Tiredness, headache, muscle/joint pain, dizziness, nausea, or diarrhea may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
Remember that this medication has been prescribed because your doctor 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.
This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high. Your doctor may control your blood pressure with medication.
This medication may rarely cause blood clots (such as pulmonary embolism, stroke, heart attack, deep vein thrombosis). You may be at increased risk for blood clots if you have had your spleen removed, or have a history of blood clots, or if you are immobile (such as on very long plane flights or being bedridden). If you use estrogen-containing products, these may also increase your risk. Before using this medication, if you have any of these conditions report them to your doctor or pharmacist. Get medical help right away if any of these side effects occur shortness of breath/rapid breathing, chest/jaw/left arm pain, unusual sweating, confusion, sudden dizziness/fainting, pain/swelling/warmth in the groin/calf, sudden/severe headaches, trouble speaking, weakness on one side of the body, sudden vision changes.
Some people who have beta thalassemia and are treated with this medication have rarely had a certain tissue problem (extramedullary hematopoietic masses-EMH masses) develop. Your risk for this problem may be higher if you have a past history of EMH masses, or have had your spleen removed, or have an enlarged spleen or liver, or have low hemoglobin levels. Careful monitoring by your doctor may decrease your risk. Tell your doctor right away if you develop symptoms such as severe back pain, numbness/weakness/loss of ability to control movement in your feet, legs, hand, or arms, loss of bowel or bladder control.
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.