Chemocare.com

Care During Chemotherapy and Beyond

Fluorouracil



Trade Name: Adrucil ®
Other Names: 5-fluorouracil, 5-FU

Drug type:

Fluorouracil is an anti-cancer ("antineoplastic" or "cytotoxic") chemotherapy drug.  Fluorouracil is classified as an "antimetabolite."  (For more detail, see "How Fluorouracil Works" section below).

What Fluorouracil Is Used For:

  • Colon and rectal cancer.
  • Breast cancer.
  • Gastrointestinal cancers including: anal, esphageal, pancreas and gastric (stomach).
  • Head and neck cancer
    * Hepatoma (liver cancer).
  • Ovarian cancer.
  • Topical use (cream or solution) in basal cell cancer of the skin and actinic keratoses. -see document Fluorouracil(cream).

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 Is Given:

  • As an injection into the vein (intravenous or IV), or as an infusion.  The amount of time and schedule of infusion varies depending on a specific protocol, it may be given over several hours to several weeks.
  • As a topical ointment, a thin coating is applied to the affected skin lesions twice a day, treatment may continue over several weeks. (see document Fluorouracil(cream).
  • The amount of Fluorouracil that you will receive depends on many factors, including your height and weight, your general health or other health problems, and the type of cancer or condition being treated.  Your doctor will determine your dose and schedule.

Side Effects of Fluorouracil:

 Important things to remember about the side effects of Fluorouracil:

  • 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 side effects of Fluorouracil and their severity depend a variety of factors including dosage, the individual's metabolism, other drugs given as part of a combination therapy, and/or the schedule and duration of treatment.

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

Nadir: Meaning low point, nadir is the point in time between chemotherapy cycles in which you experience low blood counts.

Onset: 7-10 days
Nadir: 9-14 days
Recovery: 21-28 days

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

  • Skin reactions: Dry, cracking, peeling skin.  Darkening of the skin (hyperpigmentation), darkening of the skin where previous radiation treatment has been given (radiation recall).
  • Hair thinning.
  • Nail changes - discoloration, loss of nails (rare)(see skin reactions).
  • Hand -foot syndrome (Palmar-plantar erythrodysesthesia or PPE) -skin rash, swelling, redness, pain and/or peeling of the skin on the palms of hands and soles of feet.  Usually mild, starting 5-6 weeks after start of treatment.  May require reductions in the dose of the medication.

Serious adverse reactions to Fluorouracil are; chest pain, EKG changes and increases in cardiac enzymes - which may indicate problems with the heart.  These symptoms are very rare but increased for patients with a prior history of heart disease. 

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:

Contact your health care provider immediately, day or night, if you should experience any of the following symptoms:

  • Fever of 100.4° F (38° C) or higher, chills (possible signs of infection)

The following symptoms require medical attention, but are not an emergency.  Contact your health care provider within 24 hours of noticing any of the following:

  • Nausea (interferes with ability to eat and unrelieved with prescribed medication)
  • Vomiting (vomiting more than 4-5 times in a 24 hour period)
  • Diarrhea (4-6 episodes in a 24-hour period) despite anti-diarrhea medication and diet alterations.
  • Unusual bleeding or bruising
  • Black or tarry stools, or blood in your stools or urine
  • Extreme fatigue (unable to carry on self-care activities)
  • Mouth sores (painful redness, swelling or ulcers)
  • Tingling or burning, redness, swelling of the palms of the hands or soles of feet

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

Fluorouracil Precautions: 

  • Before starting Fluorouracil 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.
  • Do not receive any kind of immunization or vaccination without your doctor's approval while taking Fluorouracil.
  • Inform your health care professional if you are pregnant or may be pregnant prior to starting this treatment. Pregnancy category D (Fluorouracil may be hazardous to the fetus.  Women who are pregnant or become pregnant must be advised of the potential hazard to the fetus). For both men and women: Do not conceive a child (get pregnant) while taking Fluorouracil. 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 Fluorouracil.

Fluorouracil Self Care Tips:

  • Use of ice chips in the mouth 10-15minutes before and after IV injections of Fluorouracil may reduce the incidence and severity of mouth sores.
  • To help treat/prevent mouth sores, use a soft toothbrush, and rinse three times a day with 1/2 to 1 teaspoon of baking soda and/or 1/2 to 1 teaspoon of salt mixed with 8 ounces of water.
  • Drink at least two to three quarts of fluid every 24 hours, unless you are instructed otherwise.
  •  Follow regimen of anti-diarrhea medication as prescribed by your health care professional. 
  • Eat foods that may help reduce diarrhea (see managing side effects - diarrhea).
  • You may be at risk of infection so try to avoid crowds or people with colds and/or not feeling well, and report fever or any other signs of infection immediately to your health care provider.
  • Wash your hands often.
  • To reduce nausea, take anti-nausea medications as prescribed by your doctor, and eat small, frequent meals.  
  • Avoid sun exposure.  Wear SPF 15 (or higher) sunblock and protective clothing.
  • Prevention of hand-foot syndrome. Modification of normal activities of daily living to reduce friction and heat exposure to hands and feet, for about a week after treatment. (for more information see - Managing side effects: hand foot syndrome).
  • Keep palms of hands and soles of feet moist using emollients.
  • You may experience drowsiness or dizziness; avoid driving or engaging in tasks that require alertness until your response to the drug is known.
  • In general, drinking alcoholic beverages should be kept to a minimum or avoided completely.  You should discuss this with your doctor.
  • Get plenty of rest. 
  • Maintain good nutrition.
  • 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 While Taking Fluorouracil:

You will be checked regularly by your health care professional while you are taking Fluorouracil, to monitor side effects and check your response to therapy.  Periodic blood work to monitor your complete blood count (CBC) as well as the function of other organs (such as your kidneys and liver) will also be ordered.   

How Fluorouracil 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.

Chemotherapy is most effective at killing cells that are rapidly dividing.  Unfortunately, chemotherapy does not know the difference between the cancerous cells and the normal cells. 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.

Fluoruracil 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.