment.  Pregnancy category X fluorouracil (cream) may cause fetal harm when given to a pregnant woman.  This drug must not be given to a pregnant woman or a woman who intends to become pregnant.  If a woman becomes pregnant while taking fluorouracil (cream), the medication must be stopped immediately and the woman given appropriate counseling).
• For both men and women: Do not conceive a child (get pregnant) while taking fluorouracil (cream). Barrier methods of contraception, such as condoms, are recommended. Discuss with your doctor when you may safely become pregnant or conceive a child after therapy.
• Do not breast feed while taking this medication.

Self-Care Tips:

• Use non-metal applicator or fingertips to apply cream.
• Use care when applying cream or solution around the eyes, nose, and mouth.  
• Wash your hands immediately after applying this medication. 
• Avoid sun exposure.  Wear SPF 15 (or higher) sunblock and protective clothing.
• If you experience symptoms or side effects, be sure to discuss them with your health care team.  They can prescribe medications and/or offer other suggestions that are effective in managing such problems.

Monitoring and Testing:

You will be checked regularly by your doctor while you are taking fluorouracil (cream), to monitor side effects and check your response to therapy.

How Fluorouracil Cream Works:

Cancerous tumors are characterized by cell division, which is no longer controlled as it is in normal tissue.   "Normal" cells stop dividing when they come into contact with like cells, a mechanism known as contact inhibition.  Cancerous cells lose this ability.  Cancer cells no longer have the normal checks and balances in place that control and limit cell division.  The process of cell division, whether normal or cancerous cells, is through the cell cycle.  The cell cycle goes from the resting phase, through active growing phases, and then to mitosis (division).

The ability of chemotherapy to kill cancer cells depends on its ability to halt cell division.  Usually, the drugs work by damaging the RNA or DNA that tells the cell how to copy itself in division.  If the cells are unable to divide, they die.  The faster the cells are dividing, the more likely it is that chemotherapy will kill the cells, causing the tumor to shrink.  They also induce cell suicide (self-death or apoptosis).

Chemotherapy drugs that affect cells only when they are dividing are called cell-cycle specific.  Chemotherapy drugs that affect cells when they are at rest are called cell-cycle non-specific.  The scheduling of chemotherapy is set based on the type of cells, rate at which they divide, and the time at which a given drug is likely to be effective.  This is why chemotherapy is typically given in cycles.

Unfortunately, chemotherapy does not know the difference between the cancerous cells and the normal cells.  Chemotherapy will kill all cells that are rapidly dividing.  The "normal" cells will grow back and be healthy but in the meantime, side effects occur.  The "normal" cells most commonly affected by chemotherapy are the blood cells, the cells in the mouth, stomach and bowel, and the hair follicles; resulting in low blood counts, mouth sores, nausea, diarrhea, and/or hair loss.  Different drugs may affect different parts of the body.

Fluorouracil belongs to the category of chemotherapy called antimetabolites.  Antimetabolites are very similar to normal substances within the cell.  When the cells incorporate these substances into the cellular metabolism, they are unable to divide.  Antimetabolites are cell-cycle specific.  They attack cells at very specific phases in the cycle.  Antimetabolites are classified according to the substances with which they interfere.

• Folic acid antagonist: Methotrexate
• Pyrimidine antagonist: 5-Fluorouracil, Foxuridine, Cytarabine, Capecitabine, and Gemcitabine
• Purine antagonist: 6-Mercaptopurine and 6-Thioguanine
• Adenosine deaminase inhibitor: Cladribine, Fludarabine and Pentostatin

Note:  We strongly encourage you to talk with your health care professional about your specific medical condition and treatments. The information contained in this website is meant to be helpful and educational, but is not a substitute for medical advice. 

Chemocare.com is designed to provide the latest information about chemotherapy to patients and their families, caregivers and friends. For information about the 4th Angel Mentoring Program visit www.4thangel.org