Mouth sores, decreased appetite, weight loss, swelling/infection around your nails, or dry skin may occur. Use a moisturizer for dry skin as soon as you start treatment with this medication. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
Temporary hair loss may occur. Normal hair growth should return after treatment has ended.
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 lessen 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 have: diarrhea that doesn't stop or is severe, signs of dehydration (such as unusual decreased urination, unusual dry mouth/thirst, fast heartbeat, dizziness/lightheadedness).
Get medical help right away if you have any very serious side effects, including: signs of a new/worsening lung problem (such as shortness of breath, cough, fever).
Dacomitinib 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. 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.