Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Halaven (Eribulin). If you are concerned about side effects, discuss the risks and benefits of Halaven (Eribulin) with your doctor.

The following side effects have been reported by at least 1% of people taking Halaven (Eribulin). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• anxiety
• changed sense of taste
• Constipation
• Diarrhea
• dizziness
• Dry Mouth
• hair loss
• headache
• heartburn
• hoarseness
• loss of appetite
• nausea
• tiredness
• trouble sleeping
• vomiting
• watery eyes
• weakness
• weight loss

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• abdominal pain or bloating
• back pain
• bone, joint, or muscle pain
• breathing problems (e.g., shortness of breath, persistent cough)
• changes in blood pressure (increase or decrease)
• chills
• cold or flu-like symptoms (e.g., sore throat, cough, runny nose)
• Fever
• mouth sores or inflammation
• muscle spasms or weakness
• numbness, tingling, or burning in hands and feet
• sensation of spinning (Vertigo)
• signs of Anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worst when breathing in, coughing, coughing up blood, sweating, or passing out)
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of dehydration (e.g., decreased urine, dry skin, dry and sticky mouth, sleepiness, dizziness, headache, thirst, confusion)
• signs of Depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of infection (e.g., fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine, change of urine colour)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• skin rash or itching
• swelling of hands, feet or limbs
• symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
• symptoms of irregular heart beat (e.g., chest pain, dizziness, rapid, pounding heartbeat, shortness of breath)
• symptoms of a lung infection (LRTI) (e.g., shortness of breath, cough, chest pain)
• symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Halaven (Eribulin).

Each 1 mL of clear, colourless, aqueous solution for IV administration contains 0.5 mg of Halaven (Eribulin). Nonmedicinal ingredients: dehydrated alcohol USP (5% v/v), hydrochloric acid (for pH adjustment), sodium hydroxide (for pH adjustment), and water for injection USP (95% v/v).

Do not take Halaven (Eribulin) if you:

• are allergic to Halaven (Eribulin) or any ingredients of the medication
• have had an allergic reaction to halichondrin B or its derivatives

There may be an interaction between Halaven (Eribulin) and any of the following:

• amantadine
• Amiodarone
• amphotericin B
• Anagrelide
• antihistamines (e.g., cetirizine, doxylamine, Diphenhydramine, Hydroxyzine, Loratadine)
• antipsychotics (e.g., chlorpromazine, Clozapine, Haloperidol, Olanzapine, Quetiapine, Risperidone)
• Apomorphine
• "azole" antifungals (e.g., itraconazole, ketoconazole, Voriconazole)
• Bosutinib
• chloroquine
• Dasatinib
• Degarelix
• Disopyramide
• dofetilide
• Domperidone
• Dronedarone
• Famotidine
• Flecainide
• formoterol
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• Maprotiline
• Methadone
• mifepristone
• Nilotinib
• pentamidine
• Primaquine
• procainamide
• Propafenone
• quinidine
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, Norfloxacin, Ofloxacin)
• rilpivirine
• ritonavir
• Romidepsin
• saquinavir
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• serotonin antagonists (antiemetic medications; e.g., Granisetron, Ondansetron)
• sotalol
• Sunitinib
• tacrolimus
• Tamoxifen
• Tetrabenazine
• tricyclic antidepressants (e.g., Amitriptyline, Clomipramine, Desipramine, Trimipramine)

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Halaven (Eribulin). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Halaven (Eribulin).

Abnormal heart rhythms: Halaven (Eribulin) can cause abnormal heart rhythms. Certain medications (e.g., Sotalol, quinidine, thioridazine, Chlorpromazine, Pimozide, moxifloxacin, Mefloquine, pentamidine, arsenic trioxide, Tacrolimus) can increase the risk of a type of abnormal heart rhythm called QT prolongation, and should not be used in combination with Halaven (Eribulin). You are more at risk for this type of abnormal heart rhythm and its complications if you:

• are female
• are older than 65 years of age
• have a family history of sudden cardiac death
• have a history of heart disease or abnormal heart rhythms
• have a slow heart rate
• have congenital prolongation of the QT interval
• have Diabetes
• have had a Stroke
• have low potassium, magnesium, or calcium levels
• have nutritional deficiencies

If you have heart disease and abnormal heart rhythms, or are taking certain medications (e.g., Verapamil, atazanavir), discuss with your doctor how Halaven (Eribulin) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Halaven (Eribulin), and whether any special monitoring is needed.

Anemia: Halaven (Eribulin) may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired, or pale skin, contact your doctor as soon as possible.

Your doctor will do blood tests regularly to monitor the number of specific types of blood cells, including red blood cells, in your blood.

Infection: As well as killing cancer cells, Halaven (Eribulin) can reduce the number of cells that fight infection in the body (white blood cells). If possible, avoid contact with people with contagious infections. Tell your doctor immediately if you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness. Your doctor will do blood tests regularly to monitor the number of specific types of blood cells in your blood.

Kidney function: Kidney Disease or reduced kidney function may cause Halaven (Eribulin) to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how Halaven (Eribulin) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Halaven (Eribulin), and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause Halaven (Eribulin) to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how Halaven (Eribulin) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Halaven (Eribulin), and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking Halaven (Eribulin).

Pregnancy: Halaven (Eribulin) may harm a developing fetus if it is used by the mother while pregnant. Halaven (Eribulin) should not be used during pregnancy. If you become pregnant while taking Halaven (Eribulin), contact your doctor immediately.

Breast-feeding: It is not known if Halaven (Eribulin) passes into breast milk. If you are a breast-feeding mother and are taking Halaven (Eribulin), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Halaven (Eribulin) have not been established for children.