Palbociclib is used in combination with another medication as an initial treatment for a certain type of hormone receptor–positive, advanced breast cancer (breast cancer that depends on hormones such as estrogen to grow) that has spread to other parts of the body. Palbociclib is also used along with fulvestrant (Faslodex) to treat a certain type of hormone receptor–positive, advanced breast cancer (breast cancer that depends on hormones such as estrogen to grow) that has spread to other parts of the body in people who have been treated successfully with an antiestrogen medication such as tamoxifen (Soltamox). Palbociclib is in a class of medications called kinase inhibitors. It works by blocking the action of the abnormal protein that signals cancer cells to multiply. This helps stop or slow the spread of cancer cells.

Palbociclib comes as a capsule and a tablet to take by mouth. It is usually taken once daily for the first 21 days of a 28-day cycle. Palbociclib capsules are usually taken with food. Palbociclib tablets may be taken with or without food Your doctor will decide how many times you should repeat this cycle. Take palbociclib at around the same time 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 palbociclib exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the capsules and tablets whole; do not open, split, chew, or crush them. Do not take capsules or tablets that are broken, cracked, or damaged.

If you vomit after taking palbociclib, do not take another dose. Continue your regular dosing schedule.

Your doctor may decrease your dose or temporarily or permanently stop your treatment if you experience certain side effects. Be sure to tell your doctor how you are feeling during your treatment with palbociclib.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Before taking palbociclib,

• tell your doctor and pharmacist if you are allergic to palbociclib, any other medications, or any of the ingredients in palbociclib capsules and tablets. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• The following nonprescription or herbal products may interact with palbociclib: St. John’s wort. Be sure to let your healthcare provider know that you are taking this medication before you start taking palbociclib. Do not start this medication while taking palbociclib without talking to your healthcare provider.
• tell your doctor if you have fever, chills, or any other signs of an infection or if you have or have ever had lung or breathing problems or liver or kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or if you plan on fathering a child. If you are female, you will need to take a pregnancy test before you start treatment and use birth control to prevent pregnancy during your treatment and for at least 3 weeks after your final dose. If you are a male, you and your partner should use birth control during your treatment with palbociclib and for 3 months after your final dose. Talk to your doctor about birth control methods that you can use during your treatment. If you or your partner become pregnant while taking palbociclib, call your doctor immediately. Palbociclib may harm the fetus.
• tell your doctor if you are breastfeeding. You should not breastfeed while you are taking palbociclib and for 3 weeks after the final dose.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking palbociclib.
• you should know that this medication may decrease fertility in men. Talk to your doctor about the risks of taking palbociclib.

Do not eat grapefruit or drink grapefruit juice while taking this medication.

Skip the missed dose and continue your regular dosing schedule. Do not take a double dose on the same day to make up for a missed one.

Palbociclib may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• nausea
• diarrhea
• vomiting
• decreased appetite
• changes in taste
• tiredness
• sores on the lips, mouth, or throat
• unusual hair thinning or hair loss
• dry skin
• rash
• eye tearing, blurred vision, or dry eye

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

• fever, chills, or signs of infection
• difficulty breathing or shortness of breath
• cough with or without mucus
• chest pain
• dizziness
• fast, irregular, or pounding heartbeat
• weakness
• unusual bleeding or bruising
• nosebleeds
• redness, pain, swelling or blisters on the palms of the hands or soles of the feet
• skin blistering and peeling
• skin redness

Palbociclib may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

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 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

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests before and during your treatment to check your body’s response to palbociclib.

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.

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