Chlorambucil (Leukeran) — Clinical FAQs

Question 1

What is Chlorambucil FDA-approved to treat?

Accepted Answer

Chlorambucil is FDA-approved for the following oncology indications: 1. Chronic lymphocytic leukemia (CLL) 2. Malignant lymphomas: lymphosarcoma, giant follicular lymphoma, Hodgkin disease.

Question 2

How does Chlorambucil work (mechanism of action)?

Accepted Answer

Chlorambucil is a bifunctional aromatic nitrogen mustard alkylating agent that cross-links DNA strands by forming covalent bonds at the N⁷ position of guanine residues, creating interstrand and intrastrand DNA cross-links that inhibit DNA replication and transcription. It also alkylates RNA and proteins. Chlorambucil is the slowest-acting and least acutely toxic of the nitrogen mustards used clinically, producing gradual lymphocytotoxic effects that are particularly suited to indolent lymphoproliferative malignancies. The drug is cell-cycle nonspecific, with cytotoxic activity across all phases of the cell cycle.

Question 3

How is Chlorambucil administered?

Accepted Answer

Chlorambucil is administered Oral (PO). Chlorambucil is available as 2-mg scored tablets for oral administration.

Question 4

What are the most common side effects of Chlorambucil?

Accepted Answer

The most commonly reported side effects of Chlorambucil (≥10% incidence) include: Myelosuppression: neutropenia, thrombocytopenia, anemia (dose-dependent; most common dose-limiting toxicity), Nausea and vomiting (mild; less common than with other alkylating agents), Diarrhea, Oral mucositis (uncommon at standard doses), Skin rash or urticaria and others (8 total). Consult your oncologist for complete prescribing information.

Question 5

Does Chlorambucil have a black box warning?

Accepted Answer

Yes. Chlorambucil carries FDA black box warning(s) regarding: 1. Myelosuppression: Chlorambucil causes dose-related myelosuppression — leukopenia, thrombocytopenia, and anemia — which may be severe and prolonged. Bone marrow suppression is irreversible in rare cases. Monitor CBCs frequently; reduce dose or discontinue for severe cytopenias. 2. Carcinogenesis and secondary malignancies: Chlorambucil is carcinogenic in humans. Secondary acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) have been reported following chlorambucil therapy, particularly with prolonged use. The risk of secondary leukemia is dose-related and cumulative. Chlorambucil should be used with caution and at the minimum effective dose and duration. 3. Infertility: Chlorambucil causes suppression of gonadal function — azoospermia in males and amenorrhea in females. The potential for permanent infertility must be discussed with patients of reproductive age prior to initiating therapy.

Question 6

Is Chlorambucil safe during pregnancy?

Accepted Answer

Chlorambucil pregnancy safety: Category D — Chlorambucil is teratogenic. Unilateral renal agenesis has been documented in the offspring of women treated during pregnancy. The drug should not be used during pregnancy. Women of childbearing potential must use effective contraception. Men should be counseled about infertility risk (azoospermia); sperm banking should be discussed prior to initiation.. Oncologists should review the complete prescribing information and discuss reproductive risks with patients before initiating therapy.

Chlorambucil — Drug Monograph

Mechanism of Action

FDA Indications

Common Side Effects

Clinical Pearl

Related Therapies & Mechanisms