Afatinib belongs to the class of medications called protein kinase inhibitors. It is used to treat certain types of lung cancer that has spread to other areas of the body. Afatinib works by blocking the activity of a group of proteins called epidermal growth factor receptors (EGFR). Epidermal growth factor receptor is a protein that is involved in the growth and spread of cancer cells; afatinib works by preventing the action of this protein.

Afatinib should not be used by people with EGFR-negative tumors.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended starting dose of afatinib is 40 mg taken by mouth, once daily.

Food reduces the amount of medication that is available for your body to use. Afatinib should be taken at least 3 hours after eating or 1 hour before eating. It should not be crushed or chewed. Swallow the tablets whole with water.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

If you vomit shortly after taking your dose of afatinib, do not take another dose. Continue with your regular dosing schedule.

It is important that this medication be taken exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose (within 8 hours), skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, in its original package. Do not remove the tablet from its blister until you are ready to take it. Protect this medication from light and moisture, and keep it out of the reach of children.

20 mg
Each film-coated, white-to-slightly-yellowish, round, biconvex, bevelled-edge tablet, debossed with the code "T20" on one side and with "BI" on the other, contains 20 mg of afatinib as afatinib dimaleate. Nonmedicinal ingredients: colloidal anhydrous silica, crospovidone, lactose monohydrate, magnesium stearate, and microcrystalline cellulose. Film coating: hypromellose 2910, macrogol 400, polysorbate 80, talc, and titanium dioxide.

30 mg
Each film-coated, dark blue, round, biconvex, bevelled-edged tablet, debossed with the code "T30" on one side and with "BI" on the other contains 30 mg of afatinib as afatinib dimaleate. Nonmedicinal ingredients: colloidal anhydrous silica, crospovidone, lactose monohydrate, magnesium stearate, and microcrystalline cellulose. Film coating: hypromellose 2910, macrogol 400, polysorbate 80, talc, titanium dioxide, and indigo carmine aluminium hydroxide.

40 mg
Each film-coated, light blue, round, biconvex, bevelled-edged tablet, debossed with the code "T40" on one side and with "BI" on the other contains 40 mg of afatinib as afatinib dimaleate. Nonmedicinal ingredients: colloidal anhydrous silica, crospovidone, lactose monohydrate, magnesium stearate, and microcrystalline cellulose. Film coating: hypromellose 2910, macrogol 400, polysorbate 80, talc, titanium dioxide. and indigo carmine aluminium hydroxide.

Do not take this medication if you are allergic to afatinib, or any ingredients of the medication.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• acne
• changed sense of taste
• decreased appetite
• dry eyes
• dry, itchy skin
• eye inflammation
• heartburn
• infection of the nailbed
• loss of appetite
• muscle spasms
• nosebleeds
• runny nose
• stomach pain
• weight loss

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• diarrhea
• eye infection
• fever
• inflammation of the lining of the mouth and lips
• rash
• redness, swelling, and pain in palms of hands and soles of feet
• signs of bladder irritation (e.g., burning feeling during urination, frequent urgent need to urinate)
• signs of corneal (anterior eye) inflammation (e.g., eye pain, vision changes, loss of vision)
• signs of dehydration (e.g., decreased urine, dry skin, dry and sticky mouth, sleepiness, dizziness, headache, thirst, confusion)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• signs of low potassium levels in the blood (e.g., weakness, fatigue, muscle cramps, irregular heartbeat)
• swelling, redness, infection around the nail beds

Stop taking the medication and seek immediate medical attention if any of the following occur:

• inflammation of the lungs (e.g., sudden difficulty breathing, cough, fever)
• gastrointestinal perforation (e.g., severe abdominal pain with fever, nausea, vomiting)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

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, you 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.

Galactose intolerance/glucose malabsorption: Afatinib tablets are prepared with lactose. If you have a lactose or galactose intolerance, tell your doctor.

Gastrointestinal perforation: Rarely, afatinib can cause perforation (holes) in the stomach or intestines. If you experience severe abdominal pain, fever, vomiting, or black and tarry stools, contact your doctor immediately.

Heart problems: This medication may reduce how well the heart is able to pump blood through the body. If you have a history of any heart 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. Difficulty breathing, unusual tiredness, and swelling of the feet, ankles or hands, may be symptoms of the heart not working efficiently. Contact your doctor as soon as possible if you experience any of these symptoms.

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. People with severely reduced liver function should not take this medication.

Nail bed inflammation: Afatinib may cause inflammation of the nail beds. This may appear as a painful, red, swollen area around the nails. Nails may look abnormally shaped, be detached, or have an unusual colour. It is important to take good care of your skin, keep your hands clean and dry, and avoid injury to your nails or fingertips. Avoid harsh chemicals such as soap, detergents and nail products.

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 people. This medication should not be taken during pregnancy. If you 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 breast-feeding and 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 people 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.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.