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

Early diagnosis of tyrosinemia type 1 is vital.

Newborn screening makes it possible to start treatment even before symptoms occur. Early detection and treatment may dramatically reduce the risk for liver failure, neurological crisis, and liver cancer.

When the presence of tyrosinemia is suspected, a baby's blood or urine will be tested for succinylacetone. It's the toxic substance that builds up in the liver, kidneys, and central nervous system when the body can't effectively break down tyrosine, a natural amino acid from food.

If both parents are carriers of the mutated gene responsible for this disorder, prenatal diagnosis is possible. FAH or succinylacetone levels are measured in the amniotic fluid.

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.
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