• Inborn errors of metabolism

Nityr Generic Name & Formulations

General Description

Nitisinone 2mg, 5mg, 10mg; tabs.

Pharmacological Class

4-hydroxyphenylpyruvate dioxygenase inhibitor.

How Supplied



Generic Availability


Nityr Indications


Treatment of hereditary tyrosinemia type 1 (HT-1) in combination with dietary restriction of tyrosine and phenylalanine.

Nityr Dosage and Administration

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. Maintenance (in patients ≥5yrs with undetectable serum and urine succinylacetone levels after a minimum of 4 weeks on stable dose): may give 1–2mg/kg once daily. Titrate individually 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 4 weeks after initiation. Max: 2mg/kg/day.

Nityr Contraindications

Not Applicable

Nityr Boxed Warnings

Not Applicable

Nityr Warnings/Precautions


Maintain dietary restriction of tyrosine and phenylalanine during therapy. Do not adjust dose to lower plasma tyrosine levels (maintain levels at <500μmol/L). Perform baseline eye exam (including slit-lamp test) prior to starting therapy and regularly thereafter; re-evaluate and assess plasma tyrosine levels if ocular symptoms develop or tyrosine >500μmol/L during therapy. 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.

Nityr Pharmacokinetics

See Literature

Nityr Interactions


May potentiate CYP2C9 substrates (eg, celecoxib, tolbutamide, phenytoin, warfarin); reduce dose of substrates by ½; drugs with narrow therapeutic index may need additional dose adjustments. May potentiate OAT1/OAT3 substrates (adefovir, ganciclovir, methotrexate); monitor.

Nityr Adverse Reactions

Adverse Reactions

Elevated tyrosine levels, thrombocytopenia, leukopenia, conjunctivitis, corneal opacity, keratitis, photophobia, eye pain, blepharitis, cataracts, granulocytopenia, epistaxis, pruritus, exfoliative dermatitis, dry skin, maculopapular rash, alopecia.

Nityr Clinical Trials

See Literature

Nityr Note

Not Applicable

Nityr Patient Counseling

See Literature