Medication: Hydroxycarbamide

Your dog has been prescribed hydroxycarbamide for the treatment of abnormal red cell production (polycythemia vera) or certain types of cancer (myeloid leukemia and meningiomas). This drug may be given in association with other medications.

Key points: 
• Chemotherapy drug which inhibits cell division.
• Do not handle hydroxycarbamide 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 open or divide capsules.
• Dogs 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

• Hydroxycarbamide (hi-drox-ee-car-ba-miyd).

Brand name

• There are no licensed veterinary products containing hydroxycarbamide.

Class of medication

• Chemotherapy/anti-cancer agent.

Storage

• Store at room temperature.

Your veterinarian has prescribed hydroxycarbamide for the treatment of a type of cancer. Types of cancer treated with this drug include cancers of the blood (ie polycythemia vera and leukemia), some brain tumors (ie meningioma) and mast cell tumors.

Hydroxycarbamide is given orally (as tablets). The frequency will depend on the size of your dog as the capsules cannot be divided.  Follow your veterinarian’s directions carefully.

The capsules must never be opened but can be given whole in food or can be given directly.

Handling hydroxycarbamide

• Do not handle hydroxycarbamide 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 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.
• Hydroxycarbamide 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 capsules directly – make sure you wash them down with some food or water by syringe afterwards to prevent them getting stuck.
• If you find a capsule on the floor after giving the medication, 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 oral 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.
• Skin reactions: hairloss, sloughing of toe nails
• Inflammation of the gums (stomatitis)
• Low white cell count (leukopenia or neutropenia)
• Low platelet counts (thrombocytopenia)
• Low red cell counts (anemia)
• Difficulty in passing urine (dysuria).

Your pet may be able to continue with the drug if side-effects are mild, but it’s best to let your veterinarian know as soon as possible if you have any concerns, so that they can decide whether additional medications or different medications are required.

The following drugs may interact with hydroxycarbamide: phenytoin and digoxin.

Hydroxycarbamide should be administered according to your veterinarian’s instructions. The length of treatment will vary between patients.

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 give a double dose.

Overdose with this drug is an emergency situation. Contact your veterinarian immediately if you think you may have overdosed your pet.

An overdose with this drug can result in a fatal condition known as methemoglobinemia. This means that the red blood cells fail to take oxygen to the tissues. Signs of overdose may include blue lips/gums, breathing difficulties, weakness and/or vomiting.

If your pet is unwell, contact your veterinarian for advice and do not give the drug until you have discussed it with your veterinarian.

Hydroxycarbamide should only be given to the dog that it has been prescribed for. If accidentally given to other pets, contact your veterinarian for advice.

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

Your veterinarian will need to check your pet regularly and may need to run weekly blood tests or perform other diagnostics to monitor your pet’s response to the treatment.

Further information 

If you have any concerns, further information on hydroxycarbamide can be found on the package insert or from your veterinarian.

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.