Idelalisib is used together with rituximab to treat chronic lymphocytic leukemia, and certain types of lymphoma.

Idelalisib is sometimes given after at least two other cancer treatments did not work or have stopped working.

Idelalisib was approved by the US Food and Drug Administration (FDA) on an "accelerated" basis to treat lymphoma. In clinical studies, some people responded to idelalisib, but further studies are needed.

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

Idelalisib can cause serious harm to your liver, lungs, or intestines. Some of these conditions may lead to fatal complications. Call your doctor right away if you have: upper stomach pain, easy bruising or bleeding, dark urine, yellowing of your skin or eyes, cough, wheezing, shortness of breath, fever, chills, worsening stomach pain, or vomiting.

You may have severe or life-threatening diarrhea while taking idelalisib. Tell your doctor at once if your daily bowel movements increase by 6 or more.

Idelalisib comes as a tablet to take by mouth. It is usually taken with or without food twice a day. Take idelalisib 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 idelalisib exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

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

Your doctor may decrease your dose of idelalisib or tell you to stop taking the medication for a time or permanently if you experience serious side effects during your treatment. This depends on how well the medication works for you and the side effects you experience. Talk to your doctor about how you are feeling during your treatment. Continue to take idelalisib even if you feel well. Do not stop taking idelalisib without talking to your doctor.

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 idelalisib with or without food.

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

You may have severe or life-threatening diarrhea while taking idelalisib. Tell your doctor at once if your daily bowel movements increase by 6 or more.

You may need frequent medical tests to be sure this medicine is not causing harmful effects. Your cancer treatments may be delayed based on the results.

Do not stop using idelalisib without your doctor's advice.

Store this medicine in the original container at room temperature, away from moisture and heat.

You may not be able to use idelalisib if you have ever had a serious skin reaction to any medicine.

Tell your doctor if you have ever had:

• liver disease;

• lung disease; or

• a perforation (a hole or tear) in your intestines.

Idelalisib can harm an unborn baby if the mother or the father is using idelalisib.

• If you are a woman, do not use idelalisib if you are pregnant. You may need to have a negative pregnancy test before starting this treatment. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 1 month after your last dose.

• If you are a man, use effective birth control if your sex partner is able to get pregnant. Keep using birth control for at least 3 months after your last dose.

• Tell your doctor right away if a pregnancy occurs while either the mother or the father is using idelalisib.

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

Idelalisib is not approved for use by anyone younger than 18 years old.

Take the medicine as soon as you can, but skip the missed dose if you are more than 6 hours late for the 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).

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.

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

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 in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include: skin rash, fever, swollen glands, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes.

Idelalisib can cause serious harm to your liver, lungs, or intestines. You may have severe or life-threatening diarrhea, or a perforation (a hole or tear) in your intestines. Some of these conditions may lead to fatal complications.

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

• severe diarrhea, increased number of stools per day;

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

• intestinal problems--worsening stomach pain, fever, chills, vomiting;

• liver problems--upper stomach pain, loss of appetite, dark urine, jaundice (yellowing of the skin or eyes);

• lung problems--worsening cough, wheezing, cough with mucus, or shortness of breath;

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

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects of idelalisib may include:

• nausea, stomach pain, diarrhea;

• fever, cough, lung problems;

• low white blood cells;

• abnormal liver function tests;

• rash; or

• feeling tired.

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 idelalisib, 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.