Orfadin Suspension

Generic name:nitisinone
Dosage form: oral suspension
Drug class:Miscellaneous metabolic agents

Medically reviewed by Drugs.com. Last updated on Jul 1, 2021.

Indications and Usage for Orfadin Suspension

ORFADIN ® is indicated for the treatment of adult and pediatric patients with hereditary tyrosinemia type 1 (HT-1) in combination with dietary restriction of tyrosine and phenylalanine.

Orfadin Suspension Dosage and Administration

Dosage

Starting Dosage

The recommended starting dosage of ORFADIN is 0.5 mg/kg administered orally twice daily

Maintenance Regimen

In patients 5 years of age and older who have undetectable serum and urine succinylacetone concentrations after a minimum of 4 weeks on a stable dosage of nitisinone, the total daily dose of ORFADIN may be given once daily (e.g., 1 to 2 mg/kg once daily) [see Clinical Pharmacology ( 12.2)] .

Dosage Titration

Titrate the dosage in each individual patient based on biochemical and/or clinical response.

• Monitor plasma and/or urine succinylacetone concentrations, liver function parameters and alpha-fetoprotein levels.
• If succinylacetone is still detectable in blood or urine 4 weeks after the start of nitisinone treatment, increase the nitisinone dosage to 0.75 mg/kg twice daily. A maximum total daily dosage of 2 mg/kg may be needed based on the evaluation of all biochemical parameters.
• If the biochemical response is satisfactory (undetectable blood and/or urine succinylacetone), the dosage should be adjusted only according to body weight gain and not according to plasma tyrosine levels.
• During initiation of therapy, when switching from twice daily to once daily dosing, or if there is a deterioration in the patient's condition, it may be necessary to follow all available biochemical parameters more closely (i.e. pla...