Nitisinonedosage

2 DOSAGE & ADMINISTRATION Recommended Dosage: The recommended starting dosage is 0.5 mg/kg orally twice daily. 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 may be given once daily. Titrate the dosage based on biochemical and/or clinical response, as described in the full prescribing information. The maximum total daily dosage is 2 mg/kg orally.

Administration: Maintain dietary restriction of tyrosine and phenylalanine. Take nitisinone capsules at least one hour before, or two hours after a meal. For patients who have difficulties swallowing capsules, the capsules may be opened and the contents suspended in a small amount of water, formula or apple sauce immediately before use.

2.1 Dosage Starting

Dosage The recommended starting dosage of nitisinone capsules 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 nitisinone may be given once daily (e.g., 1 to 2 mg/kg once daily). 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. plasma and/or urine succinylacetone, urine 5-aminolevulinate (ALA) and erythrocyte porphobilinogen (PBG)-synthase activity). Maintain plasma tyrosine levels below 500 micromol/L by dietary restriction of tyrosine and phenylalanine intake. In patients who develop plasma tyrosine levels above 500 micromol/L, assess dietary tyrosine and phenylalanine intake. Do not adjust the nitisinone dosage in order to lower the plasma tyrosine concentration.

2.2 Administration

Administration of nitisinone capsules: Maintain dietary restriction of tyrosine and phenylalanine when taking nitisinone.

Capsules: Take at least one hour before, or two hours after a meal. For patients who have difficulty swallowing the capsules, the capsules may be opened and the contents suspended in a small amount of water, formula or apple sauce immediately before use.