CONTRIBUTOR(S): Vetstream Ltd, Fergus Allerton, Fear Free,
Medication: Antihistamine
Your cat has been prescribed antihistamines to help manage allergic disease (eg atopy) or anaphylaxis.
Key points: • Antihistamines act by blocking histamine receptors. • No licensed veterinary products are available containing these drugs. Your veterinarian can advise you regarding off-license use of this medication for your pet. • Avoid using in patients with glaucoma, high blood pressure or hyperthyroidism. • Dosage: varies depending on the diagnosis. Follow your veterinarian’s directions.
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, Brand names, Class of medication and Storage
Name
- Cetirizine, chlorphenamine, clemastine, cyproheptadine, diphenhydramine, hydroxyzine, loratadine or promethazine.
Brand name
- Atarax, Periactin, Piriteze, Piriton, Nytol, Phenergan, Tavegyl, Zirtec.
Class of drug
- Antihistamine.
Storage
- Store at room temperature in well-closed containers. Some products need to be stored in a light-resistant container.
Why has my cat been prescribed antihistamines?
Antihistamines are most commonly prescribed to help with management of allergic disease (eg allergic skin disease, insect bite hypersensitivity), but can also be prescribed in cases of anaphylaxis, or pre-emptively to reduce the risk of a drug reaction (eg prior to certain chemotherapy treatments).
How is the medication given?
The medication is usually given by mouth and comes in different formulations (eg tablets or suspension). Dosing and frequency will be advised by your veterinarian. Antihistamines are often more effective when given before exposure to a potential allergen. They may also be given by injection by your veterinarian.
Are there any side-effects or drug interactions?
Antihistamines should not be given alongside drugs that depress the central nervous system. Antihistamines should be avoided (or only administered with advice from your veterinarian) in cats with glaucoma, urine retention, hyperthyroidism or high blood pressure. Possible side-effects include drowsiness, depression, vomiting or, diarrhea. May also cause paradoxical excitement in cats.
How long will my cat need to receive this medication?
Should be administered according to your veterinarian’s instructions. The treatment course may vary between patients.
How should I dispose of this medication if I don’t use it all?
Dispose of any unused antihistamines safely - do not flush down the toilet or sink. Do not save antihistamines for future use or give to other pets. Ask your veterinary team if they take back medication for disposal.
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.
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?
Antihistamines 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.
Will my cat need to be monitored while on antihistamines?
Your veterinarian may wish to monitor clinical response to treatment.