fludarabine
Meaning of fludarabine: A chemotherapy drug that impersonates a DNA building block, used mainly against slow-growing blood cancers and before transplant.
Definition of fludarabine
Fludarabine is a chemotherapy drug that resembles one of the natural building blocks of DNA closely enough to be taken up in its place. Once inside a cell it stops DNA being copied or repaired, and the cell dies. It is used mainly for chronic lymphocytic leukemia and some lymphomas, and to suppress the immune system before a donor stem cell transplant.
How does it work?
Cells convert fludarabine into an active form and then thread it into a growing strand of DNA, where it acts as a dead end and the strand cannot be extended. It also disables two enzymes the cell needs to make and mend DNA. Something unusual follows from that combination: the drug damages lymphocytes that are resting as well as those actively dividing. Most chemotherapy only reaches cells in the act of dividing, which is why slow growing blood cancers resist it. Fludarabine is classed as a purine antagonist, purine being one of the two chemical families the letters of DNA belong to.
What is it used for?
| Use | Detail |
|---|---|
| Chronic lymphocytic leukemia | Long used in combination with cyclophosphamide and an antibody drug |
| Slow growing lymphomas | Including follicular lymphoma that has returned |
| Waldenstrom macroglobulinemia | One of several accepted options |
| Conditioning before transplant | Suppresses the recipient's T cells so a donor graft is accepted |
What makes it demanding on the body?
The same power over lymphocytes that makes it effective leaves the immune system weakened for a long time afterward. T cell numbers can stay low for many months once treatment has ended, and infections that healthy immunity would ignore become possible, so preventive antimicrobials are usually given alongside. Two further effects are specific to this drug. It can trigger the immune system to destroy the body's own red blood cells. It also leaves donor lymphocytes in a transfusion able to attack the recipient, which is why blood products given to people who have received it are irradiated first. Low blood counts, tiredness and nausea are the everyday effects.
Also known as
Used in a sentence
Fludarabine was included in the conditioning regimen before the donor stem cell infusion.
Good to know
Fludarabine keeps T cell numbers low for many months after treatment ends, leaving a lasting vulnerability to unusual infections, and blood products given afterward are irradiated so donor cells cannot attack the recipient.