This medication is used along with diet changes for long-term treatment of a certain inherited disorder (phenylketonuria-PKU). It helps remove a certain chemical (phenylalanine) from the body. Too much phenylalanine in the body can cause brain damage.

Read the Patient Information Leaflet and Instructions for Use if available from your pharmacist before you start taking sepiapterin and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with food as directed by your doctor, usually once daily. After taking this medication, eat some more food.

Mix the contents of the packet with water or apple juice as directed. Certain doses may also be mixed in strawberry jam or applesauce. Ask your doctor or pharmacist how to mix and prepare your dose. Mix well and carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose. After mixing, the medication should be taken within 6 hours if stored at room temperature or within 24 hours if stored in the refrigerator. Discard any unused medication after 6 hours at room temperature or 24 hours in the refrigerator.

The dosage is based on your medical condition, response to treatment, age, weight, and lab tests.

To reduce your risk of side effects, your doctor may direct you to start this medication at a low dose and gradually increase your dose. Follow your doctor's instructions carefully.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.

Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.

Tell your doctor if you do not get better or if you get worse.

Diarrhea, abdominal pain, or headache may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

This medication may cause your stool to turn yellow or orange. This effect is harmless and will disappear when the medication is stopped.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• easy bleeding/bruising
• heavy menstrual bleeding

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking sepiapterin, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as phenylalanine blood levels) should be done before you start taking this medication and while you are taking it. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember if it is on the same day. If you do not remember until the next day, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.