Foscarnet sodium - intravenous

Patient Medicine Information
Why do I need this medicine?
Foscarnet sodium is used to treat an eye infection caused by a virus called cytomegalovirus (CMV) in patients with AIDS .

This medicine may also be used to treat herpes (a common virus that causes sores on the genitals and/or mouth) to those who have a weak immune system that are not responsive to aciclovir.
How do I use this medicine?
Foscarnet sodium is given intravenously (into the vein) via a drip. It is delivered directly into the bloodstream via the blood vessel.

Your doctor or nurse will administer this medicine for you.

The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on the type and severity of your condition.

What should I do if I have forgotten to use this medicine?
Ensure that you keep all appointments with your doctor so that you do not miss any doses. Your doctor also needs to regularly monitor your response to Foscarnet sodium.

If you miss an appointment or miss an injection, alert your doctor or nurse. A replacement appointment or injection should be given as soon as possible.
When should I not use this medicine?
Do not use this medicine if you ever had an allergic reaction (rashes, breathlessness, swollen eyes) to Foscarnet sodium.
What should I take note of while using this medicine?
Inform your doctor if you have the following conditions:
  • heart disease e.g. heart failure, heart rhythm disorder
  • imbalance of electrolytes (e.g. level of magnesium, potassium or calcium) in the body 
  • kidney disease
  • blood disorder
  • seizures
It is important that you do not get pregnant while being treated with this medicine. You may wish to discuss birth control methods with your doctor or pharmacist. Avoid pregnancy during treatment. Avoid fathering a child while using this medicine and up to 6 months after stopping treatment.

Inform your doctor if you are breastfeeding. It is best that you do not breastfeed as HIV passes into the breast milk. Avoid breastfeeding in order to reduce the risk of passing HIV to your baby. It is recommended to give your baby commercial infant formula provided that you have access to clean water and facilities.

If you are going for an operation, including minor surgery and dental work, inform your doctor or dentist that you are using this medicine.

Ensure adequate fluid intake during treatment to prevent kidney problems.

Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly. You may need to have routine blood tests (e.g. complete blood count, kidney function, and electrolytes such as calcium, magnesium, potassium, phosphorus). Your doctor will advise you about how often you will need to have these tests.
What side effects could I experience?
Foscarnet sodium may cause dizziness. If affected, do not drive or take part in any activity in which you need to be alert.

Other side effects may include any of the following: headache, fever, nausea, diarrhoea, vomiting, and pain, redness, or swelling, and tenderness at the injection site.

This medicine will cause the level of your red blood cells, white blood cells and platelets to drop.

Red blood cells carry oxygen around your body. A fall in the level of red blood cells may make you feel tired and worn out.

White blood cells help your body to fight infections. A fall in the level of your white blood cells may put you at higher risk for infections, such as coughs, colds and flu, which may lead to more serious infections. Avoid crowded places and people who are sick. Alert your doctor if you have a fever, or a cough or flu that does not go away.

Platelets help your blood to clot when there is a cut in the skin. A fall in the level of your platelets may put you at risk of bleeding more than usual. Do not take part in activities where you may fall or get injured, such as contact sports. Alert your doctor if you get any unusual bruising (large bruises or several bruises, especially if the bruises appeared on their own) or bleeding that takes a long time to stop (for example, too much bleeding when you floss or brush your teeth).

This medicine is excreted in your urine and may cause genital irritation or sores. Wash your genitals carefully after urinating, to prevent this from happening. Let your doctor know if sores appear in your genitals.

Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
  • rashes, breathlessness, swelling of the face, lips, mouth or throat
  • signs and symptoms of kidney problems e.g. change in the colour or amount of urine, pain when urinating
  • signs and symptoms of an imbalance of electrolyte in your body e.g. muscle pain or twitching, cramps, tingling or itching of the skin, increased thirst, weakness, mood changes, confusion
  • fast, slow, pounding or irregular heartbeat
  • fits or seizures
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Can I use this with other medicines?
Inform your doctor and pharmacist if you are taking any of these medicines:
  • other medicines used to treat viral infection e.g. aciclovir, valaciclovir
  • medicines for HIV infection e.g. ritonavir, saquinavir
  • certain antibiotics e.g. streptomycin, gentamicin, pentamidine
  • medicines used in organ transplant and/or certain immune disorders e.g. ciclosporin, tacrolimus
  • medicines used to treat fungal infection e.g. amphotericin B 
  • medicines for heart disease e.g. amiodarone, sotalol, quinidine
  • diuretics or “water pills” e.g. furosemide
This list does not include all medicines that may interact with Foscarnet sodium.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
What special dietary instructions should I follow?
Avoid alcohol.
How should I store this medicine?
Store in a cool, dry place away from the reach of children.

Medicines must not be used past the expiry date.

This information is independently developed by MIMS based on foscarnet sodium - intravenous and is provided for your reference only. It is not a replacement for and should only be used in conjunction with full consultation with a licensed healthcare professional, the information provided by your pharmacist and/or the manufacturer of the medication. It may not contain all the available information you require and cannot substitute professional medical care, nor does it take into account all individual circumstances. Although great effort has been made to ensure content accuracy, we shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2022 MIMS. All rights reserved. Powered by
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