What is Foscarnet?

Foscarnet is an IV drug most often used to treat cytomegalovirus (CMV) infection in AIDS patients. Foscarnet is also sometimes administered to treat herpes simplex virus infection in patients with lowered immunity, especially when other treatments have not been effective. As an intravenous drug, foscarnet is normally administered in a health care setting, by a health care provider. Like other prescription and non-prescription drugs, foscarnet may not be right for all patients, and may cause unpleasant side effects.

Cytomegalovirus, for which foscarnet is most often prescribed, is a type of herpes virus that is considered quite common. Most healthy people show no symptoms when infected with CMV, and those who do often display fatigue, fever, and swelling of the lymph glands. Persons with lowered immunity due to HIV infection are most likely to develop serious symptoms when infected with CMV.

Often, CMV causes retinitis in those with HIV/AIDS. Herpes simplex virus (HSV) can also develop into a serious infection in those with HIV/AIDS. Foscarnet can help treat symptoms of HSV when other treatment options have not been successful.

Prescription drugs such as foscarnet may not be safe for use by all patients. Persons who have suffered from, or who currently suffer from, anemia or kidney disease are generally advised to speak to their physicians before receiving foscarnet. Pregnant or breastfeeding women may not be able to use foscarnet. Patients are also generally advised to discuss their use of other prescription and non-prescription drugs with their physicians before receiving foscarnet.

Like other prescription and non-prescription drugs, foscarnet can cause unpleasant side effects. One of the most common side effects of this drug is lowered kidney function. Patients using foscarnet are generally advised to follow a physician's dietary advice to support kidney function while using foscarnet. Other side effects of this drug may include diarrhea, vomiting, stomach pain, and upset stomach. Lowered appetite, headache, confusion, and dizziness can sometimes occur.

More serious side effects of foscarnet can include changes in the frequency of urination or in the amount of urine produced at urination. Increased thirst can also be a cause for concern. Patients experiencing excessive fatigue or weakness, numbness or discomfort of the extremities may be having serious side effects of foscarnet. Other serious side effects can include tingling in or around the mouth, seizures, uncontrollable muscle movements, or pain at the site of administration. Fever, chills and sore throat are also generally considered dangerous side effects.