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Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.




WARNING: Foscarnet is used only for cytomegalovirus (CMV) eye infections and acyclovir-resistant herpes infections. Decreased kidney function is a major side effect caused by this medication. Notify your doctor immediately if you experience a change in amount of urine. Your dose may need adjustment. Foscarnet has caused seizures in some people due to changes in blood chemistry (minerals and electrolytes). You may be prescribed additional minerals and/or electrolytes to treat this. It is important you receive appropriate amounts of fluid (hydration) when this medication is used. Your doctor will monitor your blood and kidneys while you are using this medication.


This medication is an antiviral used in the management of cytomegalovirus (CMV) eye infections in persons with AIDS. It is also used to treat acyclovir-resistant herpes.

How To Use

This medication is given by injection by a health care professional. It is usually infused slowly into a vein over a period of 1-2 hours using an infusion pump. It is important to drink plenty of fluids while taking this medication to prevent kidney effects. Fluids may be given intravenously to ensure an adequate intake. Continue using this medication for the full time prescribed. Stopping therapy too soon may result in ineffective treatment.

Side Effects

This medication may cause nausea, vomiting, diarrhea, headache, dizziness, dry mouth, gas, increased sweating. If these symptoms continue or become bothersome, inform your doctor. Notify your doctor if you develop: skin rash, seizures, fever, breathing trouble, chest pain, swelling of the feet or legs, tingling of the hands or feet, vision problems, weakness, depression, hallucinations, coughing, frequent or painful urination, muscle aches. You may experience redness, irritation or pain at the injection site. Inform your doctor of this. Also notify your doctor if you experience tingling or numbness of the hands or feet during or after the infusion. Your dose may need adjustment. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor your medical history, especially of: liver disease, kidney disease, heart disease, history of seizure disorder, any allergies. This medication should be used only if clearly needed during pregnancy. Discuss the risks and benefits with your doctor. It is not known if this medication appears in breast milk. Consult your doctor before breast-feeding.

Drug Interactions

Tell your doctor of any over-the-counter or prescription medication you may take especially: zidovudine, pentamidine, diuretics (water pills). Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include seizures and numbness in arms, legs, and around the mouth.


This medication is usually administered initially in the hospital where your condition can be monitored closely. Laboratory tests will be done periodically to be sure the drug is working properly and to monitor for possible side effects.

Missed Dose

It is important to use each dose at the scheduled time. If you miss a dose, contact your doctor who will help establish a new dosing schedule. Do not "double-up" the dose to catch up.


Store this medication as directed. Properly discard of any unused medication after the expiration date.

Medical Alert

Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA), or 1-800-668-1507 (Canada).