[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Alkylating agents](https://durgical.com/en/pharmacology/classes/alkylating-agents/) › Chlorambucil

# Chlorambucil

## Alkylating agents?

Alkylating agents

## High alert?

An error with this medicine can cause serious harm: double checks and protocols are used.

A slow-acting oral nitrogen mustard, historically the classic drug for chronic lymphocytic leukaemia; still used when newer drugs are not available.

Updated Nov 1, 2026

## Quick facts

**Group**
[Alkylating agents](https://durgical.com/en/pharmacology/classes/alkylating-agents/)

**Target**
DNA (guanine N7), cross-linked by the mustard

**Used for**
Chronic lymphocytic leukaemia · Hodgkin lymphoma

**Key effects**
Gradual fall in white cells · Nausea and vomiting

**Monitor**
Blood counts regularly during treatment · Liver tests

**ATC**
L01AA02

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Clinical What the labels mean

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

Chlorambucil is an aromatic nitrogen mustard. Its two chloroethyl arms form reactive aziridinium ions that bond to guanines on both DNA strands and cross-link them. Its effects on the bone marrow, lymphoid organs and epithelia are those of the other mustards, but it acts slowly and its oral dose can be titrated against blood counts.

- The chloroethyl arms form reactive aziridinium ions
- These bond to guanines and cross-link DNA
- Lymphocytes stop dividing and die

## Indications

- Chronic lymphocytic leukaemia, when targeted drugs are not available or not tolerated, or for relapse. [Chronic lymphocytic leukaemia →](https://durgical.com/en/conditions/chronic-lymphocytic-leukaemia/)
- Some non-Hodgkin lymphomas. [Non-Hodgkin lymphoma →](https://durgical.com/en/conditions/non-hodgkin-lymphoma/)
- Hodgkin lymphoma. [Hodgkin lymphoma →](https://durgical.com/en/conditions/hodgkin-lymphoma/)

## Adverse effects

### Common

- Gradual fall in white cells and platelets
- Nausea and vomiting with larger single doses
- Mouth sores
- Irregular periods, low sperm counts

### Serious (rare, important)

- Prolonged or severe myelosuppression with bleeding or infection
- Seizures, a particular concern in people with a seizure history or head injury
- Liver injury (jaundice, right upper abdominal pain), skin rash that can become severe
- Permanent infertility and second cancers, including acute myeloid leukaemia

## Contraindications

- Hypersensitivity to chlorambucil

## Key interactions

**Other myelosuppressive drugs and radiotherapy**
Additive bone marrow suppression.

## What is monitored

- Blood counts regularly during treatment
- Liver tests
- Neurological symptoms in people with seizure risk

## Administration and safety

- Oral tablets; hazardous drug handled with gloves or clean hands.
- The dose is adjusted to blood counts; treatment may last months.
- Kept in the refrigerator in its original container, out of children's reach.

## Pregnancy and breastfeeding

Can harm the fetus; reliable contraception is used during treatment.

## Nursing care

- Ask about previous seizures or head injury before starting.
- Check counts and report bruising, black stools, fever or cough.
- Teaching: contraception; infertility can be permanent, so fertility preservation is discussed beforehand.

## Pharmacokinetics

**Absorption**
Oral, adequate and reliable.

**Metabolism**
Hydrolysed to inactive products.

**Half-life**
About an hour and a half in plasma (G&G).

## Memory aid

«CHLORAMBUCIL CHills Lymphocytes slowly»: the gentle oral mustard of CLL; titrate to counts, watch for seizures.

## Test yourself

Think of the answer, then tap the question to see it.

## Which leukaemia was chlorambucil classically used for?

Chronic lymphocytic leukaemia.

## Which neurological adverse effect is linked to chlorambucil?

Seizures, a particular concern in people with a seizure history or head injury.

## Why is chlorambucil easy to titrate?

It is oral and acts slowly, so the dose can be adjusted to the blood counts.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/chlorambucil/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## What the labels mean

**High alert**
An error with this medicine can cause serious harm: double checks and protocols are used.

## Connections

## Related drugs 2

- [Bendamustine](https://durgical.com/en/pharmacology/bendamustine/)
- [Melphalan](https://durgical.com/en/pharmacology/melphalan/)

## Related conditions 3

- [Chronic lymphocytic leukaemia](https://durgical.com/en/conditions/chronic-lymphocytic-leukaemia/)
- [Non-Hodgkin lymphoma](https://durgical.com/en/conditions/non-hodgkin-lymphoma/)
- [Hodgkin lymphoma](https://durgical.com/en/conditions/hodgkin-lymphoma/)

[← Back to the class: Alkylating agents](https://durgical.com/en/pharmacology/classes/alkylating-agents/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Chlorambucil: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a682899.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=L01AA02) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/) (World Health Organization, 2025).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/chlorambucil/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/chlorambucil/