Medication: Cyclophosphamide

Your dog has been prescribed cyclophosphamide to kill certain cancer cells or to suppress the immune system.

Key points:
• Antineoplastic chemotherapy drug.
• Alkylating agent which kills certain types of cancer cells.
• Do not handle cyclophosphamide if you are pregnant, breastfeeding, under 18, immunosuppressed or receiving chemotherapy or immunosuppressive drugs.
• Aways wear gloves to handle the tablets/capsules and wash your hands afterwards.
• Never crush or split tablets or open capsules.
• Dogs will excrete chemotherapy products for 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

• Cyclopshophamide (cy-clo-phos-pha-mide).

Brand name

• There are no licensed veterinary products containing this drug therefore human licensed products may be used.
• Endoxana® (Europe & UK).
• Cytoxan ® (US).
• Neosar ® (US).

Class of drug

• Antineoplastic chemotherapy drug.
• 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.

Cyclophosphamide is used to manage cancer including those affecting the white blood cells (lymphoma and myeloma). It is also used in metronomic chemotherapy regimens for various solid tumors such as sarcomas. It is often used in conjunction with other chemotherapy drugs.

Cyclophosphamide is given as oral tablets or capsules that are available in a variety of sizes. The capsules must never be opened and the tablets must never be crushed or split but can be given whole in food.

Handling cyclophosphamide

• Do not handle cyclophosphamide if you are pregnant, breastfeeding, under 18, immunosuppressed or receiving chemotherapy or immunosuppressive drugs.
• Aways wear gloves to handle the capsules/tablets and wash your hands afterwards.
• Never crush or split tablets or open capsules as it can result in dust which could be dangerous to those around.
• Keep your dog’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.
• Cyclophosphamide tablets or capsules can be safely given in a little bit of food but make sure it’s not left behind in the bowl or on the floor! It is also fine to give the tablets/capsules 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 medicating your dog, 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 oral medication to your dog, please contact your veterinarian for advice.

The following adverse reactions have been noted:

• Cystitis symptoms or blood in the urine can indicate sterile hemorrhagic cystitis. If you notice any blood in the urine or signs of cystitis stop cyclophosphamide. Your veterinarian will usually prescribe frusemide/furosemide to be taken at the same time as cyclophosphamide in order to reduce the risk of this side-effect.
• 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).

Hairloss is rare in dogs on chemotherapy but clipped areas may take longer to grow back in.

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

This will depend on the regimen provided 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 next dose at the correct time and do not double up a dose. Contact your veterinarian immediately if you have given your dog an overdose of cyclophosphamide.

Do not administer cyclophosphamide 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).
• There is evidence of blood in the urine or increased frequency of urination or if the volume of urine passed is small (these are signs of hemorrhagic cystitis).
• Your pet has vomited or has diarrhea.

Cyclophosphamide 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 dog

• Your dog will excrete products from the chemotherapy drug for up to 7 days after cyclophosphamide 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 dog.
• Aways wash your hands after handling your dog and before eating or drinking.
• The following people should minimize direct contact with your dog:
  • Pregnant or breastfeeding women
  • Young children who do not understand the need for hand washing after contact
  • Immunosuppressed or receiving chemotherapy or immunosuppressive drugs.
• Dogs should be exercised away from areas where children play or where there are lots of other dogs. However they are fine to remain in contact with other pets in the home.
• Double bag all feces and dispose of them as normal. We do not recommend flushing them down the toilet due to risk of aerosols forming.
• Urine passed on a surface where it can drain away (such as grass or soil) is not a problem. If your dog passes urine on a solid surface (pavements, paths etc) use a bottle of water to rinse away the urine.
• There is no risk to other pets in the home from sharing water bowls or toileting in the garden unless the other pet is likely to ingest any contaminated urine or feces. In any case feces passed in the garden should be double bagged as soon as they have been passed.
• If your dog should have an accident in the house or soil 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 dog’s bedding should be washed regularly as some toxic products may end up on your dog’s coat when they lick themselves.
• We discourage people from allowing their dog to sleep in the family beds because their coat may be contaminated.

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 and any side-effects.

Further information

If you have any concerns, further information on cyclophosphamide 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 dog’s medication.