Eribulin injection is used to treat breast cancer that has spread to other parts of the body and that has already been treated with certain other chemotherapy medications. Eribulin is in a class of anticancer medications called microtubule dynamics inhibitors. It works by stopping the growth and spread of cancer cells.

Eribulin injection comes as a solution (liquid) to be given intravenously (into a vein) over 2 to 5 minutes by a doctor or nurse in a medical office, infusion center, or hospital. It is usually given on days 1 and 8 of a 21-day cycle.

Your doctor may need to delay your treatment or decrease your dose if you experience certain side effects. Be sure to tell your doctor how you are feeling during your treatment.

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

Before receiving eribulin injection,

• tell your doctor and pharmacist if you are allergic to eribulin, any other medications, or any of the ingredients in eribulin injection. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: amiodarone (Cordarone), clarithromycin (Biaxin); disopyramide (Norpace), dofetilide (Tikosyn), dronedarone (Multaq); erythromycin (E.E.S., E-Mycin, Erythrocin), ibutilide (Corvert); certain medications for mental illness such as chlorpromazine, haloperidol (Haldol), and thioridazine; methadone (Dolophine), moxifloxacin (Avelox), pimozide (Orap), procainamide, quinidine, and sotalol (Betapace, Betapace AF),. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had long QT syndrome (condition that increases the risk of developing an irregular heartbeat that may cause loss of consciousness or sudden death); a slow heartbeat; low levels of potassium or magnesium in your blood; or heart, liver, or kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while receiving eribulin injection, call your doctor. You should use birth control to prevent pregnancy during your treatment with eribulin injection.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are receiving eribulin injection.

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.

Symptoms of overdose may include the following:

• sore throat, cough, fever, chills, burning or pain when urinating, or other signs of infection

Unless your doctor tells you otherwise, continue your normal diet.

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

• nausea
• constipation
• loss of appetite
• weight loss
• headache
• weakness
• tiredness
• bone, back, or joint pain
• hair loss

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

• sore throat, cough, fever (temperature greater than 100.5), chills, burning or pain when urinating, or other signs of infection
• numbness, burning, or tingling in the arms, legs, hands, or feet
• pale skin
• shortness of breath
• irregular heartbeat

Eribulin injection may cause other side effects. Call your doctor if you have any unusual problems while you are 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).

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

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to eribulin injection.

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.