Generic Name and Formulations:
Nitisinone 2mg, 5mg, 10mg; tabs.
Indications for NITYR:
Treatment of hereditary tyrosinemia type 1 (HT-1) in combination with dietary restriction of tyrosine and phenylalanine.
Adults and Children:
May crush tabs and mix with applesauce or disintegrate in water if difficulty swallowing tabs. Initially 0.5mg/kg twice daily. Titrate individually as needed based on response. Monitor plasma and/or urine succinylacetone levels, liver function, and alpha-fetoprotein levels. Increase to 0.75mg/kg twice daily if succinylacetone is still detectable 1 month after treatment initiation; max 1mg/kg twice daily dose may be needed.
Maintain dietary restriction of tyrosine and phenylalanine during therapy. Do not adjust dose to lower plasma tyrosine levels (maintain levels at <500μmol/L). Perform eye exams (including slit-lamp test) prior to starting therapy; re-evaluate and assess plasma tyrosine levels if ocular symptoms develop. Perform lab tests (including plasma tyrosine levels) if abrupt change in neurologic status occurs. Monitor platelets, WBC counts during therapy. Pregnancy. Nursing mothers.
4-hydroxyphenylpyruvate dioxygenase inhibitor.
May potentiate CYP2C9 substrates; monitor.
Elevated tyrosine levels, thrombocytopenia, leukopenia, conjunctivitis, corneal opacity, keratitis, photophobia, eye pain, blepharitis, cataracts, granulocytopenia, epistaxis, pruritus, exfoliative dermatitis, dry skin, maculopapular rash, alopecia.