CONTRIBUTOR(S): Vetstream Ltd, Gigi Davidson,
Medication: Phenoxybenzamine
Your cat has been prescribed phenoxybenzamine to assist with passing urine or to relieve signs associated with phaeochromocytoma (a rare tumor of the adrenal gland that can cause high blood pressure). Phenoxybenzamine may also be used to improve the effectiveness of acupuncture therapy.
ℹ️Key points: •Alpha-blocker (dilates blood vessels and relaxes certain muscles). •This is not a licensed veterinary product. Your veterinarian will explain about off-license use of medications.
ℹ️This 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, Brand names, Class of medication and Storage
Name
- Phenoxybenzamine (fen-ox-ee-ben-za-meen).
Brand name
- There are no licensed veterinary products containing this drug in the UK, Europe or the US. Your veterinarian may prescribe a human medication containing this drug. Your veterinarian can explain off-license use of medications to you.
Class of medication
- Alpha-blocker.
- Vasodilator.
Storage
- Store at room temperature.
Why has my cat been prescribed phenoxybenzamine?
Your veterinarian has prescribed phenoxybenzamine to assist your pet with passing urine or to relieve signs associated with phaeochromocytoma (a rare tumor of the adrenal gland that can cause high blood pressure). Phenoxybenzamine relaxes the muscles in the urethra and so can relieve spasm and assist with urination caused by urethral spasm. Phenoxybenzamine dilates blood vessels, which can in turn reduce high blood pressure, for example caused by phaeochromocytoma. Phenoxybenzamine may also be used to improve the effectiveness of acupuncture therapy.
How is the medication given?
Phenoxybenzamine is administered orally as capsules, usually two to three times per day – as advised by your vet. It is best given with food.
Are there any side-effects or drug interactions?
There is little data as to the side-effects experienced by cats taking this medication but side-effects may include low blood pressure, fast heart rate, nasal congestion and small pupils (miosis). It may also interfere with ejaculation so should be used carefully in breeding male cats. Let your veterinarian know if you have any concerns. Phenoxybenzamine must be used cautiously in animals with pre-existing heart or kidney disease. Phenoxybenzamine interacts with many drugs. Discuss your cat’s other medications and supplements with your veterinarian.
How long will my cat need to receive this medication?
Your veterinarian will advise as to how long your pet may need to be on this medication. It may take a week or longer before your pet’s urinary issues respond to phenoxybenzamine.
How should I dispose of this medication if I don’t use it all?
Dispose of any unused phenoxybenzamine safely - do not flush down the toilet or sink. Ask your veterinary team if they take back medication for disposal. Do not save phenoxybenzamine for future use or give to other pets.
What if I miss a dose or give an extra dose?
If you miss a dose, give the dose as soon as possible but do not give a double dose. Make sure the dose given does not exceed the total recommended dose in any 24-hour period. Contact your veterinarian straight away if you accidentally give too much phenoxybenzamine to your pet.
My cat is unwell, should I still give the drug?
If your pet is unwell, contact your veterinarian for advice.
What should I do if this medication is accidentally given to another pet or taken by a human?
Phenoxybenzamine should only be given to the cat 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 immediately.
Will my cat need to be monitored while on phenoxybenzamine?
Your cat will be monitored regularly by your veterinary surgeon whilst on this medication.
Further information
If you have any concerns, further information on phenoxybenzamine can be found on the package insert or by contacting your veterinarian.Europe & UK
- There are no licensed veterinary products containing this drug in the UK or Europe. Your vet 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 vet may prescribe a human medication containing this drug and will explain off-license use of medications to you.
