Sapropterin Dosage

Usual Adult Dose for Phenylketonuria

Initial dose: 10 to 20 mg/kg orally once a day
Maintenance dose: Once responsiveness established, dose may be adjusted within the range of 5 to 20 mg/kg/day according to response to therapy.

Comments:
-Response to therapy determined by change in blood phenylalanine (Phe); see Dose Adjustments.
-Blood Phe should be monitored periodically to assess blood Phe control.

Use: In conjunction with a Phe-restricted diet, to reduce blood Phe levels in patients with hyperphenylalaninemia due to tetrahydrobiopterin- (BH4-) responsive phenylketonuria (PKU)

Usual Pediatric Dose for Phenylketonuria

Initial dose:
1 month to 6 years: 10 mg/kg orally once a day
7 years or older: 10 to 20 mg/kg orally once a day

Maintenance dose: Once responsiveness established, dose may be adjusted within the range of 5 to 20 mg/kg/day according to response to therapy.

Comments:
-Response to therapy is determined by change in blood Phe; see Dose Adjustments.
-Blood Phe should be monitored frequently to assess blood Phe control.

Use: In conjunction with a Phe-restricted diet, to reduce blood Phe levels in patients with hyperphenylalaninemia due to BH4-responsive PKU

Renal Dose Adjustments

Data not available

Comments: Careful monitoring recommended.

Liver Dose Adjustments

Data not available

Comments: Careful monitoring recommended; hepatic damage associated with impaired Phe metabolism.

Dose Adjustments

If the starting dose is 10 mg/kg/day:
-Response to therapy is determined by change in blood Phe after treatment at this dose for up to 1 month.
-Blood Phe levels should be checked after 1 week of therapy and periodically for up to a month.
-If blood Phe does not decrease from baseline at 10 mg/kg/day, dose may be increased to 20 mg/kg/day.
-If blood Phe does not decrease after 1 month at 20 mg/kg/day, patient is a nonresponder and this drug should be discontinued.

If the starting dose is 20 mg/kg/day:
-Response to therapy is determined by change in blood Phe after treatment at this dose for 1 month.
-Blood Phe levels should be checked after 1 week of therapy and periodically during the first month.
-Therapy should be discontinued in patients who do not respond to this drug.

Precautions

Safety and efficacy have not been established in patients younger than 1 month.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:
-Take with a meal to increase absorption, preferably same time each day.
-May swallow tablets whole or dissolved in water or apple juice; take dissolved tablets within 15 minutes of dissolution.
-Take dissolved powder for oral solution within 30 minutes of dissolution.
-Take a missed dose as soon as possible, but do not take 2 doses on the same day.

Storage requirements:
-Protect from moisture.

Reconstitution/preparation techniques:
Tablets:
-May be dissolved in 120 to 240 mL of water or apple juice; the manufacturer's product information should be consulted for further information.
-May be crushed and then mixed in a small amount of soft foods (e.g., apple sauce, pudding).
Powder for oral solution:
-Should be dissolved in 120 to 240 mL of water or apple juice
-May be stirred in a small amount of soft foods
-Packet contents should be emptied in water, apple juice, or soft foods and mixed thoroughly; it should dissolve completely.
-The manufacturer product information should be consulted regarding preparation for use in infants weighing 10 kg or less.

Monitoring:
-Gastrointestinal: Signs of gastritis
-Hepatic: Liver function tests in patients with liver dysfunction
-Metabolic: Blood Phe levels (during therapy; frequently in pediatric patients)
-Nervous system: For hyperactivity

Patient advice:
-Use this drug in addition to a Phe-restricted diet.