Medication: Chlorambucil

Your cat has been prescribed chlorambucil to manage cancer (including those affecting the white blood cells such as lymphoma, chronic lymphocytic leukemia) and or immune-mediated disease (inflammatory bowel disease, pemphigus).

Key points: 
• Antineoplastic cytotoxic immunosuppressive alkylating agent. 
• Do not handle chlorambucil if you are pregnant, breastfeeding, under 18, immunosuppressed or receiving chemotherapy or immunosuppressive drugs. 
• Aways wear gloves to handle the capsules and wash your hands afterwards. 
• Never crush or split capsules. 
• Cats will excrete chemotherapy products up to 7 days after administration so precautions must be followed to reduce exposure to other people and pets. 
• Dosage: the frequency of dosing varies and should be clearly stated on the packaging provided by your veterinarian.  

This information sheet is designed to help answer commonly asked questions and help you give the medication safely and effectively to your pet. It does not contain all available information for this medication. If you have other questions or need more information, contact your veterinarian or pharmacist.Always follow the dosing instructions provided by your veterinarian.

Name 

• Chlorambucil (chlor-ambu-cil).   

Brand name 

• There are no licensed veterinary products containing this drug therefore human licensed products (eg Leukeran®) may be used. 

Class of drug 

• Antineoplastic cytotoxic immunosuppressive alkylating agent. 

Storage 

• Store at room temperature (20°-25° C (68°-77° F)) in a secure container, protected from light. 
• Wear gloves when handling and wash hands thoroughly afterwards. 
• Can cause birth defects.

Chlorambucil is used to kill certain types of cancer cells, in particular those affecting the white blood cells (lymphoma, chronic lymphocytic leukemia).  

Chlorambucil is also used to suppress the immune system in diseases such as inflammatory bowel disease and pemphigus. 

It may be used as an alternative to cyclophosphamide if your cat has developed blood in the urine (hemorrhagic cystitis). 

Chlorambucil is given as oral tablets. The tablets must never be crushed or split but can be given whole in food. It's important to ensure that the tablet has been swallowed. If you find a tablet on the ground always wear gloves to pick it up and dispose of it in a sealed bag. 

Handling chlorambucil 

• Do not handle chlorambucil if you are pregnant, breastfeeding, under 18, immunosuppressed or receiving chemotherapy or immunosuppressive drugs.
• Aways wear gloves to handle the capsules and wash your hands afterwards. 
• Never crush or split tablets as it can result in dust which could be dangerous to those around. 
• Keep your cat's drugs in the container supplied. This should be a child proof container. 
• Store them in a safe place and always out of the reach of children and pets. 
• Chlorambucil tablets are large and cats will easily spit them out if given in food. Give the capsules/tablets directly – they can be washed down with some food or water by syringe afterwards to prevent them getting stuck. 
• If you find a tablet on the floor after pilling your cat, wear gloves to pick it up and bag it. Do not give another dose until you have spoken to your veterinarian. 
• If you are unable to give tablet medication to your dog, please contact your veterinarian for advice. 

The following adverse reactions have been noted:  

• Gastrointestinal symptoms (rare): not eating, nausea, vomiting, diarrhea.   
• Low white cell count (leukopenia or neutropenia) – regular blood tests will monitor the white blood cell counts.  
• Low platelet counts (thrombocytopenia) (uncommon).  
• Low red cell counts (anemia) (rare).  

Some drugs may interact with chlorambucil. If your cat is taking other medications or supplements, please check these with your veterinarian before starting treatment. 

Always follow the dosage regime as advised by your veterinarian.  

All unused drugs should be returned to your veterinary practice for disposal and must not be placed in household waste. 

If you miss a dose, give the dose as soon as possible but do not double up a dose. Contact your veterinarian immediately if you have given your cat an overdose of chlorambucil. 

Do not administer chlorambucil if your pet is unwell – contact your veterinarian for advice.

You must also contact your veterinarian straight away if:  

• Your pet has a high temperature (above 38.8ºC/102ºF – with a fever they will usually be quiet and unwilling to eat). 
• Your pet is unwell (even without a high temperature).  
• Your pet has vomited or has diarrhea.

Chlorambucil should only be given to the dog that it has been prescribed for.  

If accidentally consumed by a human, speak to your primary care physician or poison control center. 

Handling your cat 

Your cat will excrete products from the chemotherapy drug for up to 7 days after each chlorambucil dose has been given. This period is referred to as the “chemo barrier” period. As there is a small risk of you absorbing these toxic products, there are some sensible precautions that you should take to reduce your exposure during this time. 

• Wear gloves when handling any urine, feces, vomit or saliva from your cat. 
• Aways wash your hands after handling your cat and before eating or drinking. 
• The following people should minimize direct contact with your cat: 
  • Pregnant or breastfeeding women 
  • Young children who do not understand the need for hand washing after contact 
  • Immunosuppressed or receiving chemotherapy or immunosuppressive drugs. 
• Outdoor cats should be kept indoors for 72 hours after treatment, particularly if they have access to parks or areas where children play.   
• Cat litter trays should be lined with plastic litter tray liners and filled with clumping cat litter. This is to prevent contaminated dust.   
• Wear gloves when handling the litter tray contents.    
• Empty the tray by lifting all the litter out with the liner as soon as possible after soiling to prevent your cat from scratching around in their dirty tray. It may be sensible to use a smaller amount of litter when you refill it during this time. Covered litter trays will restrict the amount of dust that can be spread into the air.   
• If your cat has an accident in the house or has soiled itself, you should wear gloves to clean the area as quickly as possible using copious amounts of soapy water. Use disposable paper towels to dry the area and dispose of these in a plastic bag in an outside bin.   
• Your cat’s bedding should be washed regularly as some toxic products may end up on your cat’s coat when they lick themselves.  
• There is no risk to other pets in the home from sharing water bowls or toileting in the same litter tray.

Your pet will require blood tests to be checked regularly throughout treatment. The frequency will vary depending on the treatment protocol your pet is receiving. Your veterinarian will want to monitor your pet to make sure that treatment is working. 

Further information 

If you have any concerns, further information on chlorambucil can be found on the package insert.

Europe & UK 

• There are no licensed veterinary products containing this drug in the UK or Europe. Your veterinarian may prescribe a human medication containing this drug and will explain off-license use of medications to you.     

US 

• There are no licensed veterinary products containing this drug in the US. Your veterinarian may prescribe a human medication containing this drug and will explain off-license use of medications to you.     

Always follow the recommended dosage and contact your veterinary team or pharmacist if you have any questions regarding your cat’s medication.