Prescribing Information | Important Safety Information
Prescribing Information | Important Safety Information

Orfadin helps prevent the buildup of specific metabolic compounds.

Orfadin (previously known as NTBC) used in conjunction with dietary restriction of tyrosine and phenylalanine was approved by the FDA in 2002 for the treatment of patients with HT-1. Before the drug Orfadin (nitisinone) was available, the only treatment for tyrosinemia was diet and ultimately a liver transplant. A liver transplant is a major operation, and people who have one usually need to take medicines (known as immunosuppressants) for the rest of their lives. Orfadin can help block the breakdown of tyrosine before it can be changed into harmful substances. Remember that staying on a diet that limits tyrosine and phenylalanine is required when taking Orfadin. Your doctor will prescribe you with a special low-protein diet. Please contact your doctor with any questions regarding your dietary needs.

Dosing Options medicine

Orfadin is prescribed for daily administration. Orfadin can be administered as capsules or as a 4 mg/mL Oral Suspension; the dose and form of Orfadin will be decided by your child's doctor. If you have questions about Orfadin capsules or the new Oral Suspension, please speak with your doctor or contact an Orfadin4U specialist at 1-877-473-3179 (between 7 AM - 6 PM CST).


For patients who prefer capsules, Orfadin is available in 2 mg/kg, 5 mg/kg, 10 mg/kg and 20 mg/kg capsules. Our 20 mg capsules may help reduce the number of pills you (or your child) take at morning and evening doses. For young children, capsules may be opened and the contents suspended in a small amount of water, formula or applesauce immediately before use. Patients/caregivers may store ORFADIN capsules at room temperature (not any higher than 77°F (25°C)) for up to 45 days. If not used within 45 days, please discard ORFADIN capsules.

Oral Suspension

Orfadin Oral Suspension was specially developed for infants and toddlers or those who may have difficulty swallowing capsules. Strawberry-flavored and available as a 4-mg/mL liquid, the Oral Suspension is administered in the child's mouth without dilution using a dosing oral syringe. The Oral Suspension may be stored for up to 60 days at room temperature (not any higher than 77°F (25°C)). After 60 days at room temperature, any unused Orfadin needs to be discarded, even if you had put it in the refrigerator for a short time. For the longest shelf life, keep Orfadin in the refrigerator all the time at 36-46°F (2-8°C). For additional information on how to properly dispense and store Oral Suspension please see the "Instructions for Use" section within the full Prescribing Information. The amount of medication needed will change as your child grows, so don't be surprised when the dose alters.

There are side effects associated with Orfadin. It is important to talk to your doctor about any adverse events your child experiences.

Important safety information related to Orfadin.

  • Treatment with Orfadin should be initiated by a physician experienced in the treatment of HT-1. Orfadin should be taken at least one hour before, or two hours after a meal.
  • For young children, capsules may be opened and the contents suspended in a small amount of water, formula or applesauce immediately before use.
  • Patients and their parents or caregivers should be advised of the need to maintain dietary restriction of tyrosine and phenylalanine when taking Orfadin.

Indication and Usage

Orfadin is a synthetic reversible inhibitor of 4-hydroxyphenylpyruvate dioxygenase indicated for use as an adjunct to dietary restriction of tyrosine and phenylalanine in the treatment of hereditary tyrosinemia type 1 (HT-1).

Important Safety Information

    • Tyrosine levels can increase in the blood if you do not restrict tyrosine and phenylalanine in your diet while taking Orfadin. Too much tyrosine in the blood can cause serious eye problems or other complications.
    • Do not adjust your Orfadin dosage in order to lower the tyrosine levels in the blood.
    • A reduction in the number of white cells and platelets in the blood have been observed during treatment with Orfadin. Your platelet and white blood cell counts should be monitored regularly during Orfadin treatment.
    • The most common adverse reactions to taking Orfadin are liver cancer, liver failure, low platelets or white cells in the blood, and complaints related to the eyes, including conjunctivitis, corneal opacity, inflammation of the cornea, and extreme sensitivity to light.
    • Tell your physician promptly if you have unexplained eye symptoms, rash, jaundice (yellowing of the skin or whites of the eyes) or excessive bleeding.
    • Use Orfadin during pregnancy only if the potential benefit justifies the potential risk to the fetus.
    • Nursing women should discontinue either Orfadin or breast-feeding based on the recommendation of your healthcare professional.
      Please see full Prescribing Information