Cytarabine is a chemotherapy drug for treating acute leukemias such as acute myeloid leukemia. Doctors also use it for some lymphomas, including Hodgkin lymphoma.

Healthcare professionals often administer the drug via a rapid intravenous (IV) infusion, although they can also deliver it through either an IV or intrathecal injection into the spinal fluid. An experienced doctor must always perform this. Cytarabine causes a drop in the number of blood cells in the bone marrow, which puts a person at risk for several side effects and complications.

This article explains how doctors use the drug and addresses its possible side effects. It also looks at precautions, interactions, and monitoring.

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Cytarabine is a generic drug, with the brand names Cytosar-U, Tarabine PFS, which is also known as:

  • Cytosine arabinoside
  • Ara-C
  • Arabinocytidine

Cytarabine prevents cancer cells from multiplying by blocking their ability to work with a person’s DNA. Doctors usually prescribe it as a course of treatment, which they may combine with other drugs.

Only a healthcare professional should administer cytarabine. The delivery method generally depends on the type of cancer, but there are three main methods:

  • IV injection into the bloodstream, usually via a drip inserted into a person’s arm or hand
  • subcutaneous injection, often administered into a person’s stomach
  • intrathecal chemotherapy injected into a person’s cerebrospinal fluid

Cytarabine is a powerful immunosuppressant that reduces the activity of the bone marrow.

There are several possible side effects, although many of them may improve after completing the treatment. Not everyone will have side effects, and there is often no clear indication of which side effects a person will experience while on the drug. The below table shows common and less common side effects of cytarabine:

Side effectCommonLess common
ulcers and pain in the mouth
anal inflammation or ulcers
liver dysfunction
kidney dysfunction
hair loss
inflammation in the pericardium
allergic edema
sinus bradycardia
kidney dysfunction

People may have other reactions to the drug, including a rare illness called cytarabine syndrome. Other reactions may result in sepsis or anaphylaxis.

Cytarabine syndrome

Rarely, an illness called cytarabine syndrome may develop within 6–12 hours after a person has received the drug. Symptoms of cytarabine syndrome include:

  • fever
  • malaise
  • joint or muscle pain
  • skin rash

Doctors often manage the condition using corticosteroids.


Severe reactions to the drug are possible, including sepsis, a life threatening infection of the blood.


Some people may experience anaphylaxis, a severe allergic reaction to the drug. Anyone experiencing the following symptoms, which may indicate anaphylaxis, should seek emergency medical attention:

  • sudden shortness of breath or difficulty breathing
  • feeling lightheaded or losing consciousness
  • fast heartbeat
  • clammy skin
  • wheezing or gasping for breath

Before administering cytarabine, a doctor will consider several factors, including a person’s medical history, allergies, active infections, and possible drug interaction with other medications.

Medical history

Before taking cytarabine, people should discuss their medical history with their doctor, including blood cell disorders such as anemia, disorders of the kidney or liver, and conditions such as gout.


Allergic reactions are possible from both the drug and other ingredients in its injected solution. If a person has an allergic sensitivity to cytarabine or any other key ingredients involved in its preparation, doctors may recommend alternatives.


Some types of active infections, such as active meningitis, may mean the person cannot take cytarabine. This is because the drug is a potent immunosuppressant that can hinder the body’s ability to fight off new infections. An individual may also wish to avoid contact with other people or limit their attendance in public spaces to reduce their exposure to possible infection while taking the drug.


Drug interactions are possible from cytarabine or ingredients in the solution. A person needs to discuss all medications, supplements, and herbal remedies that they take with a doctor before starting cytarabine. A healthcare professional may recommend changes or instruct the person to stop taking certain products before using cytarabine.


Anyone who thinks they may be pregnant or are attempting to become pregnant should discuss this with their doctor. Label data from one version of the drug notes that cytarabine is pregnancy category D, meaning it can be potentially harmful to a fetus. Similarly, doctors may recommend against attempting to become pregnant during treatment with this drug. However, there is a reduced risk of damage to the fetus if a person avoids treatment until after the first trimester.


Overdose is possible in some cases, such as with sensitive patients or very high doses. An overdose constitutes an emergency medical situation, and doctors will treat it as such.

After administering the drug, doctors will monitor the person to keep track of the drug’s effects and watch for any complications. As cytarabine may affect several different organs, healthcare professionals will use a panel test to check several functions in the body. These tests may include:

  • complete blood count
  • differential white blood cell count
  • platelet count
  • liver function tests
  • serum creatinine
  • serum uric acid
  • blood urea nitrogen

Cytarabine is a chemotherapy drug for treating cancers of the blood and cancers of the lymph glands, or lymphomas. It can severely suppress the immune system and may cause a number of side effects.

There are several ways to manage side effects from the drug — consulting with a doctor to find medications or other therapies to manage them may help. Many side effects may resolve after treatment ends.

Working with a healthcare professional may help avoid complications from the drug and allow for appropriate reaction monitoring.