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).