Imatinib, STI-571
Imatinib Mesylate Oral tablet
What is this medicine?
IMATINIB (i MAT in ib) is a medicine that targets proteins in cancer cells and stops the cancer cells from growing. It is used to treat certain leukemias, myelodysplastic syndromes, and other cancers. It is also used to treat specific digestive tract tumors called GISTs.
This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.
What should I tell my health care provider before I take this medicine?
They need to know if you have any of these conditions:
bleeding problems
infection (especially a virus infection such as chickenpox, cold sores, or herpes)
heart disease
heart failure
kidney disease
liver disease
lung disease
stomach problems
an unusual or allergic reaction to imatinib, other medicines, foods, dyes, or preservatives
pregnant or trying to get pregnant
breast-feeding
How should I use this medicine?
Take this medicine by mouth with a full glass of water. Take it with food to decrease the chance of it upsetting your stomach. Do not take with grapefruit juice. Follow the directions on the prescription label. Take your medicine at regular intervals. Do not take it more often than directed. Do not stop taking except on your doctor's advice.
If you have difficulty swallowing the tablets, let your doctor, pharmacist, or health care professional know. They can help you with advice.
Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for children as young as 1 year for selected conditions, precautions do apply.
Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose and skip your missed dose. Do not take double or extra doses.
What may interact with this medicine?
antiviral medicines for HIV or AIDS
bosentan
cisapride
clarithromycin
cyclosporine
dexamethasone
diltiazem
ergot alkaloids like dihydroergotamine, ergonovine, ergotamine, methylergonovine
erythromycin
grapefruit or grapefruit juice
medicines for cholesterol like atorvastatin lovastatin, simvastatin
medicines for depression, anxiety, or psychotic disturbances
medicines for fungal infections like ketoconazole and itraconazole
medicines for irregular heart beat like amiodarone, bepridil, dofetilide, encainide, flecainide, propafenone, quinidine
medicines for seizures like carbamazepine, phenobarbital, phenytoin
medicines for sleep
NSAIDS, medicines for pain and inflammation, like ibuprofen or naproxen
pimozide
rifabutin
rifampin
sildenafil
sirolimus
St. John's wort
tacrolimus
vaccines
verapamil
warfarin
Talk to your doctor or health care professional before taking any of these medicines:
acetaminophen
aspirin
ibuprofen
ketoprofen
naproxen
This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.
What should I watch for while using this medicine?
Visit your doctor for checks on your progress. You will need to have regular blood tests while on this medicine. Report any new symptoms promptly.
Call your doctor or health care professional for advice if you get a fever, chills or sore throat, or other symptoms of a cold or flu. Do not treat yourself. This drug decreases your body's ability to fight infections. Try to avoid being around people who are sick.
This medicine may increase your risk to bruise or bleed. Call your doctor or health care professional if you notice any unusual bleeding.
Be careful brushing and flossing your teeth or using a toothpick because you may get an infection or bleed more easily. If you have any dental work done, tell your dentist you are receiving this medicine.
Avoid taking products that contain aspirin, acetaminophen, ibuprofen, naproxen, or ketoprofen unless instructed by your doctor. These medicines may hide a fever.
Do not become pregnant while taking this medicine. Women should inform their doctor if they wish to become pregnant or think they might be pregnant. There is a potential for serious side effects to an unborn child. Men should inform their doctors if they wish to father a child. This medicine may lower sperm counts. Talk to your health care professional or pharmacist for more information. Do not breast-feed an infant while taking this medicine.
What side effects may I notice from receiving this medicine?
Side effects that you should report to your doctor or health care professional as soon as possible:
low blood counts - this medicine may decrease the number of white blood cells, red blood cells and platelets. You may be at increased risk for infections and bleeding.
signs of infection - fever or chills, cough, sore throat, pain or difficulty passing urine
signs of decreased platelets or bleeding - bruising, pinpoint red spots on the skin, black, tarry stools, blood in the urine, nosebleeds
signs of decreased red blood cells - unusually weak or tired, fainting spells, lightheadedness
allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
breathing problems
changes in vision
dark urine
general ill feeling or flu-like symptoms
light-colored stools
loss of appetite
mouth sores
redness, blistering, peeling or loosening of the skin, including inside the mouth
right upper belly pain
swelling of the legs or ankles
trouble passing urine or change in the amount of urine
vomiting
yellowing of the eyes or skin
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
decreased appetite
diarrhea
difficulty sleeping
headache
heartburn
joint pain
muscle cramps or pain
nausea
upset stomach
This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Where should I keep my medicine?
Keep out of reach of children.
Store tablets at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from moisture. Keep tightly closed. Throw away any unused medicine after the expiration date.
Updated:  
March 21, 2017
Sources:  
U.S. FDA-approved Package Insert