Pacritinib is used to treat myelofibrosis in adults.

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

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

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

If you take other kinase inhibitors such as fedratinib or ruxolitinib you should not stop using these medicines suddenly before you start taking pacritinib. Follow your doctor's instructions about tapering your dose.

Pacritinib is usually taken by mouth twice every day with or without food.

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

You will need blood tests before you start taking pacritinib and during treatment.

Your treatment with pacritinib may be delayed or permanently discontinued if you have certain side effects.

Store at room temperature away from moisture, heat, and light.

Usual Adult Dose for Myelofibrosis:

200 mg orally 2 times a day

Use: Treatment of patients with intermediate or high-risk primary or secondary (post-polycythemia vera OR post-essential thrombocythemia) myelofibrosis (MF) with a platelet count less than 50 times 10(9)/L (50 x 10(9)/L)

Some drugs should not be used with pacritinib. Your treatment plan may change if you also use:

• nefazodone;

• St. John's wort;

• an antibiotic--clarithromycin, rifabutin, rifampin, rifapentine, telithromycin;

• antifungal medicine--itraconazole, ketoconazole;

• antiviral medicine for HIV or hepatitis C--boceprevir, cobicistat, dasabuvir, elvitegravir, indinavir, lopinavir/ritonavir, nelfinavir, ombitasvir, paritaprevir, saquinavir, telaprevir, tipranavir;

• cancer medicine--apalutamide, enzalutamide, mitotane;

• seizure medicine--carbamazepine, oxcarbazepine, phenytoin, primidone; or

• steroid medicine--dexamethasone, prednisone.

Tell your doctor if you have ever had:

• liver or kidney disease;

• any other cancers;

• a blood clot, or stroke;

• a heart attack, or other heart problem;

• if you have an infection;

• if you have diarrhea (or loose stools), nausea or vomiting;

• if you smoke or were a smoker; or

• if you have active bleeding, have had severe bleeding, or plan to have surgery.

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

It may be harder for you to get a woman pregnant while you are using pacritinib.

Do not breastfeed while using this medicine, and for at least 2 weeks after your last 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 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 light, 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.

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

• bleeding, bruising, and fever;

• severe or ongoing diarrhea;

• dizziness, a light-headed feeling, like you might pass out;

• signs of a stroke--sudden numbness or weakness, severe headache, slurred speech, problems with vision or balance;

• signs of a blood clot in the lung--chest pain, sudden cough or shortness of breath, dizziness, coughing up blood;

• signs of a blood clot deep in the body--pain, swelling, or warmth in one leg;

• heart attack symptoms--chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating; or

• signs of infection--fever, chills, sore throat, body aches, unusual tiredness, loss of appetite, bruising or bleeding.

Common side effects of pacritinib may include:

• swelling in ankles, legs, and feet;

• nausea and vomiting; or

• pale skin, tiredness, feeling light-headed or short of breath, cold hands and feet.

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 pacritinib, 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.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking pacritinib.

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.