Venclexta inhibits a certain protein in cancer cells (abnormal lymphocytes produced in chronic lymphocytic leukemia) that helps keep those cells alive and makes them resistant to chemotherapy. Venetoclax binds to this protein, which helps kill the cancerous lymphocytes in blood and bone marrow.

Venclexta is a prescription medicine used to treat chronic lymphocytic leukemia (CLL) or small lymphocytic leukemia (SLL) in adults with or without 17p deletion (a specific genetic marker). Venetoclax is sometimes used in combination with rituximab to treat these conditions.

Venclexta is also used in combination with azacitidine, decitabine, or low-dose cytarabine to treat acute myeloid leukemia.This combination is for use in adults who are 75 years or older, or who cannot use standard chemotherapy due to other medical conditions.

Call your doctor at once if you have a fever, chills, joint or muscle pain, tiredness, confusion, shortness of breath, fast or slow heartbeats, nausea, vomiting, dark or cloudy urine, or a seizure (convulsions).

Drink 6 to 8 full glasses of water each day to help prevent these side effects.

Tell your doctor about all your current medicines and any you start or stop using. Many drugs can interact, and some drugs should not be used together.

Before taking this medicine

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

• an antibiotic or antifungal medicine;

• heart medication; or

• antiviral medicine to treat hepatitis C or HIV.

Do not start or stop using any medicine without asking your doctor.

To make sure Venclexta is safe for you, tell your doctor if you have ever had:

• liver or kidney disease;

• an electrolyte imbalance (such as low levels of potassium or calcium in your blood);

• gout, or high levels of uric acid in your blood; or

• if you use a blood thinner (such as warfarin) and you have routine "INR" or prothrombin time tests.

May harm an unborn baby. You may need a pregnancy test to make sure you are not pregnant. Use birth control while using Venclexta and for at least 30 days after your last dose. Tell your doctor if you become pregnant.

It may be harder for a man to get a woman pregnant while you using this medicine.

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

Take Venclexta exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

You may receive your first dose in a hospital or clinic setting to quickly treat any serious side effects.

Take Venclexta with food and water, at the same time each day.

Do not crush, chew, or break a tablet. Swallow the tablet whole.

If you vomit shortly after taking Venclexta, do not take another tablet. Take your next dose as scheduled the next day.

To prevent certain side effects, drink 6 to 8 glasses of water daily for 2 days before you start taking Venclexta. Also drink 6 to 8 glasses of water on the day you first take this medicine, and whenever your dose is changed.

You may need frequent medical tests and your cancer treatments may be delayed based on the results.

Do not stop using this medicine without first asking your doctor.

Store tablets in their original container at room temperature, away from moisture and heat. Do not put the tablets into a daily pill box.

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

• an antibiotic or antifungal medicine;

• heart medication; or

• antiviral medicine to treat hepatitis C or HIV.

Do not start or stop using any medicine without asking your doctor.

To make sure Venclexta is safe for you, tell your doctor if you have ever had:

• liver or kidney disease;

• an electrolyte imbalance (such as low levels of potassium or calcium in your blood);

• gout, or high levels of uric acid in your blood; or

• if you use a blood thinner (such as warfarin) and you have routine "INR" or prothrombin time tests.

May harm an unborn baby. You may need a pregnancy test to make sure you are not pregnant. Use birth control while using Venclexta and for at least 30 days after your last dose. Tell your doctor if you become pregnant.

It may be harder for a man to get a woman pregnant while you using this medicine.

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

Use the medicine as soon as you can, but skip the missed dose if you are more than 8 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.

Avoid receiving a "live" vaccine. The vaccine may not work as well while you are using Venclexta. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), and zoster (shingles).

Grapefruit, starfruit, and Seville oranges may interact with venetoclax and lead to unwanted side effects. Avoid consuming grapefruit products, starfruit, and orange marmalades.

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

Call your doctor at once if you have:

• symptoms of sepsis - confusion, severe drowsiness, rapid breathing, feeling very ill;

• signs of pneumonia - cough with yellow or green mucus, stabbing chest pain, wheezing, trouble breathing;

• low blood cell counts - fever, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed; or

• signs of tumor cell breakdown - chills, joint or muscle pain, feeling tired or short of breath, fast or slow heartbeats, nausea, vomiting, dark or cloudy urine, or seizure (convulsions).

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

Common Venclexta side effects may include:

• stomach pain, nausea, vomiting, diarrhea, constipation;

• feeling tired or short of breath;

• low blood pressure, feeling dizzy or lightheaded;

• muscle and joint pain;

• swelling in your arms, legs, hands, and feet;

• fever, low blood cell counts;

• pneumonia, sepsis;

• mouth pain;

• rash; or

• cold symptoms such as stuffy nose, sneezing, sore throat, cough.

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.

Many drugs can interact with venetoclax. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.