Fludarabine
Say it: floo-DARE-uh-been
Fludarabine is a chemotherapy medicine that blocks blood cancer cells from making DNA and also lowers the immune system.
What it is
Fludarabine looks like one of the building blocks of DNA. Cells take it in and cannot make new DNA. It is strong against white blood cells called lymphocytes, so it is also used to prepare the body for a stem cell transplant or cell therapy.
Often used for
- chronic lymphocytic leukemia (CLL)
- preparing the body for a stem cell transplant
- preparing the body for CAR T-cell therapy
How you get it
Fludarabine is given through a vein (IV), usually over about 30 minutes. It is often given once a day for 3 to 5 days in a row. Your schedule may be different.
Common side effects and what helps
- Low blood counts, which raise your risk of infection, bleeding, and tiredness. Wash your hands often.
- Infections. Avoid people who are sick and wash your hands often.
- Feeling tired or weak. Rest when you need to.
- Nausea and vomiting. Take your anti-nausea medicine as your team tells you.
- Fever. Check your temperature if you feel unwell.
- Cough. Tell your team if it is new.
- Numbness or tingling in the hands or feet. Tell your team.
Call your care team right away if you have
- A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills
- Confusion, vision changes, weakness, or a seizure
- Dark urine, yellow skin or eyes, or feeling very weak (signs your red blood cells are breaking down)
- Shortness of breath or a new cough
- Bleeding or bruising that will not stop, black or bloody stools, or blood in your urine
Before you start, tell your team
- If you are pregnant, may become pregnant, or are breastfeeding
- If you have kidney problems
- If you have ever had hepatitis B or other long-term infections
- If you take pentostatin
- All the medicines, vitamins, and herbal products you take
Good to know
- It weakens the immune system for months. Your team may give medicines to prevent certain infections.
- If you need a blood transfusion, the blood must be specially treated (irradiated). Tell every hospital you are on or have had fludarabine.
- Rarely, it can cause serious brain or nerve problems, mostly at high doses.
- It can cause the immune system to attack red blood cells. You will have blood tests.
Questions to ask
- Do I need medicines to prevent infections, and for how long?
- Should I carry a card saying I need irradiated blood?
- How long will my immune system be weak?
Part of these treatment plans
Side effect guides
- Fatigue (tiredness)
- Nausea and vomiting
- Low white blood cells and infection risk
- Low platelets and bleeding
- Neuropathy (numbness and tingling)
- Cough
Sources
Quick answers
- What is Fludarabine?
- Fludarabine is a chemotherapy medicine that blocks blood cancer cells from making DNA and also lowers the immune system.
- What is Fludarabine used for?
- chronic lymphocytic leukemia (CLL); preparing the body for a stem cell transplant; preparing the body for CAR T-cell therapy.
- How is Fludarabine given?
- Fludarabine is given through a vein (IV), usually over about 30 minutes. It is often given once a day for 3 to 5 days in a row. Your schedule may be different.
- What are the common side effects of Fludarabine?
- Low blood counts, which raise your risk of infection, bleeding, and tiredness. Infections. Feeling tired or weak. Nausea and vomiting. Fever. Cough. Numbness or tingling in the hands or feet.
- When should I call my care team while taking Fludarabine?
- A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills; Confusion, vision changes, weakness, or a seizure; Dark urine, yellow skin or eyes, or feeling very weak (signs your red blood cells are breaking down); Shortness of breath or a new cough; Bleeding or bruising that will not stop, black or bloody stools, or blood in your urine.
- Which chemotherapy plans include Fludarabine?
- FCR, FLAG-IDA.
Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.