Chlorambucil is a chemotherapy medicine used for certain blood cancers. You may also hear the brand name Leukeran. It works by slowing or stopping the growth of cancer cells.
Brand Name(s)
- US: Leukeran
- Canada: Leukeran
Warning(s)
-
Low blood counts (bone marrow suppression): This drug can lower white cells, red cells, and platelets. Very low counts can cause serious infections, anemia, or bleeding. Watch for signs:
- Fever, chills, very bad sore throat, cough, or a wound that won’t heal
- Easy bruising or bleeding, black or tarry stools, blood in urine, bleeding gums
- Feeling very tired, pale skin, shortness of breath
- Pregnancy and breastfeeding: This drug may harm an unborn baby. Use effective birth control while taking it. If you become pregnant, contact your care team right away. Do not breast-feed while you take this drug.
- Fertility: This drug may affect fertility in all genders. It may improve after treatment, but sometimes it does not.
- Risk of new cancers: New types of cancer have happened in people taking this drug.
- Serious skin reactions (SJS/TEN): Get help right away for red, swollen, blistered, or peeling skin; red or irritated eyes; or painful sores in your mouth, nose, throat, or eyes.
- Liver problems: Call your care team for dark urine, yellow skin or eyes, stomach pain, bad nausea or vomiting, or very tired feeling.
- Nervous system effects: Seizures can happen. Report new numbness, tingling, or unusual weakness.
- Allergic reactions: Rash, hives, itching, swelling of the face, lips, tongue, or throat, wheezing, or trouble breathing or swallowing need urgent care.
- Infection and bleeding prevention: Wash hands often. Avoid people who are sick. Use a soft toothbrush and an electric razor. Be careful to avoid injury.
- Vaccines: Check with your doctor before any vaccines. Some vaccines may not work as well or could increase infection risk while your immune system is weak.
- Drug and supplement interactions: Tell your care team about all medicines, vitamins, and herbal products you take. Do not start or stop anything without checking first.
- Monitoring: Expect regular blood tests to check your counts and organ function.
Kind of Cancers It Is Used For (not a complete list)
- Chronic lymphocytic leukemia (CLL)
- Small lymphocytic lymphoma (SLL)
- Indolent non-Hodgkin lymphomas (such as follicular lymphoma)
- Hodgkin lymphoma (less often today)
- Waldenström macroglobulinemia (sometimes)
Your care team may use this medicine for other related conditions.
Mechanism of Action
Chlorambucil is an alkylating agent (a type of chemotherapy). It damages DNA inside cells by forming crosslinks, which stops cancer cells from dividing and leads to cell death. It affects fast-growing cells most, including cancer cells and some healthy cells in the bone marrow, mouth, gut, and hair roots.
Common Side Effects
- Low blood counts (risk of infection, anemia, and bleeding)
- Nausea or vomiting
- Diarrhea or constipation
- Mouth sores
- Decreased appetite or weight loss
- Tiredness or weakness
- Skin rash or itching
- Hair thinning
- Headache or mild tremor
- Tingling or numbness in hands or feet
- Changes in menstrual periods (including missed periods)
These are not all the possible side effects. Tell your care team about any side effect that is severe, does not go away, or worries you. Call right away for signs of infection, unusual bleeding, severe rash, trouble breathing, seizures, or yellowing of the skin or eyes.
Last reviewed: 2025-12-17
