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.
Corneal perforation: Rarely, afatinib has been linked to corneal perforation, a severe injury to the part of the eye that focuses light into the eye. If you experience persistent eye pain or changes in vision, contact your doctor as soon as possible.
Dehydration: Severe dehydration can occur with the use of afatinib. This may be due to severe or persistent diarrhea, vomiting, or decreased fluid intake. Dehydration can lead to kidney failure, if it is severe enough. During treatment with this medication, your may be encouraged to drink extra water. Your doctor will do blood tests to check the function of your kidneys.
Diarrhea: Diarrhea is a common side effect of afatinib. If severe enough, it can lead to dehydration and possibly kidney failure. If you experience diarrhea while taking this medication, it is important that it be treated quickly. Your doctor may give you medication to take at the first signs of diarrhea. If you experience diarrhea that does not go away with appropriate medication, contact your doctor immediately.
Interstitial lung disease (ILD): This is a rare but serious complication. People with other lung conditions (e.g., inflammation of the lung) have an increased risk of death from ILD. If you develop symptoms of ILD such as shortness of breath with cough or fever, seek immediate medical attention.
Kidney function: Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have reduced kidney function or kidney 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. People with severely reduced kidney function should not take this medication.
Liver function: People taking afatinib may have changes in liver function that produce abnormal liver test results. Your doctor will recommend regular liver tests while you are taking this medication. If you have severe changes in liver function, your doctor may recommend that you take a lower dose of this medication or stop taking it altogether.
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.
Skin reactions: Severe skin reactions have been linked to afatinib use. Although rare, they are considered medical emergencies and require immediate medical attention.
If you experience skin blistering or peeling, a rash that covers a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort, seek medical attention immediately.
Pregnancy: There are no adequate studies of use of this medication by pregnant women. This medication should not be taken during pregnancy. If you are a woman who could become pregnant, use a reliable method of birth control (e.g., condoms, birth control pill) during treatment and for at least 2 weeks after treatment is finished. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if afatinib passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Due to the potential for serious harm to a baby if they are exposed to this medication, breast-feeding mothers are advised not use this medication.
Children: The safety and effectiveness of this medication have not been established for children.
Seniors: People over the age of 65 may be at risk of a higher incidence of side effects, particularly diarrhea. Talk to your doctor if you have any concerns.