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 Cytosar (Cytarabine). If you are concerned about side effects, discuss the risks and benefits of Cytosar (Cytarabine) with your doctor.

The following side effects have been reported by at least 1% of people taking Cytosar (Cytarabine). 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.

• Diarrhea
• dizziness
• fatigue
• freckling of skin
• headache
• itching
• loss of appetite
• personality changes
• nausea
• temporary hair loss (more common with higher doses)
• vomiting
• weakness

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:

• difficulty swallowing or sore throat
• fluid retention with swelling of the stomach, legs, ankles or feet
• flu-like symptoms (e.g., sore throat, cough, Fever, chills)
• heartburn
• muscle or bone pain
• numbness or tingling in fingers, toes, or face
• pain, redness, or swelling at the site of injection
• rash or blisters on the palms of the hands and soles of the feet
• sudden shortness of breath
• red, painful, or irritated eyes, blurred vision (more common at higher doses - your doctor may prescribe eye drops to prevent or treat this condition)
• signs of Anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of infection (symptoms may include 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, painful or difficult urination)
• 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)
• signs of pneumonia (e.g., cough with or without mucus, fever, chills, shortness of breath)
• sores in mouth and on lips

Contact your doctor immediately if any of the following side effects occur:

• confusion, memory loss, speech difficulties or difficulty with motor control (more common at higher doses)
• dizziness or unusual tiredness while you are receiving your treatment
• paralysis
• seizures
• signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of bleeding in the stomach (e.g., bloody, black, or tarry stools; spitting up of blood; vomiting blood or material that looks like coffee grounds)
• signs of a blood infection (e.g., dizziness, confusion, diarrhea, nausea, vomiting, slurred speech, severe muscle pain)
• signs of heart problems (e.g., shortness of breath, swelling of the legs, irregular heartbeat, chest pain)
• signs of tumor lysis syndrome (nausea, vomiting, decreased urination, irregular heartbeat, confusion, seizures, delirium)

A flu-like syndrome including symptoms such as fever, muscle, or joint pain; rash (especially on palms, soles, neck, and chest); a feeling of being unwell; chest pain; and redness or irritation of eyes may occur. This is most likely to occur 6 to 12 hours after your treatment. It is important to get medical help immediately if any of these symptoms occur shortly after your treatment.

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 Cytosar (Cytarabine).

Solution for injection

20 mg/mL
Each mL of sterile solution contains 20 mg of Cytosar (Cytarabine). Nonmedicinal ingredients: sodium chloride-hydrochloric acid solution and/or sodium hydroxide to adjust pH and water for injection.

100 mg/mL
Each mL of sterile solution contains 100 mg of Cytosar (Cytarabine). Nonmedicinal ingredients: sodium chloride-hydrochloric acid solution and/or sodium hydroxide to adjust pH and water for injection.

Sterile Lyophilized Powder

Each sterile vial of white-to-off-white crystalline powder contains the labeled amount of freeze-dried Cytosar (Cytarabine) USP (100 mg, 1,000 mg [1 g], or 2,000 mg [2 g]) ready for reconstitution with an appropriate solution.

Do not use Cytosar (Cytarabine) if you are allergic to Cytosar (Cytarabine) or any ingredients of the medication.

There may be an interaction between Cytosar (Cytarabine) and any of the following:

• amphotericin B
• BCG
• Clozapine
• corticosteroids (e.g., budesonide, Dexamethasone, Hydrocortisone, fluticasone, Prednisone)
• Cyclosporine
• Deferiprone
• dipyrone
• Denosumab
• Digoxin
• echinacea
• Fingolimod
• flucytosine
• gentamicin
• Hydroxyurea
• Leflunomide
• mycophenolate
• Natalizumab
• Nivolumab
• other medications to treat cancer (e.g., Carboplatin, Cyclophosphamide, Doxorubicin, Ifosfamide, Vincristine)
• Pimecrolimus
• Rituximab
• Roflumilast
• Tacrolimus
• Trastuzumab
• Tofacitinib
• vaccines

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 Cytosar (Cytarabine). 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 Cytosar (Cytarabine).

Anemia: Cytosar (Cytarabine) 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.

Blood clotting: Cytosar (Cytarabine) can reduce the number of platelet cells in the blood. Platelets help the blood to clot, and a shortage could make you bleed more easily. Tell your doctor if there are any signs that your blood is not clotting as quickly as usual. Such symptoms may include black and tarry stools, blood in the urine, easy bruising, or cuts that won't stop bleeding.

Infection: As well as killing cancer cells, Cytosar (Cytarabine) can reduce the number of cells that fight infection in the body (white blood cells). If possible, avoid contact with people who have 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.

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

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

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Lung inflammation: Lung inflammation (interstitial lung disease), causing difficulty breathing has occurred rarely in some people taking Cytosar (Cytarabine). This complication can be serious and sometimes fatal. If you experience new or worsening shortness of breath or cough (with or without fever) at any time while you are taking Cytosar (Cytarabine), contact your doctor immediately.

Pancreatitis: Cytosar (Cytarabine) can cause the pancreas to become inflamed. Report signs of pancreatitis such as abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, or swollen abdomen to your doctor immediately.

Tumour Lysis Syndrome: Cytosar (Cytarabine), like many other cancer medications, causes many cancer cells to be suddenly killed when treatment is first started. This can overwhelm the body with waste products from the cells. As a result, the body may not be able to keep up with getting rid of all the waste. When this happens, you may experience nausea, shortness of breath, cloudy urine, or joint pain. This is called tumour lysis syndrome. Your doctor may prescribe some medications to help your body get rid of the waste products. Make sure you understand how to use these medications and report any of these signs or symptoms to your doctor immediately.

Pregnancy: There is a possibility of birth defect if either the father or the mother is using Cytosar (Cytarabine) at the time of conception, or if it is taken during pregnancy. Effective birth control should be practiced while using Cytosar (Cytarabine). Tell your doctor immediately if you become pregnant while using Cytosar (Cytarabine). It should only be used during pregnancy if potential benefits clearly outweigh the risks.

Breast-feeding: It is not known whether Cytosar (Cytarabine) passes into breast milk. If you are a breast-feeding mother and are taking Cytosar (Cytarabine), it may affect your baby. Because of the risks associated with Cytosar (Cytarabine), a decision should be made to stop breast-feeding or stop taking the medication, taking into account the importance of the medication to the mother. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Cytosar (Cytarabine) have not been established for children less than 1 year of age.