Uses of Ribociclib and Letrozole:

• It is used to treat breast cancer.

What do I need to tell my doctor BEFORE I take Ribociclib and Letrozole?

• If you are allergic to ribociclib and letrozole; any part of ribociclib and letrozole; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
• If you have any of these health problems: Electrolyte problems (like calcium, magnesium, phosphorous, or potassium), heart problems like heart failure or a certain type of chest pain (unstable angina), long QT on ECG, or slow or abnormal heartbeat.
• If you have had a recent heart attack.
• If you are taking tamoxifen.
• If you are taking any drugs that can cause a certain type of heartbeat that is not normal (prolonged QT interval). There are many drugs that can do this. Ask your doctor or pharmacist if you are not sure.
• If you take any drugs (prescription or OTC, natural products, vitamins) that must not be taken with ribociclib and letrozole, like certain drugs that are used for HIV, infections, or seizures. There are many drugs that must not be taken with ribociclib and letrozole.
• If you are breast-feeding. Do not breast-feed while you take ribociclib and letrozole and for 3 weeks after your last dose.

This is not a list of all drugs or health problems that interact with ribociclib and letrozole.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take ribociclib and letrozole with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Ribociclib and Letrozole?

• Tell all of your health care providers that you take ribociclib and letrozole. This includes your doctors, nurses, pharmacists, and dentists.
• An unsafe heartbeat that is not normal (long QT on ECG) has happened with ribociclib and letrozole. This may raise the chance of sudden death. Talk with the doctor.
• You will need an ECG before starting ribociclib and letrozole and during treatment. Talk with your doctor.
• If you have upset stomach, throwing up, diarrhea, or are not hungry, talk with your doctor. There may be ways to lower these side effects.
• You may have more chance of getting an infection. Wash hands often. Stay away from people with infections, colds, or flu.
• This medicine may cause weak bones. This may happen more often if used for a long time. This may raise the chance of broken bones. Call your doctor right away if you have bone pain.
• Have a bone density test as you have been told by your doctor. Talk with your doctor.
• Have blood work checked as you have been told by the doctor. Talk with the doctor.
• Avoid grapefruit and grapefruit juice.
• This medicine may affect fertility. Fertility problems may lead to not being able to get pregnant or father a child.
• This medicine may cause harm to an unborn baby. A pregnancy test will be done before you start ribociclib and letrozole to show that you are NOT pregnant.
• Women must use birth control while taking ribociclib and letrozole and for some time after the last dose. Ask your doctor how long to use birth control. If you get pregnant, call your doctor right away.

How is this medicine (Ribociclib and Letrozole) best taken?

Use ribociclib and letrozole as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• Take with or without food.
• Take in the morning.
• Take ribociclib and letrozole at the same time of day.
• Swallow whole. Do not chew, break, or crush.
• Do not take chipped or broken tablets.
• If you throw up after taking a dose, do not repeat the dose. Take your next dose at your normal time.
• Keep taking ribociclib and letrozole as you have been told by your doctor or other health care provider, even if you feel well.

What do I do if I miss a dose?

• Skip the missed dose and go back to your normal time.
• Do not take 2 doses at the same time or extra doses.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of infection like fever, chills, very bad sore throat, ear or sinus pain, cough, more sputum or change in color of sputum, pain with passing urine, mouth sores, or wound that will not heal.
• Signs of a urinary tract infection (UTI) like blood in the urine, burning or pain when passing urine, feeling the need to pass urine often or right away, fever, lower stomach pain, or pelvic pain.
• Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
• Signs of electrolyte problems like mood changes, confusion, muscle pain or weakness, a heartbeat that does not feel normal, seizures, not hungry, or very bad upset stomach or throwing up.
• Dizziness or passing out.
• Fast or abnormal heartbeat.
• Feeling very tired or weak.
• Swelling in the arms or legs.
• Any unexplained bruising or bleeding.
• Some people have had lung problems with ribociclib and letrozole. Sometimes, this has been deadly. Call your doctor right away if you have signs of lung problems like shortness of breath or other trouble breathing, cough that is new or worse, or fever.

What are some other side effects of Ribociclib and Letrozole?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Constipation, diarrhea, stomach pain, upset stomach, throwing up, or feeling less hungry.
• Hair loss.
• Feeling tired or weak.
• Headache.
• Back pain.
• Trouble sleeping.
• Mouth irritation or mouth sores.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Ribociclib and Letrozole?

• Store in the original container at room temperature.
• Store in a dry place. Do not store in a bathroom.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

Consumer Information Use and Disclaimer

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else's drugs.
• Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about ribociclib and letrozole, please talk with your doctor, nurse, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.