This medication is given by injection into a vein as directed by your doctor, usually every 1 to 2 weeks. It is injected slowly into a vein over 1 hour. This medication should not be injected into the eyes. Permanent loss of vision may occur.

Dosage is based on your medical condition, body weight, and response to treatment. You will usually receive IV fluids before your dose of cidofovir. Your doctor will also direct you to take probenecid by mouth before and after you receive cidofovir. To prevent kidney problems, drink plenty of fluids unless otherwise directed by your doctor. This is especially important if you are vomiting or having diarrhea.

If you are giving this medication to yourself at home, learn all preparation and usage instructions from your health care professional. Before using, check this product visually for particles or discoloration. If either is present, do not use the liquid. Learn how to store and discard medical supplies safely.

It is very important to use the probenecid with this medication exactly as prescribed by your doctor. Nausea and vomiting due to probenecid may be prevented by taking it after meals. Your doctor may also prescribe another medication to prevent nausea, and may direct you to take antihistamines (such as diphenhydramine) and/or acetaminophen to prevent allergic reactions to probenecid.

This medication works best when it is used regularly. Keep all your medical appointments. You may want to mark a calendar to help you remember.

Do not use more or less of this drug than prescribed or stop using it (or your HIV medicines) even for a short time unless directed to do so by your doctor. Doing so may cause the amount of virus to increase, make the infection more difficult to treat (resistant), or worsen side effects.

Avoid direct contact of this medicine with the skin/eyes/mouth. If contact occurs, wash thoroughly with soap and water. For eyes, rinse with a steady stream of tap water for at least 5 minutes.