Chlorambucil

What it is and how it works

Mechanism of Action Chlorambucil, an aromatic nitrogen mustard derivative, is an alkylating agent. Chlorambucil interferes with DNA replication and induces cellular apoptosis via the accumulation of cytosolic p53 and subsequent activation of Bax, an apoptosis promoter.

Mechanism class: Alkylating Activity

Indications

INDICATIONS AND USAGE LEUKERAN (chlorambucil) is indicated in the treatment of chronic lymphatic (lymphocytic) leukemia, malignant lymphomas including lymphosarcoma, giant follicular lymphoma, and Hodgkin’s disease. It is not curative in any of these disorders but may produce clinically useful palliation.

Dosage and administration (summary)

DOSAGE AND ADMINISTRATION The usual oral dosage is 0.1 to 0.2 mg/kg body weight daily for 3 to 6 weeks as required. This usually amounts to 4 to 10 mg per day for the average patient. The entire daily dose may be given at one time. These dosages are for initiation of therapy or for short courses of treatment. The dosage must be carefully adjusted according to the response of the patient and must be reduced as soon as there is an abrupt fall in the white blood cell count. Patients with Hodgkin’s disease usually require 0.2 mg/kg daily, whereas patients with other lymphomas or chronic lymphocytic leukemia usually require only 0.1 mg/kg daily.

Contraindications

CONTRAINDICATIONS Chlorambucil should not be used in patients whose disease has demonstrated a prior resistance to the agent. Patients who have demonstrated hypersensitivity to chlorambucil should not be given the drug. There may be cross-hypersensitivity (skin rash) between chlorambucil and other alkylating agents.

Warnings and precautions

WARNINGS Because of its carcinogenic properties, chlorambucil should not be given to patients with conditions other than chronic lymphatic leukemia or malignant lymphomas. Convulsions, infertility, leukemia, and secondary malignancies have been observed when chlorambucil was employed in the therapy of malignant and non-malignant diseases. There are many reports of acute leukemia arising in patients with both malignant and non-malignant diseases following chlorambucil treatment. In many instances, these patients also received other chemotherapeutic agents or some form of radiation therapy.

Pregnancy

Pregnancy Chlorambucil can cause fetal harm when administered to a pregnant woman. Unilateral renal agenesis has been observed in 2 offspring whose mothers received chlorambucil during the first trimester. Urogenital malformations, including absence of a kidney, were found in fetuses of rats given chlorambucil.

Storage and supply

HOW SUPPLIED LEUKERAN is supplied as brown, film-coated, round, biconvex tablets containing 2 mg chlorambucil in amber glass bottles with child-resistant closures. One side is engraved with “GX EG3” and the other side is engraved with an “L.” Bottle of 25 (NDC 80725-610-25) Store in a refrigerator, 2° to 8°C (36° to 46°F).

Source: Chlorambucil (Leukeran) — US FDA prescribing information, 2025-01-08, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.