SIDE EFFECTS: Mouth sores, pain/redness/swelling of lips, dry/itchy skin, acne, nose bleed, runny nose, nausea/vomiting, or loss of appetite may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Diarrhea is a common side effect. Drink plenty of fluids as directed by your doctor to reduce your risk of losing too much body water (dehydration). Your doctor may prescribe anti-diarrhea medication (such as loperamide) to control your symptoms. Tell your doctor right away if you develop: severe or persistent diarrhea, symptoms of dehydration (such as unusual decreased urination, unusual dry mouth/thirst, fast heartbeat, or dizziness/lightheadedness). Tell your doctor right away if you have any serious side effects, including: signs of eye disease (such as vision changes, eye redness/pain, light sensitivity, eye discharge), signs of low level of potassium in the blood (such as muscle cramps, weakness, irregular heartbeat), signs of bladder infection (such as burning/pain when you urinate, urgent or frequent urination, fever), signs of skin infection around nails/toenails (such as skin irritation/redness around the nail, change in nail color). Get medical help right away if you have any very serious side effects, including: symptoms of lung problems (such as trouble breathing, chest pain), symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain). Afatinib may rarely cause serious (possibly fatal) liver disease. Get medical help right away if you have any symptoms of liver damage, including: dark urine, persistent nausea/vomiting/loss of appetite, stomach/abdominal pain, yellowing eyes/skin. Afatinib can commonly cause a rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe reaction. Therefore, get medical help right away if you develop any rash. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking afatinib, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems, liver problems, eye disease (such as severe dry eyes, keratitis), use of contact lenses. This drug may cause blurred vision. Do not drive, use machinery, or do any activity that requires clear vision until you are sure you can perform such activities safely. Limit alcoholic beverages. This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness. Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). This medication is not recommended for use during pregnancy. It may harm an unborn baby. It is important to prevent pregnancy while taking this medication and for at least 2 weeks after treatment. Therefore, females must use reliable forms of birth control (such as condoms, birth control pills) during treatment and for at least 2 weeks after the end of treatment. If you become pregnant or think you may be pregnant, tell your doctor right away. Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets. It is unknown if this drug passes into breast milk. Because of the possible risk to the infant, breast-feeding while using this drug and for 2 weeks after stopping this drug is not recommended. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Other medications can affect the removal of afatinib from your body, which may affect how afatinib works. Examples include rifamycins (such as rifabutin), St. John's wort, drugs used to treat seizures (such as phenytoin, phenobarbital), among others.

OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe nausea/vomiting/stomach pain, severe dizziness, weakness.