See also Warning section.
Nausea, vomiting, dizziness, headache, cough, weakness, diarrhea, joint/muscle pain, trouble sleeping, stomach/abdominal pain, constipation, or pain/swelling/redness at injection site may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
People using this medication may 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: pain/swelling/redness of arms or legs, mental/mood changes, seizures, shortness of breath.
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.
Cladribine can commonly cause a mild 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 allergic reaction. Therefore, get medical help right away if you develop any rash.
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.