Brand Names

Category

• Antineoplastic

Description

Irinotecan (eye-ri-noe-TEE-kan) belongs to the group of medicines called antineoplastics. It is used to treat cancer of the colon or rectum.

Irinotecan interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal cells may also be affected by the medicine, other effects may also occur. Some of these may be serious and must be reported to your doctor. Other effects, like hair loss, may not be serious but may cause concern. Some effects may occur after treatment with irinotecan has been stopped. Be sure that you have discussed with your doctor the possible side effects of this medicine as well as the good it can do.

This medicine is available only with your doctor's prescription, in the following dosage form(s):

Parenteral
• Injection (U.S. and Canada)

Before Using This Medicine

In deciding to use a medicine, the risks of using the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For irinotecan, the following should be considered:

Allergies--Tell your doctor if you have ever had any unusual or allergic reaction to irinotecan. Also tell your health care professional if you are allergic to any other substances.

Pregnancy--Tell your doctor if you are pregnant. Studies in rats and rabbits have shown that irinotecan causes birth defects and deaths of fetuses.

Be sure that you have discussed this with your doctor before starting treatment with this medicine. It is best to use birth control while you are receiving irinotecan. Also, tell your doctor right away if you think you have become pregnant during treatment.

Breast-feeding--It is not known whether irinotecan passes into breast milk. However, because this medicine may cause serious side effects, breast-feeding is generally not recommended while you are receiving it.

Children--Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of irinotecan in children with use in other age groups.

Older adults--This medicine has been tested in patients 65 years of age and older and has not been shown to cause different side effects or problems in older people than it does in younger adults. However, severe diarrhea caused by irinotecan may occur more often in elderly patients.

Other medicines--Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking irinotecan, it is especially important that your health care professional know if you are taking any of the following:

• Amphotericin B by injection (e.g., Fungizone) or
• Antithyroid agents (medicine for overactive thyroid) or
• Azathioprine (e.g., Imuran) or
• Chloramphenicol (e.g., Chloromycetin) or
• Colchicine or
• Flucytosine (e.g., Ancobon) or
• Ganciclovir (e.g., Cytovene) or
• Interferon alfa (e.g., Intron A, Roferon-A) or
• Plicamycin (e.g., Mithracin) or
• Zidovudine (e.g., AZT, Retrovir) or
• If you have ever been treated with radiation or other cancer medicines--The risk of dangerously low blood counts may be increased

• Azathioprine (e.g., Imuran) or
• Chlorambucil (e.g., Leukeran) or
• Corticosteroids (cortisone-like medicine) or
• Cyclophosphamide (e.g., Cytoxan) or
• Cyclosporine (e.g., Sandimmune) or
• Mercaptopurine (e.g., Purinethol) or
• Muromonab-CD3 (monoclonal antibody) (e.g., Orthoclone OKT3) or
• Mycophenolate (e.g., CellCept) or
• Tacrolimus (e.g., Prograf)--The risk of infection may be increased because these medicines and irinotecan can all decrease your body's resistance to infection

• Diuretics (water pills)--There may be an increased risk of serious problems caused by loss of body fluid if severe diarrhea or vomiting occurs during irinotecan treatment

• Laxatives--Use of laxatives together with irinotecan may increase the risk of severe diarrhea

Other medical problems--The presence of other medical problems may affect the use of irinotecan. Make sure you tell your doctor if you have any other medical problems, especially:

• Chickenpox (including recent exposure) or
• Herpes zoster (shingles)--Irinotecan may cause these conditions to get worse and spread to other parts of your body

• Infection--Irinotecan may decrease your body's ability to fight an infection

• Liver disease--The risk of dangerously low white blood cell counts may be increased

• Lung disease--An unusual side effect consisting of fever and of shortness of breath and other problems with the lungs has occurred, very rarely, in some people with lung disease who received irinotecan

Proper Use of This Medicine

Irinotecan often causes nausea and vomiting. It is very important that you continue to receive the medicine even if it makes you feel ill. Ask your health care professional about ways to lessen these effects.

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects. Some of the side effects of this medicine do not have any symptoms and must be found with a blood test.

While you are being treated with irinotecan, and after you stop treatment with it, do not have any immunizations (vaccinations) without your doctor's approval . Irinotecan may lower your body's resistance, and there is a chance you might get the infection the immunization is meant to prevent. In addition, other persons living in your household should not take oral polio vaccine, since there is a chance they could pass the polio virus on to you. Also, avoid persons who have taken oral polio vaccine within the past several months. Do not get close to them and do not stay in the same room with them for very long. If you cannot take these precautions, you should consider wearing a protective face mask that covers the nose and mouth.

Irinotecan may cause diarrhea, which can last long enough and be severe enough to cause serious medical problems. If diarrhea occurs while you are being treated with irinotecan:

• Check with your doctor immediately . Be sure to let your doctor know if the diarrhea started during an irinotecan injection or less than 24 hours afterwards. Also, be sure to tell your doctor if you had any other symptoms, such as stomach cramps or sweating, before the diarrhea started. This means that you are having a certain kind of diarrhea that may need to be treated by your doctor.
• If diarrhea first occurs more than 24 hours after a dose of irinotecan, start taking loperamide (e.g., Imodium A-D) as soon as you notice that your bowel movements are occurring more often, or are looser, than usual. Loperamide is available without a prescription. Buy some of it ahead of time, so that you will have it on hand in case it is needed. Unless otherwise directed by your doctor, take 4 milligrams (mg) of loperamide (2 capsules or tablets, or 4 teaspoonfuls of the oral solution dosage form) for the first dose, then 2 mg (1 capsule or tablet, or 2 teaspoonfuls of the oral solution dosage form) every two hours. To interrupt your sleep less often, you may take 4 mg of loperamide every four hours during the night. Continue taking loperamide, day and night, until you have not had any diarrhea for twelve hours. It is very important that you follow these (or your doctor's) directions, even though they are different from the directions on the nonprescription (over-the-counter [OTC]) loperamide package label. The largest amount of loperamide recommended on the package label for use in a twenty-four-hour period (8 mg) is not enough for treating diarrhea caused by irinotecan.
• Diarrhea causes loss of body fluid, which can lead to dehydration, a serious medical problem. To prevent this, it is very important that you replace the lost fluid. While you have diarrhea, and for a day or two after the diarrhea has stopped, drink plenty of clear liquids , such as ginger ale, caffeine-free cola, decaffeinated tea, and broth. Ask your doctor about the amount of liquid you should be drinking every day. Also, ask your doctor whether you should use a sports drink (e.g., Gatorade), which contains other substances, such as sodium and potassium, that may be lost along with body fluid. Follow your doctor's directions very carefully.
• Because alcohol and caffeine can increase fluid loss, you should not drink beverages or take any medicines that contain them while you have diarrhea. Also, avoid eating foods that may make diarrhea worse, such as bran, raw fruits or vegetables, or fatty, fried, or spicy foods.
• Vomiting can also increase the amount of fluid lost by the body and increase the risk of dehydration. If vomiting occurs at the same time as diarrhea, check with your doctor right away.
• Signs of too much fluid loss (dehydration) include decreased urination, dizziness or lightheadedness, dryness of the mouth, fainting, increased thirst, and wrinkled skin. If any of these occur, check with your doctor immediately .

Irinotecan can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. It can also lower the number of platelets, which are needed for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

• If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
• Check with your doctor immediately if you notice any unusual bleeding or bruising; black, tarry stools; blood in urine or stools; or pinpoint red spots on your skin.
• Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Also, check with your medical doctor before having any dental work done.
• Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
• Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
• Avoid contact sports or other situations where bruising or injury could occur.

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Diarrhea, with or without stomach cramps or sweating; fever; shortness of breath or troubled breathing

Less common

Cough or hoarseness (accompanied by fever or chills); dizziness or lightheadedness; fainting; fever or chills; lower back or side pain (accompanied by fever or chills); painful or difficult urination (accompanied by fever or chills); runny or stuffy nose; sore throat; swelling of abdomen or stomach area; swelling of face, fingers, feet, or lower legs

The side effects listed above may occur, or continue to occur, after treatment with irinotecan has ended. Check with your doctor if you notice any of them after you stop receiving the medicine.

Also, check with your doctor as soon as possible if any of the following side effects occur:

More common

Black, tarry stools; blood in urine or stools; pinpoint red spots on skin; unusual bleeding or bruising; Unusual tiredness or weakness (severe)

Less common

Rare

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

More common

Abdominal (stomach) cramps or pain; constipation; decrease in or loss of appetite; nausea and vomiting; weakness; weight loss

Less common

Bloated feeling or gas; headache; increased sweating; indigestion; skin rash

Irinotecan may also cause a temporary loss of hair in some people. After treatment with irinotecan has ended, normal hair growth should return.

Irinotecan sometimes causes flushing of the face. This effect is harmless and does not need medical treatment.

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

Developed: 06/27/1998
Revised: 08/30/2000
Interim revision:

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