Imatinib

Imatinib is used to treat certain types of leukemia (cancer that begins in the white blood cells) and other cancers and disorders of the blood cells. Imatinib is also used to treat certain types of gastrointestinal stromal tumors (GIST; a type of tumor that grows in the walls of the digestive passages and may spread to other parts of the body). Imatinib is also used to treat dermatofibrosarcoma protuberans (a tumor that forms under the top layer of skin) when the tumor cannot be removed surgically, has spread to other parts of the body, or has come back after surgery. Imatinib is in a class of medications called kinase inhibitors. It works by blocking the action of the abnormal protein that signals cancer cells to multiply. This helps stop the spread of cancer cells.

🔔 How should this medicine be used?

Imatinib comes as a tablet to take by mouth. It is usually taken with a meal and a large glass of water once or twice a day. Take imatinib at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take imatinib exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets whole; do not chew or crush them. If you touch or come into direct contact with a crushed tablet, wash the area thoroughly.

If you are unable to swallow imatinib tablets, you may place all of the tablets that you need for one dose into a glass of water or apple juice. Use 50 milliliters (a little less than 2 ounces) of liquid for each 100-mg tablet and 200 milliliters (a little less than 7 ounces) of liquid for each 400-mg tablet. Stir with a spoon until the tablets crumble completely and drink the mixture immediately.

If your doctor has told you to take 800 mg of imatinib, you should take 2 of the 400-mg tablets. Do not take 8 of the 100-mg tablets. The tablet coating contains iron, and you will receive too much iron if you take 8 of the 100-mg tablets.

Your doctor may increase or decrease your dose of imatinib during your treatment. This depends on how well the medication works for you and on the side effects you experience. Talk to your doctor about how you are feeling during your treatment. Continue to take imatinib even if you feel well. Do not stop taking imatinib without talking to your doctor.

🔔 Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

🔔 What special precautions should I follow?

Before taking imatinib,

• tell your doctor and pharmacist if you are allergic to imatinib, any other medications, or any of the ingredients in imatinib tablets. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Be sure to mention any of the following: acetaminophen (Tylenol), alprazolam (Xanax), amlodipine (Norvasc, in Caduet, Lotrel, Tribenzor, others), atazanavir (Reyataz), atorvastatin (Lipitor, in Caduet), carbamazepine (Carbatrol, Equetro, Tegretol, others), clarithromycin (Biaxin, in Prevpac), cyclosporine (Gengraf, Neoral, Sandimmune), dexamethasone, ergotamine (Ergomar, in Migergot, Cafergot), erythromycin (E.E.S., Eryc, Eryped, others), estazolam, felodipine, fentanyl (Duragesic, Subsys, Fentora, others), fosphenytoin (Cerebyx), indinavir (Crixivan), iron, or iron containing supplements, isradipine, itraconazole (Onmel, Sporanox), ketoconazole, lovastatin (Altoprev), metoprolol (Lopressor, Toprol XL, in Dutoprol), nefazodone, nelfinavir (Viracept), nicardipine (Cardene), nifedipine (Adalat CC, Procardia, others), nimodipine (Nymalize), nisoldipine (Sular), oxcarbazepine (Oxtellar XR, Trileptal), phenobarbital, phenytoin (Dilantin, Phenytek), pimozide (Orap), primidone (Mysoline), quinidine (in Nuedexta), rifabutin (Mycobutin), rifampin (rifadin, rimactane, in Rifamate, Rifater), ritonavir (Norvir, in Kaletra, Technivie, Viekira), saquinavir (Fortovase, Invirase), simvastatin (Zocor, in Vytorin), sirolimus (Rapamune), tacrolimus (Astagraf XL, Envarsus XR, Prograf), telithromycin, triazolam (Halcion), voriconazole (Vfend), and warfarin (Coumadin, Jantoven). Many other medications may also interact with imatinib, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor what herbal products you are taking, especially St. John’s wort.
• tell your doctor if you have or have ever had heart, lung, thyroid, kidney, or liver disease.
• tell your doctor if you are pregnant or plan to become pregnant. You will have to take a pregnancy test before starting treatment, You should not become pregnant while you are taking imatinib and for 14 days after your final dose. Talk to your doctor about birth control methods that you can use during your treatment. If you become pregnant while taking imatinib, call your doctor. Imatinib may harm the fetus.
• tell your doctor if you are breastfeeding. You should not breastfeed while you are taking imatinib and for one month after your final dose.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking imatinib.
• you should know that imatinib may make you dizzy, drowsy, or cause blurred vision. Do not drive a car or operate machinery until you know how this medication affects you.

🔔 What special dietary instructions should I follow?

Do not eat grapefruit or drink grapefruit juice while taking this medication.