What is Cidofovir?

Acute renal failure resulting in dialysis or contributing to death has been reported. Use intravenous prehydration with normal saline and administration of probenecid with each cidofovir infusion to reduce nephrotoxicity. Monitor renal function within 48 hours prior to each dose and adjust dose as appropriate. Cidofovir is contraindicated in patients who are receiving other nephrotoxic agents. Neutropenia has been observed; monitor neutrophil counts during therapy. Cidofovir was carcinogenic, teratogenic, and caused hypospermia in animal studies .

Cidofovir is an antiviral. It is used to treat infections caused by viruses.

Cidofovir is used to treat the symptoms of cytomegalovirus (CMV) infection of the eyes (CMV retinitis) in patients with acquired immune deficiency syndrome (AIDS). Cidofovir will not cure this eye infection, but it may help to keep the symptoms from becoming worse.

This medicine is available only with your doctor's prescription.

To get the best results, cidofovir must be given for the full time of treatment. Also, this medicine works best when there is a constant amount in the blood. To help keep the amount constant, cidofovir must be given on a regular schedule.

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For injection dosage form:
  • For treatment of cytomegalovirus (CMV) retinitis:
    • Adults—Dose is based on body weight and must be determined by your doctor. At first, 5 milligrams (mg) per kilogram (kg) (2.3 mg per pound) of body weight is injected slowly into a vein once a week for two weeks in a row. Then the dose is reduced to 5 mg per kg (2.3 mg per pound) of body weight injected slowly into a vein once every two weeks. Probenecid is taken along with each dose of cidofovir; follow your doctor's instructions for how much and when to take probenecid.
    • Children—Use and dose must be determined by your doctor.

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Cidofovir can cause serious side effects, including possible cancer and trouble in having children later. Therefore, it is especially important that you discuss with the child's doctor the good that this medicine may do as well as the risks of using it.

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of cidofovir in the elderly with use in other age groups.

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Amikacin
• Dibekacin
• Foscarnet
• Framycetin
• Gentamicin
• Kanamycin
• Neomycin
• Netilmicin
• Pentamidine
• Streptomycin
• Tobramycin

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Kidney disease—Cidofovir can cause harmful effects on the kidney

It is very important that your doctor check you at regular visits for any blood problems that may be caused by this medicine.

It is very important that your ophthalmologist (eye doctor) check your eyes at regular visits since it is still possible that you may have some loss of eyesight during cidofovir treatment.