Hydroxycarbamide (Hydroxyurea)
Also known as: Hydrea
- **Cytotoxic Drug Warning**: This is a chemotherapy medication. Always wear disposable gloves when handling the medication and when cleaning up your pet's urine, faeces, or vomit for at least 48 hours after administration. - **Do not crush or open capsules/tablets**. - **Monitoring is Critical**: Strict adherence to the blood testing schedule is essential to prevent life-threatening drops in white blood cells. - Contact your veterinarian immediately if your pet shows signs of extreme lethargy, unexplained bruising/bleeding, vomiting, diarrhoea, or loss of appetite.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Polycythaemia vera, chronic myeloid leukaemia, mast cell tumours, meningiomas
- Polycythaemia vera, chronic myeloid leukaemia
How it is given
Possible side effects
- Myelosuppression (dose-limiting)
- Nausea
- Vomiting
- Diarrhoea
- Anorexia
- Dysuria
- Stomatitis
- Sloughing of nails
- Alopecia
- Methaemoglobinaemia (in cats at high doses)
- Cardiovascular changes (increased diastolic BP/HR, decreased systolic BP)
Cautions & contraindications
- Pre-existing bone marrow suppression
- > **Cytotoxic Handling**: Must be handled with appropriate precautions (gloves, avoiding splitting/crushing). - **Feline Sensitivity**: Cats are at greater risk of myelosuppression compared to dogs; weekly haematology is mandatory at the start of therapy. - **Renal Impairment**: Use with caution in patients with renal dysfunction; dose reduction may be required. - **Other Cautions**: Use cautiously in patients with a history of urate stones, or those that have received previous chemotherapy and/or radiotherapy.
Drug interactions
- Other myelosuppressive agents: Increased risk of severe bone marrow suppression
Frequently asked questions
What is Hydroxycarbamide (Hydroxyurea) used for in pets?
- **Cytotoxic Drug Warning**: This is a chemotherapy medication. Always wear disposable gloves when handling the medication and when cleaning up your pet's urine, faeces, or vomit for at least 48 hours after administration. - **Do not crush or open capsules/tablets**. - **Monitoring is Critical**: Strict adherence to the blood testing schedule is essential to prevent life-threatening drops in white blood cells. - Contact your veterinarian immediately if your pet shows signs of extreme lethargy, unexplained bruising/bleeding, vomiting, diarrhoea, or loss of appetite.
Is Hydroxycarbamide (Hydroxyurea) safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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