Inborn errors of metabolism:

Indications for ORFADIN:

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

Adults and Children:

Caps: take ≥1hr before or 2hrs after a meal. May open and mix contents in water, formula, or applesauce if difficulty swallowing caps or intolerant to oral susp. 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 2mg/kg total daily dose may be needed. Maintenance: ≥5yrs with undetectable succinylacetone levels after a minimum of 4wks therapy on a stable dose: may give total daily dose once daily (eg, 1–2mg/kg once daily).


Maintain dietary restriction of tyrosine and phenylalanine during therapy. Do not adjust dose to lower plasma tyrosine levels (maintain levels at 20mL as a single-dose) may increase risk of adverse effects (eg, headache, upset stomach, diarrhea). Elderly. Pregnancy. Nursing mothers.

Pharmacologic Class:

4-hydroxyphenylpyruvate dioxygenase inhibitor.


May potentiate CYP2C9 substrates; monitor.

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.

Generic Availability:


How Supplied:

Caps—60; Oral susp—90mL

Pricing for ORFADIN

5mg capsule (Qty: 30)
Appx. price $6747