Imatinib (Gleevec®)

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About This Drug

Imatinib is used to treat cancer. It is given orally (by mouth).

Possible Side Effects

  • Bone marrow suppression. This is a decrease in the number of white blood cells, red blood cells, and platelets. This may raise your risk of infection, make you tired and weak (fatigue), and raise your risk of bleeding. 
  • Nausea and vomiting (throwing up)
  • Diarrhea (loose bowel movements)
  • Pain in your abdomen
  • Tiredness
  • Swelling of your legs, ankles and/or feet
  • Joint, bone and/or muscle pain
  • Muscle cramps
  • Rash

Note: Each of the side effects above was reported in 30% or greater of patients treated with imatinib. Not all possible side effects are included above.

Warnings and Precautions 

  • Severe swelling of your legs, ankles and/or feet, or fluid build-up around your lungs, heart or elsewhere.
  • Severe bone marrow suppression.
  • Abnormal bleeding. Symptoms may be coughing up blood, throwing up blood (may look like coffee grounds), red or black tarry bowel movements, abnormally heavy menstrual flow, nosebleeds or any other unusual bleeding.
  • Congestive heart failure and/or other effects on the heart.
  • Changes in your liver function which can cause liver failure.
  • Small holes or tears in the lining of your stomach or your intestines which can be life-threatening.
  • Severe skin reactions. You may develop blisters on your skin that are filled with fluid or a severe red rash all over your body.
  • Tumor lysis syndrome. This drug may act on your cancer cells very quickly. This may affect how your kidneys work and can be life-threatening.
  • Changes in your thyroid function if you have had your thyroid removed.
  • Changes in your kidney function.

Note: Some of the side effects above are very rare. If you have concerns and/or questions, please discuss them with your medical team.

Important Information

  • This drug may impair your ability to drive or use machinery. Use caution and tell your nurse or doctor if you feel dizzy, very sleepy, or have blurred vision

How to Take your Medication

  • Take this drug with food and a large glass of water to avoid upset stomach.
  • Swallow the medicine whole. Do not chew, break or crush it.
  • If you have difficulty swallowing the tablets, the tablets can be dissolved in a glass of water or apple juice. The required number of tablets should be placed in the correct amount of liquid (approximately 50 mL for a 100 mg tablet, and 200 mL for a 400 mg tablet). Stir the mixture with a spoon and drink immediately after complete disintegration of the tablet(s).
  • Missed dose: If you vomit or miss a dose, take your next dose at the regular time, and contact your physician. Do not take 2 doses at the same time and do not double up on the next dose. 
  • Handling: Wash your hands after handling your medicine, your caretakers should not handle your medicine with bare hands and should wear latex gloves.
  • If any of the tablets are broken, do not touch them with bare hands. If you get any of the content of a broken tablets on your skin, you should wash the area of the skin well with soap and water  right away. Call your doctor if you get a skin reaction.
  • This drug may be present in the saliva, tears, sweat, urine, stool, vomit, semen, and vaginal secretions. Talk to your doctor and/or your nurse about the necessary precautions to take during this time.
  • Storage: Store this medicine in the original container at room temperature. Keep tightly closed. Protect from moisture.
  • Disposal of unused medicine: Do not flush any expired and/or unused medicine down the toilet or drain unless you are specifically instructed to do so on the medication label. Some facilities have take-back programs and/or other options. If you do not have a take-back program in your area, then please discuss with your nurse or your doctor how to dispose of unused medicine.

Treating Side Effects

  • Manage tiredness by pacing your activities for the day.
  • Be sure to include periods of rest between energy-draining activities.
  • To decrease the risk of infection, wash your hands regularly.
  • Avoid close contact with people who have a cold, the flu, or other infections.
  • Take your temperature as your doctor or nurse tells you, and whenever you feel like you may have a fever.
  • To help decrease the risk of bleeding, use a soft toothbrush. Check with your nurse before using dental floss.
  • Be very careful when using knives or tools.
  • Use an electric shaver instead of a razor.
  • Drink plenty of fluids (a minimum of eight glasses per day is recommended).
  • If you throw up or have loose bowel movements, you should drink more fluids so that you do not become dehydrated (lack of water in the body from losing too much fluid).
  • To help with nausea and vomiting, eat small, frequent meals instead of three large meals a day.
  • Choose foods and drinks that are at room temperature. Ask your nurse or doctor about other helpful tips and medicine that is available to help stop or lessen these symptoms.
  • If you have diarrhea, eat low-fiber foods that are high in protein and calories and avoid foods that can irritate your digestive tracts or lead to cramping. Ask your nurse or doctor about medicine that can lessen or stop your diarrhea.
  • Keeping your pain under control is important to your well-being. Please tell your doctor or nurse if you are experiencing pain.
  • If you get a rash do not put anything on it unless your doctor or nurse says you may. Keep the areas around the rash clean and dry. Ask your doctor for medicine if your rash bothers you.

Food and Drug Interactions

  • Avoid grapefruit or grapefruit juice while taking this medicine as it may raise the levels of imatinib in your body which could make side effects worse.
  • Check with your doctor or pharmacist about all other prescription medicines and over-the-counter medicines and dietary supplements (vitamins, minerals, herbs and others) you are taking before starting this medicine as there are known drug interactions with imatinib. Also, check with your doctor or pharmacist before starting any new prescription or over-the-counter medicines, or dietary supplements to make sure that there are no interactions.
  • There are known interactions of imatinib with other medicines and products such as acetaminophen, warfarin, phenytoin, statin drugs, calcium channel blockers and benzodiazepines. Ask your doctor what over-the-counter (OTC) medicines you can take for fever, headache and muscle and joint pain, and discuss other possible drug interactions. Avoid the use of St. John’s Wort while taking imatinib as this may lower the levels of the drug in your body, which can make it less effective.

When to Call the Doctor

Call your doctor or nurse if you have any of these symptoms and/or any new or unusual symptoms:

  • Fever of 100.4 F (38 C) or higher
  • Chills
  • Feeling dizzy or lightheaded
  • Tiredness that interferes with your daily activities
  • Feeling that your heart is beating in a fast or not normal way (palpitations)
  • Wheezing or trouble breathing
  • Nausea that is not relieved by prescribed medicine, or that stops you from eating or drinking or throwing up more than 3 times a day
  • Lasting loss of appetite or rapid weight loss of five pounds in a week
  • Diarrhea, 4 times in one day or diarrhea with weakness or lightheadedness
  • Severe abdominal pain
  • Decreased urine or very dark urine
  • Easy bleeding or bruising
  • Heavy menstrual period that lasts longer than normal
  • Blood in your urine, vomit (bright red or coffee-ground) and/or stools (bright red, or black/tarry)
  • Coughing up blood
  • New rash or itching, or rash that worsens, and/or is not relieved by prescribed medicine
  • Swelling of legs, ankles, or feet
  • Weight gain of 5 pounds in one week (fluid retention)
  • Pain in your muscles or joints that is not relieved by prescribed medication
  • Signs of liver problems: dark urine, pale bowel movements, bad stomach pain, feeling very tired and weak, unusual itching, or yellowing of the eyes or skin
  • Signs of tumor lysis: Confusion or agitation, decreased urine, nausea/vomiting, diarrhea, muscle cramping, numbness and/or tingling, seizures
  • If you think you may be pregnant

Reproduction Warnings 

  • Pregnancy: This drug can have harmful effects on the unborn baby. Women of childbearing potential should use effective methods of birth control during your cancer treatment and for 14 days after treatment. Let your doctor know right away if you think you may be pregnant.
  • Breastfeeding: Women should not breastfeed during treatment and for 1 month after treatment because this drug could enter the breast milk and badly harm a breastfeeding baby.
  • Fertility Warning: Human fertility studies have not been done with this drug. Talk with your doctor or nurse if you plan to have children. Ask for information on sperm or egg banking.

Revised May 2019

This patient information was developed by Via Oncology, LLC © 2019. This information is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have.

CLIENT acknowledges that the Via Pathways and Via Portal are information management tools only, and that Via Oncology, LLC has not represented the Via Pathways or Via Portal as having the ability to diagnose disease, prescribe treatment, or perform any other tasks that constitute the practice of medicine. The clinical information contained in the Via Pathways and Via Portal are intended as a supplement to, and not a substitute for, the knowledge, expertise, skill, and judgment of physicians, pharmacists and other healthcare professionals involved with patient care at CLIENT facilities.