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.
Abnormal bleeding: The use of gefitinib may increase the risk of bleeding. If you have signs of unusual bleeding, such as passing black tarry stools, have bloody diarrhea, vomit or cough up blood, or have unusual bruising, contact your doctor right away. People with bleeding disorders should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether and special monitoring is needed. People taking blood thinners such as warfarin should have regular blood tests to check how quickly their blood is clotting.
Dehydration: Gefitinb commonly causes diarrhea, nausea, and vomiting, which can contribute to dehydration and additional ill effects. If you experience severe diarrhea or diarrhea and vomiting for several days in a row, contact your doctor as soon as possible.
Grapefruit juice: Grapefruit juice prevents this medication from leaving the body as it should, causing the medication to build up in the body and result in side effects. People should not drink grapefruit juice while taking this medication.
Heart rhythm: Gefitinib may cause abnormal changes in electrocardiograms (ECGs). People who have any heart rhythm disorder should be monitored by their doctor while taking this medication.
Interstitial lung disease (ILD): This is a rare but serious complication. People who are over 55, those with other lung or heart conditions, and people who smoke have an increased risk of death from ILD. This medication should be stopped if ILD develops. Contact your doctor if you develop symptoms of ILD, such as shortness of breath, cough, and fever.
Kidney function: Gefitinib may cause kidney damage or decreased kidney function as a result of dehydration. People with reduced kidney function or kidney disease should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: Gefitinib may cause liver damage or decreased liver function. People with reduced liver function or liver disease should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor will monitor your liver function with blood tests while you are taking gefitinib.
If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.
Weakness or impairment: This medication usually does not make you drowsy or impair your ability to drive or operate machinery. However, it may make some people feel weak. Do not drive or operate machinery if you feel weak.
Pregnancy: There are no adequate studies of use of gefitinib by pregnant women. This medication may cause harm to an unborn baby if it is taken during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if gefitinib passes into breast milk. If you are a breast-feeding mother and are taking this medication, 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 under 16 years of age.