Kuvan

Generic Name: sapropterin (SAP roe TER in)
Brand Names: Kuvan

What is Kuvan?

Kuvan (sapropterin) is a synthetic form of a natural substance that activates an enzyme needed to break down phenylalanine in the body.

Phenylketonuria (PKU) is a disorder in which the body cannot break down phenylalanine. Elevated phenylalanine levels can cause problems with thinking and behavior.

Kuvan is used to lower blood levels of phenylalanine in people with a certain type of PKU.

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

Important information

Before using Kuvan, tell your doctor if you are allergic to any drugs, or if you have liver disease, a history of stomach ulcer or bleeding, or a seizure disorder.

Also tell your doctor about any medications you use, especially levodopa (Larodopa, Altamet, Parcopa, Sinemet), methotrexate (Rheumatrex, Trexall), or any medication to treat erectile dysfunction, such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra).

Slideshow: View Frightful (But Dead Serious) Drug Side Effects

If Kuvan is not controlling your condition properly, you may have symptoms such as behavior changes, numbness or tingling, or problems with speech, vision, or balance. Call your doctor if you have any of these symptoms.

Before taking this medicine

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

To make sure Kuvan is safe for you, tell your doctor if you have:

• liver or kidney disease;

• a fever or loss of appetite;

• a history of stomach ulcer or bleeding;

• epilepsy or other seizure disorder;

• if you are malnourished;

• if you take levodopa or methotrexate; or

• if you take sildenafil (Viagra) or other erectile dysfunction medicines (Cialis, Levitra, Stendra).

FDA pregnancy category C. It is not known whether Kuvan will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.

See also: Pregnancy and breastfeeding warnings (in more detail)

If you are pregnant, your name may be listed on a pregnancy registry. This is to track the outcome of the pregnancy and to evaluate any effects of sapropterin on the baby.

It is not known whether sapropterin passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

Kuvan should not be given to a child younger than 4 years old without a doctor's advice.

How should I take Kuvan?

Kuvan is usually given once daily. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Kuvan works best if you take it with food.

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.

Kuvan can reduce your phenylalanine blood levels within 24 hours of when you take it. However, it may take up to 30 days of using this medicine before it reaches its fullest effect in your body. For best results, keep using the medication as directed.

Kuvan is only part of a complete program of treatment that also includes a special diet. Follow the diet plan created for you by your doctor or nutrition counselor. Get familiar with the list of foods you must avoid to help control your condition.

While using Kuvan, you may need frequent blood tests.

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

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Do not take 2 doses on the same 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 Kuvan?

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

Kuvan side effects

If Kuvan is not controlling your condition properly, you may have symptoms such as behavior changes, numbness or tingling, or problems with speech, vision, or balance. Call your doctor right away if you have any of these symptoms.

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

Call your doctor at once if you have:

• severe stomach discomfort;

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

• hyperactive behavior;

• seizure (convulsions); or

• chest pain or pressure, pain spreading to your jaw or shoulder.

Common Kuvan side effects may include:

• headache, dizziness;

• feeling agitated or irritable;

• nausea, vomiting, stomach pain, diarrhea;

• swelling in your hands or feet;

• joint pain;

• increased urination; or

• cold symptoms such as runny or stuffy nose, sneezing, 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.

See also: Side effects (in more detail)

What other drugs will affect Kuvan?

Other drugs may interact with sapropterin, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Where can I get more information?

• Your pharmacist can provide more information about Kuvan.