Clofarabine is a chemotherapy medicine used for certain leukemias. It is given by infusion in a clinic or hospital. This overview explains what it is used for, how it works, important safety warnings, and common side effects.
Brand Name(s)
- US: Clolar (discontinued)
- Canada: Clolar
Warning(s)
Serious side effects can happen with clofarabine. You will have regular blood tests and checkups during treatment. Tell all of your health care providers that you receive this medicine, including dentists and pharmacists.
- Low blood counts are common. This can raise your risk of infection, bleeding, and anemia. Wash your hands often and try to avoid people who are sick.
- Some medicines can increase the chance of kidney or liver problems. Tell your care team about all medicines, vitamins, and herbal products you use. Do not start or stop medicines without checking first.
- Vaccines: Live vaccines may not be safe, and other vaccines may not work as well while you are on this drug. Talk with your care team before getting any vaccine.
- Pregnancy and breastfeeding: Clofarabine may harm an unborn baby. You will have a pregnancy test before starting. Use effective birth control during treatment and for a time after the last dose (ask how long). Do not breastfeed during treatment and for 2 weeks after the last dose.
- Fertility: This medicine may affect your ability to become pregnant or to father a child. In some cases, this may be permanent.
Call your care team right away if you have any of the following:
- Signs of infection: fever, chills, very sore throat, cough, mouth sores, or a wound that will not heal.
- Bleeding or bruising you cannot explain; black or tarry stools; blood in urine; vomiting blood or vomit that looks like coffee grounds.
- Possible liver problems: yellow skin or eyes, dark urine, severe stomach pain, nausea, vomiting, pale stools, or unusual tiredness.
- Possible kidney problems: very little or no urine, blood in urine, sudden weight gain, or swelling.
- Tumor lysis syndrome (TLS): very tired or sluggish, fast or abnormal heartbeat, fainting, trouble passing urine, muscle cramps or weakness, severe nausea, vomiting, or diarrhea, or loss of appetite.
- Cytokine-release symptoms: fever, fast heartbeat, fast breathing, shortness of breath, severe dizziness, or fainting.
- Severe skin reaction: rash with blisters or peeling, red or irritated eyes, or painful sores in the mouth, throat, nose, or eyes.
- Blood pressure or heart changes: severe headache, dizziness, changes in vision, chest pain, or shortness of breath.
- Stroke-like symptoms: weakness on one side, trouble speaking or thinking clearly, trouble with balance, or blurred vision.
- Confusion or sudden mood changes.
Kind of Cancers It Is Used For (not a complete list)
- Acute lymphoblastic leukemia (ALL), often when other treatments have not worked or have stopped working.
- It may also be used in certain other leukemias as part of combination regimens, based on your care teams plan.
Mechanism of Action
- Clofarabine is a nucleoside analog (an antimetabolite). It is taken up by leukemia cells and changed into an active form.
- It blocks enzymes that cells need to make and copy DNA (including DNA polymerase and ribonucleotide reductase).
- This stops cancer cells from dividing and triggers programmed cell death (apoptosis). Healthy cells can also be affected, which can lead to side effects.
Common Side Effects
- Low blood cell counts (anemia, low white cells, low platelets)
- Nausea, vomiting, diarrhea, stomach pain, or decreased appetite
- Mouth irritation or mouth sores
- Headache or feeling sleepy
- Tiredness or weakness
- Skin changes: irritation, itching, rash, or flushing
- Back, bone, joint, muscle, arm, or leg pain
- Anxiety
- Cold-like symptoms (for example, runny or stuffy nose)
More information: MedlinePlus, Clofarabine Injection
Last reviewed: 2025-12-17
