Chemotherapy Patient Resource Area

Imatinib Mesylate/Gleevec^®

Drug
Imatinib mesylate (generic name) is manufactured as Gleevec^® (trade name) (Novartis Pharmaceuticals Corp., East Hanover, NJ).

Action
Imatinib mesylate blocks the growth of abnormal white blood cells. It is a protein-tyrosine kinase inhibitor and is used to treat chronic myeloid leukemia and gastrointestinal stromal tumors.

What does the drug look like?
Imatinib mesylate is supplied as 100-mg and 400-mg brownish-orange tablets.

How long will I take the drug?
The length of treatment varies and depends on your diagnosis and how well your body responds to treatment.

How do I take the drug?
Imatinib is taken by mouth once or twice a day with a meal and a large glass of water. The dose of imatinib mesylate is determined by your doctor, and your doctor and pharmacist will tell you how many tablets to take each day. Depending on your dose, you may need to cut a tablet in half. The 100-mg tablets are scored, which means they have a mark on them that makes it easier to break them in half. If you are instructed to break the tablets in half, be sure to wash your hands thoroughly before and after breaking the tablet(s). Be sure to read the label on your medicine closely so that you take the dose you need. The tablets may be dispersed in a glass of water, orange juice, or apple juice if you are unable to swallow the tablets. Stir the tablets until they dissolve, and drink the beverage containing the iminitib immediately. The drug should not be taken with grapefruit, grapefruit juice, or caffeine-containing products. (Grapefruit, grapefruit juice, and caffeine-containing products also should be avoided for one hour before and one hour after taking the drug.) Swallow each tablet whole; do not chew them. Sit upright for one hour after you take the drug. If you miss a dose, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses. If you accidentally take too many pills or someone else accidentally takes your medicine, contact your doctor or the nearest emergency room immediately.

Storage
Store this medicine at room temperature, away from excess heat and moisture (do not store on a windowsill or in a bathroom). Keep this medicine in its original container, out of the reach of children or pets. Do not keep outdated medication that you no longer need. Ask your nurse or pharmacist how you should dispose of any medicine you do not use.

• Imatinib mesylate lowers the number of white blood cells in your blood, increasing your chance of getting an infection. Avoid crowds and people who have infections. Call your doctor immediately if you develop a temperature higher than 100.5^oF or have chills, a cough, or painful urination. Your complete blood count (CBC) will be monitored frequently throughout treatment, and dosage adjustments (or stopping treatment for a few days) may be needed.
• Imatinib mesylate also lowers the number of platelets in your blood, which are necessary for proper blood clotting. Call your doctor immediately if you notice unusual bleeding or bruising, have black or tar-like stools, see blood in your urine, or develop pinpoint red spots on your skin. Use a soft toothbrush, and use care when flossing. Your healthcare providers may give you suggestions on how to care for your mouth, and these directions should be followed carefully.
• Imatinib mesylate may cause mild to moderate nausea, which is reduced by taking the drug with food and a large glass of water.
• Imatinib mesylate may cause mild muscle cramps. If muscle cramps are persistent or moderate to severe, contact your doctor. Muscle cramps often are relieved by taking calcium supplements, and your doctor will advise you if this is necessary and will tell you the amount of calcium to take.
• Imatinib mesylate may cause fluid retention and edema (puffiness and swelling of the tissues). Notify your doctor if you notice puffiness around your eyes or swelling of your legs. Weigh yourself twice a week on the same scale at the same time of day. Record your weight, and if a weight gain of five pounds or more from baseline (when you started treatment with imatinib mesylate) occurs, notify your doctor.
• Imatinib mesylate may cause liver function impairment. Your liver function tests (blood tests) will be monitored periodically. Notify your doctor immediately if your skin or eyes turn yellow or orange in color.
• Imatinib mesylate may interfere with the normal menstrual cycle (period) in women and may stop sperm production in men. However, you must use a reliable birth control method and not assume that you cannot get pregnant or get someone else pregnant. Women who are pregnant or would like to become pregnant need to discuss this with their doctors before taking this drug.

Drug and food interactions
Do not take aspirin or aspirin- or acetaminophen-containing products while taking imatinib mesylate (for example, Tylenol^® [McNeil Consumer Products Co., Fort Washington, PA]). Notify your doctor if you are taking heart medications, antidepressants, blood thinners, antifungal medicines, or antinausea drugs because they may interfere with the absorption of imatinib mesylate. Also, if you are taking vitamins, herbs, or nutritional supplements, be sure to let your doctor know. Avoid taking imatinib mesylate with grapefruit, grapefruit juice, or caffeine-containing foods or drinks (avoid them for one hour before and one hour after taking imatinib mesylate).

• Temperature (fever) higher than 100.5^oF
• Any signs of infection, such as chills or cough
• Painful urination
• Moderate to severe nausea and vomiting
• Weight gain of more than five pounds from pretreatment weight
• Puffiness around the eyes or ankles
• Any bleeding, such as from your nose or gums or in your urine
• Dark-colored (black or tar-like) stools
• Unusual bruising
• Pinpoint red spots on your skin