Palbociclib is used to treat a certain type of breast cancer. It works by slowing or stopping the growth of cancer cells.

Read the Patient Information Leaflet if available from your pharmacist before you start taking palbociclib and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth as directed by your doctor, usually once daily for 21 days, then stopping the medication for 7 days. This is one cycle of treatment. Keep taking the medication this way as directed by your doctor.

This medication comes in a capsule or tablet. The capsule should be taken with food while the tablet can be taken with or without food. Swallow the medication whole. Do not crush or chew, or open the capsules, or split the tablets.

Do not take capsules or tablets that are broken or look damaged. If you vomit after taking the medication, do not take another dose of the medication that day. Take the next dose at the usual time the next day.

The dosage is based on your medical condition, lab tests, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). Your doctor may stop your medication for a while or reduce your dose if you get any side effects. Talk to your doctor for more details.

Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more details.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time on the days you are scheduled to take the medication.

Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of serious side effects will increase.

Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the capsules.

Nausea, vomiting, loss of appetite, diarrhea, tiredness, weakness, hair loss, mouth sores, or numbness/tingling of arms/legs may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

People using this medication may have serious side effects. However, you have been prescribed this drug because your doctor has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.

Tell your doctor right away if you have any serious side effects, including:

• signs of anemia (such as unusual tiredness, pale skin, fast heartbeat)
• easy bruising/bleeding (such as nosebleed)
• signs of lung problems (such as chest pain, shortness of breath)

This medication may lower your ability to fight infections. This may make you more likely to get a serious infection or make any infection you have worse. Tell your doctor right away if you have any signs of infection (such as sore throat that doesn't go away, fever, chills, cough).

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking palbociclib, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• liver disease

Palbociclib can make you more likely to get infections or may make current infections worse. Stay away from anyone who has an infection that may easily spread (such as chickenpox, COVID-19, measles, flu). Talk to your doctor if you have been exposed to an infection or for more details.

Tell your health care professional that you are using palbociclib before having any immunizations/vaccinations. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).

To lower the chance of getting cut, bruised, or injured, use caution with sharp objects like razors and nail cutters, and avoid activities such as contact sports.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This medication can affect fertility in males. Ask your doctor for more details.

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using palbociclib. Palbociclib may harm an unborn baby. Your doctor should order a pregnancy test before you start this medication. Women using this medication should ask about reliable forms of birth control during treatment and for at least 3 weeks after the last dose. Men using this medication should ask about reliable forms of birth control during treatment and for 3 months after the last dose. If you or your partner becomes pregnant, talk to your doctor right away about the risks and benefits of this medication.

Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the capsules.

It is unknown if this drug passes into breast milk. Because of the possible risk to the infant, breastfeeding is not recommended while using this drug and for at least 3 weeks after the last dose. Consult your doctor before breastfeeding.

See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Other medications can affect the removal of palbociclib from your body, which may affect how palbociclib works. Examples include azole antifungals (such as itraconazole, ketoconazole), carbamazepine, phenytoin, rifamycins (such as rifampin), St. John's wort, among others.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as complete blood count) should be done before you start taking this medication and while you are taking it. Keep all medical and lab appointments.

If you miss a dose, skip the missed dose. Take your next dose at the regular time the next day. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).