foscarnet (generic name)

It is used to treat or prevent infections caused by certain kinds of viruses
(fos KAR net)
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What is this medicine?

FOSCARNET (fos KAR net) is an antiviral medicine. It is used to treat or prevent infections caused by certain kinds of viruses. Examples of these infections include herpes and cytomegalovirus (CMV).

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
  • anemia
  • heart disease
  • kidney disease
  • low blood calcium
  • nervous system disease
  • seizures
  • an unusual or allergic reaction to foscarnet, other medicines, drugs, dyes, or preservatives
  • pregnant or trying to get pregnant
  • breast-feeding

How should I use this medicine?

This medicine is for infusion into a vein. It is given by a health care professional in a hospital or clinic setting.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

What if I miss a dose?

This does not apply.

What may interact with this medicine?

Do not take this medicine with any of the following medications:
  • cidofovir

This medicine may also interact with the following medications:

  • acyclovir
  • amphotericin B
  • certain antibiotics given by injection
  • cisplatin
  • cyclosporine
  • pentamidine
  • ritonavir
  • saquinavir

What should I watch for while using this medicine?

Visit your doctor or health care professional for regular check ups. Discuss any new symptoms with your doctor. You will need to have important blood work done while on this medicine. If you have a CMV eye infection have your eyes checked every 4 to 6 weeks.

Drink 6 to 8 glasses of water or fluids daily while taking this medicine to help prevent side effects.

Tell your doctor right away if you have any tingling or numbness in your mouth or in your arms or legs. This may be a sign of a serious problem.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:
  • allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
  • breathing problems
  • changes in vision
  • fast or irregular heartbeat
  • fever or chills, sore throat
  • muscle twitch
  • pain, swelling at site where injected
  • seizures
  • numb, tingling pain
  • trouble passing urine or change in the amount of urine
  • unusual bleeding or bruising
  • unusually tired or weak

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

  • aches and pains
  • anxiety
  • diarrhea
  • headache
  • loss of appetite
  • nausea, vomiting
  • stomach pain
  • weight loss

Where should I keep my medicine?

Keep out of the reach of children.

If you are using this medicine at home, you will be instructed on how to store this medicine. Throw away any unused medicine after the expiration date on the label.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Last Updated: November 19, 2008
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