Dacomitinib is used to treat a certain type of non-small-cell lung cancer (NSCLC) that has spread to other parts of the body. Dacomitinib is in a class of medications called kinase inhibitors. It works by blocking the action of an abnormal protein that signals cancer cells to multiply. This helps slow or stop the spread of cancer cells.

Side Effects Of Dacomitinib

Dacomitinib may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

  • diarrhea
  • shortness of breath, cough, and fever
  • dry skin, redness, rash, acne, itchy skin, and peeling or blistering of your skin
  • chest pain
  • Dacomitinib may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

Warnings & Precautions

Before taking dacomitinib:

  • tell your doctor and pharmacist if you are allergic to dacomitinib, any other medications, or any of the ingredients in dacomitinib tablets. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: antidepressants such as amitriptyline, clomipramine (Anafranil), desipramine (Norpramin), duloxetine (Cymbalta), fluoxetine (Prozac), imipramine (Tofranil), paroxetine (Paxil, Pexeva), and venlafaxine (Effexor); antipsychotics such as aripiprazole (Abilify), haloperidol (Haldol), risperidone (Risperdal), and thioridazine; atomoxetine (Strattera); beta-blockers such as carvedilol (Coreg), metoprolol (Dutoprol), and timolol; codeine; dextromethorphan (found in many cough medications; in Nuedexta); flecainide (Tambocar); mexiletine; ondansetron (Zofran, Zuplenz); oxycodone (Oxaydo, Xtampza ER); propafenone (Rythmol SR); proton-pump inhibitors such as dexlanspoprazole (Dexilant), esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec), pantoprazole (Protonix), and rabeprazole (AcipHex); tamoxifen (Soltamox); and tramadol (Conzip, Ultram). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • if you are taking a medication for indigestion, heartburn, or ulcers such as cimetidine (Tagamet), famotidine (Pepcid, in Duexis), nizatidine (Axid), or ranitidine (Zantac), take dacomitinib at least 6 hours before or at least 10 hours after taking one of these medications.
  • tell your doctor if you have frequent diarrhea episodes, lung disease, breathing problems other than lung cancer, or liver or kidney disease.
  • tell your doctor if you are pregnant or plan to become pregnant. You must take a pregnancy test before starting treatment. You should not become pregnant while you are taking dacomitinib. You should use a reliable method of birth control while taking dacomitinib and for at least 17 days after your final dose. If you become pregnant while taking dacomitinib, call your doctor immediately. Dacomitinib may harm the fetus.
  • tell your doctor if you are breastfeeding. You should not breastfeed while you are taking dacomitinib and for 17 days after your final dose.
  • plan to use a moisturizer, avoid unnecessary or prolonged exposure to sunlight, and to wear protective clothing, sunglasses, and sunscreen. Dacomitinib may make your skin sensitive to sunlight.

Dacomitinib Dosage

Dacomitinib comes as a tablet to take by mouth. It is usually taken once daily with or without food. Take dacomitinib at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take dacomitinib exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

If you vomit after you take dacomitinib, do not immediately take another dose. Continue your regular dosing schedule.

Your doctor may temporarily or permanently stop your treatment or decrease your dose if you experience certain side effects of dacomitinib. Tell your doctor how you are feeling during your treatment. Continue to take dacomitinib even if you feel well. Do not stop taking dacomitinib without talking to your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.


Keep all appointments with your doctor and the laboratory. Your doctor will order a lab test before you begin your treatment to see whether your cancer can be treated with dacomitinib.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.