Inborn errors of metabolism:
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 tab; see full labeling. 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). Consider baseline eye exam (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. Hyperkeratotic plaques (on the soles & palms). 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.