Full Prescribing Information Important Safety Information

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Our treatment

Orfadin is the first FDA-approved therapy of HT-1 along with a tyrosine and phenylalanine-restricted diet. But our product innovation extends beyond Orfadin’s medicinal properties. We are constantly striving to make dosing and administration as simple and personalized as possible.

One dose a day

Orfadin is the first and only FDA-approved, once-daily dosing option for patients 5 years of age and older, who have undetectable serum and urine succinylacetone concentrations after a minimum of 4 weeks on a stable dosage of nitisinone. All dosages, including the oral suspension, may only need to be taken once a day.

Henry, patient

Room temperature storage

Orfadin can be stored at room temperature for more than a month, so you can take it on sleepovers, camping, road trips, and long vacations.

  • Orfadin capsules can be safely stored at room temperature (77°F/25°C or lower) for up to 45 days.

  • Orfadin oral suspension can be safely stored at room temperature (77°F/25°C or lower) for up to 60 days after opening.

Flexible dosing options

When it comes to HT-1 treatment, there is no "one size fits all." We offer a range of dosing options so you and your doctor can tailor your treatment plan.

  • Orfadin is the only liquid oral suspension nitisinone that comes ready to use, for administering treatment to infants and young children.

  • Orfadin is available in 2-mg, 5-mg, 10-mg, and 20-mg capsules so the treatment plan can be tailored to the patient.

  • Our 20-mg option can reduce the number of capsules you need to take.

Organization made easy

Our easy-to-use blister pack may help you keep track of the pills you’ve already taken, and the ones you still need to take.

Tasneem, patient


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).


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