Foscarnet natri


Generic Name: Foscarnet natri Brand Name(s): Generics only. No brands available.


What is foscarnet natri used for?

Foscarnet natri is an antiviral agent. It works by inhibiting the growth and reproduction of viruses, which helps fight off infections caused by viruses.

Foscarnet natri is commonly used for treating eye problems caused by CMV in people with AIDS. It is also used to treat a type of HSV that cannot be treated by another medicine in people with the weak immune system.

It may also be used for other conditions as determined by your doctor.

How should I take foscarnet natri?

Foscarnet is given as an injection at your doctor’s office, hospital, or clinic. Contact your health care provider if you have any questions.

Drinking extra fluids while you are taking foscarnet is recommended. Check with your doctor for instructions.

Ask your health care provider any questions you may have about how to use foscarnet.

How do I store foscarnet natri ?

Foscarnet will be handled and stored by a health care provider. You will not store it at home.

Precautions & warnings

What should I know before using foscarnet natri?

Before using foscarnet natri, tell your doctor if:

  • You are allergic to any ingredient in foscarnet natri.
  • You have certain heart problems or you are on a low-sodium diet.
  • You are on hemodialysis.
  • You are pregnant, planning to become pregnant, or are breastfeeding.
  • You are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement.
  • You have allergies to medicines, foods, or other substances.

Foscarnet may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use foscarnet with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.

If you have seizures, dizziness, or drowsiness while using foscarnet, do not drive or perform other possibly unsafe tasks. Discuss any questions or concerns with your doctor.

Foscarnet is not a cure for CMV infection, and eye inflammation may progress during and after treatment.

Foscarnet is not a cure for HSV infections. While complete healing is possible, the infection may return.

Seizures have happened with foscarnet. Sometimes, deaths have happened with seizures. Discuss any questions or concerns with your doctor.

Foscarnet may irritate the vein. It may burn the skin if the medicine leaks from the vein when it is given. Tell your nurse if you have any redness, burning, pain, swelling, or leaking of fluid where the medicine is going into your body.

Lab tests, including eye exams, kidney function tests, and electrolyte levels, may be performed while you use foscarnet. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.

Safety and effectiveness in children have not been confirmed. Use foscarnet with caution if it is given to a child. Talk with the doctor.

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using foscarnet natri during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking foscarnet natri. Foscarnet natri is pregnancy risk category C, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side effects

What side effects can occur from foscarnet natri?

Some common side effects may include:

  • Anxiety
  • Decreased appetite
  • Diarrhea
  • Dizziness
  • Headache
  • Nausea
  • Stomach pain
  • Sweating
  • Tiredness
  • Vomiting
  • Weakness

Seek medical attention right away if any of these severe side effects occur:

  • Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue)
  • Burning, numbness, or tingling
  • Depression
  • Genital ulcers or irritation
  • Not able to control muscle movements
  • Seizures
  • Shortness of breath
  • Symptoms of fluid and electrolyte problems (e.g., mood changes; confusion; muscle cramps, pain, spasms, or weakness; numbness or tingling around the mouth or in the arms or legs; fast or irregular heartbeat; seizures; loss of appetite; severe nausea or vomiting; severe dizziness or fainting; more thirst; dry mouth or eyes)
  • Symptoms of infection (e.g., fever, chills, cough, sore throat)
  • Symptoms of kidney problems (e.g., not able to pass urine, change in how much urine is passed, blood in the urine, big weight gain)
  • Unusual tiredness or weakness
  • Vision changes

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with foscarnet natri?

Foscarnet natri may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Does food or alcohol interact with foscarnet natri?

Foscarnet natri may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with foscarnet natri?

Foscarnet natri may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

These health conditions are:

  • Central nervous system problems
  • Blood electrolyte problems (e.g., calcium, phosphate, magnesium, potassium)
  • Heart problems
  • Kidney problems
  • Dehydrated
  • A blood problem (e.g., anemia, low white blood cell counts)
  • A history of seizures


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using foscarnet natri.

What is the dose of foscarnet natri for an adult?

CMV Retinitis

Patients with AIDS: Combination therapy with ganciclovir indated for patients who have relapsed following monotherapy with either foscarnet or ganciclovir.

Induction: the recommended dose is 60 mg/kg q8hr IV x14-21 days; infuse IV over at least 60 min.

Maintenance: the recommended dose is 90-120 mg/kg IV qDay; infuse IV over at least 60-90 min.

Herpes Simplex

Indicated for Herpes simplex in patients with acyclovir resistance who are immunocompromised.

Option 1: the recommended dose is 40 mg/kg IV q8hr x14-21 days; infuse IV over at least 60 min.

Option 2: the recommended dose is 40-60 mg/kg IV q12hr x14-21 days; infuse IV over at least 60 min.

What is the dose of foscarnet natri for a child?

The dosage has not been established in pediatric patients under 18 years old. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is foscarnet natri available?

Foscarnet natri is available in the following dosage forms and strengths:

  • Injection 24mg/ml

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of foscarnet, contact your doctor right away.

Hello Health Group does not provide medical advice, diagnosis or treatment.

msBahasa Malaysia

Review Date: April 1, 2017 | Last Modified: April 1, 2017