Sapropterin Dosage

Medically reviewed by Drugs.com. Last updated on Jun 23, 2023.

Applies to the following strengths: 100 mg; 500 mg

Usual Adult Dose for Phenylketonuria

Initial dose: 10 to 20 mg/kg orally once a day

Blood phenylalanine (Phe) levels should be measured after 1 week, and then periodically; dose should be increased to 20 mg/kg/day if blood Phe levels have not decreased

Maintenance dose: Once responsiveness has been established, dose should be adjusted within the range of 5 to 20 mg/kg/day according to biochemical response.

Non-Responders:

Patients whose phenylalanine levels do not decrease with treatment at 20 mg/kg/day for 1 month should be considered non-responders and treatment should be discontinued.

Comments:

This drug should be used in conjunction with a phenylalanine-restricted diet.
Existing dietary protein and Phe intake should not be modified during the evaluation period
Response to therapy is determined by change in blood phenylalanine levels.

Use: To reduce blood phenylalanine levels in patients with hyperphenylalaninemia due to tetrahydrobiopterin- (BH4-) responsive phenylketonuria (PKU).

Usual Pediatric Dose for Phenylketonuria

1 month to 6 years:

Initial dose: 10 mg/kg orally once a day

7 years or older:

Initial dose: 10 to 20 mg/kg orally once a day

Measure blood phenylalanine levels after 1 week, and then periodically; dose should be increased to 20 mg/kg/day if blood phenylalanine levels have not decreased

Maintenance dose: Once responsiveness has been established, dose should be adjusted within the range of 5 to 20 mg/kg/day according to biochemical response.

Non-Responders:

Patients whose phenylalanine levels do not decrease with treatment at 20 mg/kg/day for 1 month should be considered non-responders and treatment should be discontinued.

Comments:

This drug should be used in conjunction with a phenylalanine-restricted diet.
Existing dietary protein and Phe intake should not be modified during the evaluation period
Response to therapy is determined by change in blood phenylalanine levels.

Use: To reduce blood phenylalanine levels in patients with hyperphenylalaninemia due to tetrahydrobiopterin- (BH4-) responsive phenylketonuria (PKU).

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Data not available

Precautions

CONTRAINDICATIONS:

None

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 at the same time each day

Tablets:

Swallow whole; dissolve in water or apple juice and consume; or crush tablets and mix with a small amount of soft food such as apple sauce or pudding and consume
To dissolve: Place whole, or to speed up process, crushed tablets in 120 to 240 mL of water or apple juice; stir until dissolved (it may take a few minutes for tablets to dissolve and tablets may not completely dissolve)
Consume tablet solution orally within 15 minutes of dissolution; if any pieces of tablet remain, add additional water or apple juice, stir, and take orally, repeat until all of the tablet is consumed

Powder for Oral Solution:

Dissolve powder for oral solution in 120 to 240 mL of water or apple juice and take within 30 minutes of dissolution
Powder for oral solution may also be stirred in a small amount of soft food such as apple sauce or pudding and consumed
Patients weighing less than 10 kg: Package Labeling may be consulted for dose chart
Dissolve oral solution in as little as 5 mL of water or apple juice and provide a portion of solution corresponding daily dose via an oral dosing syringe

Missed dose: Take as soon as possible; do not take 2 doses on the same day

Storage requirements:

Protect from moisture

General:

Therapy should be directed by physicians knowledgeable in the management of phenylketonuria (PKU).
All patients should be receiving a phenylalanine-restricted diet.

Monitoring:

Gastrointestinal: Signs of gastritis
Metabolic: Blood Phe levels (during therapy; frequently in pediatric patients)
Nervous system: For hyperactivity

Patient advice:

Patients/caregivers should be instructed to read the FDA-approved patient labeling (Patient Information and Instructions for Use).
Patients/caregivers should understand this drug must be used in conjunction with a phenylalanine-restricted diet; they should be informed of the consequences of increased or decreased phenylalanine blood concentrations.
Patients/caregivers should understand that they will need blood tests to determine if this drug is working for them and to maintain phenylalanine levels in the desired range.
Patients/caregivers should be instructed to notify their healthcare provider if they experience gastritis, hyperactivity, or any new symptoms.
Patients/caregivers should be instructed to speak with their healthcare provider before starting any new medications.
Patients who are pregnant or interested in becoming pregnant should speak with their healthcare provider.