It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.
Make sure your doctor knows if you are pregnant before you receive this medicine. Using this medicine while you are pregnant can harm your unborn baby. If you think you have become pregnant while using the medicine, tell your doctor right away.
This medicine may cause a serious type of allergic reaction called anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have chills; fever; hives; hoarseness; itching; rash; trouble breathing; trouble swallowing; or any swelling of your hands, face, or mouth after you receive the medicine.
While you are being treated with irinotecan, and after you stop treatment, 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 get live vaccines (e.g., nasal influenza or flu vaccine). Try to avoid persons who have taken live vaccines. 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 wear 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 (Imodium A-D®) as soon as you notice that your bowel movements are occurring more often or are more loose 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. Notify your doctor if the diarrhea is not controlled within 24 hours.
- 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 light-headedness, 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 the 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.
Call your doctor right away if you have an unexplained fever, cough, shortness of breath, trouble with breathing, or wheezing after receiving this medicine. These may be symptoms of a serious lung problem.
This medicine may increase your risk of having blood clots. Tell your doctor right away if you start having a sudden and severe headache, trouble with breathing, or problems with vision, speech, or walking.
This medicine may cause some people to become dizzy, drowsy, or less alert than they are normally. This medicine may also cause blurred vision or other vision problems. If any of these side effects occur, do not drive, use machines, or do anything else that could be dangerous if you are not alert or not able to see well. If these reactions are especially bothersome, check with your doctor.
Ketoconazole (Nizoral®) and St. John's wort should not be used while you are receiving irinotecan. If you are using St. John's Wort, it should be discontinued at least 2 weeks before the first cycle of irinotecan. If you are using ketoconazole, it should be discontinued at least 1 week before starting irinotecan treatment.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.