What is cidofovir ophthalmic?
Cidofovir ophthalmic is a topical antiviral medication used to treat viral infections of the eye, such as feline herpesvirus-1 (FHV-1), in cats.
When cidofovir is prescribed in the treatment of herpesvirus in cats, it is referred to as ‘off-label’ use. Many drugs are commonly prescribed for off-label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions very carefully, as their directions may be significantly different from those on the label.
Cidofovir needs to be compounded by a veterinarian or a veterinary pharmacy into an eye drop solution for cats.
How do I give cidofovir to my cat?
Your veterinarian will provide specific instructions for use in your cat. It is important that you administer the exact prescribed amount to your cat’s eye. Wait 5-10 minutes before applying any other medications to the eye.
If this medication spills onto your cat’s hair, clean it off with a damp cloth before your cat can lick it. It is important to avoid contamination of the eye medication’s applicator tip. Do not touch your cat's eye with the dropper tip and keep a tight lid on the bottle when not in use. Wear disposable gloves when handling this medication. Do not give this medication if the solution becomes cloudy or if it appears to contain particulate matter.
For helpful tips on administering eye drops, see the handout “Applying Eye Drops to Cats”.
This medication can take up to a few weeks before full effects are noted, but gradual improvements are usually appreciable after a few days.
What if I miss giving a dose to my cat?
If you miss a dose, give the next dose as soon as you remember, but if it is close to the next scheduled dose when you remember, skip the missed dose and give it at the next scheduled time and return to the regular dosing schedule. Never give your pet two doses at once or give extra doses.
Are there any potential side effects?
Side effects of cidofovir may include eye irritation, such as a mild stinging sensation or redness of the eyes. More severe yet rare side effects that must be reported to your veterinarian right away include difficult or noisy breathing, lack of appetite, yellowing of the whites of the eyes, pain in the back or sides, increased urination, weakness, lethargy, limb pain, and mouth sores.
This short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.
Are there any risk factors for this medication?
Cidofovir should not be used in patients with hypersensitivity to the drug, in breeding animals, or in animals with kidney disease. It should not be given with other medications that can cause damage to the kidneys (nephrotoxic).
Avoid contact with your skin, eyes, or gums. As this medication is excreted in saliva, urine and feces, wear gloves when cleaning up after your cat and do not allow your cat to lick your skin. If skin exposure occurs, wash thoroughly with soap and water.
Pregnant women should not handle this medication.
Are there any drug interactions I should be aware of?
Certain drugs can interact with this medication, so be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.
Is there any monitoring that needs to be done with this medication?
Your veterinarian may monitor your cat to ensure that the clinical signs are resolving or have resolved. Advise your veterinarian of any side effects right away.
How do I store cidofovir ophthalmic?
This medication is typically stored in the refrigerator, protected from light and freezing. However, since this medication must be compounded, always follow the storage directions on the medication label.
What should I do in case of an emergency?
An overdose of eye medication is unlikely but side effects or toxic effects can occur if your cat ingests it. If you suspect an overdose or adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.
