Fedratinib is used to treat myelofibrosis in adults.

Myelofibrosis is a rare type of bone marrow cancer that affects your body's ability to produce blood cells.

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

Some people using fedratinib have developed vitamin B1 deficiency that resulted in serious and sometimes fatal brain damage. Your vitamin B1 levels will need to be checked before and during treatment, and you may need to take a vitamin B1 supplement.

Get emergency medical help if you have symptoms such as drowsiness, confusion, memory problems, vision problems, unusual eye movements, or problems with coordination and muscle movement.

Call your doctor if you are sick with vomiting or diarrhea even while taking medications to prevent these side effects.

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.

You may take fedratinib with or without food. Take with a high-fat meal if fedratinib upsets your stomach.

Your vitamin B1 (thiamine) levels will need to be checked before and during treatment with fedratinib. You may need to take a vitamin B1 supplement.

You may be given other medications to help prevent nausea, vomiting, and diarrhea. Keep using these medicines for as long as your doctor has prescribed.

Some people using fedratinib have developed vitamin B1 deficiency that resulted in serious and sometimes fatal brain damage. Your vitamin B1 levels will need to be checked before and during treatment with fedratinib. You may need to take a vitamin B1 supplement.

Call your doctor if you are sick with vomiting or diarrhea even while taking medications to prevent these side effects. You can easily become malnourished from vomiting and diarrhea. This can lead to low vitamin B1 levels.

Fedratinib can lower your blood cell counts and affect liver function. Your blood will need to be tested often. Your cancer treatments may be delayed based on the results.

Do not change your dose or stop taking fedratinib without your doctor's advice.

Store at room temperature away from moisture and heat.

Usual Adult Dose for Myelofibrosis:

For patients with a baseline platelet count of 50 x 10(9)/L or greater:
400 mg orally once a day

Comments:
-Patients who are taking ruxolitinib: Patients should taper off and discontinue ruxolitinib prior to starting this drug.
-Assess thiamine (vitamin B1) levels and nutritional status prior to starting therapy, periodically during therapy, and as indicated.
-Administration with a high fat meal may reduce the incidence of nausea and vomiting.
-Subsequent doses of this drug are subject to dose adjustments based on the concomitant use of CYP450 3A4 inhibitors, renal function, prior adverse reactions, and/or thiamine levels.

Use: For the treatment of patients with intermediate-2 or high-risk primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis (MF)

Tell your doctor if you have ever had:

• low levels of platelets or red blood cells;

• liver disease;

• kidney disease; or

• if you have been taking ruxolitinib (Jakafi).

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

You should not breastfeed while using this medicine, and for at least 1 month after your last dose.

Skip the missed dose and use your next dose at the regular time. 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).

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.

Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medication.

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.

Some people using fedratinib have developed vitamin B1 deficiency that resulted in serious and sometimes fatal brain damage. Seek emergency medical attention if you have symptoms such as:

• drowsiness, confusion, memory problems;

• vision problems, unusual eye movements; or

• problems with coordination and muscle movement.

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

• severe or ongoing nausea, vomiting, or diarrhea (even while you are taking medication to prevent these effects);

• easy bruising, unusual bleeding, purple or red spots under your skin;

• low red blood cells (anemia)--pale skin, unusual tiredness, feeling light-headed or short of breath, cold hands and feet; or

• low white blood cell counts--fever, mouth sores, skin sores, sore throat, cough, trouble breathing.

You may need a blood transfusion if your blood counts get too low.

Common side effects of fedratinib may include:

• nausea, vomiting;

• diarrhea; or

• anemia.

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 medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Other drugs may affect fedratinib, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

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.