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

If not diagnosed at birth, signs often appear within the first few months.

Most often, HT-1 is diagnosed at birth through new born screening. If not diagnosed at birth, signs often develop during the first few months of life.

Babies may show visible signs of the condition within the first months of life, however, symptoms of the disease may not be evident to the parents. Failure to thrive, an enlarged liver, poor weight gain, abdominal pain, vomiting and diarrhea are possible signs of this disorder.

Signs and symptoms may include:

  • Lack of weight gain
  • Irritability
  • Fever
  • Diarrhea
  • Vomiting
  • Swollen belly (due to an enlarged liver)
  • Bruising
  • Jaundice
  • Nose bleeds

A child with HT-1 may develop liver, renal and other complications.

Children with tyrosinemia type 1 have an increased risk of developing liver problems. Signs of liver distress and failure include gastrointestinal bleeding and jaundice, a yellowing of the whites of the eyes as well as the skin. The liver failure later leads to a characteristic odor of 'boiled cabbage' or 'rotten mushrooms' from the child's skin or urine.

A build up of succinylacetone can be a sign of HT-1.

When the body cannot break down tyrosine, an amino acid that comes from food, high levels of it build up in the blood and form a toxic substance known as succinylacetone. Elevated levels of succinylacetone are always present in children with tyrosinemia type 1, and can be measured in both the blood and urine. During treatment, succinylacetone quickly disappears.

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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