Chlorambucil is a nitrogen mustard derivative alkylating agent used primarily in the treatment of chronic lymphocytic leukemia (CLL) and certain lymphomas. It is a slow-acting, orally administered chemotherapeutic agent that cross-links DNA, inhibiting its replication and transcription, leading to cell death, particularly in rapidly dividing cells like lymphocytes. In the Indian context, it is a cost-effective option for long-term management of indolent hematological malignancies.
Adult: For CLL/NHL: Initial dose typically 0.1 mg/kg to 0.2 mg/kg body weight daily (approx. 4-10 mg daily) as a single dose for 3 to 6 weeks, then adjusted based on response and blood counts. Maintenance: 0.03-0.1 mg/kg daily or intermittent pulse dosing (e.g., 14 mg/m² daily for 5 days every 28 days).
Note: Administer orally, as a single daily dose, preferably on an empty stomach (1 hour before or 2 hours after food) to ensure consistent absorption. Tablet should be swallowed whole with a full glass of water. Do not crush or chew. Handle tablets with care; caregivers should avoid direct contact with skin. Adherence to the prescribed schedule is critical.
Chlorambucil is a bifunctional alkylating agent of the nitrogen mustard type. It forms highly reactive ethylenimonium intermediates that covalently bind to nucleophilic sites on DNA, primarily the N-7 position of guanine. This leads to intrastrand and interstrand cross-linking of DNA strands, preventing DNA replication and transcription. It is non-cell-cycle specific but is most active in the G1 and S phases.
Pregnancy: Category D. Can cause fetal harm. Known to be teratogenic and embryotoxic. Contraindicated in pregnancy. Women of childbearing potential must use effective contraception during and for at least 6 months after therapy.
Driving: May cause dizziness or fatigue. Patients should be cautioned about operating machinery or driving if they experience these effects.
| Live Vaccines (e.g., MMR, Varicella, Yellow Fever) | Increased risk of vaccine-induced infection due to immunosuppression | Major |
| Allopurinol | May increase risk of bone marrow suppression; monitor blood counts closely | Moderate |
| Phenobarbital, Phenytoin | May increase metabolism of chlorambucil, reducing its efficacy | Moderate |
| Warfarin | Chlorambucil may potentiate anticoagulant effect; monitor INR | Moderate |
| Myelosuppressive drugs (e.g., Azathioprine, other chemotherapies) | Additive risk of severe bone marrow toxicity | Major |
Same composition (Chlorambucil (5mg)), different brands: