The suspension may cause headache, upset stomach, or diarrhea. If any of these effects occur, tell your doctor or pharmacist promptly and discuss switching to other forms of nitisinone.
Remember that this medication has been prescribed because the doctor has judged that the benefit is greater than the risk of side effects. Many people using this medication do not have serious side effects.
This medication may rarely cause a low number of blood cells such as white cells and platelets. This effect can decrease your body's ability to fight an infection or cause easy bruising/bleeding. Tell your doctor right away if you develop any of the following symptoms: signs of infection (such as sore throat that doesn't go away, fever, chills), easy bruising/bleeding.
Your condition and this medication can cause liver problems. Tell the doctor right away if any of these symptoms of liver problems occur: nausea or vomiting that doesn't stop, severe stomach/abdominal pain, yellowing eyes/skin, dark urine.
Your condition and this medication can cause high levels of tyrosine in the blood. It is very important to follow the low protein/low tyrosine diet recommended by your doctor. See also Precautions section. Too much tyrosine may cause skin, eye, or brain problems. Tell the doctor right away if any of these symptoms occur: eye redness/itching/discharge, vision changes, eye pain, eye sensitivity (especially to light), dry/itchy skin, sores on palms of hands/soles of feet, developmental delays (such as holding head up, rolling over, crawling).
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 the 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 MedWatch: The FDA Safety Information and Adverse Event Reporting Program.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.