Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Anemia: Imatinib may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired, or pale skin, contact your doctor as soon as possible.
Your doctor will do blood tests regularly to monitor the number of specific types of blood cells, including red blood cells, in your blood.
Bleeding: Imatinib may cause a reduced number of platelets in the blood, which can make it difficult to stop cuts from bleeding. If you notice any signs of bleeding, such as frequent nosebleeds, unexplained bruising, or black and tarry stools, notify your doctor as soon as possible. Your doctor will order routine blood tests to make sure potential problems are caught early.
Drowsiness/reduced alertness: This medication is not expected to make you drowsy and impair your ability to drive or use machinery. However, it may make some people feel weak. Do not drive or use machinery until you know how this medication affects you.
Fluid retention: This medication can cause serious fluid retention. If you experience unexpected rapid weight gain or swelling in your feet, ankles, lower legs, or hands, contact your doctor immediately. Your doctor will weigh and monitor you regularly for signs of fluid retention while you are taking this medication.
Grapefruit juice: Grapefruit juice affects how imatinib is removed from the body and may cause too much of the medication to build up in the body. Do not drink grapefruit juice while taking this medication.
Heart problems and heart failure: Rarely, heart problems including heart failure, have been reported with the use of imatinib. If you are at risk for heart problems such as heart failure (e.g., people with high blood pressure, diabetes, and coronary artery disease), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Contact your doctor immediately if you have symptoms of heart failure such as leg swelling, chest pain, or shortness of breath.
Infection: As well as killing cancer cells, imatinib can reduce the number of cells that fight infection in the body (white blood cells). If possible, avoid contact with people with contagious infections. Tell your doctor immediately if you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness. Your doctor will do blood tests regularly to monitor the number of specific types of blood cells in your blood.
Kidney function: If you have kidney problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: Imatinib may affect liver function. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function with blood tests regularly while you are taking this medication.
Muscle effects: In rare cases, serious muscle damage has been associated with the use of this medication. Report any unexplained muscle pain, tenderness, weakness or cramps, or any brown or discoloured urine to your doctor immediately, particularly if you are also experiencing malaise (a general feeling of being unwell) or fever.
Stomach problems: Imatinib may cause stomach irritation or bleeding. To reduce stomach irritation, take this medication with food and a large glass of water. If you experience signs of stomach bleeding (e.g., severe stomach pain, black stools, vomiting blood, dizziness), get immediate medical attention.
Thyroid: If you have hypothyroidism due to removal of thyroid gland, you may need closer monitoring of your thyroid levels. Let your doctor know if you are experiencing unusual tiredness, weight gain, hair loss, unusually dry skin, mood changes, and intolerance to cold temperatures.
Tumour lysis syndrome: Imatinib, like many other cancer medications, causes many cancer cells to be suddenly killed when treatment is first started. This can overwhelm the body with waste products from the cells. As a result, the body may not be able to keep up with getting rid of all the waste. When this happens, you may experience nausea and shortness of breath, and notice cloudy urine or joint pain. This is called tumour lysis syndrome. Your doctor may prescribe some medications to help your body get rid of the waste products. Make sure you understand how to use these medications and report any of these signs or symptoms to your doctor immediately.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately. Women of childbearing age who are taking imatinib should use an effective method of birth control during treatment.
Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking imatinib, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for children less than 2 years of age. Growth may be slowed in children and adolescents that take this medication.
Seniors: Seniors have a greater risk of fluid retention than younger patients. Contact your doctor if you experience a sudden increase in weight or swelling of the ankles, lower legs, or hands. Your doctor will weigh and monitor you closely.