See also Warning section.
Fever, chills, dizziness, muscle stiffness, nausea, vomiting, headache, diarrhea, mild rash/itching, tiredness, flushing, or trouble breathing may occur during or after the infusion. These reactions occur more often during the first week of treatment. Tell your doctor or pharmacist immediately if any of these effects occur, persist, or worsen. Your doctor may prescribe additional medications to help control these symptoms. Mouth sores, loss of appetite, shaking (tremor), stomach/abdominal pain, constipation, drowsiness, cough, increased sweating, or trouble sleeping may also occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Many people using this medication have serious side effects. However, your doctor has prescribed this drug because he or she has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.
Tell your doctor right away if you have any serious side effects, including: shortness of breath, mental/mood changes (such as depression, anxiety), bone/joint/back pain, muscle pain/spasm, unusual weakness, swelling ankles/feet, yellowing skin/eyes, change in the amount of urine, painful urination, pink/bloody urine, numbness/tingling of arms/legs, pain/redness/swelling of arms/legs/injection site.
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.
Get medical help right away if you have any very serious side effects, including: fainting, trouble breathing, chest/jaw/left arm pain, irregular heartbeat, weakness on one side of the body.
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.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.