See also Warning section.
Temporary hair loss may occur. Normal hair growth should return after treatment has ended.
Stomach/intestinal symptoms such as nausea, vomiting, diarrhea, or loss of appetite may occur. These symptoms may be reduced by giving the medication after a meal or in divided doses. If any of these effects persist or worsen, tell your doctor or pharmacist immediately.
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.
Although unlikely, more severe stomach/intestinal symptoms (e.g., severe nausea/vomiting/>diarrhea, stomach/>abdominal pain) may occur as part of a very serious allergic reaction. Seek immediate medical attention if you have severe stomach/intestinal symptoms or other symptoms of a serious allergic reaction, which may include: fever, severe chills, rash, itching/swelling (especially of the face/>tongue/throat), severe dizziness, trouble breathing, cough, new or worsening joint/muscle aches, dark urine.
Tell your doctor immediately if any of these unlikely but serious side effects occur: muscle weakness, cold/numbness in the fingers, mouth sores, difficult/painful swallowing, greasy stools.
Seek immediate medical attention if any of these rare but very serious side effects occur: yellowing eyes/skin, swelling/extra fluid around the abdomen, vomit that contains blood or looks like coffee grounds, black stools.
This medication may increase your risk of getting a rare but very serious (sometimes fatal) brain infection (progressive multifocal leukoencephalopathy-PML). Get medical help right away if any of these rare but very serious side effects occur: clumsiness, loss of coordination, weakness, sudden change in your thinking (such as confusion, difficulty concentrating), difficulty moving your muscles, problems with speech, seizure, vision changes.
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.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.