Mitapivat is used to treat low red blood cell counts caused by hemolytic anemia (early breakdown of red blood cells) in adults with pyruvate kinase deficiency.

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

Call your doctor at once if you have jaundice (yellowing of the skin or eyes), dark urine, dizziness, confusion, tiredness, or shortness of breath.

Mitapivat comes as a tablet to take by mouth. It is usually taken with or without food 2 times a day. Take mitapivat at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take mitapivat exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets/capsules whole; do not split, chew, or crush them.

Your doctor will probably start you on a low dose of mitapivat and gradually increase your dose, typically every 4 weeks.

Mitapivat controls hemolytic anemia from pyruvate kinase deficiency but does not cure it. Continue to take mitapivat even if you feel well. Do not stop taking mitapivat without talking to your doctor. If you suddenly stop taking mitapivat, you may experience symptoms of acute hemolysis and anemia (yellowing of the skin or whites of the eyes, dark urine, dizziness, confusion, tiredness, difficulty breathing). Your doctor will probably decrease your dose gradually.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

You may take mitapivat with or without food.

Swallow the tablet whole and do not crush, chew, or break it.

Do not share mitapivat with another person, even if they have the same symptoms you have.

Do not change your dose or stop using mitapivat without talking to your doctor. Your doctor will give you instructions for stopping mitapivat.

Store this medicine in the original container at room temperature.

Tell your doctor if you have ever had:

• liver disease.

Tell your doctor if you are pregnant or breastfeeding.

Use the medicine as soon as you can, but skip the missed dose if you are more than 4 hours late for the dose. Do not use two doses at one time.

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

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Mitapivat tablets should stay in their original blister packaging until ready to use.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

Unless your doctor tells you otherwise, continue your normal diet.

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

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

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

• jaundice (yellowing of the skin or eyes);

• dark urine;

• dizziness;

• confusion;

• tiredness; or

• shortness of breath.

Common side effects of mitapivat may include:

• flushing (sudden warmth, redness, or tingly feeling);

• breast swelling and tenderness;

• changes in sexual function;

• irregular heart rhythm;

• abnormal blood tests; or

• back or joint pain.

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.

Sometimes it is not safe to use certain medicines at the same time. Some drugs can affect your blood levels of other drugs you use, which may increase side effects or make the medicines less effective.

Other drugs may affect mitapivat, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to mitapivat.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.