Chlorambucil

Key facts

• Chlorambucil is an oral alkylating chemotherapy drug used mainly for chronic lymphocytic leukaemia and certain slow-growing non-Hodgkin lymphomas.
• You take it as tablets on a schedule your oncology team sets exactly, often as short cycles or a low continuous dose; never adjust the dose yourself.
• Chlorambucil suppresses the bone marrow's production of white cells, red cells and platelets, so regular blood counts are mandatory before treatment starts and throughout.
• Seek urgent care for fever, chills, unusual bleeding or bruising, or shortness of breath, these can signal dangerously low blood counts or a serious infection.

What chlorambucil treats

Chlorambucil treats chronic lymphocytic leukaemia, a slow-growing cancer of white blood cells, and certain low-grade non-Hodgkin lymphomas. It is occasionally used for severe autoimmune conditions, such as certain forms of nephrotic syndrome or rheumatoid arthritis, when other treatments have failed. It is not a treatment for infections or for fast-growing cancers outside these blood and immune conditions.

How chlorambucil works

Chlorambucil attaches chemical groups to the DNA inside cells, cross-linking the two strands so the cell cannot copy its genetic material correctly. Cells that divide often, including the leukaemia or lymphoma cells it targets, are hit hardest and die or stop multiplying. Healthy tissues that also divide quickly, particularly bone marrow, are affected too, which is why blood counts fall during treatment.

Before you take it

• Do not take chlorambucil during pregnancy, it damages DNA and can seriously harm a developing baby; effective contraception is needed during treatment and for a period afterward, for both men and women.
• Tell your oncology team about any recent infection, seizure history, or other chemotherapy or radiation, these raise the risk of severe marrow suppression.
• Avoid live vaccines during treatment, your immune response to them may be blunted and, rarely, they can cause the infection they are meant to prevent.
• Other bone-marrow-suppressing drugs increase the risk of severe low blood counts when combined with chlorambucil.

Side effects

Common effects include nausea, tiredness, reduced appetite, and easy bruising as blood counts fall.

Stop and seek urgent medical care for any of these:

• Fever, chills or sweats that do not settle.
• Unusual bleeding, bruising, or bleeding gums.
• Severe shortness of breath or chest pain.

Safety essentials

• Blood counts must be checked regularly before and during treatment. Chlorambucil's marrow-suppressing effect is dose-limiting and can become severe without warning.
• Long-term or high cumulative use raises the risk of secondary blood cancers, including leukaemia, years later, your oncology team weighs this against the benefit of treating your current disease.
• Pregnancy is contraindicated. Confirm reliable contraception before starting and discuss timing if you are planning a family.
• Report any fever promptly. With a suppressed immune system, infection can progress quickly and needs same-day medical attention.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.