Sapropterin

Generic name: sapropterin [ SAP-roe-TER-in ]
Brand names: Javygtor, Kuvan
Dosage forms: oral powder for reconstitution (100 mg; 500 mg), oral tablet (100 mg), oral tablet, soluble (100 mg)
Drug class: Miscellaneous metabolic agents

Medically reviewed by Drugs.com on Jun 23, 2023. Written by Cerner Multum.

What is sapropterin?

Sapropterin is used to lower blood levels of phenylalanine in adults and children at least one month old with a certain type of phenylketonuria (PKU).

Sapropterin may also be used for purposes not listed in this medication guide.

Sapropterin side effects

Get emergency medical help if you have signs of an allergic reaction: hives, rash, wheezing, cough, difficult breathing, nausea, feeling light-headed, flushing (warmth, redness, or tingly feeling), swelling of your face, lips, tongue, or throat.

Sapropterin may cause serious side effects. Call your doctor at once if you have:

• behavior changes, seizures, or problems with speech;

• fever, loss of appetite, difficulty swallowing, throat pain, severe stomach discomfort or pain, nausea, vomiting;

• bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds; or

• hyperactive behavior, such as fidgeting or moving around often, or talking too much.

Common side effects of sapropterin may include:

• headache;

• diarrhea;

• vomiting; or

• runny or stuffy nose, sore throat, cough.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Warnings

Use only as directed. Tell your doctor if you use other medicines or have other medical conditions or allergies.

Before taking this medicine

You should not use sapropterin if you are allergic to it.

Tell your doctor if you have ever had:

• stomach ulcer or bleeding; or

• loss of appetite, or if you are malnourished.

It is not known if sapropterin will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of sapropterin on the baby.

Ask a doctor if it is safe to breastfeed while using sapropterin.

How should I take sapropterin?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Sapropterin can cause phenylalanine levels to get too low in children younger than 7 years old who use this medicine.

Take the medicine with food at the same time each day.

You may swallow the tablet whole or dissolve it in 4 to 8 ounces of water or apple juice.

• It will take a few minutes for the tablet to dissolve, and you may see small pieces in the liquid. These pieces are safe for you to swallow.

• Stir the mixture and then drink all of it within 15 minutes after the tablet dissolves.

• To get the entire dose, add a little more water to the same glass, swirl gently and drink right away.

• You may also crush the tablet and mix it with a small amount of soft food such as pudding or applesauce.

The powder for oral solution must be dissolved in 4 to 8 ounces of water or apple juice.

• If you are giving this medicine to a baby who weighs less than 22 pounds, you may dissolve the powder in as little as 1 teaspoon of water or apple juice. Then give the liquid to the baby using an oral dosing syringe. If you do not have a dosing syringe, ask your pharmacist for one.

• Stir the mixture and then drink all of it within 30 minutes after the powder dissolves.

• You may also mix the powder with a small amount of soft food such as pudding or applesauce.

• Make sure the powder is completely dissolved before drinking or eating the mixture.

Doses are based on weight in children and teenagers. Your child's dose may change if the child gains or loses weight.

You may need to follow a special diet. Follow all instructions of your doctor or dietitian. Learn about the foods you should eat or avoid.

While using sapropterin, you may need frequent blood tests.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

Sapropterin dosing information

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).

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses in a day.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking sapropterin?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect sapropterin?

Tell your doctor about all your other medicines, especially:

• levodopa;

• methotrexate, valproic acid, phenobarbital, trimethoprim; or

• medicine to treat impotence or pulmonary arterial hypertension--sildenafil (Viagra, Revatio), avanafil (Stendra), tadalafil (Adcirca, Cialis) vardenafil (Levitra, Staxyn).

This list is not complete. Other drugs may affect sapropterin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

Copyright 1996-2024 Cerner Multum, Inc. Version: 7.01.