What is zidovudine?
Zidovudine is an antiviral agent used to treat feline leukemia virus (FeLV) and/or feline immunodeficiency virus (FIV) in cats.
It is used off label (extra label) in veterinary medicine. Many drugs are commonly prescribed for off-label use in veterinary medicine.
“Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions very carefully, as their directions may be significantly different from those on the label.
How do I give my pet zidovudine?
- Zidovudine comes in capsule, tablet, liquid suspension, and injectable forms.
- Capsules, tablets, and liquid suspensions are given orally (by mouth).
- The injectable form is given subcutaneously (under the skin).
- Zidovudine may be given with or without food. If your pet vomits or acts sick after receiving the drug on an empty stomach, try giving the next dose with food or a small treat. If vomiting continues, contact your veterinarian.
- Give this medication to your pet for the entire time prescribed by your veterinarian, even if it appears that your pet is feeling better.
This medication should take effect within 1–2 days, although outward effects may not be seen immediately.
What if I miss giving my pet the medication?
If you miss a dose, give it as soon as you remember, and then continue with the regular dosing schedule. However, if it is almost time for the next dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once or give extra doses.
Are there any potential side effects from zidovudine?
Zidovudine may cause the following side effects:
- Diarrhea
- Weakness
Serious adverse reactions may occur. If any of the following signs develop, stop giving zidovudine and contact your veterinarian immediately:
- An allergic reaction such as irregular breathing, rash, fever, puffiness and swelling around the face
- Lethargy
- Pale gum color
Drug sensitivities can develop over time with repeated exposure. Your pet may have no reaction after the first few doses, but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment.
Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This short-acting medication should stop working within 24 hours, though effects can be longer in pets with kidney and/or liver disease.
Are there any risk factors for this medication?
DO NOT USE in:
- Cats that are allergic to any component
USE WITH CAUTION in:
- Cats with kidney, liver, and/or bone marrow disease
Are there any drug interactions I should be aware of?
The following medications should be used with caution when given with zidovudine:
- Antineoplastic drugs (e.g., vincristine, fluorouracil)
- Benzodiazepines
- Certain antibiotics (e.g., chloramphenicol, nitrofurantoin)
- Certain antifungals (e.g., fluconazole, amphotericin B)
- Myelosuppressive drugs (e.g., leflunomide, methotrexate, methimazole)
- Other antivirals (e.g., acyclovir)
- Steroids (e.g., prednisolone, dexamethasone)
Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.
Is any monitoring needed with this medication?
- Baseline and periodic complete blood count (CBC) are required. Your veterinarian may also check other blood work.
- Your veterinarian will let you know when and how they want to reassess your pet to ensure the medication is working and not causing side effects.
- At home, monitor for any side effects such as those noted above. If any occur, stop using the medication and contact your veterinarian.
How do I store zidovudine?
- Store the oral forms of the medication at room temperature (59°F–77°F or 15°C–25°C).
- Store injectable form at room temperature (68°F–77°F or 20°C–25°C).
- Once the injectable form is diluted, discard it after 24 hours if kept at room temperature and after 48 hours if refrigerated.
- Protect from light, humidity, and moisture.
- Keep medication out of reach of children and pets.
What should I do in case of emergency?
If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet’s weight and symptoms.
