Orfadin inhibits 4-hydroxyphenylpyruvate dioxygenase. Orfadin is used as an adjunct to dietary restriction of tyrosine and phenylalanine in the treatment of hereditary tyrosinemia type 1 (HT-1).
Important Safety Information
Not restricting tyrosine and phenylalanine in the diet while taking Orfadin can lead to increases of tyrosine in the blood. Too much Tyrosine in the blood can cause serious eye problems or other complications.
Do not adjust 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. Platelet and white blood cell counts should be monitored regularly during Orfadin treatment.
Most common adverse reactions are liver cancer, liver failure, low platelets or white cells in the blood, complaints related to the eyes, including conjunctivitis, corneal opacity, inflammation of the cornea, and extreme sensitivity to light.
Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Exercise caution when used by a nursing woman.