Foscarnet Injection

What is this medication?

FOSCARNET (fos KAR net) treats infections caused by viruses. This medication works by limiting the spread of the virus in your body. It belongs to a group of medications called antivirals. This medication does not kill the virus and it may still be possible to spread the virus to others. It will not treat colds, the flu, or infections caused by bacteria.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Foscavir

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

• Heart disease
• High levels of phosphorus in the blood
• Kidney disease
• Low blood counts, such as white cell, platelets, or red cell counts
• Low levels of calcium, magnesium, phosphorus, or potassium in the blood
• Seizures
• An unusual or allergic reaction to foscarnet, other medications, foods, dyes, or preservatives
• Pregnant or trying to get pregnant
• Breast-feeding

How should I use this medication?

This medication is infused into a vein. It is given by your care team in a hospital or clinic setting.

Talk to your care team about the use of this medication in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

This does not apply.

What may interact with this medication?

Do not take this medication with any of the following:

• Cidofovir
• Dronedarone
• Pimozide
• Thioridazine

This medication may also interact with the following:

• Aspirin and aspirin-like medications
• Cisplatin
• Cyclosporine
• Diuretics
• Dofetilide
• Medications for infection, such as acyclovir, adefovir, amphotericin B, bacitracin, ganciclovir, gentamicin, pentamidine, vancomycin
• Methotrexate
• NSAIDs, medications for pain and inflammation, such as ibuprofen or naproxen
• Other medications that cause heart rhythm changes
• Pamidronate
• Ritonavir
• Saquinavir
• Tacrolimus
• Ziprasidone
• Zoledronic acid

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Visit your care team for regular checks on your progress. Discuss any new symptoms with your care team.

Your vision and blood may be tested before and during use of this medication.

Check with your care team if you have severe diarrhea, nausea, and vomiting, or if you sweat a lot. The loss of too much body fluid can make it dangerous for you to take this medication.

Tell your care team 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.

This medication may affect your coordination, reaction time, or judgment. Do not drive or operate machinery until you know how this medication affects you. Sit up or stand slowly to reduce the risk of dizzy or fainting spells. Drinking alcohol with this medication can increase the risk of these side effects.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

• Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
• Heart rhythm changes—fast or irregular heartbeat, dizziness, feeling faint or lightheaded, chest pain, trouble breathing
• High phosphorus level—muscle pain or cramps, bone or joint pain, numbness and tingling around the mouth
• Kidney injury—decrease in the amount of urine, swelling of the ankles, hands, or feet
• Low calcium level—muscle pain or cramps, confusion, tingling, or numbness in the hands or feet
• Low magnesium level—muscle pain or cramps, unusual weakness or fatigue, fast or irregular heartbeat, tremors
• Low potassium level—muscle pain or cramps, unusual weakness or fatigue, fast or irregular heartbeat, constipation
• Seizures

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

• Diarrhea
• Fever
• Headache
• Nausea

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

You will be instructed on how to store this medication. Get rid of any unused medication after the expiration date.

To get rid of medications that are no longer needed or have expired:

• Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
• If you cannot return the medication, ask your pharmacist or care team how to get rid of this medication safely.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.